2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2002 Thomas Vander Stichele <thomas@apestaart.org>
5 * 2004 Wim Taymans <wim@fluendo.com>
6 * 2015 Jan Schmidt <jan@centricular.com>
8 * gstutils.c: Utility functions
10 * This library is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Library General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Library General Public License for more details.
20 * You should have received a copy of the GNU Library General Public
21 * License along with this library; if not, write to the
22 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
23 * Boston, MA 02110-1301, USA.
29 * @short_description: Various utility functions
33 /* FIXME 2.0: suppress warnings for deprecated API such as GValueArray
34 * with newer GLib versions (>= 2.31.0) */
35 #define GLIB_DISABLE_DEPRECATION_WARNINGS
37 #include "gst_private.h"
41 #include "gstghostpad.h"
48 #include <glib/gi18n-lib.h>
49 #include "glib-compat-private.h"
54 gst_util_dump_mem_offset (const guchar * mem, guint size, guint offset)
57 GString *string = g_string_sized_new (50);
58 GString *chars = g_string_sized_new (18);
62 if (g_ascii_isprint (mem[i]))
63 g_string_append_c (chars, mem[i]);
65 g_string_append_c (chars, '.');
67 g_string_append_printf (string, "%02x ", mem[i]);
72 if (j == 16 || i == size) {
73 g_print ("%08x (%p): %-48.48s %-16.16s\n", i - j + offset, mem + i - j,
74 string->str, chars->str);
75 g_string_set_size (string, 0);
76 g_string_set_size (chars, 0);
80 g_string_free (string, TRUE);
81 g_string_free (chars, TRUE);
86 * @mem: (array length=size): a pointer to the memory to dump
87 * @size: the size of the memory block to dump
89 * Dumps the memory block into a hex representation. Useful for debugging.
92 gst_util_dump_mem (const guchar * mem, guint size)
94 gst_util_dump_mem_offset (mem, size, 0);
98 * gst_util_dump_buffer:
99 * @buf: a #GstBuffer whose memory to dump
101 * Dumps the buffer memory into a hex representation. Useful for debugging.
106 gst_util_dump_buffer (GstBuffer * buf)
114 n_memory = gst_buffer_n_memory (buf);
117 if (gst_buffer_map (buf, &map, GST_MAP_READ)) {
118 gst_util_dump_mem (map.data, map.size);
119 gst_buffer_unmap (buf, &map);
121 } else if (n_memory > 1) {
122 /* gst_buffer_map() will merge multiple memory segments into one contiguous
123 * area so we need to use gst_memory_map() in order not to affect the
126 for (i = 0; i < n_memory; ++i) {
127 g_print ("[Memory #%u]\n", i);
128 mem = gst_buffer_get_memory (buf, i);
129 if (gst_memory_map (mem, &map, GST_MAP_READ)) {
130 gst_util_dump_mem_offset (map.data, map.size, offset);
132 gst_memory_unmap (mem, &map);
134 gst_memory_unref (mem);
137 g_print ("[Empty]\n");
142 * gst_util_set_value_from_string:
143 * @value: (out caller-allocates): the value to set
144 * @value_str: the string to get the value from
146 * Converts the string to the type of the value and
147 * sets the value with it.
149 * Note that this function is dangerous as it does not return any indication
150 * if the conversion worked or not.
153 gst_util_set_value_from_string (GValue * value, const gchar * value_str)
157 g_return_if_fail (value != NULL);
158 g_return_if_fail (value_str != NULL);
160 GST_CAT_DEBUG (GST_CAT_PARAMS, "parsing '%s' to type %s", value_str,
161 g_type_name (G_VALUE_TYPE (value)));
163 res = gst_value_deserialize (value, value_str);
164 if (!res && G_VALUE_TYPE (value) == G_TYPE_BOOLEAN) {
165 /* backwards compat, all booleans that fail to parse are false */
166 g_value_set_boolean (value, FALSE);
169 g_return_if_fail (res);
173 * gst_util_set_object_arg:
174 * @object: the object to set the argument of
175 * @name: the name of the argument to set
176 * @value: the string value to set
178 * Converts the string value to the type of the objects argument and
179 * sets the argument with it.
181 * Note that this function silently returns if @object has no property named
182 * @name or when @value cannot be converted to the type of the property.
185 gst_util_set_object_arg (GObject * object, const gchar * name,
192 g_return_if_fail (G_IS_OBJECT (object));
193 g_return_if_fail (name != NULL);
194 g_return_if_fail (value != NULL);
196 pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (object), name);
200 value_type = pspec->value_type;
202 GST_DEBUG ("pspec->flags is %d, pspec->value_type is %s",
203 pspec->flags, g_type_name (value_type));
205 if (!(pspec->flags & G_PARAM_WRITABLE))
208 g_value_init (&v, value_type);
210 /* special case for element <-> xml (de)serialisation */
211 if (value_type == GST_TYPE_STRUCTURE && strcmp (value, "NULL") == 0) {
212 g_value_set_boxed (&v, NULL);
216 if (!gst_value_deserialize_with_pspec (&v, value, pspec))
221 g_object_set_property (object, pspec->name, &v);
226 * gst_util_set_object_array:
227 * @object: the object to set the array to
228 * @name: the name of the property to set
229 * @array: a #GValueArray containing the values
231 * Transfer a #GValueArray to %GST_TYPE_ARRAY and set this value on the
232 * specified property name. This allow language bindings to set GST_TYPE_ARRAY
233 * properties which are otherwise not an accessible type.
238 gst_util_set_object_array (GObject * object, const gchar * name,
239 const GValueArray * array)
241 GValue v1 = G_VALUE_INIT, v2 = G_VALUE_INIT;
242 gboolean ret = FALSE;
244 g_value_init (&v1, G_TYPE_VALUE_ARRAY);
245 g_value_init (&v2, GST_TYPE_ARRAY);
247 g_value_set_static_boxed (&v1, array);
249 if (g_value_transform (&v1, &v2)) {
250 g_object_set_property (object, name, &v2);
261 * gst_util_get_object_array:
262 * @object: the object to set the array to
263 * @name: the name of the property to set
264 * @array: (out): a return #GValueArray
266 * Get a property of type %GST_TYPE_ARRAY and transform it into a
267 * #GValueArray. This allow language bindings to get GST_TYPE_ARRAY
268 * properties which are otherwise not an accessible type.
273 gst_util_get_object_array (GObject * object, const gchar * name,
274 GValueArray ** array)
276 GValue v1 = G_VALUE_INIT, v2 = G_VALUE_INIT;
277 gboolean ret = FALSE;
279 g_value_init (&v1, G_TYPE_VALUE_ARRAY);
280 g_value_init (&v2, GST_TYPE_ARRAY);
282 g_object_get_property (object, name, &v2);
284 if (g_value_transform (&v2, &v1)) {
285 *array = g_value_get_boxed (&v1);
294 /* work around error C2520: conversion from unsigned __int64 to double
295 * not implemented, use signed __int64
297 * These are implemented as functions because on some platforms a 64bit int to
298 * double conversion is not defined/implemented.
302 * gst_util_guint64_to_gdouble:
303 * @value: The #guint64 value to convert to double
305 * Returns: @value casted to #gdouble
308 gst_util_guint64_to_gdouble (guint64 value)
310 if (value & G_GINT64_CONSTANT (0x8000000000000000))
311 return (gdouble) ((gint64) value) + (gdouble) 18446744073709551616.;
313 return (gdouble) ((gint64) value);
317 * gst_util_gdouble_to_guint64:
318 * @value: The #gdouble value to convert guint64 double
320 * Returns: @value casted to #guint64
323 gst_util_gdouble_to_guint64 (gdouble value)
325 if (value < (gdouble) 9223372036854775808.) /* 1 << 63 */
326 return ((guint64) ((gint64) value));
328 value -= (gdouble) 18446744073709551616.;
329 return ((guint64) ((gint64) value));
332 #ifndef HAVE_UINT128_T
333 /* convenience struct for getting high and low uint32 parts of
340 #if G_BYTE_ORDER == G_BIG_ENDIAN
348 #if defined (__x86_64__) && defined (__GNUC__)
350 gst_util_uint64_mul_uint64 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
353 __asm__ __volatile__ ("mulq %3":"=a" (c0->ll), "=d" (c1->ll)
354 :"a" (arg1), "g" (arg2)
357 #else /* defined (__x86_64__) */
358 /* multiply two 64-bit unsigned ints into a 128-bit unsigned int. the high
359 * and low 64 bits of the product are placed in c1 and c0 respectively.
360 * this operation cannot overflow. */
362 gst_util_uint64_mul_uint64 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
372 /* do 128 bits multiply
380 * -------------------
383 * "a0" is optimized away, result is stored directly in c0. "b1" is
384 * optimized away, result is stored directly in c1.
386 c0->ll = (guint64) v.l.low * n.l.low;
387 a1.ll = (guint64) v.l.low * n.l.high;
388 b0.ll = (guint64) v.l.high * n.l.low;
390 /* add the high word of a0 to the low words of a1 and b0 using c1 as
391 * scratch space to capture the carry. the low word of the result becomes
392 * the final high word of c0 */
393 c1->ll = (guint64) c0->l.high + a1.l.low + b0.l.low;
394 c0->l.high = c1->l.low;
396 /* add the carry from the result above (found in the high word of c1) and
397 * the high words of a1 and b0 to b1, the result is c1. */
398 c1->ll = (guint64) v.l.high * n.l.high + c1->l.high + a1.l.high + b0.l.high;
400 #endif /* defined (__x86_64__) */
402 #if defined (__x86_64__) && defined (__GNUC__)
403 static inline guint64
404 gst_util_div128_64 (GstUInt64 c1, GstUInt64 c0, guint64 denom)
408 __asm__ __volatile__ ("divq %3":"=a" (res)
409 :"d" (c1.ll), "a" (c0.ll), "g" (denom)
415 /* count leading zeros */
417 gst_util_clz (guint32 val)
421 s = val | (val >> 1);
425 s = ~(s | (s >> 16));
426 s = s - ((s >> 1) & 0x55555555);
427 s = (s & 0x33333333) + ((s >> 2) & 0x33333333);
428 s = (s + (s >> 4)) & 0x0f0f0f0f;
430 s = (s + (s >> 16)) & 0x3f;
435 /* based on Hacker's Delight p152 */
436 static inline guint64
437 gst_util_div128_64 (GstUInt64 c1, GstUInt64 c0, guint64 denom)
439 GstUInt64 q1, q0, rhat;
440 GstUInt64 v, cmp1, cmp2;
445 /* count number of leading zeroes, we know they must be in the high
446 * part of denom since denom > G_MAXUINT32. */
447 s = gst_util_clz (v.l.high);
450 /* normalize divisor and dividend */
452 c1.ll = (c1.ll << s) | (c0.l.high >> (32 - s));
456 q1.ll = c1.ll / v.l.high;
457 rhat.ll = c1.ll - q1.ll * v.l.high;
459 cmp1.l.high = rhat.l.low;
460 cmp1.l.low = c0.l.high;
461 cmp2.ll = q1.ll * v.l.low;
463 while (q1.l.high || cmp2.ll > cmp1.ll) {
468 cmp1.l.high = rhat.l.low;
471 c1.l.high = c1.l.low;
472 c1.l.low = c0.l.high;
473 c1.ll -= q1.ll * v.ll;
474 q0.ll = c1.ll / v.l.high;
475 rhat.ll = c1.ll - q0.ll * v.l.high;
477 cmp1.l.high = rhat.l.low;
478 cmp1.l.low = c0.l.low;
479 cmp2.ll = q0.ll * v.l.low;
481 while (q0.l.high || cmp2.ll > cmp1.ll) {
486 cmp1.l.high = rhat.l.low;
489 q0.l.high += q1.l.low;
493 #endif /* defined (__GNUC__) */
495 /* This always gives the correct result because:
496 * a) val <= G_MAXUINT64-1
497 * b) (c0,c1) <= G_MAXUINT64 * (G_MAXUINT64-1)
499 * (c0,c1) == G_MAXUINT64 * G_MAXUINT64 and denom < G_MAXUINT64
500 * (note: num==denom case is handled by short path)
501 * This means that (c0,c1) either has enough space for val
502 * or that the overall result will overflow anyway.
505 /* add correction with carry */
506 #define CORRECT(c0,c1,val) \
508 if (G_MAXUINT64 - c0.ll < val) { \
509 if (G_UNLIKELY (c1.ll == G_MAXUINT64)) \
511 return G_MAXUINT64; \
518 gst_util_uint64_scale_uint64_unchecked (guint64 val, guint64 num,
519 guint64 denom, guint64 correct)
523 /* compute 128-bit numerator product */
524 gst_util_uint64_mul_uint64 (&c1, &c0, val, num);
526 /* perform rounding correction */
527 CORRECT (c0, c1, correct);
529 /* high word as big as or bigger than denom --> overflow */
530 if (G_UNLIKELY (c1.ll >= denom))
533 /* compute quotient, fits in 64 bits */
534 return gst_util_div128_64 (c1, c0, denom);
538 #define GST_MAXUINT128 ((__uint128_t) -1)
540 gst_util_uint64_scale_uint64_unchecked (guint64 val, guint64 num,
541 guint64 denom, guint64 correct)
545 /* Calculate val * num */
546 tmp = ((__uint128_t) val) * ((__uint128_t) num);
548 /* overflow checks */
549 if (G_UNLIKELY (GST_MAXUINT128 - correct < tmp))
552 /* perform rounding correction */
555 /* Divide by denom */
558 /* if larger than G_MAXUINT64 --> overflow */
559 if (G_UNLIKELY (tmp > G_MAXUINT64))
562 /* compute quotient, fits in 64 bits */
563 return (guint64) tmp;
568 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
570 gst_util_uint64_mul_uint32 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
577 c0->ll = (guint64) a.l.low * arg2;
578 c1->ll = (guint64) a.l.high * arg2 + c0->l.high;
582 /* divide a 96-bit unsigned int by a 32-bit unsigned int when we know the
583 * quotient fits into 64 bits. the high 64 bits and low 32 bits of the
584 * numerator are expected in c1 and c0 respectively. */
585 static inline guint64
586 gst_util_div96_32 (guint64 c1, guint64 c0, guint32 denom)
588 c0 += (c1 % denom) << 32;
589 return ((c1 / denom) << 32) + (c0 / denom);
592 static inline guint64
593 gst_util_uint64_scale_uint32_unchecked (guint64 val, guint32 num,
594 guint32 denom, guint32 correct)
598 /* compute 96-bit numerator product */
599 gst_util_uint64_mul_uint32 (&c1, &c0, val, num);
601 /* condition numerator based on rounding mode */
602 CORRECT (c0, c1, correct);
604 /* high 32 bits as big as or bigger than denom --> overflow */
605 if (G_UNLIKELY (c1.l.high >= denom))
608 /* compute quotient, fits in 64 bits */
609 return gst_util_div96_32 (c1.ll, c0.ll, denom);
613 /* the guts of the gst_util_uint64_scale() variants */
615 _gst_util_uint64_scale (guint64 val, guint64 num, guint64 denom,
618 g_return_val_if_fail (denom != 0, G_MAXUINT64);
620 if (G_UNLIKELY (num == 0))
623 if (G_UNLIKELY (num == denom))
626 /* on 64bits we always use a full 128bits multiply/division */
627 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
628 /* denom is low --> try to use 96 bit muldiv */
629 if (G_LIKELY (denom <= G_MAXUINT32)) {
630 /* num is low --> use 96 bit muldiv */
631 if (G_LIKELY (num <= G_MAXUINT32))
632 return gst_util_uint64_scale_uint32_unchecked (val, (guint32) num,
633 (guint32) denom, correct);
635 /* num is high but val is low --> swap and use 96-bit muldiv */
636 if (G_LIKELY (val <= G_MAXUINT32))
637 return gst_util_uint64_scale_uint32_unchecked (num, (guint32) val,
638 (guint32) denom, correct);
640 #endif /* !defined (__x86_64__) && !defined (HAVE_UINT128_T) */
642 /* val is high and num is high --> use 128-bit muldiv */
643 return gst_util_uint64_scale_uint64_unchecked (val, num, denom, correct);
647 * gst_util_uint64_scale:
648 * @val: the number to scale
649 * @num: the numerator of the scale ratio
650 * @denom: the denominator of the scale ratio
652 * Scale @val by the rational number @num / @denom, avoiding overflows and
653 * underflows and without loss of precision.
655 * This function can potentially be very slow if val and num are both
656 * greater than G_MAXUINT32.
658 * Returns: @val * @num / @denom. In the case of an overflow, this
659 * function returns G_MAXUINT64. If the result is not exactly
660 * representable as an integer it is truncated. See also
661 * gst_util_uint64_scale_round(), gst_util_uint64_scale_ceil(),
662 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
663 * gst_util_uint64_scale_int_ceil().
666 gst_util_uint64_scale (guint64 val, guint64 num, guint64 denom)
668 return _gst_util_uint64_scale (val, num, denom, 0);
672 * gst_util_uint64_scale_round:
673 * @val: the number to scale
674 * @num: the numerator of the scale ratio
675 * @denom: the denominator of the scale ratio
677 * Scale @val by the rational number @num / @denom, avoiding overflows and
678 * underflows and without loss of precision.
680 * This function can potentially be very slow if val and num are both
681 * greater than G_MAXUINT32.
683 * Returns: @val * @num / @denom. In the case of an overflow, this
684 * function returns G_MAXUINT64. If the result is not exactly
685 * representable as an integer, it is rounded to the nearest integer
686 * (half-way cases are rounded up). See also gst_util_uint64_scale(),
687 * gst_util_uint64_scale_ceil(), gst_util_uint64_scale_int(),
688 * gst_util_uint64_scale_int_round(), gst_util_uint64_scale_int_ceil().
691 gst_util_uint64_scale_round (guint64 val, guint64 num, guint64 denom)
693 return _gst_util_uint64_scale (val, num, denom, denom >> 1);
697 * gst_util_uint64_scale_ceil:
698 * @val: the number to scale
699 * @num: the numerator of the scale ratio
700 * @denom: the denominator of the scale ratio
702 * Scale @val by the rational number @num / @denom, avoiding overflows and
703 * underflows and without loss of precision.
705 * This function can potentially be very slow if val and num are both
706 * greater than G_MAXUINT32.
708 * Returns: @val * @num / @denom. In the case of an overflow, this
709 * function returns G_MAXUINT64. If the result is not exactly
710 * representable as an integer, it is rounded up. See also
711 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
712 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
713 * gst_util_uint64_scale_int_ceil().
716 gst_util_uint64_scale_ceil (guint64 val, guint64 num, guint64 denom)
718 return _gst_util_uint64_scale (val, num, denom, denom - 1);
721 /* the guts of the gst_util_uint64_scale_int() variants */
723 _gst_util_uint64_scale_int (guint64 val, gint num, gint denom, gint correct)
725 g_return_val_if_fail (denom > 0, G_MAXUINT64);
726 g_return_val_if_fail (num >= 0, G_MAXUINT64);
728 if (G_UNLIKELY (num == 0))
731 if (G_UNLIKELY (num == denom))
734 if (val <= G_MAXUINT32) {
735 /* simple case. num and denom are not negative so casts are OK. when
736 * not truncating, the additions to the numerator cannot overflow
737 * because val*num <= G_MAXUINT32 * G_MAXINT32 < G_MAXUINT64 -
738 * G_MAXINT32, so there's room to add another gint32. */
739 val *= (guint64) num;
740 /* add rounding correction */
743 return val / (guint64) denom;
745 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
746 /* num and denom are not negative so casts are OK */
747 return gst_util_uint64_scale_uint32_unchecked (val, (guint32) num,
748 (guint32) denom, (guint32) correct);
750 /* always use full 128bits scale */
751 return gst_util_uint64_scale_uint64_unchecked (val, num, denom, correct);
756 * gst_util_uint64_scale_int:
757 * @val: guint64 (such as a #GstClockTime) to scale.
758 * @num: numerator of the scale factor.
759 * @denom: denominator of the scale factor.
761 * Scale @val by the rational number @num / @denom, avoiding overflows and
762 * underflows and without loss of precision. @num must be non-negative and
763 * @denom must be positive.
765 * Returns: @val * @num / @denom. In the case of an overflow, this
766 * function returns G_MAXUINT64. If the result is not exactly
767 * representable as an integer, it is truncated. See also
768 * gst_util_uint64_scale_int_round(), gst_util_uint64_scale_int_ceil(),
769 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
770 * gst_util_uint64_scale_ceil().
773 gst_util_uint64_scale_int (guint64 val, gint num, gint denom)
775 return _gst_util_uint64_scale_int (val, num, denom, 0);
779 * gst_util_uint64_scale_int_round:
780 * @val: guint64 (such as a #GstClockTime) to scale.
781 * @num: numerator of the scale factor.
782 * @denom: denominator of the scale factor.
784 * Scale @val by the rational number @num / @denom, avoiding overflows and
785 * underflows and without loss of precision. @num must be non-negative and
786 * @denom must be positive.
788 * Returns: @val * @num / @denom. In the case of an overflow, this
789 * function returns G_MAXUINT64. If the result is not exactly
790 * representable as an integer, it is rounded to the nearest integer
791 * (half-way cases are rounded up). See also gst_util_uint64_scale_int(),
792 * gst_util_uint64_scale_int_ceil(), gst_util_uint64_scale(),
793 * gst_util_uint64_scale_round(), gst_util_uint64_scale_ceil().
796 gst_util_uint64_scale_int_round (guint64 val, gint num, gint denom)
798 /* we can use a shift to divide by 2 because denom is required to be
800 return _gst_util_uint64_scale_int (val, num, denom, denom >> 1);
804 * gst_util_uint64_scale_int_ceil:
805 * @val: guint64 (such as a #GstClockTime) to scale.
806 * @num: numerator of the scale factor.
807 * @denom: denominator of the scale factor.
809 * Scale @val by the rational number @num / @denom, avoiding overflows and
810 * underflows and without loss of precision. @num must be non-negative and
811 * @denom must be positive.
813 * Returns: @val * @num / @denom. In the case of an overflow, this
814 * function returns G_MAXUINT64. If the result is not exactly
815 * representable as an integer, it is rounded up. See also
816 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
817 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
818 * gst_util_uint64_scale_ceil().
821 gst_util_uint64_scale_int_ceil (guint64 val, gint num, gint denom)
823 return _gst_util_uint64_scale_int (val, num, denom, denom - 1);
827 * gst_util_seqnum_next:
829 * Return a constantly incrementing sequence number.
831 * This function is used internally to GStreamer to be able to determine which
832 * events and messages are "the same". For example, elements may set the seqnum
833 * on a segment-done message to be the same as that of the last seek event, to
834 * indicate that event and the message correspond to the same segment.
836 * This function never returns %GST_SEQNUM_INVALID (which is 0).
838 * Returns: A constantly incrementing 32-bit unsigned integer, which might
839 * overflow at some point. Use gst_util_seqnum_compare() to make sure
840 * you handle wraparound correctly.
843 gst_util_seqnum_next (void)
845 static gint counter = 1;
846 gint ret = g_atomic_int_add (&counter, 1);
848 /* Make sure we don't return 0 */
849 if (G_UNLIKELY (ret == GST_SEQNUM_INVALID))
850 ret = g_atomic_int_add (&counter, 1);
856 * gst_util_seqnum_compare:
857 * @s1: A sequence number.
858 * @s2: Another sequence number.
860 * Compare two sequence numbers, handling wraparound.
862 * The current implementation just returns (gint32)(@s1 - @s2).
864 * Returns: A negative number if @s1 is before @s2, 0 if they are equal, or a
865 * positive number if @s1 is after @s2.
868 gst_util_seqnum_compare (guint32 s1, guint32 s2)
870 return (gint32) (s1 - s2);
873 /* -----------------------------------------------------
875 * The following code will be moved out of the main
876 * gstreamer library someday.
882 * gst_element_create_all_pads:
883 * @element: (transfer none): a #GstElement to create pads for
885 * Creates a pad for each pad template that is always available.
886 * This function is only useful during object initialization of
887 * subclasses of #GstElement.
890 gst_element_create_all_pads (GstElement * element)
894 /* FIXME: lock element */
897 gst_element_class_get_pad_template_list (GST_ELEMENT_CLASS
898 (G_OBJECT_GET_CLASS (element)));
901 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
903 if (padtempl->presence == GST_PAD_ALWAYS) {
906 pad = gst_pad_new_from_template (padtempl, padtempl->name_template);
908 gst_element_add_pad (element, pad);
910 padlist = padlist->next;
915 * gst_element_get_compatible_pad_template:
916 * @element: (transfer none): a #GstElement to get a compatible pad template for
917 * @compattempl: (transfer none): the #GstPadTemplate to find a compatible
920 * Retrieves a pad template from @element that is compatible with @compattempl.
921 * Pads from compatible templates can be linked together.
923 * Returns: (transfer none) (nullable): a compatible #GstPadTemplate,
924 * or %NULL if none was found. No unreferencing is necessary.
927 gst_element_get_compatible_pad_template (GstElement * element,
928 GstPadTemplate * compattempl)
930 GstPadTemplate *newtempl = NULL;
932 GstElementClass *class;
935 g_return_val_if_fail (element != NULL, NULL);
936 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
937 g_return_val_if_fail (compattempl != NULL, NULL);
939 class = GST_ELEMENT_GET_CLASS (element);
941 padlist = gst_element_class_get_pad_template_list (class);
943 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
944 "Looking for a suitable pad template in %s out of %d templates...",
945 GST_ELEMENT_NAME (element), g_list_length (padlist));
948 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
952 * Check direction (must be opposite)
955 GST_CAT_LOG (GST_CAT_CAPS,
956 "checking pad template %s", padtempl->name_template);
957 if (padtempl->direction != compattempl->direction) {
958 GST_CAT_DEBUG (GST_CAT_CAPS,
959 "compatible direction: found %s pad template \"%s\"",
960 padtempl->direction == GST_PAD_SRC ? "src" : "sink",
961 padtempl->name_template);
963 GST_CAT_DEBUG (GST_CAT_CAPS,
964 "intersecting %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (compattempl));
965 GST_CAT_DEBUG (GST_CAT_CAPS,
966 "..and %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (padtempl));
968 compatible = gst_caps_can_intersect (GST_PAD_TEMPLATE_CAPS (compattempl),
969 GST_PAD_TEMPLATE_CAPS (padtempl));
971 GST_CAT_DEBUG (GST_CAT_CAPS, "caps are %scompatible",
972 (compatible ? "" : "not "));
980 padlist = g_list_next (padlist);
983 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
984 "Returning new pad template %p", newtempl);
986 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "No compatible pad template found");
992 * gst_element_get_pad_from_template:
993 * @element: (transfer none): a #GstElement.
994 * @templ: (transfer none): a #GstPadTemplate belonging to @element.
996 * Gets a pad from @element described by @templ. If the presence of @templ is
997 * #GST_PAD_REQUEST, requests a new pad. Can return %NULL for #GST_PAD_SOMETIMES
1000 * Returns: (transfer full) (nullable): the #GstPad, or %NULL if one
1001 * could not be found or created.
1004 gst_element_get_pad_from_template (GstElement * element, GstPadTemplate * templ)
1007 GstPadPresence presence;
1009 /* If this function is ever exported, we need check the validity of `element'
1010 * and `templ', and to make sure the template actually belongs to the
1013 presence = GST_PAD_TEMPLATE_PRESENCE (templ);
1016 case GST_PAD_ALWAYS:
1017 case GST_PAD_SOMETIMES:
1018 ret = gst_element_get_static_pad (element, templ->name_template);
1019 if (!ret && presence == GST_PAD_ALWAYS)
1021 ("Element %s has an ALWAYS template %s, but no pad of the same name",
1022 GST_OBJECT_NAME (element), templ->name_template);
1025 case GST_PAD_REQUEST:
1026 ret = gst_element_request_pad (element, templ, NULL, NULL);
1034 * gst_element_request_compatible_pad:
1035 * @element: a #GstElement.
1036 * @templ: the #GstPadTemplate to which the new pad should be able to link.
1038 * Requests a pad from @element. The returned pad should be unlinked and
1039 * compatible with @templ. Might return an existing pad, or request a new one.
1041 * Returns: (nullable): a #GstPad, or %NULL if one could not be found
1045 gst_element_request_compatible_pad (GstElement * element,
1046 GstPadTemplate * templ)
1048 GstPadTemplate *templ_new;
1051 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1052 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
1054 /* FIXME: should really loop through the templates, testing each for
1055 * compatibility and pad availability. */
1056 templ_new = gst_element_get_compatible_pad_template (element, templ);
1058 pad = gst_element_get_pad_from_template (element, templ_new);
1059 /* This can happen for non-request pads. */
1060 if (pad && GST_PAD_PEER (pad)) {
1061 gst_object_unref (pad);
1069 * Checks if the source pad and the sink pad can be linked.
1070 * Both @srcpad and @sinkpad must be unlinked and have a parent.
1073 gst_pad_check_link (GstPad * srcpad, GstPad * sinkpad)
1075 /* generic checks */
1076 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1077 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1079 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1080 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1082 if (GST_PAD_PEER (srcpad) != NULL) {
1083 GST_CAT_INFO (GST_CAT_PADS, "Source pad %s:%s has a peer, failed",
1084 GST_DEBUG_PAD_NAME (srcpad));
1087 if (GST_PAD_PEER (sinkpad) != NULL) {
1088 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has a peer, failed",
1089 GST_DEBUG_PAD_NAME (sinkpad));
1092 if (!GST_PAD_IS_SRC (srcpad)) {
1093 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s is not source pad, failed",
1094 GST_DEBUG_PAD_NAME (srcpad));
1097 if (!GST_PAD_IS_SINK (sinkpad)) {
1098 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s is not sink pad, failed",
1099 GST_DEBUG_PAD_NAME (sinkpad));
1102 if (GST_PAD_PARENT (srcpad) == NULL) {
1103 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s has no parent, failed",
1104 GST_DEBUG_PAD_NAME (srcpad));
1107 if (GST_PAD_PARENT (sinkpad) == NULL) {
1108 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has no parent, failed",
1109 GST_DEBUG_PAD_NAME (srcpad));
1117 * gst_element_get_compatible_pad:
1118 * @element: (transfer none): a #GstElement in which the pad should be found.
1119 * @pad: (transfer none): the #GstPad to find a compatible one for.
1120 * @caps: (allow-none): the #GstCaps to use as a filter.
1122 * Looks for an unlinked pad to which the given pad can link. It is not
1123 * guaranteed that linking the pads will work, though it should work in most
1126 * This function will first attempt to find a compatible unlinked ALWAYS pad,
1127 * and if none can be found, it will request a compatible REQUEST pad by looking
1128 * at the templates of @element.
1130 * Returns: (transfer full) (nullable): the #GstPad to which a link
1131 * can be made, or %NULL if one cannot be found. gst_object_unref()
1135 gst_element_get_compatible_pad (GstElement * element, GstPad * pad,
1139 GstPadTemplate *templ;
1141 GstPad *foundpad = NULL;
1143 GValue padptr = { 0, };
1145 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1146 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1148 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1149 "finding pad in %s compatible with %s:%s",
1150 GST_ELEMENT_NAME (element), GST_DEBUG_PAD_NAME (pad));
1152 g_return_val_if_fail (GST_PAD_PEER (pad) == NULL, NULL);
1156 /* try to get an existing unlinked pad */
1157 if (GST_PAD_IS_SRC (pad)) {
1158 pads = gst_element_iterate_sink_pads (element);
1159 } else if (GST_PAD_IS_SINK (pad)) {
1160 pads = gst_element_iterate_src_pads (element);
1162 pads = gst_element_iterate_pads (element);
1166 switch (gst_iterator_next (pads, &padptr)) {
1167 case GST_ITERATOR_OK:
1174 current = g_value_get_object (&padptr);
1176 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
1177 GST_DEBUG_PAD_NAME (current));
1179 if (GST_PAD_IS_SRC (current)) {
1186 peer = gst_pad_get_peer (current);
1188 if (peer == NULL && gst_pad_check_link (srcpad, sinkpad)) {
1189 GstCaps *temp, *intersection;
1190 gboolean compatible;
1192 /* Now check if the two pads' caps are compatible */
1193 temp = gst_pad_query_caps (pad, NULL);
1195 intersection = gst_caps_intersect (temp, caps);
1196 gst_caps_unref (temp);
1198 intersection = temp;
1201 temp = gst_pad_query_caps (current, NULL);
1202 compatible = gst_caps_can_intersect (temp, intersection);
1203 gst_caps_unref (temp);
1204 gst_caps_unref (intersection);
1207 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1208 "found existing unlinked compatible pad %s:%s",
1209 GST_DEBUG_PAD_NAME (current));
1210 gst_iterator_free (pads);
1212 current = gst_object_ref (current);
1213 g_value_unset (&padptr);
1217 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "incompatible pads");
1220 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1221 "already linked or cannot be linked (peer = %p)", peer);
1223 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unreffing pads");
1225 g_value_reset (&padptr);
1227 gst_object_unref (peer);
1230 case GST_ITERATOR_DONE:
1233 case GST_ITERATOR_RESYNC:
1234 gst_iterator_resync (pads);
1236 case GST_ITERATOR_ERROR:
1237 g_assert_not_reached ();
1241 g_value_unset (&padptr);
1242 gst_iterator_free (pads);
1244 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
1245 "Could not find a compatible unlinked always pad to link to %s:%s, now checking request pads",
1246 GST_DEBUG_PAD_NAME (pad));
1248 /* try to create a new one */
1249 /* requesting is a little crazy, we need a template. Let's create one */
1250 templcaps = gst_pad_query_caps (pad, NULL);
1252 GstCaps *inter = gst_caps_intersect (templcaps, caps);
1254 gst_caps_unref (templcaps);
1257 templ = gst_pad_template_new ((gchar *) GST_PAD_NAME (pad),
1258 GST_PAD_DIRECTION (pad), GST_PAD_ALWAYS, templcaps);
1259 gst_caps_unref (templcaps);
1261 foundpad = gst_element_request_compatible_pad (element, templ);
1262 gst_object_unref (templ);
1265 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1266 "found existing request pad %s:%s", GST_DEBUG_PAD_NAME (foundpad));
1270 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element,
1271 "Could not find a compatible pad to link to %s:%s",
1272 GST_DEBUG_PAD_NAME (pad));
1277 * gst_element_state_get_name:
1278 * @state: a #GstState to get the name of.
1280 * Gets a string representing the given state.
1282 * Returns: (transfer none): a string with the name of the state.
1285 gst_element_state_get_name (GstState state)
1288 case GST_STATE_VOID_PENDING:
1289 return "VOID_PENDING";
1290 case GST_STATE_NULL:
1292 case GST_STATE_READY:
1294 case GST_STATE_PLAYING:
1296 case GST_STATE_PAUSED:
1299 /* This is a memory leak */
1300 return g_strdup_printf ("UNKNOWN!(%d)", state);
1305 * gst_element_state_change_return_get_name:
1306 * @state_ret: a #GstStateChangeReturn to get the name of.
1308 * Gets a string representing the given state change result.
1310 * Returns: (transfer none): a string with the name of the state
1314 gst_element_state_change_return_get_name (GstStateChangeReturn state_ret)
1316 switch (state_ret) {
1317 case GST_STATE_CHANGE_FAILURE:
1319 case GST_STATE_CHANGE_SUCCESS:
1321 case GST_STATE_CHANGE_ASYNC:
1323 case GST_STATE_CHANGE_NO_PREROLL:
1324 return "NO PREROLL";
1326 /* This is a memory leak */
1327 return g_strdup_printf ("UNKNOWN!(%d)", state_ret);
1332 * gst_state_change_get_name:
1333 * @transition: a #GstStateChange to get the name of.
1335 * Gets a string representing the given state transition.
1337 * Returns: (transfer none): a string with the name of the state
1343 gst_state_change_get_name (GstStateChange transition)
1345 switch (transition) {
1346 case GST_STATE_CHANGE_NULL_TO_READY:
1347 return "NULL->READY";
1348 case GST_STATE_CHANGE_READY_TO_PAUSED:
1349 return "READY->PAUSED";
1350 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
1351 return "PAUSED->PLAYING";
1352 case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
1353 return "PLAYING->PAUSED";
1354 case GST_STATE_CHANGE_PAUSED_TO_READY:
1355 return "PAUSED->READY";
1356 case GST_STATE_CHANGE_READY_TO_NULL:
1357 return "READY->NULL";
1358 case GST_STATE_CHANGE_NULL_TO_NULL:
1359 return "NULL->NULL";
1360 case GST_STATE_CHANGE_READY_TO_READY:
1361 return "READY->READY";
1362 case GST_STATE_CHANGE_PAUSED_TO_PAUSED:
1363 return "PAUSED->PAUSED";
1364 case GST_STATE_CHANGE_PLAYING_TO_PLAYING:
1365 return "PLAYING->PLAYING";
1368 return "Unknown state return";
1373 gst_element_factory_can_accept_all_caps_in_direction (GstElementFactory *
1374 factory, const GstCaps * caps, GstPadDirection direction)
1378 g_return_val_if_fail (factory != NULL, FALSE);
1379 g_return_val_if_fail (caps != NULL, FALSE);
1381 templates = factory->staticpadtemplates;
1384 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1386 if (template->direction == direction) {
1387 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1389 if (gst_caps_is_always_compatible (caps, templcaps)) {
1390 gst_caps_unref (templcaps);
1393 gst_caps_unref (templcaps);
1395 templates = g_list_next (templates);
1402 gst_element_factory_can_accept_any_caps_in_direction (GstElementFactory *
1403 factory, const GstCaps * caps, GstPadDirection direction)
1407 g_return_val_if_fail (factory != NULL, FALSE);
1408 g_return_val_if_fail (caps != NULL, FALSE);
1410 templates = factory->staticpadtemplates;
1413 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1415 if (template->direction == direction) {
1416 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1418 if (gst_caps_can_intersect (caps, templcaps)) {
1419 gst_caps_unref (templcaps);
1422 gst_caps_unref (templcaps);
1424 templates = g_list_next (templates);
1431 * gst_element_factory_can_sink_all_caps:
1432 * @factory: factory to query
1433 * @caps: the caps to check
1435 * Checks if the factory can sink all possible capabilities.
1437 * Returns: %TRUE if the caps are fully compatible.
1440 gst_element_factory_can_sink_all_caps (GstElementFactory * factory,
1441 const GstCaps * caps)
1443 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1448 * gst_element_factory_can_src_all_caps:
1449 * @factory: factory to query
1450 * @caps: the caps to check
1452 * Checks if the factory can src all possible capabilities.
1454 * Returns: %TRUE if the caps are fully compatible.
1457 gst_element_factory_can_src_all_caps (GstElementFactory * factory,
1458 const GstCaps * caps)
1460 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1465 * gst_element_factory_can_sink_any_caps:
1466 * @factory: factory to query
1467 * @caps: the caps to check
1469 * Checks if the factory can sink any possible capability.
1471 * Returns: %TRUE if the caps have a common subset.
1474 gst_element_factory_can_sink_any_caps (GstElementFactory * factory,
1475 const GstCaps * caps)
1477 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1482 * gst_element_factory_can_src_any_caps:
1483 * @factory: factory to query
1484 * @caps: the caps to check
1486 * Checks if the factory can src any possible capability.
1488 * Returns: %TRUE if the caps have a common subset.
1491 gst_element_factory_can_src_any_caps (GstElementFactory * factory,
1492 const GstCaps * caps)
1494 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1498 /* if return val is true, *direct_child is a caller-owned ref on the direct
1499 * child of ancestor that is part of object's ancestry */
1501 object_has_ancestor (GstObject * object, GstObject * ancestor,
1502 GstObject ** direct_child)
1504 GstObject *child, *parent;
1507 *direct_child = NULL;
1509 child = gst_object_ref (object);
1510 parent = gst_object_get_parent (object);
1513 if (ancestor == parent) {
1515 *direct_child = child;
1517 gst_object_unref (child);
1518 gst_object_unref (parent);
1522 gst_object_unref (child);
1524 parent = gst_object_get_parent (parent);
1527 gst_object_unref (child);
1532 /* caller owns return */
1534 find_common_root (GstObject * o1, GstObject * o2)
1536 GstObject *top = o1;
1537 GstObject *kid1, *kid2;
1538 GstObject *root = NULL;
1540 while (GST_OBJECT_PARENT (top))
1541 top = GST_OBJECT_PARENT (top);
1543 /* the itsy-bitsy spider... */
1545 if (!object_has_ancestor (o2, top, &kid2))
1548 root = gst_object_ref (top);
1550 if (!object_has_ancestor (o1, kid2, &kid1)) {
1551 gst_object_unref (kid2);
1554 gst_object_unref (root);
1556 if (!object_has_ancestor (o2, kid1, &kid2)) {
1557 gst_object_unref (kid1);
1560 gst_object_unref (root);
1565 /* caller does not own return */
1567 ghost_up (GstElement * e, GstPad * pad)
1569 static gint ghost_pad_index = 0;
1574 GstObject *parent = GST_OBJECT_PARENT (e);
1576 name = g_strdup_printf ("ghost%d", ghost_pad_index++);
1577 gpad = gst_ghost_pad_new (name, pad);
1580 GST_STATE_LOCK (parent);
1581 gst_element_get_state (GST_ELEMENT (parent), ¤t, &next, 0);
1583 if (current > GST_STATE_READY || next >= GST_STATE_PAUSED)
1584 gst_pad_set_active (gpad, TRUE);
1586 if (!gst_element_add_pad ((GstElement *) parent, gpad)) {
1587 g_warning ("Pad named %s already exists in element %s\n",
1588 GST_OBJECT_NAME (gpad), GST_OBJECT_NAME (parent));
1589 GST_STATE_UNLOCK (parent);
1592 GST_STATE_UNLOCK (parent);
1598 remove_pad (gpointer ppad, gpointer unused)
1602 if (!gst_element_remove_pad ((GstElement *) GST_OBJECT_PARENT (pad), pad))
1603 g_warning ("Couldn't remove pad %s from element %s",
1604 GST_OBJECT_NAME (pad), GST_OBJECT_NAME (GST_OBJECT_PARENT (pad)));
1608 prepare_link_maybe_ghosting (GstPad ** src, GstPad ** sink,
1609 GSList ** pads_created)
1613 GSList *pads_created_local = NULL;
1615 g_assert (pads_created);
1617 e1 = GST_OBJECT_PARENT (*src);
1618 e2 = GST_OBJECT_PARENT (*sink);
1620 if (G_UNLIKELY (e1 == NULL)) {
1621 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1622 GST_PTR_FORMAT, *src);
1625 if (G_UNLIKELY (e2 == NULL)) {
1626 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1627 GST_PTR_FORMAT, *sink);
1631 if (GST_OBJECT_PARENT (e1) == GST_OBJECT_PARENT (e2)) {
1632 GST_CAT_INFO (GST_CAT_PADS, "%s and %s in same bin, no need for ghost pads",
1633 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1637 GST_CAT_INFO (GST_CAT_PADS, "%s and %s not in same bin, making ghost pads",
1638 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1640 /* we need to setup some ghost pads */
1641 root = find_common_root (e1, e2);
1643 if (GST_OBJECT_PARENT (e1) == NULL)
1644 g_warning ("Trying to link elements %s and %s that don't share a common "
1645 "ancestor: %s hasn't been added to a bin or pipeline, but %s is in %s",
1646 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1647 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1648 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1649 else if (GST_OBJECT_PARENT (e2) == NULL)
1650 g_warning ("Trying to link elements %s and %s that don't share a common "
1651 "ancestor: %s hasn't been added to a bin or pipeline, and %s is in %s",
1652 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1653 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (e1),
1654 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)));
1656 g_warning ("Trying to link elements %s and %s that don't share a common "
1657 "ancestor: %s is in %s, and %s is in %s",
1658 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1659 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)),
1660 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1664 while (GST_OBJECT_PARENT (e1) != root) {
1665 *src = ghost_up ((GstElement *) e1, *src);
1668 e1 = GST_OBJECT_PARENT (*src);
1669 pads_created_local = g_slist_prepend (pads_created_local, *src);
1671 while (GST_OBJECT_PARENT (e2) != root) {
1672 *sink = ghost_up ((GstElement *) e2, *sink);
1675 e2 = GST_OBJECT_PARENT (*sink);
1676 pads_created_local = g_slist_prepend (pads_created_local, *sink);
1679 gst_object_unref (root);
1680 *pads_created = g_slist_concat (*pads_created, pads_created_local);
1684 gst_object_unref (root);
1685 g_slist_foreach (pads_created_local, remove_pad, NULL);
1686 g_slist_free (pads_created_local);
1691 pad_link_maybe_ghosting (GstPad * src, GstPad * sink, GstPadLinkCheck flags)
1693 GSList *pads_created = NULL;
1696 if (!prepare_link_maybe_ghosting (&src, &sink, &pads_created)) {
1699 ret = (gst_pad_link_full (src, sink, flags) == GST_PAD_LINK_OK);
1703 g_slist_foreach (pads_created, remove_pad, NULL);
1705 g_slist_free (pads_created);
1711 * gst_pad_link_maybe_ghosting_full:
1714 * @flags: some #GstPadLinkCheck flags
1716 * Links @src to @sink, creating any #GstGhostPad's in between as necessary.
1718 * This is a convenience function to save having to create and add intermediate
1719 * #GstGhostPad's as required for linking across #GstBin boundaries.
1721 * If @src or @sink pads don't have parent elements or do not share a common
1722 * ancestor, the link will fail.
1724 * Calling gst_pad_link_maybe_ghosting_full() with
1725 * @flags == %GST_PAD_LINK_CHECK_DEFAULT is the recommended way of linking
1726 * pads with safety checks applied.
1728 * Returns: whether the link succeeded.
1733 gst_pad_link_maybe_ghosting_full (GstPad * src, GstPad * sink,
1734 GstPadLinkCheck flags)
1736 g_return_val_if_fail (GST_IS_PAD (src), FALSE);
1737 g_return_val_if_fail (GST_IS_PAD (sink), FALSE);
1739 return pad_link_maybe_ghosting (src, sink, flags);
1743 * gst_pad_link_maybe_ghosting:
1747 * Links @src to @sink, creating any #GstGhostPad's in between as necessary.
1749 * This is a convenience function to save having to create and add intermediate
1750 * #GstGhostPad's as required for linking across #GstBin boundaries.
1752 * If @src or @sink pads don't have parent elements or do not share a common
1753 * ancestor, the link will fail.
1755 * Returns: whether the link succeeded.
1760 gst_pad_link_maybe_ghosting (GstPad * src, GstPad * sink)
1762 g_return_val_if_fail (GST_IS_PAD (src), FALSE);
1763 g_return_val_if_fail (GST_IS_PAD (sink), FALSE);
1765 return gst_pad_link_maybe_ghosting_full (src, sink,
1766 GST_PAD_LINK_CHECK_DEFAULT);
1770 release_and_unref_pad (GstElement * element, GstPad * pad, gboolean requestpad)
1774 gst_element_release_request_pad (element, pad);
1775 gst_object_unref (pad);
1780 * gst_element_link_pads_full:
1781 * @src: a #GstElement containing the source pad.
1782 * @srcpadname: (allow-none): the name of the #GstPad in source element
1783 * or %NULL for any pad.
1784 * @dest: (transfer none): the #GstElement containing the destination pad.
1785 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1786 * or %NULL for any pad.
1787 * @flags: the #GstPadLinkCheck to be performed when linking pads.
1789 * Links the two named pads of the source and destination elements.
1790 * Side effect is that if one of the pads has no parent, it becomes a
1791 * child of the parent of the other element. If they have different
1792 * parents, the link fails.
1794 * Calling gst_element_link_pads_full() with @flags == %GST_PAD_LINK_CHECK_DEFAULT
1795 * is the same as calling gst_element_link_pads() and the recommended way of
1796 * linking pads with safety checks applied.
1798 * This is a convenience function for gst_pad_link_full().
1800 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1803 gst_element_link_pads_full (GstElement * src, const gchar * srcpadname,
1804 GstElement * dest, const gchar * destpadname, GstPadLinkCheck flags)
1806 const GList *srcpads, *destpads, *srctempls, *desttempls, *l;
1807 GstPad *srcpad, *destpad;
1808 GstPadTemplate *srctempl, *desttempl;
1809 GstElementClass *srcclass, *destclass;
1810 gboolean srcrequest, destrequest;
1813 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1814 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1816 GST_CAT_INFO (GST_CAT_ELEMENT_PADS,
1817 "trying to link element %s:%s to element %s:%s", GST_ELEMENT_NAME (src),
1818 srcpadname ? srcpadname : "(any)", GST_ELEMENT_NAME (dest),
1819 destpadname ? destpadname : "(any)");
1822 destrequest = FALSE;
1826 /* name specified, look it up */
1827 if (!(srcpad = gst_element_get_static_pad (src, srcpadname))) {
1828 if ((srcpad = gst_element_request_pad_simple (src, srcpadname)))
1832 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1833 GST_ELEMENT_NAME (src), srcpadname);
1836 if (!(GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC)) {
1837 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no src pad",
1838 GST_DEBUG_PAD_NAME (srcpad));
1839 release_and_unref_pad (src, srcpad, srcrequest);
1842 if (GST_PAD_PEER (srcpad) != NULL) {
1843 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1844 "pad %s:%s is already linked to %s:%s", GST_DEBUG_PAD_NAME (srcpad),
1845 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1846 /* already linked request pads look like static pads, so the request pad
1847 * was never requested a second time above, so no need to release it */
1848 gst_object_unref (srcpad);
1854 /* no name given, get the first available pad */
1855 GST_OBJECT_LOCK (src);
1856 srcpads = GST_ELEMENT_PADS (src);
1857 srcpad = srcpads ? GST_PAD_CAST (srcpads->data) : NULL;
1859 gst_object_ref (srcpad);
1860 GST_OBJECT_UNLOCK (src);
1863 /* get a destination pad */
1865 /* name specified, look it up */
1866 if (!(destpad = gst_element_get_static_pad (dest, destpadname))) {
1867 if ((destpad = gst_element_request_pad_simple (dest, destpadname)))
1871 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1872 GST_ELEMENT_NAME (dest), destpadname);
1873 release_and_unref_pad (src, srcpad, srcrequest);
1876 if (!(GST_PAD_DIRECTION (destpad) == GST_PAD_SINK)) {
1877 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no sink pad",
1878 GST_DEBUG_PAD_NAME (destpad));
1879 release_and_unref_pad (src, srcpad, srcrequest);
1880 release_and_unref_pad (dest, destpad, destrequest);
1883 if (GST_PAD_PEER (destpad) != NULL) {
1884 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1885 "pad %s:%s is already linked to %s:%s",
1886 GST_DEBUG_PAD_NAME (destpad),
1887 GST_DEBUG_PAD_NAME (GST_PAD_PEER (destpad)));
1888 release_and_unref_pad (src, srcpad, srcrequest);
1889 /* already linked request pads look like static pads, so the request pad
1890 * was never requested a second time above, so no need to release it */
1891 gst_object_unref (destpad);
1897 /* no name given, get the first available pad */
1898 GST_OBJECT_LOCK (dest);
1899 destpads = GST_ELEMENT_PADS (dest);
1900 destpad = destpads ? GST_PAD_CAST (destpads->data) : NULL;
1902 gst_object_ref (destpad);
1903 GST_OBJECT_UNLOCK (dest);
1906 if (srcpadname && destpadname) {
1909 /* two explicitly specified pads */
1910 result = pad_link_maybe_ghosting (srcpad, destpad, flags);
1913 gst_object_unref (srcpad);
1914 gst_object_unref (destpad);
1916 release_and_unref_pad (src, srcpad, srcrequest);
1917 release_and_unref_pad (dest, destpad, destrequest);
1923 /* loop through the allowed pads in the source, trying to find a
1924 * compatible destination pad */
1925 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1926 "looping through allowed src and dest pads");
1928 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying src pad %s:%s",
1929 GST_DEBUG_PAD_NAME (srcpad));
1930 if ((GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC) &&
1931 (GST_PAD_PEER (srcpad) == NULL)) {
1932 gboolean temprequest = FALSE;
1937 gst_object_ref (temp);
1939 temp = gst_element_get_compatible_pad (dest, srcpad, NULL);
1940 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1941 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
1947 if (temp && pad_link_maybe_ghosting (srcpad, temp, flags)) {
1948 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1949 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (temp));
1951 gst_object_unref (destpad);
1952 gst_object_unref (srcpad);
1953 gst_object_unref (temp);
1959 gst_element_release_request_pad (dest, temp);
1960 gst_object_unref (temp);
1963 /* find a better way for this mess */
1965 srcpads = g_list_next (srcpads);
1967 gst_object_unref (srcpad);
1968 srcpad = GST_PAD_CAST (srcpads->data);
1969 gst_object_ref (srcpad);
1975 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s:%s to %s",
1976 GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (dest));
1977 /* no need to release any request pad as both src- and destpadname must be
1978 * set to end up here, but this case has already been taken care of above */
1980 gst_object_unref (destpad);
1984 release_and_unref_pad (src, srcpad, srcrequest);
1989 /* loop through the existing pads in the destination */
1991 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying dest pad %s:%s",
1992 GST_DEBUG_PAD_NAME (destpad));
1993 if ((GST_PAD_DIRECTION (destpad) == GST_PAD_SINK) &&
1994 (GST_PAD_PEER (destpad) == NULL)) {
1995 GstPad *temp = gst_element_get_compatible_pad (src, destpad, NULL);
1996 gboolean temprequest = FALSE;
1998 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1999 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
2004 if (temp && pad_link_maybe_ghosting (temp, destpad, flags)) {
2005 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
2006 GST_DEBUG_PAD_NAME (temp), GST_DEBUG_PAD_NAME (destpad));
2007 gst_object_unref (temp);
2008 gst_object_unref (destpad);
2012 release_and_unref_pad (src, temp, temprequest);
2015 destpads = g_list_next (destpads);
2017 gst_object_unref (destpad);
2018 destpad = GST_PAD_CAST (destpads->data);
2019 gst_object_ref (destpad);
2026 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s:%s",
2027 GST_ELEMENT_NAME (src), GST_DEBUG_PAD_NAME (destpad));
2028 release_and_unref_pad (dest, destpad, destrequest);
2031 /* no need to release any request pad as the case of unset destpatname and
2032 * destpad being a request pad has already been taken care of when looking
2033 * though the destination pads above */
2035 gst_object_unref (destpad);
2040 srcclass = GST_ELEMENT_GET_CLASS (src);
2041 destclass = GST_ELEMENT_GET_CLASS (dest);
2043 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
2044 "we might have request pads on both sides, checking...");
2045 srctempls = gst_element_class_get_pad_template_list (srcclass);
2046 desttempls = gst_element_class_get_pad_template_list (destclass);
2048 if (srctempls && desttempls) {
2050 srctempl = (GstPadTemplate *) srctempls->data;
2051 if (srctempl->presence == GST_PAD_REQUEST) {
2052 for (l = desttempls; l; l = l->next) {
2053 desttempl = (GstPadTemplate *) l->data;
2054 if (desttempl->presence == GST_PAD_REQUEST &&
2055 desttempl->direction != srctempl->direction) {
2056 GstCaps *srccaps, *destcaps;
2058 srccaps = gst_pad_template_get_caps (srctempl);
2059 destcaps = gst_pad_template_get_caps (desttempl);
2060 if (gst_caps_is_always_compatible (srccaps, destcaps)) {
2062 gst_element_request_pad (src, srctempl,
2063 srctempl->name_template, NULL);
2065 gst_element_request_pad (dest, desttempl,
2066 desttempl->name_template, NULL);
2067 if (srcpad && destpad
2068 && pad_link_maybe_ghosting (srcpad, destpad, flags)) {
2069 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
2070 "linked pad %s:%s to pad %s:%s",
2071 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (destpad));
2072 gst_object_unref (srcpad);
2073 gst_object_unref (destpad);
2074 gst_caps_unref (srccaps);
2075 gst_caps_unref (destcaps);
2078 /* it failed, so we release the request pads */
2080 gst_element_release_request_pad (src, srcpad);
2081 gst_object_unref (srcpad);
2084 gst_element_release_request_pad (dest, destpad);
2085 gst_object_unref (destpad);
2088 gst_caps_unref (srccaps);
2089 gst_caps_unref (destcaps);
2093 srctempls = srctempls->next;
2097 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s",
2098 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2103 * gst_element_link_pads:
2104 * @src: a #GstElement containing the source pad.
2105 * @srcpadname: (allow-none): the name of the #GstPad in source element
2106 * or %NULL for any pad.
2107 * @dest: (transfer none): the #GstElement containing the destination pad.
2108 * @destpadname: (allow-none): the name of the #GstPad in destination element,
2109 * or %NULL for any pad.
2111 * Links the two named pads of the source and destination elements.
2112 * Side effect is that if one of the pads has no parent, it becomes a
2113 * child of the parent of the other element. If they have different
2114 * parents, the link fails.
2116 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2119 gst_element_link_pads (GstElement * src, const gchar * srcpadname,
2120 GstElement * dest, const gchar * destpadname)
2122 return gst_element_link_pads_full (src, srcpadname, dest, destpadname,
2123 GST_PAD_LINK_CHECK_DEFAULT);
2127 * gst_element_link_pads_filtered:
2128 * @src: a #GstElement containing the source pad.
2129 * @srcpadname: (allow-none): the name of the #GstPad in source element
2130 * or %NULL for any pad.
2131 * @dest: (transfer none): the #GstElement containing the destination pad.
2132 * @destpadname: (allow-none): the name of the #GstPad in destination element
2133 * or %NULL for any pad.
2134 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
2135 * or %NULL for no filter.
2137 * Links the two named pads of the source and destination elements. Side effect
2138 * is that if one of the pads has no parent, it becomes a child of the parent of
2139 * the other element. If they have different parents, the link fails. If @caps
2140 * is not %NULL, makes sure that the caps of the link is a subset of @caps.
2142 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2145 gst_element_link_pads_filtered (GstElement * src, const gchar * srcpadname,
2146 GstElement * dest, const gchar * destpadname, GstCaps * filter)
2149 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
2150 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
2151 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), FALSE);
2154 GstElement *capsfilter;
2156 GstState state, pending;
2159 capsfilter = gst_element_factory_make ("capsfilter", NULL);
2161 GST_ERROR ("Could not make a capsfilter");
2165 parent = gst_object_get_parent (GST_OBJECT (src));
2166 g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
2168 gst_element_get_state (GST_ELEMENT_CAST (parent), &state, &pending, 0);
2170 if (!gst_bin_add (GST_BIN (parent), capsfilter)) {
2171 GST_ERROR ("Could not add capsfilter");
2172 gst_object_unref (parent);
2176 if (pending != GST_STATE_VOID_PENDING)
2179 gst_element_set_state (capsfilter, state);
2181 gst_object_unref (parent);
2183 g_object_set (capsfilter, "caps", filter, NULL);
2185 lr1 = gst_element_link_pads (src, srcpadname, capsfilter, "sink");
2186 lr2 = gst_element_link_pads (capsfilter, "src", dest, destpadname);
2191 GST_INFO ("Could not link pads: %s:%s - capsfilter:sink",
2192 GST_ELEMENT_NAME (src), srcpadname);
2194 GST_INFO ("Could not link pads: capsfilter:src - %s:%s",
2195 GST_ELEMENT_NAME (dest), destpadname);
2197 gst_element_set_state (capsfilter, GST_STATE_NULL);
2198 /* this will unlink and unref as appropriate */
2199 gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (capsfilter)), capsfilter);
2203 if (gst_element_link_pads (src, srcpadname, dest, destpadname)) {
2206 GST_INFO ("Could not link pads: %s:%s - %s:%s", GST_ELEMENT_NAME (src),
2207 srcpadname, GST_ELEMENT_NAME (dest), destpadname);
2215 * @src: (transfer none): a #GstElement containing the source pad.
2216 * @dest: (transfer none): the #GstElement containing the destination pad.
2218 * Links @src to @dest. The link must be from source to
2219 * destination; the other direction will not be tried. The function looks for
2220 * existing pads that aren't linked yet. It will request new pads if necessary.
2221 * Such pads need to be released manually when unlinking.
2222 * If multiple links are possible, only one is established.
2224 * Make sure you have added your elements to a bin or pipeline with
2225 * gst_bin_add() before trying to link them.
2227 * Returns: %TRUE if the elements could be linked, %FALSE otherwise.
2230 gst_element_link (GstElement * src, GstElement * dest)
2232 return gst_element_link_pads (src, NULL, dest, NULL);
2236 * gst_element_link_many:
2237 * @element_1: (transfer none): the first #GstElement in the link chain.
2238 * @element_2: (transfer none): the second #GstElement in the link chain.
2239 * @...: the %NULL-terminated list of elements to link in order.
2241 * Chain together a series of elements. Uses gst_element_link().
2242 * Make sure you have added your elements to a bin or pipeline with
2243 * gst_bin_add() before trying to link them.
2245 * Returns: %TRUE on success, %FALSE otherwise.
2248 gst_element_link_many (GstElement * element_1, GstElement * element_2, ...)
2250 gboolean res = TRUE;
2253 g_return_val_if_fail (GST_IS_ELEMENT (element_1), FALSE);
2254 g_return_val_if_fail (GST_IS_ELEMENT (element_2), FALSE);
2256 va_start (args, element_2);
2259 if (!gst_element_link (element_1, element_2)) {
2264 element_1 = element_2;
2265 element_2 = va_arg (args, GstElement *);
2274 * gst_element_link_filtered:
2275 * @src: a #GstElement containing the source pad.
2276 * @dest: (transfer none): the #GstElement containing the destination pad.
2277 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
2278 * or %NULL for no filter.
2280 * Links @src to @dest using the given caps as filtercaps.
2281 * The link must be from source to
2282 * destination; the other direction will not be tried. The function looks for
2283 * existing pads that aren't linked yet. It will request new pads if necessary.
2284 * If multiple links are possible, only one is established.
2286 * Make sure you have added your elements to a bin or pipeline with
2287 * gst_bin_add() before trying to link them.
2289 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2292 gst_element_link_filtered (GstElement * src, GstElement * dest,
2295 return gst_element_link_pads_filtered (src, NULL, dest, NULL, filter);
2299 * gst_element_unlink_pads:
2300 * @src: a (transfer none): #GstElement containing the source pad.
2301 * @srcpadname: the name of the #GstPad in source element.
2302 * @dest: (transfer none): a #GstElement containing the destination pad.
2303 * @destpadname: the name of the #GstPad in destination element.
2305 * Unlinks the two named pads of the source and destination elements.
2307 * This is a convenience function for gst_pad_unlink().
2310 gst_element_unlink_pads (GstElement * src, const gchar * srcpadname,
2311 GstElement * dest, const gchar * destpadname)
2313 GstPad *srcpad, *destpad;
2314 gboolean srcrequest, destrequest;
2316 srcrequest = destrequest = FALSE;
2318 g_return_if_fail (src != NULL);
2319 g_return_if_fail (GST_IS_ELEMENT (src));
2320 g_return_if_fail (srcpadname != NULL);
2321 g_return_if_fail (dest != NULL);
2322 g_return_if_fail (GST_IS_ELEMENT (dest));
2323 g_return_if_fail (destpadname != NULL);
2325 /* obtain the pads requested */
2326 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
2327 if ((srcpad = gst_element_request_pad_simple (src, srcpadname)))
2329 if (srcpad == NULL) {
2330 GST_WARNING_OBJECT (src, "source element has no pad \"%s\"", srcpadname);
2333 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
2334 if ((destpad = gst_element_request_pad_simple (dest, destpadname)))
2336 if (destpad == NULL) {
2337 GST_WARNING_OBJECT (dest, "destination element has no pad \"%s\"",
2342 /* we're satisfied they can be unlinked, let's do it */
2343 gst_pad_unlink (srcpad, destpad);
2346 gst_element_release_request_pad (dest, destpad);
2347 gst_object_unref (destpad);
2351 gst_element_release_request_pad (src, srcpad);
2352 gst_object_unref (srcpad);
2356 * gst_element_unlink_many:
2357 * @element_1: (transfer none): the first #GstElement in the link chain.
2358 * @element_2: (transfer none): the second #GstElement in the link chain.
2359 * @...: the %NULL-terminated list of elements to unlink in order.
2361 * Unlinks a series of elements. Uses gst_element_unlink().
2364 gst_element_unlink_many (GstElement * element_1, GstElement * element_2, ...)
2368 g_return_if_fail (element_1 != NULL && element_2 != NULL);
2369 g_return_if_fail (GST_IS_ELEMENT (element_1) && GST_IS_ELEMENT (element_2));
2371 va_start (args, element_2);
2374 gst_element_unlink (element_1, element_2);
2376 element_1 = element_2;
2377 element_2 = va_arg (args, GstElement *);
2384 * gst_element_unlink:
2385 * @src: (transfer none): the source #GstElement to unlink.
2386 * @dest: (transfer none): the sink #GstElement to unlink.
2388 * Unlinks all source pads of the source element with all sink pads
2389 * of the sink element to which they are linked.
2391 * If the link has been made using gst_element_link(), it could have created an
2392 * requestpad, which has to be released using gst_element_release_request_pad().
2395 gst_element_unlink (GstElement * src, GstElement * dest)
2398 gboolean done = FALSE;
2399 GValue data = { 0, };
2401 g_return_if_fail (GST_IS_ELEMENT (src));
2402 g_return_if_fail (GST_IS_ELEMENT (dest));
2404 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unlinking \"%s\" and \"%s\"",
2405 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2407 pads = gst_element_iterate_pads (src);
2409 switch (gst_iterator_next (pads, &data)) {
2410 case GST_ITERATOR_OK:
2412 GstPad *pad = g_value_get_object (&data);
2414 if (GST_PAD_IS_SRC (pad)) {
2415 GstPad *peerpad = gst_pad_get_peer (pad);
2417 /* see if the pad is linked and is really a pad of dest */
2419 GstElement *peerelem;
2421 peerelem = gst_pad_get_parent_element (peerpad);
2423 if (peerelem == dest) {
2424 gst_pad_unlink (pad, peerpad);
2427 gst_object_unref (peerelem);
2429 gst_object_unref (peerpad);
2432 g_value_reset (&data);
2435 case GST_ITERATOR_RESYNC:
2436 gst_iterator_resync (pads);
2438 case GST_ITERATOR_DONE:
2442 g_assert_not_reached ();
2446 g_value_unset (&data);
2447 gst_iterator_free (pads);
2451 * gst_element_query_position:
2452 * @element: a #GstElement to invoke the position query on.
2453 * @format: the #GstFormat requested
2454 * @cur: (out) (allow-none): a location in which to store the current
2455 * position, or %NULL.
2457 * Queries an element (usually top-level pipeline or playbin element) for the
2458 * stream position in nanoseconds. This will be a value between 0 and the
2459 * stream duration (if the stream duration is known). This query will usually
2460 * only work once the pipeline is prerolled (i.e. reached PAUSED or PLAYING
2461 * state). The application will receive an ASYNC_DONE message on the pipeline
2462 * bus when that is the case.
2464 * If one repeatedly calls this function one can also create a query and reuse
2465 * it in gst_element_query().
2467 * Returns: %TRUE if the query could be performed.
2470 gst_element_query_position (GstElement * element, GstFormat format,
2477 *cur = GST_CLOCK_TIME_NONE;
2479 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2480 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2482 query = gst_query_new_position (format);
2483 ret = gst_element_query (element, query);
2486 gst_query_parse_position (query, NULL, cur);
2488 gst_query_unref (query);
2494 * gst_element_query_duration:
2495 * @element: a #GstElement to invoke the duration query on.
2496 * @format: the #GstFormat requested
2497 * @duration: (out) (allow-none): A location in which to store the total duration, or %NULL.
2499 * Queries an element (usually top-level pipeline or playbin element) for the
2500 * total stream duration in nanoseconds. This query will only work once the
2501 * pipeline is prerolled (i.e. reached PAUSED or PLAYING state). The application
2502 * will receive an ASYNC_DONE message on the pipeline bus when that is the case.
2504 * If the duration changes for some reason, you will get a DURATION_CHANGED
2505 * message on the pipeline bus, in which case you should re-query the duration
2506 * using this function.
2508 * Returns: %TRUE if the query could be performed.
2511 gst_element_query_duration (GstElement * element, GstFormat format,
2517 if (duration != NULL)
2518 *duration = GST_CLOCK_TIME_NONE;
2520 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2521 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2523 query = gst_query_new_duration (format);
2524 ret = gst_element_query (element, query);
2527 gst_query_parse_duration (query, NULL, duration);
2529 gst_query_unref (query);
2535 * gst_element_query_convert:
2536 * @element: a #GstElement to invoke the convert query on.
2537 * @src_format: a #GstFormat to convert from.
2538 * @src_val: a value to convert.
2539 * @dest_format: the #GstFormat to convert to.
2540 * @dest_val: (out): a pointer to the result.
2542 * Queries an element to convert @src_val in @src_format to @dest_format.
2544 * Returns: %TRUE if the query could be performed.
2547 gst_element_query_convert (GstElement * element, GstFormat src_format,
2548 gint64 src_val, GstFormat dest_format, gint64 * dest_val)
2553 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2554 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2555 g_return_val_if_fail (dest_val != NULL, FALSE);
2557 if (dest_format == src_format || src_val == -1) {
2558 *dest_val = src_val;
2562 query = gst_query_new_convert (src_format, src_val, dest_format);
2563 ret = gst_element_query (element, query);
2566 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2568 gst_query_unref (query);
2574 * gst_element_seek_simple:
2575 * @element: a #GstElement to seek on
2576 * @format: a #GstFormat to execute the seek in, such as #GST_FORMAT_TIME
2577 * @seek_flags: seek options; playback applications will usually want to use
2578 * GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT here
2579 * @seek_pos: position to seek to (relative to the start); if you are doing
2580 * a seek in #GST_FORMAT_TIME this value is in nanoseconds -
2581 * multiply with #GST_SECOND to convert seconds to nanoseconds or
2582 * with #GST_MSECOND to convert milliseconds to nanoseconds.
2584 * Simple API to perform a seek on the given element, meaning it just seeks
2585 * to the given position relative to the start of the stream. For more complex
2586 * operations like segment seeks (e.g. for looping) or changing the playback
2587 * rate or seeking relative to the last configured playback segment you should
2588 * use gst_element_seek().
2590 * In a completely prerolled PAUSED or PLAYING pipeline, seeking is always
2591 * guaranteed to return %TRUE on a seekable media type or %FALSE when the media
2592 * type is certainly not seekable (such as a live stream).
2594 * Some elements allow for seeking in the READY state, in this
2595 * case they will store the seek event and execute it when they are put to
2596 * PAUSED. If the element supports seek in READY, it will always return %TRUE when
2597 * it receives the event in the READY state.
2599 * Returns: %TRUE if the seek operation succeeded. Flushing seeks will trigger a
2600 * preroll, which will emit %GST_MESSAGE_ASYNC_DONE.
2603 gst_element_seek_simple (GstElement * element, GstFormat format,
2604 GstSeekFlags seek_flags, gint64 seek_pos)
2606 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2607 g_return_val_if_fail (seek_pos >= 0, FALSE);
2609 return gst_element_seek (element, 1.0, format, seek_flags,
2610 GST_SEEK_TYPE_SET, seek_pos, GST_SEEK_TYPE_SET, GST_CLOCK_TIME_NONE);
2614 * gst_pad_use_fixed_caps:
2615 * @pad: the pad to use
2617 * A helper function you can use that sets the FIXED_CAPS flag
2618 * This way the default CAPS query will always return the negotiated caps
2619 * or in case the pad is not negotiated, the padtemplate caps.
2621 * The negotiated caps are the caps of the last CAPS event that passed on the
2622 * pad. Use this function on a pad that, once it negotiated to a CAPS, cannot
2623 * be renegotiated to something else.
2626 gst_pad_use_fixed_caps (GstPad * pad)
2628 GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FIXED_CAPS);
2632 * gst_pad_get_parent_element:
2635 * Gets the parent of @pad, cast to a #GstElement. If a @pad has no parent or
2636 * its parent is not an element, return %NULL.
2638 * Returns: (transfer full) (nullable): the parent of the pad. The
2639 * caller has a reference on the parent, so unref when you're finished
2645 gst_pad_get_parent_element (GstPad * pad)
2649 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2651 p = gst_object_get_parent (GST_OBJECT_CAST (pad));
2653 if (p && !GST_IS_ELEMENT (p)) {
2654 gst_object_unref (p);
2657 return GST_ELEMENT_CAST (p);
2661 * gst_object_default_error:
2662 * @source: the #GstObject that initiated the error.
2663 * @error: (in): the GError.
2664 * @debug: (in) (allow-none): an additional debug information string, or %NULL
2666 * A default error function that uses g_printerr() to display the error message
2667 * and the optional debug string..
2669 * The default handler will simply print the error string using g_print.
2672 gst_object_default_error (GstObject * source, const GError * error,
2673 const gchar * debug)
2675 gchar *name = gst_object_get_path_string (source);
2677 g_printerr (_("ERROR: from element %s: %s\n"), name, error->message);
2679 g_printerr (_("Additional debug info:\n%s\n"), debug);
2685 * gst_bin_add_many: (skip)
2687 * @element_1: (transfer floating): the #GstElement element to add to the bin
2688 * @...: additional elements to add to the bin
2690 * Adds a %NULL-terminated list of elements to a bin. This function is
2691 * equivalent to calling gst_bin_add() for each member of the list. The return
2692 * value of each gst_bin_add() is ignored.
2695 gst_bin_add_many (GstBin * bin, GstElement * element_1, ...)
2699 g_return_if_fail (GST_IS_BIN (bin));
2700 g_return_if_fail (GST_IS_ELEMENT (element_1));
2702 va_start (args, element_1);
2705 gst_bin_add (bin, element_1);
2707 element_1 = va_arg (args, GstElement *);
2714 * gst_bin_remove_many: (skip)
2716 * @element_1: (transfer none): the first #GstElement to remove from the bin
2717 * @...: (transfer none): %NULL-terminated list of elements to remove from the bin
2719 * Removes a list of elements from a bin. This function is equivalent
2720 * to calling gst_bin_remove() with each member of the list.
2723 gst_bin_remove_many (GstBin * bin, GstElement * element_1, ...)
2727 g_return_if_fail (GST_IS_BIN (bin));
2728 g_return_if_fail (GST_IS_ELEMENT (element_1));
2730 va_start (args, element_1);
2733 gst_bin_remove (bin, element_1);
2735 element_1 = va_arg (args, GstElement *);
2745 } QueryAcceptCapsData;
2748 query_accept_caps_func (GstPad * pad, QueryAcceptCapsData * data)
2750 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2753 gst_query_parse_accept_caps_result (data->query, &result);
2754 data->ret &= result;
2760 * gst_pad_proxy_query_accept_caps:
2761 * @pad: a #GstPad to proxy.
2762 * @query: an ACCEPT_CAPS #GstQuery.
2764 * Checks if all internally linked pads of @pad accepts the caps in @query and
2765 * returns the intersection of the results.
2767 * This function is useful as a default accept caps query function for an element
2768 * that can handle any stream format, but requires caps that are acceptable for
2769 * all opposite pads.
2771 * Returns: %TRUE if @query could be executed
2774 gst_pad_proxy_query_accept_caps (GstPad * pad, GstQuery * query)
2776 QueryAcceptCapsData data;
2778 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2779 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2780 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS, FALSE);
2782 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2783 "proxying accept caps query for %s:%s", GST_DEBUG_PAD_NAME (pad));
2786 /* value to hold the return, by default it holds TRUE */
2787 /* FIXME: TRUE is wrong when there are no pads */
2790 gst_pad_forward (pad, (GstPadForwardFunction) query_accept_caps_func, &data);
2791 gst_query_set_accept_caps_result (query, data.ret);
2793 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying accept caps query: %d",
2806 query_caps_func (GstPad * pad, QueryCapsData * data)
2808 gboolean empty = FALSE;
2810 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2811 GstCaps *peercaps, *intersection;
2813 gst_query_parse_caps_result (data->query, &peercaps);
2814 GST_DEBUG_OBJECT (pad, "intersect with result %" GST_PTR_FORMAT, peercaps);
2815 intersection = gst_caps_intersect (data->ret, peercaps);
2816 GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, intersection);
2818 gst_caps_unref (data->ret);
2819 data->ret = intersection;
2821 /* stop when empty */
2822 empty = gst_caps_is_empty (intersection);
2828 * gst_pad_proxy_query_caps:
2829 * @pad: a #GstPad to proxy.
2830 * @query: a CAPS #GstQuery.
2832 * Calls gst_pad_query_caps() for all internally linked pads of @pad and returns
2833 * the intersection of the results.
2835 * This function is useful as a default caps query function for an element
2836 * that can handle any stream format, but requires all its pads to have
2837 * the same caps. Two such elements are tee and adder.
2839 * Returns: %TRUE if @query could be executed
2842 gst_pad_proxy_query_caps (GstPad * pad, GstQuery * query)
2844 GstCaps *filter, *templ, *result;
2847 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2848 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2849 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CAPS, FALSE);
2851 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying caps query for %s:%s",
2852 GST_DEBUG_PAD_NAME (pad));
2856 /* value to hold the return, by default it holds the filter or ANY */
2857 gst_query_parse_caps (query, &filter);
2858 data.ret = filter ? gst_caps_ref (filter) : gst_caps_new_any ();
2860 gst_pad_forward (pad, (GstPadForwardFunction) query_caps_func, &data);
2862 templ = gst_pad_get_pad_template_caps (pad);
2863 result = gst_caps_intersect (data.ret, templ);
2864 gst_caps_unref (data.ret);
2865 gst_caps_unref (templ);
2867 gst_query_set_caps_result (query, result);
2868 gst_caps_unref (result);
2870 /* FIXME: return something depending on the processing */
2875 * gst_pad_query_position:
2876 * @pad: a #GstPad to invoke the position query on.
2877 * @format: the #GstFormat requested
2878 * @cur: (out) (allow-none): A location in which to store the current position, or %NULL.
2880 * Queries a pad for the stream position.
2882 * Returns: %TRUE if the query could be performed.
2885 gst_pad_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2891 *cur = GST_CLOCK_TIME_NONE;
2893 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2894 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2896 query = gst_query_new_position (format);
2897 if ((ret = gst_pad_query (pad, query)))
2898 gst_query_parse_position (query, NULL, cur);
2899 gst_query_unref (query);
2905 * gst_pad_peer_query_position:
2906 * @pad: a #GstPad on whose peer to invoke the position query on.
2907 * Must be a sink pad.
2908 * @format: the #GstFormat requested
2909 * @cur: (out) (allow-none): a location in which to store the current
2910 * position, or %NULL.
2912 * Queries the peer of a given sink pad for the stream position.
2914 * Returns: %TRUE if the query could be performed.
2917 gst_pad_peer_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2920 gboolean ret = FALSE;
2923 *cur = GST_CLOCK_TIME_NONE;
2925 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2926 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2928 query = gst_query_new_position (format);
2929 if ((ret = gst_pad_peer_query (pad, query)))
2930 gst_query_parse_position (query, NULL, cur);
2931 gst_query_unref (query);
2937 * gst_pad_query_duration:
2938 * @pad: a #GstPad to invoke the duration query on.
2939 * @format: the #GstFormat requested
2940 * @duration: (out) (allow-none): a location in which to store the total
2941 * duration, or %NULL.
2943 * Queries a pad for the total stream duration.
2945 * Returns: %TRUE if the query could be performed.
2948 gst_pad_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2953 if (duration != NULL)
2954 *duration = GST_CLOCK_TIME_NONE;
2956 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2957 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2959 query = gst_query_new_duration (format);
2960 if ((ret = gst_pad_query (pad, query)))
2961 gst_query_parse_duration (query, NULL, duration);
2962 gst_query_unref (query);
2968 * gst_pad_peer_query_duration:
2969 * @pad: a #GstPad on whose peer pad to invoke the duration query on.
2970 * Must be a sink pad.
2971 * @format: the #GstFormat requested
2972 * @duration: (out) (allow-none): a location in which to store the total
2973 * duration, or %NULL.
2975 * Queries the peer pad of a given sink pad for the total stream duration.
2977 * Returns: %TRUE if the query could be performed.
2980 gst_pad_peer_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2983 gboolean ret = FALSE;
2985 if (duration != NULL)
2986 *duration = GST_CLOCK_TIME_NONE;
2988 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2989 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2990 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2992 query = gst_query_new_duration (format);
2993 if ((ret = gst_pad_peer_query (pad, query)))
2994 gst_query_parse_duration (query, NULL, duration);
2995 gst_query_unref (query);
3001 * gst_pad_query_convert:
3002 * @pad: a #GstPad to invoke the convert query on.
3003 * @src_format: a #GstFormat to convert from.
3004 * @src_val: a value to convert.
3005 * @dest_format: the #GstFormat to convert to.
3006 * @dest_val: (out): a pointer to the result.
3008 * Queries a pad to convert @src_val in @src_format to @dest_format.
3010 * Returns: %TRUE if the query could be performed.
3013 gst_pad_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
3014 GstFormat dest_format, gint64 * dest_val)
3019 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3020 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
3021 g_return_val_if_fail (dest_val != NULL, FALSE);
3023 if (dest_format == src_format || src_val == -1) {
3024 *dest_val = src_val;
3028 query = gst_query_new_convert (src_format, src_val, dest_format);
3029 if ((ret = gst_pad_query (pad, query)))
3030 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
3031 gst_query_unref (query);
3037 * gst_pad_peer_query_convert:
3038 * @pad: a #GstPad, on whose peer pad to invoke the convert query on.
3039 * Must be a sink pad.
3040 * @src_format: a #GstFormat to convert from.
3041 * @src_val: a value to convert.
3042 * @dest_format: the #GstFormat to convert to.
3043 * @dest_val: (out): a pointer to the result.
3045 * Queries the peer pad of a given sink pad to convert @src_val in @src_format
3048 * Returns: %TRUE if the query could be performed.
3051 gst_pad_peer_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
3052 GstFormat dest_format, gint64 * dest_val)
3055 gboolean ret = FALSE;
3057 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3058 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
3059 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
3060 g_return_val_if_fail (dest_val != NULL, FALSE);
3062 query = gst_query_new_convert (src_format, src_val, dest_format);
3063 if ((ret = gst_pad_peer_query (pad, query)))
3064 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
3065 gst_query_unref (query);
3071 * gst_pad_query_caps:
3072 * @pad: a #GstPad to get the capabilities of.
3073 * @filter: (allow-none): suggested #GstCaps, or %NULL
3075 * Gets the capabilities this pad can produce or consume.
3076 * Note that this method doesn't necessarily return the caps set by sending a
3077 * gst_event_new_caps() - use gst_pad_get_current_caps() for that instead.
3078 * gst_pad_query_caps returns all possible caps a pad can operate with, using
3079 * the pad's CAPS query function, If the query fails, this function will return
3080 * @filter, if not %NULL, otherwise ANY.
3082 * When called on sinkpads @filter contains the caps that
3083 * upstream could produce in the order preferred by upstream. When
3084 * called on srcpads @filter contains the caps accepted by
3085 * downstream in the preferred order. @filter might be %NULL but
3086 * if it is not %NULL the returned caps will be a subset of @filter.
3088 * Note that this function does not return writable #GstCaps, use
3089 * gst_caps_make_writable() before modifying the caps.
3091 * Returns: (transfer full): the caps of the pad with incremented ref-count.
3094 gst_pad_query_caps (GstPad * pad, GstCaps * filter)
3096 GstCaps *result = NULL;
3099 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3100 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
3102 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3103 "get pad caps with filter %" GST_PTR_FORMAT, filter);
3105 query = gst_query_new_caps (filter);
3106 if (gst_pad_query (pad, query)) {
3107 gst_query_parse_caps_result (query, &result);
3108 gst_caps_ref (result);
3109 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3110 "query returned %" GST_PTR_FORMAT, result);
3111 } else if (filter) {
3112 result = gst_caps_ref (filter);
3114 result = gst_caps_new_any ();
3116 gst_query_unref (query);
3122 * gst_pad_peer_query_caps:
3123 * @pad: a #GstPad to get the capabilities of.
3124 * @filter: (allow-none): a #GstCaps filter, or %NULL.
3126 * Gets the capabilities of the peer connected to this pad. Similar to
3127 * gst_pad_query_caps().
3129 * When called on srcpads @filter contains the caps that
3130 * upstream could produce in the order preferred by upstream. When
3131 * called on sinkpads @filter contains the caps accepted by
3132 * downstream in the preferred order. @filter might be %NULL but
3133 * if it is not %NULL the returned caps will be a subset of @filter.
3135 * Returns: (transfer full): the caps of the peer pad with incremented
3136 * ref-count. When there is no peer pad, this function returns @filter or,
3137 * when @filter is %NULL, ANY caps.
3140 gst_pad_peer_query_caps (GstPad * pad, GstCaps * filter)
3142 GstCaps *result = NULL;
3145 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3146 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
3148 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3149 "get pad peer caps with filter %" GST_PTR_FORMAT, filter);
3151 query = gst_query_new_caps (filter);
3152 if (gst_pad_peer_query (pad, query)) {
3153 gst_query_parse_caps_result (query, &result);
3154 gst_caps_ref (result);
3155 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3156 "peer query returned %" GST_PTR_FORMAT, result);
3157 } else if (filter) {
3158 result = gst_caps_ref (filter);
3160 result = gst_caps_new_any ();
3162 gst_query_unref (query);
3168 * gst_pad_query_accept_caps:
3169 * @pad: a #GstPad to check
3170 * @caps: a #GstCaps to check on the pad
3172 * Check if the given pad accepts the caps.
3174 * Returns: %TRUE if the pad can accept the caps.
3177 gst_pad_query_accept_caps (GstPad * pad, GstCaps * caps)
3179 gboolean res = TRUE;
3182 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3183 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
3185 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %"
3186 GST_PTR_FORMAT, caps);
3188 query = gst_query_new_accept_caps (caps);
3189 if (gst_pad_query (pad, query)) {
3190 gst_query_parse_accept_caps_result (query, &res);
3191 GST_DEBUG_OBJECT (pad, "query returned %d", res);
3193 gst_query_unref (query);
3199 * gst_pad_peer_query_accept_caps:
3200 * @pad: a #GstPad to check the peer of
3201 * @caps: a #GstCaps to check on the pad
3203 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
3206 * Returns: %TRUE if the peer of @pad can accept the caps or @pad has no peer.
3209 gst_pad_peer_query_accept_caps (GstPad * pad, GstCaps * caps)
3211 gboolean res = TRUE;
3214 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3215 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
3217 query = gst_query_new_accept_caps (caps);
3218 if (gst_pad_peer_query (pad, query)) {
3219 gst_query_parse_accept_caps_result (query, &res);
3220 GST_DEBUG_OBJECT (pad, "query returned %d", res);
3222 gst_query_unref (query);
3228 element_find_unlinked_pad (GstElement * element, GstPadDirection direction)
3231 GstPad *unlinked_pad = NULL;
3233 GValue data = { 0, };
3235 switch (direction) {
3237 iter = gst_element_iterate_src_pads (element);
3240 iter = gst_element_iterate_sink_pads (element);
3243 g_return_val_if_reached (NULL);
3248 switch (gst_iterator_next (iter, &data)) {
3249 case GST_ITERATOR_OK:{
3251 GstPad *pad = g_value_get_object (&data);
3253 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
3254 GST_DEBUG_PAD_NAME (pad));
3256 peer = gst_pad_get_peer (pad);
3258 unlinked_pad = gst_object_ref (pad);
3260 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
3261 "found existing unlinked pad %s:%s",
3262 GST_DEBUG_PAD_NAME (unlinked_pad));
3264 gst_object_unref (peer);
3266 g_value_reset (&data);
3269 case GST_ITERATOR_DONE:
3272 case GST_ITERATOR_RESYNC:
3273 gst_iterator_resync (iter);
3275 case GST_ITERATOR_ERROR:
3276 g_return_val_if_reached (NULL);
3280 g_value_unset (&data);
3281 gst_iterator_free (iter);
3283 return unlinked_pad;
3287 * gst_bin_find_unlinked_pad:
3288 * @bin: bin in which to look for elements with unlinked pads
3289 * @direction: whether to look for an unlinked source or sink pad
3291 * Recursively looks for elements with an unlinked pad of the given
3292 * direction within the specified bin and returns an unlinked pad
3293 * if one is found, or %NULL otherwise. If a pad is found, the caller
3294 * owns a reference to it and should use gst_object_unref() on the
3295 * pad when it is not needed any longer.
3297 * Returns: (transfer full) (nullable): unlinked pad of the given
3301 gst_bin_find_unlinked_pad (GstBin * bin, GstPadDirection direction)
3306 GValue data = { 0, };
3308 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3309 g_return_val_if_fail (direction != GST_PAD_UNKNOWN, NULL);
3312 iter = gst_bin_iterate_recurse (bin);
3314 switch (gst_iterator_next (iter, &data)) {
3315 case GST_ITERATOR_OK:{
3316 GstElement *element = g_value_get_object (&data);
3318 pad = element_find_unlinked_pad (element, direction);
3321 g_value_reset (&data);
3324 case GST_ITERATOR_DONE:
3327 case GST_ITERATOR_RESYNC:
3328 gst_iterator_resync (iter);
3330 case GST_ITERATOR_ERROR:
3331 g_return_val_if_reached (NULL);
3335 g_value_unset (&data);
3336 gst_iterator_free (iter);
3342 gst_bin_sync_children_states_foreach (const GValue * value, gpointer user_data)
3344 gboolean *success = user_data;
3345 GstElement *element = g_value_get_object (value);
3347 if (gst_element_is_locked_state (element)) {
3350 *success = *success && gst_element_sync_state_with_parent (element);
3352 if (GST_IS_BIN (element))
3354 && gst_bin_sync_children_states (GST_BIN_CAST (element));
3359 * gst_bin_sync_children_states:
3362 * Synchronizes the state of every child of @bin with the state
3363 * of @bin. See also gst_element_sync_state_with_parent().
3365 * Returns: %TRUE if syncing the state was successful for all children,
3371 gst_bin_sync_children_states (GstBin * bin)
3374 GstIteratorResult res = GST_ITERATOR_OK;
3375 gboolean success = TRUE;
3377 it = gst_bin_iterate_sorted (bin);
3380 if (res == GST_ITERATOR_RESYNC) {
3382 gst_iterator_resync (it);
3385 gst_iterator_foreach (it, gst_bin_sync_children_states_foreach,
3387 } while (res == GST_ITERATOR_RESYNC);
3388 gst_iterator_free (it);
3394 * gst_parse_bin_from_description:
3395 * @bin_description: command line describing the bin
3396 * @ghost_unlinked_pads: whether to automatically create ghost pads
3397 * for unlinked source or sink pads within the bin
3398 * @err: where to store the error message in case of an error, or %NULL
3400 * This is a convenience wrapper around gst_parse_launch() to create a
3401 * #GstBin from a gst-launch-style pipeline description. See
3402 * gst_parse_launch() and the gst-launch man page for details about the
3403 * syntax. Ghost pads on the bin for unlinked source or sink pads
3404 * within the bin can automatically be created (but only a maximum of
3405 * one ghost pad for each direction will be created; if you expect
3406 * multiple unlinked source pads or multiple unlinked sink pads
3407 * and want them all ghosted, you will have to create the ghost pads
3410 * Returns: (transfer floating) (type Gst.Bin): a
3411 * newly-created bin, or %NULL if an error occurred.
3414 gst_parse_bin_from_description (const gchar * bin_description,
3415 gboolean ghost_unlinked_pads, GError ** err)
3417 return gst_parse_bin_from_description_full (bin_description,
3418 ghost_unlinked_pads, NULL, GST_PARSE_FLAG_NONE, err);
3422 * gst_parse_bin_from_description_full:
3423 * @bin_description: command line describing the bin
3424 * @ghost_unlinked_pads: whether to automatically create ghost pads
3425 * for unlinked source or sink pads within the bin
3426 * @context: (transfer none) (allow-none): a parse context allocated with
3427 * gst_parse_context_new(), or %NULL
3428 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
3429 * @err: where to store the error message in case of an error, or %NULL
3431 * This is a convenience wrapper around gst_parse_launch() to create a
3432 * #GstBin from a gst-launch-style pipeline description. See
3433 * gst_parse_launch() and the gst-launch man page for details about the
3434 * syntax. Ghost pads on the bin for unlinked source or sink pads
3435 * within the bin can automatically be created (but only a maximum of
3436 * one ghost pad for each direction will be created; if you expect
3437 * multiple unlinked source pads or multiple unlinked sink pads
3438 * and want them all ghosted, you will have to create the ghost pads
3441 * Returns: (transfer floating) (type Gst.Element): a newly-created
3442 * element, which is guaranteed to be a bin unless
3443 * #GST_PARSE_FLAG_NO_SINGLE_ELEMENT_BINS was passed, or %NULL if an error
3447 gst_parse_bin_from_description_full (const gchar * bin_description,
3448 gboolean ghost_unlinked_pads, GstParseContext * context,
3449 GstParseFlags flags, GError ** err)
3451 #ifndef GST_DISABLE_PARSE
3453 GstElement *element;
3457 g_return_val_if_fail (bin_description != NULL, NULL);
3458 g_return_val_if_fail (err == NULL || *err == NULL, NULL);
3460 GST_DEBUG ("Making bin from description '%s'", bin_description);
3462 /* parse the pipeline to a bin */
3463 if (flags & GST_PARSE_FLAG_NO_SINGLE_ELEMENT_BINS) {
3464 element = gst_parse_launch_full (bin_description, context, flags, err);
3466 desc = g_strdup_printf ("bin.( %s )", bin_description);
3467 element = gst_parse_launch_full (desc, context, flags, err);
3471 if (element == NULL || (err && *err != NULL)) {
3473 gst_object_unref (element);
3477 if (GST_IS_BIN (element)) {
3478 bin = GST_BIN (element);
3483 /* find pads and ghost them if necessary */
3484 if (ghost_unlinked_pads) {
3485 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SRC))) {
3486 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("src", pad));
3487 gst_object_unref (pad);
3489 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SINK))) {
3490 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("sink", pad));
3491 gst_object_unref (pad);
3495 return GST_ELEMENT (bin);
3499 GST_WARNING ("Disabled API called");
3501 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
3502 g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);
3510 * gst_util_get_timestamp:
3512 * Get a timestamp as GstClockTime to be used for interval measurements.
3513 * The timestamp should not be interpreted in any other way.
3515 * Returns: the timestamp
3518 gst_util_get_timestamp (void)
3520 #if defined (HAVE_POSIX_TIMERS) && defined(HAVE_MONOTONIC_CLOCK) &&\
3521 defined (HAVE_CLOCK_GETTIME)
3522 struct timespec now;
3524 clock_gettime (CLOCK_MONOTONIC, &now);
3525 return GST_TIMESPEC_TO_TIME (now);
3527 return g_get_monotonic_time () * 1000;
3532 * gst_util_array_binary_search:
3533 * @array: the sorted input array
3534 * @num_elements: number of elements in the array
3535 * @element_size: size of every element in bytes
3536 * @search_func: (scope call): function to compare two elements, @search_data will always be passed as second argument
3537 * @mode: search mode that should be used
3538 * @search_data: element that should be found
3539 * @user_data: (closure): data to pass to @search_func
3541 * Searches inside @array for @search_data by using the comparison function
3542 * @search_func. @array must be sorted ascending.
3544 * As @search_data is always passed as second argument to @search_func it's
3545 * not required that @search_data has the same type as the array elements.
3547 * The complexity of this search function is O(log (num_elements)).
3549 * Returns: (transfer none) (nullable): The address of the found
3550 * element or %NULL if nothing was found
3553 gst_util_array_binary_search (gpointer array, guint num_elements,
3554 gsize element_size, GCompareDataFunc search_func, GstSearchMode mode,
3555 gconstpointer search_data, gpointer user_data)
3557 glong left = 0, right = num_elements - 1, m;
3559 guint8 *data = (guint8 *) array;
3561 g_return_val_if_fail (array != NULL, NULL);
3562 g_return_val_if_fail (element_size > 0, NULL);
3563 g_return_val_if_fail (search_func != NULL, NULL);
3565 /* 0. No elements => return NULL */
3566 if (num_elements == 0)
3569 /* 1. If search_data is before the 0th element return the 0th element */
3570 ret = search_func (data, search_data, user_data);
3571 if ((ret >= 0 && mode == GST_SEARCH_MODE_AFTER) || ret == 0)
3576 /* 2. If search_data is after the last element return the last element */
3578 search_func (data + (num_elements - 1) * element_size, search_data,
3580 if ((ret <= 0 && mode == GST_SEARCH_MODE_BEFORE) || ret == 0)
3581 return data + (num_elements - 1) * element_size;
3585 /* 3. else binary search */
3587 m = left + (right - left) / 2;
3589 ret = search_func (data + m * element_size, search_data, user_data);
3592 return data + m * element_size;
3593 } else if (ret < 0) {
3599 /* No exact match found */
3601 if (mode == GST_SEARCH_MODE_EXACT) {
3603 } else if (mode == GST_SEARCH_MODE_AFTER) {
3605 return (m < num_elements) ? data + (m + 1) * element_size : NULL;
3607 return data + m * element_size;
3610 return data + m * element_size;
3612 return (m > 0) ? data + (m - 1) * element_size : NULL;
3618 /* Finds the greatest common divisor.
3619 * Returns 1 if none other found.
3620 * This is Euclid's algorithm. */
3623 * gst_util_greatest_common_divisor:
3624 * @a: First value as #gint
3625 * @b: Second value as #gint
3627 * Calculates the greatest common divisor of @a
3630 * Returns: Greatest common divisor of @a and @b
3633 gst_util_greatest_common_divisor (gint a, gint b)
3646 * gst_util_greatest_common_divisor_int64:
3647 * @a: First value as #gint64
3648 * @b: Second value as #gint64
3650 * Calculates the greatest common divisor of @a
3653 * Returns: Greatest common divisor of @a and @b
3656 gst_util_greatest_common_divisor_int64 (gint64 a, gint64 b)
3670 * gst_util_fraction_to_double:
3671 * @src_n: Fraction numerator as #gint
3672 * @src_d: Fraction denominator #gint
3673 * @dest: (out): pointer to a #gdouble for the result
3675 * Transforms a fraction to a #gdouble.
3678 gst_util_fraction_to_double (gint src_n, gint src_d, gdouble * dest)
3680 g_return_if_fail (dest != NULL);
3681 g_return_if_fail (src_d != 0);
3683 *dest = ((gdouble) src_n) / ((gdouble) src_d);
3686 #define MAX_TERMS 30
3687 #define MIN_DIVISOR 1.0e-10
3688 #define MAX_ERROR 1.0e-20
3690 /* use continued fractions to transform a double into a fraction,
3691 * see http://mathforum.org/dr.math/faq/faq.fractions.html#decfrac.
3692 * This algorithm takes care of overflows.
3696 * gst_util_double_to_fraction:
3697 * @src: #gdouble to transform
3698 * @dest_n: (out): pointer to a #gint to hold the result numerator
3699 * @dest_d: (out): pointer to a #gint to hold the result denominator
3701 * Transforms a #gdouble to a fraction and simplifies
3705 gst_util_double_to_fraction (gdouble src, gint * dest_n, gint * dest_d)
3708 gdouble V, F; /* double being converted */
3709 gint N, D; /* will contain the result */
3710 gint A; /* current term in continued fraction */
3711 gint64 N1, D1; /* numerator, denominator of last approx */
3712 gint64 N2, D2; /* numerator, denominator of previous approx */
3715 gboolean negative = FALSE;
3717 g_return_if_fail (dest_n != NULL);
3718 g_return_if_fail (dest_d != NULL);
3720 /* initialize fraction being converted */
3728 /* initialize fractions with 1/0, 0/1 */
3736 for (i = 0; i < MAX_TERMS; i++) {
3738 A = (gint) F; /* no floor() needed, F is always >= 0 */
3739 /* get new divisor */
3742 /* calculate new fraction in temp */
3746 /* guard against overflow */
3747 if (N2 > G_MAXINT || D2 > G_MAXINT) {
3754 /* save last two fractions */
3760 /* quit if dividing by zero or close enough to target */
3761 if (F < MIN_DIVISOR || fabs (V - ((gdouble) N) / D) < MAX_ERROR) {
3765 /* Take reciprocal */
3768 /* fix for overflow */
3773 /* fix for negative */
3778 gcd = gst_util_greatest_common_divisor (N, D);
3790 * gst_util_fraction_multiply:
3791 * @a_n: Numerator of first value
3792 * @a_d: Denominator of first value
3793 * @b_n: Numerator of second value
3794 * @b_d: Denominator of second value
3795 * @res_n: (out): Pointer to #gint to hold the result numerator
3796 * @res_d: (out): Pointer to #gint to hold the result denominator
3798 * Multiplies the fractions @a_n/@a_d and @b_n/@b_d and stores
3799 * the result in @res_n and @res_d.
3801 * Returns: %FALSE on overflow, %TRUE otherwise.
3804 gst_util_fraction_multiply (gint a_n, gint a_d, gint b_n, gint b_d,
3805 gint * res_n, gint * res_d)
3809 g_return_val_if_fail (res_n != NULL, FALSE);
3810 g_return_val_if_fail (res_d != NULL, FALSE);
3811 g_return_val_if_fail (a_d != 0, FALSE);
3812 g_return_val_if_fail (b_d != 0, FALSE);
3814 /* early out if either is 0, as its gcd would be 0 */
3815 if (a_n == 0 || b_n == 0) {
3821 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3825 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3829 gcd = gst_util_greatest_common_divisor (a_n, b_d);
3833 gcd = gst_util_greatest_common_divisor (a_d, b_n);
3837 /* This would result in overflow */
3838 if (a_n != 0 && G_MAXINT / ABS (a_n) < ABS (b_n))
3840 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3846 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3854 * gst_util_fraction_add:
3855 * @a_n: Numerator of first value
3856 * @a_d: Denominator of first value
3857 * @b_n: Numerator of second value
3858 * @b_d: Denominator of second value
3859 * @res_n: (out): Pointer to #gint to hold the result numerator
3860 * @res_d: (out): Pointer to #gint to hold the result denominator
3862 * Adds the fractions @a_n/@a_d and @b_n/@b_d and stores
3863 * the result in @res_n and @res_d.
3865 * Returns: %FALSE on overflow, %TRUE otherwise.
3868 gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint * res_n,
3873 g_return_val_if_fail (res_n != NULL, FALSE);
3874 g_return_val_if_fail (res_d != NULL, FALSE);
3875 g_return_val_if_fail (a_d != 0, FALSE);
3876 g_return_val_if_fail (b_d != 0, FALSE);
3878 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3882 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3897 /* This would result in overflow */
3898 if (G_MAXINT / ABS (a_n) < ABS (b_n))
3900 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3903 *res_n = (a_n * b_d) + (a_d * b_n);
3906 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3919 * gst_util_fraction_compare:
3920 * @a_n: Numerator of first value
3921 * @a_d: Denominator of first value
3922 * @b_n: Numerator of second value
3923 * @b_d: Denominator of second value
3925 * Compares the fractions @a_n/@a_d and @b_n/@b_d and returns
3926 * -1 if a < b, 0 if a = b and 1 if a > b.
3928 * Returns: -1 if a < b; 0 if a = b; 1 if a > b.
3931 gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d)
3937 g_return_val_if_fail (a_d != 0 && b_d != 0, 0);
3940 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3944 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3948 /* fractions are reduced when set, so we can quickly see if they're equal */
3949 if (a_n == b_n && a_d == b_d)
3952 /* extend to 64 bits */
3953 new_num_1 = ((gint64) a_n) * b_d;
3954 new_num_2 = ((gint64) b_n) * a_d;
3955 if (new_num_1 < new_num_2)
3957 if (new_num_1 > new_num_2)
3960 /* Should not happen because a_d and b_d are not 0 */
3961 g_return_val_if_reached (0);
3965 gst_pad_create_stream_id_internal (GstPad * pad, GstElement * parent,
3966 const gchar * stream_id)
3968 GstEvent *upstream_event;
3969 gchar *upstream_stream_id = NULL, *new_stream_id;
3972 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3973 g_return_val_if_fail (GST_PAD_IS_SRC (pad), NULL);
3974 g_return_val_if_fail (GST_IS_ELEMENT (parent), NULL);
3976 g_return_val_if_fail (parent->numsinkpads <= 1, NULL);
3978 /* If the element has multiple source pads it must
3979 * provide a stream-id for every source pad, otherwise
3980 * all source pads will have the same and are not
3981 * distinguishable */
3982 g_return_val_if_fail (parent->numsrcpads <= 1 || stream_id, NULL);
3984 /* First try to get the upstream stream-start stream-id from the sinkpad.
3985 * This will only work for non-source elements */
3986 sinkpad = gst_element_get_static_pad (parent, "sink");
3989 gst_pad_get_sticky_event (sinkpad, GST_EVENT_STREAM_START, 0);
3990 if (upstream_event) {
3993 gst_event_parse_stream_start (upstream_event, &tmp);
3995 upstream_stream_id = g_strdup (tmp);
3996 gst_event_unref (upstream_event);
3998 gst_object_unref (sinkpad);
4001 /* The only case where we don't have an upstream stream-start event
4002 * here is for source elements */
4003 if (!upstream_stream_id) {
4007 /* Try to generate one from the URI query and
4008 * if it fails take a random number instead */
4009 query = gst_query_new_uri ();
4010 if (gst_element_query (parent, query)) {
4011 gst_query_parse_uri (query, &uri);
4017 /* And then generate an SHA256 sum of the URI */
4018 cs = g_checksum_new (G_CHECKSUM_SHA256);
4019 g_checksum_update (cs, (const guchar *) uri, strlen (uri));
4021 upstream_stream_id = g_strdup (g_checksum_get_string (cs));
4022 g_checksum_free (cs);
4024 /* Just get some random number if the URI query fails */
4025 GST_FIXME_OBJECT (pad, "Creating random stream-id, consider "
4026 "implementing a deterministic way of creating a stream-id");
4027 upstream_stream_id =
4028 g_strdup_printf ("%08x%08x%08x%08x", g_random_int (), g_random_int (),
4029 g_random_int (), g_random_int ());
4032 gst_query_unref (query);
4036 new_stream_id = g_strconcat (upstream_stream_id, "/", stream_id, NULL);
4038 new_stream_id = g_strdup (upstream_stream_id);
4041 g_free (upstream_stream_id);
4043 return new_stream_id;
4047 * gst_pad_create_stream_id_printf_valist:
4048 * @pad: A source #GstPad
4049 * @parent: Parent #GstElement of @pad
4050 * @stream_id: (allow-none): The stream-id
4051 * @var_args: parameters for the @stream_id format string
4053 * Creates a stream-id for the source #GstPad @pad by combining the
4054 * upstream information with the optional @stream_id of the stream
4055 * of @pad. @pad must have a parent #GstElement and which must have zero
4056 * or one sinkpad. @stream_id can only be %NULL if the parent element
4057 * of @pad has only a single source pad.
4059 * This function generates an unique stream-id by getting the upstream
4060 * stream-start event stream ID and appending @stream_id to it. If the
4061 * element has no sinkpad it will generate an upstream stream-id by
4062 * doing an URI query on the element and in the worst case just uses
4063 * a random number. Source elements that don't implement the URI
4064 * handler interface should ideally generate a unique, deterministic
4065 * stream-id manually instead.
4067 * Returns: A stream-id for @pad. g_free() after usage.
4070 gst_pad_create_stream_id_printf_valist (GstPad * pad, GstElement * parent,
4071 const gchar * stream_id, va_list var_args)
4073 gchar *expanded = NULL, *new_stream_id;
4076 expanded = g_strdup_vprintf (stream_id, var_args);
4078 new_stream_id = gst_pad_create_stream_id_internal (pad, parent, expanded);
4082 return new_stream_id;
4086 * gst_pad_create_stream_id_printf:
4087 * @pad: A source #GstPad
4088 * @parent: Parent #GstElement of @pad
4089 * @stream_id: (allow-none): The stream-id
4090 * @...: parameters for the @stream_id format string
4092 * Creates a stream-id for the source #GstPad @pad by combining the
4093 * upstream information with the optional @stream_id of the stream
4094 * of @pad. @pad must have a parent #GstElement and which must have zero
4095 * or one sinkpad. @stream_id can only be %NULL if the parent element
4096 * of @pad has only a single source pad.
4098 * This function generates an unique stream-id by getting the upstream
4099 * stream-start event stream ID and appending @stream_id to it. If the
4100 * element has no sinkpad it will generate an upstream stream-id by
4101 * doing an URI query on the element and in the worst case just uses
4102 * a random number. Source elements that don't implement the URI
4103 * handler interface should ideally generate a unique, deterministic
4104 * stream-id manually instead.
4106 * Returns: A stream-id for @pad. g_free() after usage.
4109 gst_pad_create_stream_id_printf (GstPad * pad, GstElement * parent,
4110 const gchar * stream_id, ...)
4113 gchar *new_stream_id;
4115 va_start (var_args, stream_id);
4117 gst_pad_create_stream_id_printf_valist (pad, parent, stream_id, var_args);
4120 return new_stream_id;
4124 * gst_pad_create_stream_id:
4125 * @pad: A source #GstPad
4126 * @parent: Parent #GstElement of @pad
4127 * @stream_id: (allow-none): The stream-id
4129 * Creates a stream-id for the source #GstPad @pad by combining the
4130 * upstream information with the optional @stream_id of the stream
4131 * of @pad. @pad must have a parent #GstElement and which must have zero
4132 * or one sinkpad. @stream_id can only be %NULL if the parent element
4133 * of @pad has only a single source pad.
4135 * This function generates an unique stream-id by getting the upstream
4136 * stream-start event stream ID and appending @stream_id to it. If the
4137 * element has no sinkpad it will generate an upstream stream-id by
4138 * doing an URI query on the element and in the worst case just uses
4139 * a random number. Source elements that don't implement the URI
4140 * handler interface should ideally generate a unique, deterministic
4141 * stream-id manually instead.
4143 * Since stream IDs are sorted alphabetically, any numbers in the
4144 * stream ID should be printed with a fixed number of characters,
4145 * preceded by 0's, such as by using the format \%03u instead of \%u.
4147 * Returns: A stream-id for @pad. g_free() after usage.
4150 gst_pad_create_stream_id (GstPad * pad, GstElement * parent,
4151 const gchar * stream_id)
4153 return gst_pad_create_stream_id_internal (pad, parent, stream_id);
4157 * gst_pad_get_stream_id:
4158 * @pad: A source #GstPad
4160 * Returns the current stream-id for the @pad, or %NULL if none has been
4161 * set yet, i.e. the pad has not received a stream-start event yet.
4163 * This is a convenience wrapper around gst_pad_get_sticky_event() and
4164 * gst_event_parse_stream_start().
4166 * The returned stream-id string should be treated as an opaque string, its
4167 * contents should not be interpreted.
4169 * Returns: (nullable): a newly-allocated copy of the stream-id for
4170 * @pad, or %NULL. g_free() the returned string when no longer
4176 gst_pad_get_stream_id (GstPad * pad)
4178 const gchar *stream_id = NULL;
4182 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
4184 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
4185 if (event != NULL) {
4186 gst_event_parse_stream_start (event, &stream_id);
4187 ret = g_strdup (stream_id);
4188 gst_event_unref (event);
4189 GST_LOG_OBJECT (pad, "pad has stream-id '%s'", ret);
4191 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");
4198 * gst_pad_get_stream:
4199 * @pad: A source #GstPad
4201 * Returns the current #GstStream for the @pad, or %NULL if none has been
4202 * set yet, i.e. the pad has not received a stream-start event yet.
4204 * This is a convenience wrapper around gst_pad_get_sticky_event() and
4205 * gst_event_parse_stream().
4207 * Returns: (nullable) (transfer full): the current #GstStream for @pad, or %NULL.
4208 * unref the returned stream when no longer needed.
4213 gst_pad_get_stream (GstPad * pad)
4215 GstStream *stream = NULL;
4218 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
4220 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
4221 if (event != NULL) {
4222 gst_event_parse_stream (event, &stream);
4223 gst_event_unref (event);
4224 GST_LOG_OBJECT (pad, "pad has stream object %p", stream);
4226 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");
4233 * gst_util_group_id_next:
4235 * Return a constantly incrementing group id.
4237 * This function is used to generate a new group-id for the
4238 * stream-start event.
4240 * This function never returns %GST_GROUP_ID_INVALID (which is 0)
4242 * Returns: A constantly incrementing unsigned integer, which might
4243 * overflow back to 0 at some point.
4246 gst_util_group_id_next (void)
4248 static gint counter = 1;
4249 gint ret = g_atomic_int_add (&counter, 1);
4251 /* Make sure we don't return GST_GROUP_ID_INVALID */
4252 if (G_UNLIKELY (ret == GST_GROUP_ID_INVALID))
4253 ret = g_atomic_int_add (&counter, 1);
4258 /* Compute log2 of the passed 64-bit number by finding the highest set bit */
4260 gst_log2 (GstClockTime in)
4263 { 0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000, 0xFFFFFFFF00000000LL };
4264 const guint64 S[] = { 1, 2, 4, 8, 16, 32 };
4268 for (i = 5; i >= 0; i--) {
4279 * gst_calculate_linear_regression: (skip)
4280 * @xy: Pairs of (x,y) values
4281 * @temp: Temporary scratch space used by the function
4282 * @n: number of (x,y) pairs
4283 * @m_num: (out): numerator of calculated slope
4284 * @m_denom: (out): denominator of calculated slope
4285 * @b: (out): Offset at Y-axis
4286 * @xbase: (out): Offset at X-axis
4287 * @r_squared: (out): R-squared
4289 * Calculates the linear regression of the values @xy and places the
4290 * result in @m_num, @m_denom, @b and @xbase, representing the function
4291 * y(x) = m_num/m_denom * (x - xbase) + b
4292 * that has the least-square distance from all points @x and @y.
4294 * @r_squared will contain the remaining error.
4296 * If @temp is not %NULL, it will be used as temporary space for the function,
4297 * in which case the function works without any allocation at all. If @temp is
4298 * %NULL, an allocation will take place. @temp should have at least the same
4299 * amount of memory allocated as @xy, i.e. 2*n*sizeof(GstClockTime).
4301 * > This function assumes (x,y) values with reasonable large differences
4302 * > between them. It will not calculate the exact results if the differences
4303 * > between neighbouring values are too small due to not being able to
4304 * > represent sub-integer values during the calculations.
4306 * Returns: %TRUE if the linear regression was successfully calculated
4310 /* http://mathworld.wolfram.com/LeastSquaresFitting.html
4314 gst_calculate_linear_regression (const GstClockTime * xy,
4315 GstClockTime * temp, guint n,
4316 GstClockTime * m_num, GstClockTime * m_denom,
4317 GstClockTime * b, GstClockTime * xbase, gdouble * r_squared)
4319 const GstClockTime *x, *y;
4320 GstClockTime *newx, *newy;
4321 GstClockTime xmin, ymin, xbar, ybar, xbar4, ybar4;
4322 GstClockTime xmax, ymax;
4323 GstClockTimeDiff sxx, sxy, syy;
4328 g_return_val_if_fail (xy != NULL, FALSE);
4329 g_return_val_if_fail (m_num != NULL, FALSE);
4330 g_return_val_if_fail (m_denom != NULL, FALSE);
4331 g_return_val_if_fail (b != NULL, FALSE);
4332 g_return_val_if_fail (xbase != NULL, FALSE);
4333 g_return_val_if_fail (r_squared != NULL, FALSE);
4338 xbar = ybar = sxx = syy = sxy = 0;
4340 xmin = ymin = G_MAXUINT64;
4342 for (i = j = 0; i < n; i++, j += 2) {
4343 xmin = MIN (xmin, x[j]);
4344 ymin = MIN (ymin, y[j]);
4346 xmax = MAX (xmax, x[j]);
4347 ymax = MAX (ymax, y[j]);
4351 /* Allocate up to 1kb on the stack, otherwise heap */
4352 newx = n > 64 ? g_new (GstClockTime, 2 * n) : g_newa (GstClockTime, 2 * n);
4359 /* strip off unnecessary bits of precision */
4360 for (i = j = 0; i < n; i++, j += 2) {
4361 newx[j] = x[j] - xmin;
4362 newy[j] = y[j] - ymin;
4365 #ifdef DEBUGGING_ENABLED
4366 GST_CAT_DEBUG (GST_CAT_CLOCK, "reduced numbers:");
4367 for (i = j = 0; i < n; i++, j += 2)
4368 GST_CAT_DEBUG (GST_CAT_CLOCK,
4369 " %" G_GUINT64_FORMAT " %" G_GUINT64_FORMAT, newx[j], newy[j]);
4372 /* have to do this precisely otherwise the results are pretty much useless.
4373 * should guarantee that none of these accumulators can overflow */
4375 /* quantities on the order of 1e10 to 1e13 -> 30-35 bits;
4376 * window size a max of 2^10, so
4377 this addition could end up around 2^45 or so -- ample headroom */
4378 for (i = j = 0; i < n; i++, j += 2) {
4379 /* Just in case assumptions about headroom prove false, let's check */
4380 if ((newx[j] > 0 && G_MAXUINT64 - xbar <= newx[j]) ||
4381 (newy[j] > 0 && G_MAXUINT64 - ybar <= newy[j])) {
4382 GST_CAT_WARNING (GST_CAT_CLOCK,
4383 "Regression overflowed in clock slaving! xbar %"
4384 G_GUINT64_FORMAT " newx[j] %" G_GUINT64_FORMAT " ybar %"
4385 G_GUINT64_FORMAT " newy[j] %" G_GUINT64_FORMAT, xbar, newx[j], ybar,
4387 if (temp == NULL && n > 64)
4398 /* multiplying directly would give quantities on the order of 1e20-1e26 ->
4399 * 60 bits to 70 bits times the window size that's 80 which is too much.
4400 * Instead we (1) subtract off the xbar*ybar in the loop instead of after,
4401 * to avoid accumulation; (2) shift off some estimated number of bits from
4402 * each multiplicand to limit the expected ceiling. For strange
4403 * distributions of input values, things can still overflow, in which
4404 * case we drop precision and retry - at most a few times, in practice rarely
4407 /* Guess how many bits we might need for the usual distribution of input,
4408 * with a fallback loop that drops precision if things go pear-shaped */
4409 max_bits = gst_log2 (MAX (xmax - xmin, ymax - ymin)) * 7 / 8 + gst_log2 (n);
4411 pshift = max_bits - 64;
4415 #ifdef DEBUGGING_ENABLED
4416 GST_CAT_DEBUG (GST_CAT_CLOCK,
4417 "Restarting regression with precision shift %u", pshift);
4420 xbar4 = xbar >> pshift;
4421 ybar4 = ybar >> pshift;
4422 sxx = syy = sxy = 0;
4423 for (i = j = 0; i < n; i++, j += 2) {
4424 GstClockTime newx4, newy4;
4425 GstClockTimeDiff tmp;
4427 newx4 = newx[j] >> pshift;
4428 newy4 = newy[j] >> pshift;
4430 tmp = (newx4 + xbar4) * (newx4 - xbar4);
4431 if (G_UNLIKELY (tmp > 0 && sxx > 0 && (G_MAXINT64 - sxx <= tmp))) {
4433 /* Drop some precision and restart */
4437 } while (G_MAXINT64 - sxx <= tmp);
4439 } else if (G_UNLIKELY (tmp < 0 && sxx < 0 && (G_MININT64 - sxx >= tmp))) {
4441 /* Drop some precision and restart */
4445 } while (G_MININT64 - sxx >= tmp);
4450 tmp = newy4 * newy4 - ybar4 * ybar4;
4451 if (G_UNLIKELY (tmp > 0 && syy > 0 && (G_MAXINT64 - syy <= tmp))) {
4456 } while (G_MAXINT64 - syy <= tmp);
4458 } else if (G_UNLIKELY (tmp < 0 && syy < 0 && (G_MININT64 - syy >= tmp))) {
4463 } while (G_MININT64 - syy >= tmp);
4468 tmp = newx4 * newy4 - xbar4 * ybar4;
4469 if (G_UNLIKELY (tmp > 0 && sxy > 0 && (G_MAXINT64 - sxy <= tmp))) {
4474 } while (G_MAXINT64 - sxy <= tmp);
4476 } else if (G_UNLIKELY (tmp < 0 && sxy < 0 && (G_MININT64 - sxy >= tmp))) {
4481 } while (G_MININT64 - sxy >= tmp);
4488 if (G_UNLIKELY (sxx == 0))
4493 *b = (ymin + ybar) - gst_util_uint64_scale_round (xbar, *m_num, *m_denom);
4494 /* Report base starting from the most recent observation */
4496 *b += gst_util_uint64_scale_round (xmax - xmin, *m_num, *m_denom);
4498 *r_squared = ((double) sxy * (double) sxy) / ((double) sxx * (double) syy);
4500 #ifdef DEBUGGING_ENABLED
4501 GST_CAT_DEBUG (GST_CAT_CLOCK, " m = %g", ((double) *m_num) / *m_denom);
4502 GST_CAT_DEBUG (GST_CAT_CLOCK, " b = %" G_GUINT64_FORMAT, *b);
4503 GST_CAT_DEBUG (GST_CAT_CLOCK, " xbase = %" G_GUINT64_FORMAT, *xbase);
4504 GST_CAT_DEBUG (GST_CAT_CLOCK, " r2 = %g", *r_squared);
4507 if (temp == NULL && n > 64)
4514 GST_CAT_DEBUG (GST_CAT_CLOCK, "sxx == 0, regression failed");
4515 if (temp == NULL && n > 64)
4522 * gst_type_mark_as_plugin_api:
4524 * @flags: a set of #GstPluginAPIFlags to further inform cache generation.
4526 * Marks @type as plugin API. This should be called in `class_init` of
4527 * elements that expose new types (i.e. enums, flags or internal GObjects) via
4528 * properties, signals or pad templates.
4530 * Types exposed by plugins are not automatically added to the documentation
4531 * as they might originate from another library and should in that case be
4532 * documented via that library instead.
4534 * By marking a type as plugin API it will be included in the documentation of
4535 * the plugin that defines it.
4540 gst_type_mark_as_plugin_api (GType type, GstPluginAPIFlags flags)
4542 g_type_set_qdata (type, GST_QUARK (PLUGIN_API), GINT_TO_POINTER (TRUE));
4543 g_type_set_qdata (type, GST_QUARK (PLUGIN_API_FLAGS),
4544 GINT_TO_POINTER (flags));
4548 * gst_type_is_plugin_api:
4550 * @flags: (out) (nullable): What #GstPluginAPIFlags the plugin was marked with
4552 * Checks if @type is plugin API. See gst_type_mark_as_plugin_api() for
4555 * Returns: %TRUE if @type is plugin API or %FALSE otherwise.
4560 gst_type_is_plugin_api (GType type, GstPluginAPIFlags * flags)
4563 ! !GPOINTER_TO_INT (g_type_get_qdata (type, GST_QUARK (PLUGIN_API)));
4567 GPOINTER_TO_INT (g_type_get_qdata (type, GST_QUARK (PLUGIN_API_FLAGS)));