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"
47 #include "gst-i18n-lib.h"
48 #include "glib-compat-private.h"
53 * @mem: a pointer to the memory to dump
54 * @size: the size of the memory block to dump
56 * Dumps the memory block into a hex representation. Useful for debugging.
59 gst_util_dump_mem (const guchar * mem, guint size)
62 GString *string = g_string_sized_new (50);
63 GString *chars = g_string_sized_new (18);
67 if (g_ascii_isprint (mem[i]))
68 g_string_append_c (chars, mem[i]);
70 g_string_append_c (chars, '.');
72 g_string_append_printf (string, "%02x ", mem[i]);
77 if (j == 16 || i == size) {
78 g_print ("%08x (%p): %-48.48s %-16.16s\n", i - j, mem + i - j,
79 string->str, chars->str);
80 g_string_set_size (string, 0);
81 g_string_set_size (chars, 0);
85 g_string_free (string, TRUE);
86 g_string_free (chars, TRUE);
91 * gst_util_set_value_from_string:
92 * @value: (out caller-allocates): the value to set
93 * @value_str: the string to get the value from
95 * Converts the string to the type of the value and
96 * sets the value with it.
98 * Note that this function is dangerous as it does not return any indication
99 * if the conversion worked or not.
102 gst_util_set_value_from_string (GValue * value, const gchar * value_str)
106 g_return_if_fail (value != NULL);
107 g_return_if_fail (value_str != NULL);
109 GST_CAT_DEBUG (GST_CAT_PARAMS, "parsing '%s' to type %s", value_str,
110 g_type_name (G_VALUE_TYPE (value)));
112 res = gst_value_deserialize (value, value_str);
113 if (!res && G_VALUE_TYPE (value) == G_TYPE_BOOLEAN) {
114 /* backwards compat, all booleans that fail to parse are false */
115 g_value_set_boolean (value, FALSE);
118 g_return_if_fail (res);
122 * gst_util_set_object_arg:
123 * @object: the object to set the argument of
124 * @name: the name of the argument to set
125 * @value: the string value to set
127 * Converts the string value to the type of the objects argument and
128 * sets the argument with it.
130 * Note that this function silently returns if @object has no property named
131 * @name or when @value cannot be converted to the type of the property.
134 gst_util_set_object_arg (GObject * object, const gchar * name,
141 g_return_if_fail (G_IS_OBJECT (object));
142 g_return_if_fail (name != NULL);
143 g_return_if_fail (value != NULL);
145 pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (object), name);
149 value_type = pspec->value_type;
151 GST_DEBUG ("pspec->flags is %d, pspec->value_type is %s",
152 pspec->flags, g_type_name (value_type));
154 if (!(pspec->flags & G_PARAM_WRITABLE))
157 g_value_init (&v, value_type);
159 /* special case for element <-> xml (de)serialisation */
160 if (value_type == GST_TYPE_STRUCTURE && strcmp (value, "NULL") == 0) {
161 g_value_set_boxed (&v, NULL);
165 if (!gst_value_deserialize (&v, value))
170 g_object_set_property (object, pspec->name, &v);
175 * gst_util_set_object_array:
176 * @object: the object to set the array to
177 * @name: the name of the property to set
178 * @array: a #GValueArray containing the values
180 * Transfer a #GValueArray to %GST_TYPE_ARRAY and set this value on the
181 * specified property name. This allow language bindings to set GST_TYPE_ARRAY
182 * properties which are otherwise not an accessible type.
187 gst_util_set_object_array (GObject * object, const gchar * name,
188 const GValueArray * array)
190 GValue v1 = G_VALUE_INIT, v2 = G_VALUE_INIT;
191 gboolean ret = FALSE;
193 g_value_init (&v1, G_TYPE_VALUE_ARRAY);
194 g_value_init (&v2, GST_TYPE_ARRAY);
196 g_value_set_static_boxed (&v1, array);
198 if (g_value_transform (&v1, &v2)) {
199 g_object_set_property (object, name, &v2);
210 * gst_util_get_object_array:
211 * @object: the object to set the array to
212 * @name: the name of the property to set
213 * @array: (out): a return #GValueArray
215 * Get a property of type %GST_TYPE_ARRAY and transform it into a
216 * #GValueArray. This allow language bindings to get GST_TYPE_ARRAY
217 * properties which are otherwise not an accessible type.
222 gst_util_get_object_array (GObject * object, const gchar * name,
223 GValueArray ** array)
225 GValue v1 = G_VALUE_INIT, v2 = G_VALUE_INIT;
226 gboolean ret = FALSE;
228 g_value_init (&v1, G_TYPE_VALUE_ARRAY);
229 g_value_init (&v2, GST_TYPE_ARRAY);
231 g_object_get_property (object, name, &v2);
233 if (g_value_transform (&v2, &v1)) {
234 *array = g_value_get_boxed (&v1);
243 /* work around error C2520: conversion from unsigned __int64 to double
244 * not implemented, use signed __int64
246 * These are implemented as functions because on some platforms a 64bit int to
247 * double conversion is not defined/implemented.
251 gst_util_guint64_to_gdouble (guint64 value)
253 if (value & G_GINT64_CONSTANT (0x8000000000000000))
254 return (gdouble) ((gint64) value) + (gdouble) 18446744073709551616.;
256 return (gdouble) ((gint64) value);
260 gst_util_gdouble_to_guint64 (gdouble value)
262 if (value < (gdouble) 9223372036854775808.) /* 1 << 63 */
263 return ((guint64) ((gint64) value));
265 value -= (gdouble) 18446744073709551616.;
266 return ((guint64) ((gint64) value));
269 #ifndef HAVE_UINT128_T
270 /* convenience struct for getting high and low uint32 parts of
277 #if G_BYTE_ORDER == G_BIG_ENDIAN
285 #if defined (__x86_64__) && defined (__GNUC__)
287 gst_util_uint64_mul_uint64 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
290 __asm__ __volatile__ ("mulq %3":"=a" (c0->ll), "=d" (c1->ll)
291 :"a" (arg1), "g" (arg2)
294 #else /* defined (__x86_64__) */
295 /* multiply two 64-bit unsigned ints into a 128-bit unsigned int. the high
296 * and low 64 bits of the product are placed in c1 and c0 respectively.
297 * this operation cannot overflow. */
299 gst_util_uint64_mul_uint64 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
309 /* do 128 bits multiply
317 * -------------------
320 * "a0" is optimized away, result is stored directly in c0. "b1" is
321 * optimized away, result is stored directly in c1.
323 c0->ll = (guint64) v.l.low * n.l.low;
324 a1.ll = (guint64) v.l.low * n.l.high;
325 b0.ll = (guint64) v.l.high * n.l.low;
327 /* add the high word of a0 to the low words of a1 and b0 using c1 as
328 * scrach space to capture the carry. the low word of the result becomes
329 * the final high word of c0 */
330 c1->ll = (guint64) c0->l.high + a1.l.low + b0.l.low;
331 c0->l.high = c1->l.low;
333 /* add the carry from the result above (found in the high word of c1) and
334 * the high words of a1 and b0 to b1, the result is c1. */
335 c1->ll = (guint64) v.l.high * n.l.high + c1->l.high + a1.l.high + b0.l.high;
337 #endif /* defined (__x86_64__) */
339 #if defined (__x86_64__) && defined (__GNUC__)
340 static inline guint64
341 gst_util_div128_64 (GstUInt64 c1, GstUInt64 c0, guint64 denom)
345 __asm__ __volatile__ ("divq %3":"=a" (res)
346 :"d" (c1.ll), "a" (c0.ll), "g" (denom)
352 /* count leading zeros */
354 gst_util_clz (guint32 val)
358 s = val | (val >> 1);
362 s = ~(s | (s >> 16));
363 s = s - ((s >> 1) & 0x55555555);
364 s = (s & 0x33333333) + ((s >> 2) & 0x33333333);
365 s = (s + (s >> 4)) & 0x0f0f0f0f;
367 s = (s + (s >> 16)) & 0x3f;
372 /* based on Hacker's Delight p152 */
373 static inline guint64
374 gst_util_div128_64 (GstUInt64 c1, GstUInt64 c0, guint64 denom)
376 GstUInt64 q1, q0, rhat;
377 GstUInt64 v, cmp1, cmp2;
382 /* count number of leading zeroes, we know they must be in the high
383 * part of denom since denom > G_MAXUINT32. */
384 s = gst_util_clz (v.l.high);
387 /* normalize divisor and dividend */
389 c1.ll = (c1.ll << s) | (c0.l.high >> (32 - s));
393 q1.ll = c1.ll / v.l.high;
394 rhat.ll = c1.ll - q1.ll * v.l.high;
396 cmp1.l.high = rhat.l.low;
397 cmp1.l.low = c0.l.high;
398 cmp2.ll = q1.ll * v.l.low;
400 while (q1.l.high || cmp2.ll > cmp1.ll) {
405 cmp1.l.high = rhat.l.low;
408 c1.l.high = c1.l.low;
409 c1.l.low = c0.l.high;
410 c1.ll -= q1.ll * v.ll;
411 q0.ll = c1.ll / v.l.high;
412 rhat.ll = c1.ll - q0.ll * v.l.high;
414 cmp1.l.high = rhat.l.low;
415 cmp1.l.low = c0.l.low;
416 cmp2.ll = q0.ll * v.l.low;
418 while (q0.l.high || cmp2.ll > cmp1.ll) {
423 cmp1.l.high = rhat.l.low;
426 q0.l.high += q1.l.low;
430 #endif /* defined (__GNUC__) */
432 /* This always gives the correct result because:
433 * a) val <= G_MAXUINT64-1
434 * b) (c0,c1) <= G_MAXUINT64 * (G_MAXUINT64-1)
436 * (c0,c1) == G_MAXUINT64 * G_MAXUINT64 and denom < G_MAXUINT64
437 * (note: num==denom case is handled by short path)
438 * This means that (c0,c1) either has enough space for val
439 * or that the overall result will overflow anyway.
442 /* add correction with carry */
443 #define CORRECT(c0,c1,val) \
445 if (G_MAXUINT64 - c0.ll < val) { \
446 if (G_UNLIKELY (c1.ll == G_MAXUINT64)) \
448 return G_MAXUINT64; \
455 gst_util_uint64_scale_uint64_unchecked (guint64 val, guint64 num,
456 guint64 denom, guint64 correct)
460 /* compute 128-bit numerator product */
461 gst_util_uint64_mul_uint64 (&c1, &c0, val, num);
463 /* perform rounding correction */
464 CORRECT (c0, c1, correct);
466 /* high word as big as or bigger than denom --> overflow */
467 if (G_UNLIKELY (c1.ll >= denom))
470 /* compute quotient, fits in 64 bits */
471 return gst_util_div128_64 (c1, c0, denom);
475 #define GST_MAXUINT128 ((__uint128_t) -1)
477 gst_util_uint64_scale_uint64_unchecked (guint64 val, guint64 num,
478 guint64 denom, guint64 correct)
482 /* Calculate val * num */
483 tmp = ((__uint128_t) val) * ((__uint128_t) num);
485 /* overflow checks */
486 if (G_UNLIKELY (GST_MAXUINT128 - correct < tmp))
489 /* perform rounding correction */
492 /* Divide by denom */
495 /* if larger than G_MAXUINT64 --> overflow */
496 if (G_UNLIKELY (tmp > G_MAXUINT64))
499 /* compute quotient, fits in 64 bits */
500 return (guint64) tmp;
505 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
507 gst_util_uint64_mul_uint32 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
514 c0->ll = (guint64) a.l.low * arg2;
515 c1->ll = (guint64) a.l.high * arg2 + c0->l.high;
519 /* divide a 96-bit unsigned int by a 32-bit unsigned int when we know the
520 * quotient fits into 64 bits. the high 64 bits and low 32 bits of the
521 * numerator are expected in c1 and c0 respectively. */
522 static inline guint64
523 gst_util_div96_32 (guint64 c1, guint64 c0, guint32 denom)
525 c0 += (c1 % denom) << 32;
526 return ((c1 / denom) << 32) + (c0 / denom);
529 static inline guint64
530 gst_util_uint64_scale_uint32_unchecked (guint64 val, guint32 num,
531 guint32 denom, guint32 correct)
535 /* compute 96-bit numerator product */
536 gst_util_uint64_mul_uint32 (&c1, &c0, val, num);
538 /* condition numerator based on rounding mode */
539 CORRECT (c0, c1, correct);
541 /* high 32 bits as big as or bigger than denom --> overflow */
542 if (G_UNLIKELY (c1.l.high >= denom))
545 /* compute quotient, fits in 64 bits */
546 return gst_util_div96_32 (c1.ll, c0.ll, denom);
550 /* the guts of the gst_util_uint64_scale() variants */
552 _gst_util_uint64_scale (guint64 val, guint64 num, guint64 denom,
555 g_return_val_if_fail (denom != 0, G_MAXUINT64);
557 if (G_UNLIKELY (num == 0))
560 if (G_UNLIKELY (num == denom))
563 /* on 64bits we always use a full 128bits multiply/division */
564 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
565 /* denom is low --> try to use 96 bit muldiv */
566 if (G_LIKELY (denom <= G_MAXUINT32)) {
567 /* num is low --> use 96 bit muldiv */
568 if (G_LIKELY (num <= G_MAXUINT32))
569 return gst_util_uint64_scale_uint32_unchecked (val, (guint32) num,
570 (guint32) denom, correct);
572 /* num is high but val is low --> swap and use 96-bit muldiv */
573 if (G_LIKELY (val <= G_MAXUINT32))
574 return gst_util_uint64_scale_uint32_unchecked (num, (guint32) val,
575 (guint32) denom, correct);
577 #endif /* !defined (__x86_64__) && !defined (HAVE_UINT128_T) */
579 /* val is high and num is high --> use 128-bit muldiv */
580 return gst_util_uint64_scale_uint64_unchecked (val, num, denom, correct);
584 * gst_util_uint64_scale:
585 * @val: the number to scale
586 * @num: the numerator of the scale ratio
587 * @denom: the denominator of the scale ratio
589 * Scale @val by the rational number @num / @denom, avoiding overflows and
590 * underflows and without loss of precision.
592 * This function can potentially be very slow if val and num are both
593 * greater than G_MAXUINT32.
595 * Returns: @val * @num / @denom. In the case of an overflow, this
596 * function returns G_MAXUINT64. If the result is not exactly
597 * representable as an integer it is truncated. See also
598 * gst_util_uint64_scale_round(), gst_util_uint64_scale_ceil(),
599 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
600 * gst_util_uint64_scale_int_ceil().
603 gst_util_uint64_scale (guint64 val, guint64 num, guint64 denom)
605 return _gst_util_uint64_scale (val, num, denom, 0);
609 * gst_util_uint64_scale_round:
610 * @val: the number to scale
611 * @num: the numerator of the scale ratio
612 * @denom: the denominator of the scale ratio
614 * Scale @val by the rational number @num / @denom, avoiding overflows and
615 * underflows and without loss of precision.
617 * This function can potentially be very slow if val and num are both
618 * greater than G_MAXUINT32.
620 * Returns: @val * @num / @denom. In the case of an overflow, this
621 * function returns G_MAXUINT64. If the result is not exactly
622 * representable as an integer, it is rounded to the nearest integer
623 * (half-way cases are rounded up). See also gst_util_uint64_scale(),
624 * gst_util_uint64_scale_ceil(), gst_util_uint64_scale_int(),
625 * gst_util_uint64_scale_int_round(), gst_util_uint64_scale_int_ceil().
628 gst_util_uint64_scale_round (guint64 val, guint64 num, guint64 denom)
630 return _gst_util_uint64_scale (val, num, denom, denom >> 1);
634 * gst_util_uint64_scale_ceil:
635 * @val: the number to scale
636 * @num: the numerator of the scale ratio
637 * @denom: the denominator of the scale ratio
639 * Scale @val by the rational number @num / @denom, avoiding overflows and
640 * underflows and without loss of precision.
642 * This function can potentially be very slow if val and num are both
643 * greater than G_MAXUINT32.
645 * Returns: @val * @num / @denom. In the case of an overflow, this
646 * function returns G_MAXUINT64. If the result is not exactly
647 * representable as an integer, it is rounded up. See also
648 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
649 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
650 * gst_util_uint64_scale_int_ceil().
653 gst_util_uint64_scale_ceil (guint64 val, guint64 num, guint64 denom)
655 return _gst_util_uint64_scale (val, num, denom, denom - 1);
658 /* the guts of the gst_util_uint64_scale_int() variants */
660 _gst_util_uint64_scale_int (guint64 val, gint num, gint denom, gint correct)
662 g_return_val_if_fail (denom > 0, G_MAXUINT64);
663 g_return_val_if_fail (num >= 0, G_MAXUINT64);
665 if (G_UNLIKELY (num == 0))
668 if (G_UNLIKELY (num == denom))
671 if (val <= G_MAXUINT32) {
672 /* simple case. num and denom are not negative so casts are OK. when
673 * not truncating, the additions to the numerator cannot overflow
674 * because val*num <= G_MAXUINT32 * G_MAXINT32 < G_MAXUINT64 -
675 * G_MAXINT32, so there's room to add another gint32. */
676 val *= (guint64) num;
677 /* add rounding correction */
680 return val / (guint64) denom;
682 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
683 /* num and denom are not negative so casts are OK */
684 return gst_util_uint64_scale_uint32_unchecked (val, (guint32) num,
685 (guint32) denom, (guint32) correct);
687 /* always use full 128bits scale */
688 return gst_util_uint64_scale_uint64_unchecked (val, num, denom, correct);
693 * gst_util_uint64_scale_int:
694 * @val: guint64 (such as a #GstClockTime) to scale.
695 * @num: numerator of the scale factor.
696 * @denom: denominator of the scale factor.
698 * Scale @val by the rational number @num / @denom, avoiding overflows and
699 * underflows and without loss of precision. @num must be non-negative and
700 * @denom must be positive.
702 * Returns: @val * @num / @denom. In the case of an overflow, this
703 * function returns G_MAXUINT64. If the result is not exactly
704 * representable as an integer, it is truncated. See also
705 * gst_util_uint64_scale_int_round(), gst_util_uint64_scale_int_ceil(),
706 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
707 * gst_util_uint64_scale_ceil().
710 gst_util_uint64_scale_int (guint64 val, gint num, gint denom)
712 return _gst_util_uint64_scale_int (val, num, denom, 0);
716 * gst_util_uint64_scale_int_round:
717 * @val: guint64 (such as a #GstClockTime) to scale.
718 * @num: numerator of the scale factor.
719 * @denom: denominator of the scale factor.
721 * Scale @val by the rational number @num / @denom, avoiding overflows and
722 * underflows and without loss of precision. @num must be non-negative and
723 * @denom must be positive.
725 * Returns: @val * @num / @denom. In the case of an overflow, this
726 * function returns G_MAXUINT64. If the result is not exactly
727 * representable as an integer, it is rounded to the nearest integer
728 * (half-way cases are rounded up). See also gst_util_uint64_scale_int(),
729 * gst_util_uint64_scale_int_ceil(), gst_util_uint64_scale(),
730 * gst_util_uint64_scale_round(), gst_util_uint64_scale_ceil().
733 gst_util_uint64_scale_int_round (guint64 val, gint num, gint denom)
735 /* we can use a shift to divide by 2 because denom is required to be
737 return _gst_util_uint64_scale_int (val, num, denom, denom >> 1);
741 * gst_util_uint64_scale_int_ceil:
742 * @val: guint64 (such as a #GstClockTime) to scale.
743 * @num: numerator of the scale factor.
744 * @denom: denominator of the scale factor.
746 * Scale @val by the rational number @num / @denom, avoiding overflows and
747 * underflows and without loss of precision. @num must be non-negative and
748 * @denom must be positive.
750 * Returns: @val * @num / @denom. In the case of an overflow, this
751 * function returns G_MAXUINT64. If the result is not exactly
752 * representable as an integer, it is rounded up. See also
753 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
754 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
755 * gst_util_uint64_scale_ceil().
758 gst_util_uint64_scale_int_ceil (guint64 val, gint num, gint denom)
760 return _gst_util_uint64_scale_int (val, num, denom, denom - 1);
764 * gst_util_seqnum_next:
766 * Return a constantly incrementing sequence number.
768 * This function is used internally to GStreamer to be able to determine which
769 * events and messages are "the same". For example, elements may set the seqnum
770 * on a segment-done message to be the same as that of the last seek event, to
771 * indicate that event and the message correspond to the same segment.
773 * This function never returns GST_SEQNUM_INVALID (which is 0).
775 * Returns: A constantly incrementing 32-bit unsigned integer, which might
776 * overflow at some point. Use gst_util_seqnum_compare() to make sure
777 * you handle wraparound correctly.
780 gst_util_seqnum_next (void)
782 static gint counter = 1;
783 gint ret = g_atomic_int_add (&counter, 1);
785 /* Make sure we don't return 0 */
786 if (G_UNLIKELY (ret == GST_SEQNUM_INVALID))
787 ret = g_atomic_int_add (&counter, 1);
793 * gst_util_seqnum_compare:
794 * @s1: A sequence number.
795 * @s2: Another sequence number.
797 * Compare two sequence numbers, handling wraparound.
799 * The current implementation just returns (gint32)(@s1 - @s2).
801 * Returns: A negative number if @s1 is before @s2, 0 if they are equal, or a
802 * positive number if @s1 is after @s2.
805 gst_util_seqnum_compare (guint32 s1, guint32 s2)
807 return (gint32) (s1 - s2);
810 /* -----------------------------------------------------
812 * The following code will be moved out of the main
813 * gstreamer library someday.
819 * gst_element_create_all_pads:
820 * @element: (transfer none): a #GstElement to create pads for
822 * Creates a pad for each pad template that is always available.
823 * This function is only useful during object initialization of
824 * subclasses of #GstElement.
827 gst_element_create_all_pads (GstElement * element)
831 /* FIXME: lock element */
834 gst_element_class_get_pad_template_list (GST_ELEMENT_CLASS
835 (G_OBJECT_GET_CLASS (element)));
838 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
840 if (padtempl->presence == GST_PAD_ALWAYS) {
843 pad = gst_pad_new_from_template (padtempl, padtempl->name_template);
845 gst_element_add_pad (element, pad);
847 padlist = padlist->next;
852 * gst_element_get_compatible_pad_template:
853 * @element: (transfer none): a #GstElement to get a compatible pad template for
854 * @compattempl: (transfer none): the #GstPadTemplate to find a compatible
857 * Retrieves a pad template from @element that is compatible with @compattempl.
858 * Pads from compatible templates can be linked together.
860 * Returns: (transfer none) (nullable): a compatible #GstPadTemplate,
861 * or %NULL if none was found. No unreferencing is necessary.
864 gst_element_get_compatible_pad_template (GstElement * element,
865 GstPadTemplate * compattempl)
867 GstPadTemplate *newtempl = NULL;
869 GstElementClass *class;
872 g_return_val_if_fail (element != NULL, NULL);
873 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
874 g_return_val_if_fail (compattempl != NULL, NULL);
876 class = GST_ELEMENT_GET_CLASS (element);
878 padlist = gst_element_class_get_pad_template_list (class);
880 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
881 "Looking for a suitable pad template in %s out of %d templates...",
882 GST_ELEMENT_NAME (element), g_list_length (padlist));
885 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
889 * Check direction (must be opposite)
892 GST_CAT_LOG (GST_CAT_CAPS,
893 "checking pad template %s", padtempl->name_template);
894 if (padtempl->direction != compattempl->direction) {
895 GST_CAT_DEBUG (GST_CAT_CAPS,
896 "compatible direction: found %s pad template \"%s\"",
897 padtempl->direction == GST_PAD_SRC ? "src" : "sink",
898 padtempl->name_template);
900 GST_CAT_DEBUG (GST_CAT_CAPS,
901 "intersecting %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (compattempl));
902 GST_CAT_DEBUG (GST_CAT_CAPS,
903 "..and %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (padtempl));
905 compatible = gst_caps_can_intersect (GST_PAD_TEMPLATE_CAPS (compattempl),
906 GST_PAD_TEMPLATE_CAPS (padtempl));
908 GST_CAT_DEBUG (GST_CAT_CAPS, "caps are %scompatible",
909 (compatible ? "" : "not "));
917 padlist = g_list_next (padlist);
920 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
921 "Returning new pad template %p", newtempl);
923 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "No compatible pad template found");
929 * gst_element_get_pad_from_template:
930 * @element: (transfer none): a #GstElement.
931 * @templ: (transfer none): a #GstPadTemplate belonging to @element.
933 * Gets a pad from @element described by @templ. If the presence of @templ is
934 * #GST_PAD_REQUEST, requests a new pad. Can return %NULL for #GST_PAD_SOMETIMES
937 * Returns: (transfer full) (nullable): the #GstPad, or %NULL if one
938 * could not be found or created.
941 gst_element_get_pad_from_template (GstElement * element, GstPadTemplate * templ)
944 GstPadPresence presence;
946 /* If this function is ever exported, we need check the validity of `element'
947 * and `templ', and to make sure the template actually belongs to the
950 presence = GST_PAD_TEMPLATE_PRESENCE (templ);
954 case GST_PAD_SOMETIMES:
955 ret = gst_element_get_static_pad (element, templ->name_template);
956 if (!ret && presence == GST_PAD_ALWAYS)
958 ("Element %s has an ALWAYS template %s, but no pad of the same name",
959 GST_OBJECT_NAME (element), templ->name_template);
962 case GST_PAD_REQUEST:
963 ret = gst_element_request_pad (element, templ, NULL, NULL);
971 * gst_element_request_compatible_pad:
972 * @element: a #GstElement.
973 * @templ: the #GstPadTemplate to which the new pad should be able to link.
975 * Requests a pad from @element. The returned pad should be unlinked and
976 * compatible with @templ. Might return an existing pad, or request a new one.
978 * Returns: (nullable): a #GstPad, or %NULL if one could not be found
982 gst_element_request_compatible_pad (GstElement * element,
983 GstPadTemplate * templ)
985 GstPadTemplate *templ_new;
988 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
989 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
991 /* FIXME: should really loop through the templates, testing each for
992 * compatibility and pad availability. */
993 templ_new = gst_element_get_compatible_pad_template (element, templ);
995 pad = gst_element_get_pad_from_template (element, templ_new);
996 /* This can happen for non-request pads. */
997 if (pad && GST_PAD_PEER (pad)) {
998 gst_object_unref (pad);
1006 * Checks if the source pad and the sink pad can be linked.
1007 * Both @srcpad and @sinkpad must be unlinked and have a parent.
1010 gst_pad_check_link (GstPad * srcpad, GstPad * sinkpad)
1012 /* generic checks */
1013 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
1014 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
1016 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
1017 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
1019 if (GST_PAD_PEER (srcpad) != NULL) {
1020 GST_CAT_INFO (GST_CAT_PADS, "Source pad %s:%s has a peer, failed",
1021 GST_DEBUG_PAD_NAME (srcpad));
1024 if (GST_PAD_PEER (sinkpad) != NULL) {
1025 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has a peer, failed",
1026 GST_DEBUG_PAD_NAME (sinkpad));
1029 if (!GST_PAD_IS_SRC (srcpad)) {
1030 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s is not source pad, failed",
1031 GST_DEBUG_PAD_NAME (srcpad));
1034 if (!GST_PAD_IS_SINK (sinkpad)) {
1035 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s is not sink pad, failed",
1036 GST_DEBUG_PAD_NAME (sinkpad));
1039 if (GST_PAD_PARENT (srcpad) == NULL) {
1040 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s has no parent, failed",
1041 GST_DEBUG_PAD_NAME (srcpad));
1044 if (GST_PAD_PARENT (sinkpad) == NULL) {
1045 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has no parent, failed",
1046 GST_DEBUG_PAD_NAME (srcpad));
1054 * gst_element_get_compatible_pad:
1055 * @element: (transfer none): a #GstElement in which the pad should be found.
1056 * @pad: (transfer none): the #GstPad to find a compatible one for.
1057 * @caps: (allow-none): the #GstCaps to use as a filter.
1059 * Looks for an unlinked pad to which the given pad can link. It is not
1060 * guaranteed that linking the pads will work, though it should work in most
1063 * This function will first attempt to find a compatible unlinked ALWAYS pad,
1064 * and if none can be found, it will request a compatible REQUEST pad by looking
1065 * at the templates of @element.
1067 * Returns: (transfer full) (nullable): the #GstPad to which a link
1068 * can be made, or %NULL if one cannot be found. gst_object_unref()
1072 gst_element_get_compatible_pad (GstElement * element, GstPad * pad,
1076 GstPadTemplate *templ;
1078 GstPad *foundpad = NULL;
1080 GValue padptr = { 0, };
1082 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1083 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1085 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1086 "finding pad in %s compatible with %s:%s",
1087 GST_ELEMENT_NAME (element), GST_DEBUG_PAD_NAME (pad));
1089 g_return_val_if_fail (GST_PAD_PEER (pad) == NULL, NULL);
1093 /* try to get an existing unlinked pad */
1094 if (GST_PAD_IS_SRC (pad)) {
1095 pads = gst_element_iterate_sink_pads (element);
1096 } else if (GST_PAD_IS_SINK (pad)) {
1097 pads = gst_element_iterate_src_pads (element);
1099 pads = gst_element_iterate_pads (element);
1103 switch (gst_iterator_next (pads, &padptr)) {
1104 case GST_ITERATOR_OK:
1111 current = g_value_get_object (&padptr);
1113 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
1114 GST_DEBUG_PAD_NAME (current));
1116 if (GST_PAD_IS_SRC (current)) {
1123 peer = gst_pad_get_peer (current);
1125 if (peer == NULL && gst_pad_check_link (srcpad, sinkpad)) {
1126 GstCaps *temp, *intersection;
1127 gboolean compatible;
1129 /* Now check if the two pads' caps are compatible */
1130 temp = gst_pad_query_caps (pad, NULL);
1132 intersection = gst_caps_intersect (temp, caps);
1133 gst_caps_unref (temp);
1135 intersection = temp;
1138 temp = gst_pad_query_caps (current, NULL);
1139 compatible = gst_caps_can_intersect (temp, intersection);
1140 gst_caps_unref (temp);
1141 gst_caps_unref (intersection);
1144 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1145 "found existing unlinked compatible pad %s:%s",
1146 GST_DEBUG_PAD_NAME (current));
1147 gst_iterator_free (pads);
1149 current = gst_object_ref (current);
1150 g_value_unset (&padptr);
1154 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "incompatible pads");
1157 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1158 "already linked or cannot be linked (peer = %p)", peer);
1160 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unreffing pads");
1162 g_value_reset (&padptr);
1164 gst_object_unref (peer);
1167 case GST_ITERATOR_DONE:
1170 case GST_ITERATOR_RESYNC:
1171 gst_iterator_resync (pads);
1173 case GST_ITERATOR_ERROR:
1174 g_assert_not_reached ();
1178 g_value_unset (&padptr);
1179 gst_iterator_free (pads);
1181 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
1182 "Could not find a compatible unlinked always pad to link to %s:%s, now checking request pads",
1183 GST_DEBUG_PAD_NAME (pad));
1185 /* try to create a new one */
1186 /* requesting is a little crazy, we need a template. Let's create one */
1187 templcaps = gst_pad_query_caps (pad, NULL);
1189 GstCaps *inter = gst_caps_intersect (templcaps, caps);
1191 gst_caps_unref (templcaps);
1194 templ = gst_pad_template_new ((gchar *) GST_PAD_NAME (pad),
1195 GST_PAD_DIRECTION (pad), GST_PAD_ALWAYS, templcaps);
1196 gst_caps_unref (templcaps);
1198 foundpad = gst_element_request_compatible_pad (element, templ);
1199 gst_object_unref (templ);
1202 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1203 "found existing request pad %s:%s", GST_DEBUG_PAD_NAME (foundpad));
1207 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element,
1208 "Could not find a compatible pad to link to %s:%s",
1209 GST_DEBUG_PAD_NAME (pad));
1214 * gst_element_state_get_name:
1215 * @state: a #GstState to get the name of.
1217 * Gets a string representing the given state.
1219 * Returns: (transfer none): a string with the name of the state.
1222 gst_element_state_get_name (GstState state)
1225 case GST_STATE_VOID_PENDING:
1226 return "VOID_PENDING";
1227 case GST_STATE_NULL:
1229 case GST_STATE_READY:
1231 case GST_STATE_PLAYING:
1233 case GST_STATE_PAUSED:
1236 /* This is a memory leak */
1237 return g_strdup_printf ("UNKNOWN!(%d)", state);
1242 * gst_element_state_change_return_get_name:
1243 * @state_ret: a #GstStateChangeReturn to get the name of.
1245 * Gets a string representing the given state change result.
1247 * Returns: (transfer none): a string with the name of the state
1251 gst_element_state_change_return_get_name (GstStateChangeReturn state_ret)
1253 switch (state_ret) {
1254 case GST_STATE_CHANGE_FAILURE:
1256 case GST_STATE_CHANGE_SUCCESS:
1258 case GST_STATE_CHANGE_ASYNC:
1260 case GST_STATE_CHANGE_NO_PREROLL:
1261 return "NO PREROLL";
1263 /* This is a memory leak */
1264 return g_strdup_printf ("UNKNOWN!(%d)", state_ret);
1269 * gst_state_change_get_name:
1270 * @transition: a #GstStateChange to get the name of.
1272 * Gets a string representing the given state transition.
1274 * Returns: (transfer none): a string with the name of the state
1280 gst_state_change_get_name (GstStateChange transition)
1282 switch (transition) {
1283 case GST_STATE_CHANGE_NULL_TO_READY:
1284 return "NULL->READY";
1285 case GST_STATE_CHANGE_READY_TO_PAUSED:
1286 return "READY->PAUSED";
1287 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
1288 return "PAUSED->PLAYING";
1289 case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
1290 return "PLAYING->PAUSED";
1291 case GST_STATE_CHANGE_PAUSED_TO_READY:
1292 return "PAUSED->READY";
1293 case GST_STATE_CHANGE_READY_TO_NULL:
1294 return "READY->NULL";
1295 case GST_STATE_CHANGE_NULL_TO_NULL:
1296 return "NULL->NULL";
1297 case GST_STATE_CHANGE_READY_TO_READY:
1298 return "READY->READY";
1299 case GST_STATE_CHANGE_PAUSED_TO_PAUSED:
1300 return "PAUSED->PAUSED";
1301 case GST_STATE_CHANGE_PLAYING_TO_PLAYING:
1302 return "PLAYING->PLAYING";
1305 return "Unknown state return";
1310 gst_element_factory_can_accept_all_caps_in_direction (GstElementFactory *
1311 factory, const GstCaps * caps, GstPadDirection direction)
1315 g_return_val_if_fail (factory != NULL, FALSE);
1316 g_return_val_if_fail (caps != NULL, FALSE);
1318 templates = factory->staticpadtemplates;
1321 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1323 if (template->direction == direction) {
1324 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1326 if (gst_caps_is_always_compatible (caps, templcaps)) {
1327 gst_caps_unref (templcaps);
1330 gst_caps_unref (templcaps);
1332 templates = g_list_next (templates);
1339 gst_element_factory_can_accept_any_caps_in_direction (GstElementFactory *
1340 factory, const GstCaps * caps, GstPadDirection direction)
1344 g_return_val_if_fail (factory != NULL, FALSE);
1345 g_return_val_if_fail (caps != NULL, FALSE);
1347 templates = factory->staticpadtemplates;
1350 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1352 if (template->direction == direction) {
1353 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1355 if (gst_caps_can_intersect (caps, templcaps)) {
1356 gst_caps_unref (templcaps);
1359 gst_caps_unref (templcaps);
1361 templates = g_list_next (templates);
1368 * gst_element_factory_can_sink_all_caps:
1369 * @factory: factory to query
1370 * @caps: the caps to check
1372 * Checks if the factory can sink all possible capabilities.
1374 * Returns: %TRUE if the caps are fully compatible.
1377 gst_element_factory_can_sink_all_caps (GstElementFactory * factory,
1378 const GstCaps * caps)
1380 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1385 * gst_element_factory_can_src_all_caps:
1386 * @factory: factory to query
1387 * @caps: the caps to check
1389 * Checks if the factory can src all possible capabilities.
1391 * Returns: %TRUE if the caps are fully compatible.
1394 gst_element_factory_can_src_all_caps (GstElementFactory * factory,
1395 const GstCaps * caps)
1397 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1402 * gst_element_factory_can_sink_any_caps:
1403 * @factory: factory to query
1404 * @caps: the caps to check
1406 * Checks if the factory can sink any possible capability.
1408 * Returns: %TRUE if the caps have a common subset.
1411 gst_element_factory_can_sink_any_caps (GstElementFactory * factory,
1412 const GstCaps * caps)
1414 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1419 * gst_element_factory_can_src_any_caps:
1420 * @factory: factory to query
1421 * @caps: the caps to check
1423 * Checks if the factory can src any possible capability.
1425 * Returns: %TRUE if the caps have a common subset.
1428 gst_element_factory_can_src_any_caps (GstElementFactory * factory,
1429 const GstCaps * caps)
1431 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1435 /* if return val is true, *direct_child is a caller-owned ref on the direct
1436 * child of ancestor that is part of object's ancestry */
1438 object_has_ancestor (GstObject * object, GstObject * ancestor,
1439 GstObject ** direct_child)
1441 GstObject *child, *parent;
1444 *direct_child = NULL;
1446 child = gst_object_ref (object);
1447 parent = gst_object_get_parent (object);
1450 if (ancestor == parent) {
1452 *direct_child = child;
1454 gst_object_unref (child);
1455 gst_object_unref (parent);
1459 gst_object_unref (child);
1461 parent = gst_object_get_parent (parent);
1464 gst_object_unref (child);
1469 /* caller owns return */
1471 find_common_root (GstObject * o1, GstObject * o2)
1473 GstObject *top = o1;
1474 GstObject *kid1, *kid2;
1475 GstObject *root = NULL;
1477 while (GST_OBJECT_PARENT (top))
1478 top = GST_OBJECT_PARENT (top);
1480 /* the itsy-bitsy spider... */
1482 if (!object_has_ancestor (o2, top, &kid2))
1485 root = gst_object_ref (top);
1487 if (!object_has_ancestor (o1, kid2, &kid1)) {
1488 gst_object_unref (kid2);
1491 gst_object_unref (root);
1493 if (!object_has_ancestor (o2, kid1, &kid2)) {
1494 gst_object_unref (kid1);
1497 gst_object_unref (root);
1502 /* caller does not own return */
1504 ghost_up (GstElement * e, GstPad * pad)
1506 static gint ghost_pad_index = 0;
1511 GstObject *parent = GST_OBJECT_PARENT (e);
1513 name = g_strdup_printf ("ghost%d", ghost_pad_index++);
1514 gpad = gst_ghost_pad_new (name, pad);
1517 GST_STATE_LOCK (parent);
1518 gst_element_get_state (GST_ELEMENT (parent), ¤t, &next, 0);
1520 if (current > GST_STATE_READY || next >= GST_STATE_PAUSED)
1521 gst_pad_set_active (gpad, TRUE);
1523 if (!gst_element_add_pad ((GstElement *) parent, gpad)) {
1524 g_warning ("Pad named %s already exists in element %s\n",
1525 GST_OBJECT_NAME (gpad), GST_OBJECT_NAME (parent));
1526 GST_STATE_UNLOCK (parent);
1529 GST_STATE_UNLOCK (parent);
1535 remove_pad (gpointer ppad, gpointer unused)
1539 if (!gst_element_remove_pad ((GstElement *) GST_OBJECT_PARENT (pad), pad))
1540 g_warning ("Couldn't remove pad %s from element %s",
1541 GST_OBJECT_NAME (pad), GST_OBJECT_NAME (GST_OBJECT_PARENT (pad)));
1545 prepare_link_maybe_ghosting (GstPad ** src, GstPad ** sink,
1546 GSList ** pads_created)
1550 GSList *pads_created_local = NULL;
1552 g_assert (pads_created);
1554 e1 = GST_OBJECT_PARENT (*src);
1555 e2 = GST_OBJECT_PARENT (*sink);
1557 if (G_UNLIKELY (e1 == NULL)) {
1558 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1559 GST_PTR_FORMAT, *src);
1562 if (G_UNLIKELY (e2 == NULL)) {
1563 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1564 GST_PTR_FORMAT, *sink);
1568 if (GST_OBJECT_PARENT (e1) == GST_OBJECT_PARENT (e2)) {
1569 GST_CAT_INFO (GST_CAT_PADS, "%s and %s in same bin, no need for ghost pads",
1570 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1574 GST_CAT_INFO (GST_CAT_PADS, "%s and %s not in same bin, making ghost pads",
1575 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1577 /* we need to setup some ghost pads */
1578 root = find_common_root (e1, e2);
1580 if (GST_OBJECT_PARENT (e1) == NULL)
1581 g_warning ("Trying to link elements %s and %s that don't share a common "
1582 "ancestor: %s hasn't been added to a bin or pipeline, but %s is in %s",
1583 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1584 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1585 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1586 else if (GST_OBJECT_PARENT (e2) == NULL)
1587 g_warning ("Trying to link elements %s and %s that don't share a common "
1588 "ancestor: %s hasn't been added to a bin or pipeline, and %s is in %s",
1589 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1590 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (e1),
1591 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)));
1593 g_warning ("Trying to link elements %s and %s that don't share a common "
1594 "ancestor: %s is in %s, and %s is in %s",
1595 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1596 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)),
1597 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1601 while (GST_OBJECT_PARENT (e1) != root) {
1602 *src = ghost_up ((GstElement *) e1, *src);
1605 e1 = GST_OBJECT_PARENT (*src);
1606 pads_created_local = g_slist_prepend (pads_created_local, *src);
1608 while (GST_OBJECT_PARENT (e2) != root) {
1609 *sink = ghost_up ((GstElement *) e2, *sink);
1612 e2 = GST_OBJECT_PARENT (*sink);
1613 pads_created_local = g_slist_prepend (pads_created_local, *sink);
1616 gst_object_unref (root);
1617 *pads_created = g_slist_concat (*pads_created, pads_created_local);
1621 gst_object_unref (root);
1622 g_slist_foreach (pads_created_local, remove_pad, NULL);
1623 g_slist_free (pads_created_local);
1628 pad_link_maybe_ghosting (GstPad * src, GstPad * sink, GstPadLinkCheck flags)
1630 GSList *pads_created = NULL;
1633 if (!prepare_link_maybe_ghosting (&src, &sink, &pads_created)) {
1636 ret = (gst_pad_link_full (src, sink, flags) == GST_PAD_LINK_OK);
1640 g_slist_foreach (pads_created, remove_pad, NULL);
1642 g_slist_free (pads_created);
1648 * gst_pad_link_maybe_ghosting_full:
1651 * @flags: some #GstPadLinkCheck flags
1653 * Links @src to @sink, creating any #GstGhostPad's in between as necessary.
1655 * This is a convenience function to save having to create and add intermediate
1656 * #GstGhostPad's as required for linking across #GstBin boundaries.
1658 * If @src or @sink pads don't have parent elements or do not share a common
1659 * ancestor, the link will fail.
1661 * Calling gst_pad_link_maybe_ghosting_full() with
1662 * @flags == %GST_PAD_LINK_CHECK_DEFAULT is the recommended way of linking
1663 * pads with safety checks applied.
1665 * Returns: whether the link succeeded.
1670 gst_pad_link_maybe_ghosting_full (GstPad * src, GstPad * sink,
1671 GstPadLinkCheck flags)
1673 g_return_val_if_fail (GST_IS_PAD (src), FALSE);
1674 g_return_val_if_fail (GST_IS_PAD (sink), FALSE);
1676 return pad_link_maybe_ghosting (src, sink, flags);
1680 * gst_pad_link_maybe_ghosting:
1684 * Links @src to @sink, creating any #GstGhostPad's in between as necessary.
1686 * This is a convenience function to save having to create and add intermediate
1687 * #GstGhostPad's as required for linking across #GstBin boundaries.
1689 * If @src or @sink pads don't have parent elements or do not share a common
1690 * ancestor, the link will fail.
1692 * Returns: whether the link succeeded.
1697 gst_pad_link_maybe_ghosting (GstPad * src, GstPad * sink)
1699 g_return_val_if_fail (GST_IS_PAD (src), FALSE);
1700 g_return_val_if_fail (GST_IS_PAD (sink), FALSE);
1702 return gst_pad_link_maybe_ghosting_full (src, sink,
1703 GST_PAD_LINK_CHECK_DEFAULT);
1707 release_and_unref_pad (GstElement * element, GstPad * pad, gboolean requestpad)
1711 gst_element_release_request_pad (element, pad);
1712 gst_object_unref (pad);
1717 * gst_element_link_pads_full:
1718 * @src: a #GstElement containing the source pad.
1719 * @srcpadname: (allow-none): the name of the #GstPad in source element
1720 * or %NULL for any pad.
1721 * @dest: (transfer none): the #GstElement containing the destination pad.
1722 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1723 * or %NULL for any pad.
1724 * @flags: the #GstPadLinkCheck to be performed when linking pads.
1726 * Links the two named pads of the source and destination elements.
1727 * Side effect is that if one of the pads has no parent, it becomes a
1728 * child of the parent of the other element. If they have different
1729 * parents, the link fails.
1731 * Calling gst_element_link_pads_full() with @flags == %GST_PAD_LINK_CHECK_DEFAULT
1732 * is the same as calling gst_element_link_pads() and the recommended way of
1733 * linking pads with safety checks applied.
1735 * This is a convenience function for gst_pad_link_full().
1737 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1740 gst_element_link_pads_full (GstElement * src, const gchar * srcpadname,
1741 GstElement * dest, const gchar * destpadname, GstPadLinkCheck flags)
1743 const GList *srcpads, *destpads, *srctempls, *desttempls, *l;
1744 GstPad *srcpad, *destpad;
1745 GstPadTemplate *srctempl, *desttempl;
1746 GstElementClass *srcclass, *destclass;
1747 gboolean srcrequest, destrequest;
1750 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1751 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1753 GST_CAT_INFO (GST_CAT_ELEMENT_PADS,
1754 "trying to link element %s:%s to element %s:%s", GST_ELEMENT_NAME (src),
1755 srcpadname ? srcpadname : "(any)", GST_ELEMENT_NAME (dest),
1756 destpadname ? destpadname : "(any)");
1759 destrequest = FALSE;
1763 /* name specified, look it up */
1764 if (!(srcpad = gst_element_get_static_pad (src, srcpadname))) {
1765 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
1769 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1770 GST_ELEMENT_NAME (src), srcpadname);
1773 if (!(GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC)) {
1774 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no src pad",
1775 GST_DEBUG_PAD_NAME (srcpad));
1776 release_and_unref_pad (src, srcpad, srcrequest);
1779 if (GST_PAD_PEER (srcpad) != NULL) {
1780 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1781 "pad %s:%s is already linked to %s:%s", GST_DEBUG_PAD_NAME (srcpad),
1782 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1783 /* already linked request pads look like static pads, so the request pad
1784 * was never requested a second time above, so no need to release it */
1785 gst_object_unref (srcpad);
1791 /* no name given, get the first available pad */
1792 GST_OBJECT_LOCK (src);
1793 srcpads = GST_ELEMENT_PADS (src);
1794 srcpad = srcpads ? GST_PAD_CAST (srcpads->data) : NULL;
1796 gst_object_ref (srcpad);
1797 GST_OBJECT_UNLOCK (src);
1800 /* get a destination pad */
1802 /* name specified, look it up */
1803 if (!(destpad = gst_element_get_static_pad (dest, destpadname))) {
1804 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
1808 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1809 GST_ELEMENT_NAME (dest), destpadname);
1810 release_and_unref_pad (src, srcpad, srcrequest);
1813 if (!(GST_PAD_DIRECTION (destpad) == GST_PAD_SINK)) {
1814 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no sink pad",
1815 GST_DEBUG_PAD_NAME (destpad));
1816 release_and_unref_pad (src, srcpad, srcrequest);
1817 release_and_unref_pad (dest, destpad, destrequest);
1820 if (GST_PAD_PEER (destpad) != NULL) {
1821 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1822 "pad %s:%s is already linked to %s:%s",
1823 GST_DEBUG_PAD_NAME (destpad),
1824 GST_DEBUG_PAD_NAME (GST_PAD_PEER (destpad)));
1825 release_and_unref_pad (src, srcpad, srcrequest);
1826 /* already linked request pads look like static pads, so the request pad
1827 * was never requested a second time above, so no need to release it */
1828 gst_object_unref (destpad);
1834 /* no name given, get the first available pad */
1835 GST_OBJECT_LOCK (dest);
1836 destpads = GST_ELEMENT_PADS (dest);
1837 destpad = destpads ? GST_PAD_CAST (destpads->data) : NULL;
1839 gst_object_ref (destpad);
1840 GST_OBJECT_UNLOCK (dest);
1843 if (srcpadname && destpadname) {
1846 /* two explicitly specified pads */
1847 result = pad_link_maybe_ghosting (srcpad, destpad, flags);
1850 gst_object_unref (srcpad);
1851 gst_object_unref (destpad);
1853 release_and_unref_pad (src, srcpad, srcrequest);
1854 release_and_unref_pad (dest, destpad, destrequest);
1860 /* loop through the allowed pads in the source, trying to find a
1861 * compatible destination pad */
1862 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1863 "looping through allowed src and dest pads");
1865 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying src pad %s:%s",
1866 GST_DEBUG_PAD_NAME (srcpad));
1867 if ((GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC) &&
1868 (GST_PAD_PEER (srcpad) == NULL)) {
1869 gboolean temprequest = FALSE;
1874 gst_object_ref (temp);
1876 temp = gst_element_get_compatible_pad (dest, srcpad, NULL);
1877 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1878 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
1884 if (temp && pad_link_maybe_ghosting (srcpad, temp, flags)) {
1885 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1886 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (temp));
1888 gst_object_unref (destpad);
1889 gst_object_unref (srcpad);
1890 gst_object_unref (temp);
1896 gst_element_release_request_pad (dest, temp);
1897 gst_object_unref (temp);
1900 /* find a better way for this mess */
1902 srcpads = g_list_next (srcpads);
1904 gst_object_unref (srcpad);
1905 srcpad = GST_PAD_CAST (srcpads->data);
1906 gst_object_ref (srcpad);
1912 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s:%s to %s",
1913 GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (dest));
1914 /* no need to release any request pad as both src- and destpadname must be
1915 * set to end up here, but this case has already been taken care of above */
1917 gst_object_unref (destpad);
1921 release_and_unref_pad (src, srcpad, srcrequest);
1926 /* loop through the existing pads in the destination */
1928 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying dest pad %s:%s",
1929 GST_DEBUG_PAD_NAME (destpad));
1930 if ((GST_PAD_DIRECTION (destpad) == GST_PAD_SINK) &&
1931 (GST_PAD_PEER (destpad) == NULL)) {
1932 GstPad *temp = gst_element_get_compatible_pad (src, destpad, NULL);
1933 gboolean temprequest = FALSE;
1935 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1936 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
1941 if (temp && pad_link_maybe_ghosting (temp, destpad, flags)) {
1942 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1943 GST_DEBUG_PAD_NAME (temp), GST_DEBUG_PAD_NAME (destpad));
1944 gst_object_unref (temp);
1945 gst_object_unref (destpad);
1949 release_and_unref_pad (src, temp, temprequest);
1952 destpads = g_list_next (destpads);
1954 gst_object_unref (destpad);
1955 destpad = GST_PAD_CAST (destpads->data);
1956 gst_object_ref (destpad);
1963 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s:%s",
1964 GST_ELEMENT_NAME (src), GST_DEBUG_PAD_NAME (destpad));
1965 release_and_unref_pad (dest, destpad, destrequest);
1968 /* no need to release any request pad as the case of unset destpatname and
1969 * destpad being a requst pad has already been taken care of when looking
1970 * though the destination pads above */
1972 gst_object_unref (destpad);
1977 srcclass = GST_ELEMENT_GET_CLASS (src);
1978 destclass = GST_ELEMENT_GET_CLASS (dest);
1980 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1981 "we might have request pads on both sides, checking...");
1982 srctempls = gst_element_class_get_pad_template_list (srcclass);
1983 desttempls = gst_element_class_get_pad_template_list (destclass);
1985 if (srctempls && desttempls) {
1987 srctempl = (GstPadTemplate *) srctempls->data;
1988 if (srctempl->presence == GST_PAD_REQUEST) {
1989 for (l = desttempls; l; l = l->next) {
1990 desttempl = (GstPadTemplate *) l->data;
1991 if (desttempl->presence == GST_PAD_REQUEST &&
1992 desttempl->direction != srctempl->direction) {
1993 GstCaps *srccaps, *destcaps;
1995 srccaps = gst_pad_template_get_caps (srctempl);
1996 destcaps = gst_pad_template_get_caps (desttempl);
1997 if (gst_caps_is_always_compatible (srccaps, destcaps)) {
1999 gst_element_request_pad (src, srctempl,
2000 srctempl->name_template, NULL);
2002 gst_element_request_pad (dest, desttempl,
2003 desttempl->name_template, NULL);
2004 if (srcpad && destpad
2005 && pad_link_maybe_ghosting (srcpad, destpad, flags)) {
2006 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
2007 "linked pad %s:%s to pad %s:%s",
2008 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (destpad));
2009 gst_object_unref (srcpad);
2010 gst_object_unref (destpad);
2011 gst_caps_unref (srccaps);
2012 gst_caps_unref (destcaps);
2015 /* it failed, so we release the request pads */
2017 gst_element_release_request_pad (src, srcpad);
2018 gst_object_unref (srcpad);
2021 gst_element_release_request_pad (dest, destpad);
2022 gst_object_unref (destpad);
2025 gst_caps_unref (srccaps);
2026 gst_caps_unref (destcaps);
2030 srctempls = srctempls->next;
2034 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s",
2035 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2040 * gst_element_link_pads:
2041 * @src: a #GstElement containing the source pad.
2042 * @srcpadname: (allow-none): the name of the #GstPad in source element
2043 * or %NULL for any pad.
2044 * @dest: (transfer none): the #GstElement containing the destination pad.
2045 * @destpadname: (allow-none): the name of the #GstPad in destination element,
2046 * or %NULL for any pad.
2048 * Links the two named pads of the source and destination elements.
2049 * Side effect is that if one of the pads has no parent, it becomes a
2050 * child of the parent of the other element. If they have different
2051 * parents, the link fails.
2053 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2056 gst_element_link_pads (GstElement * src, const gchar * srcpadname,
2057 GstElement * dest, const gchar * destpadname)
2059 return gst_element_link_pads_full (src, srcpadname, dest, destpadname,
2060 GST_PAD_LINK_CHECK_DEFAULT);
2064 * gst_element_link_pads_filtered:
2065 * @src: a #GstElement containing the source pad.
2066 * @srcpadname: (allow-none): the name of the #GstPad in source element
2067 * or %NULL for any pad.
2068 * @dest: (transfer none): the #GstElement containing the destination pad.
2069 * @destpadname: (allow-none): the name of the #GstPad in destination element
2070 * or %NULL for any pad.
2071 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
2072 * or %NULL for no filter.
2074 * Links the two named pads of the source and destination elements. Side effect
2075 * is that if one of the pads has no parent, it becomes a child of the parent of
2076 * the other element. If they have different parents, the link fails. If @caps
2077 * is not %NULL, makes sure that the caps of the link is a subset of @caps.
2079 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2082 gst_element_link_pads_filtered (GstElement * src, const gchar * srcpadname,
2083 GstElement * dest, const gchar * destpadname, GstCaps * filter)
2086 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
2087 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
2088 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), FALSE);
2091 GstElement *capsfilter;
2093 GstState state, pending;
2096 capsfilter = gst_element_factory_make ("capsfilter", NULL);
2098 GST_ERROR ("Could not make a capsfilter");
2102 parent = gst_object_get_parent (GST_OBJECT (src));
2103 g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
2105 gst_element_get_state (GST_ELEMENT_CAST (parent), &state, &pending, 0);
2107 if (!gst_bin_add (GST_BIN (parent), capsfilter)) {
2108 GST_ERROR ("Could not add capsfilter");
2109 gst_object_unref (parent);
2113 if (pending != GST_STATE_VOID_PENDING)
2116 gst_element_set_state (capsfilter, state);
2118 gst_object_unref (parent);
2120 g_object_set (capsfilter, "caps", filter, NULL);
2122 lr1 = gst_element_link_pads (src, srcpadname, capsfilter, "sink");
2123 lr2 = gst_element_link_pads (capsfilter, "src", dest, destpadname);
2128 GST_INFO ("Could not link pads: %s:%s - capsfilter:sink",
2129 GST_ELEMENT_NAME (src), srcpadname);
2131 GST_INFO ("Could not link pads: capsfilter:src - %s:%s",
2132 GST_ELEMENT_NAME (dest), destpadname);
2134 gst_element_set_state (capsfilter, GST_STATE_NULL);
2135 /* this will unlink and unref as appropriate */
2136 gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (capsfilter)), capsfilter);
2140 if (gst_element_link_pads (src, srcpadname, dest, destpadname)) {
2143 GST_INFO ("Could not link pads: %s:%s - %s:%s", GST_ELEMENT_NAME (src),
2144 srcpadname, GST_ELEMENT_NAME (dest), destpadname);
2152 * @src: (transfer none): a #GstElement containing the source pad.
2153 * @dest: (transfer none): the #GstElement containing the destination pad.
2155 * Links @src to @dest. The link must be from source to
2156 * destination; the other direction will not be tried. The function looks for
2157 * existing pads that aren't linked yet. It will request new pads if necessary.
2158 * Such pads need to be released manually when unlinking.
2159 * If multiple links are possible, only one is established.
2161 * Make sure you have added your elements to a bin or pipeline with
2162 * gst_bin_add() before trying to link them.
2164 * Returns: %TRUE if the elements could be linked, %FALSE otherwise.
2167 gst_element_link (GstElement * src, GstElement * dest)
2169 return gst_element_link_pads (src, NULL, dest, NULL);
2173 * gst_element_link_many:
2174 * @element_1: (transfer none): the first #GstElement in the link chain.
2175 * @element_2: (transfer none): the second #GstElement in the link chain.
2176 * @...: the %NULL-terminated list of elements to link in order.
2178 * Chain together a series of elements. Uses gst_element_link().
2179 * Make sure you have added your elements to a bin or pipeline with
2180 * gst_bin_add() before trying to link them.
2182 * Returns: %TRUE on success, %FALSE otherwise.
2185 gst_element_link_many (GstElement * element_1, GstElement * element_2, ...)
2187 gboolean res = TRUE;
2190 g_return_val_if_fail (GST_IS_ELEMENT (element_1), FALSE);
2191 g_return_val_if_fail (GST_IS_ELEMENT (element_2), FALSE);
2193 va_start (args, element_2);
2196 if (!gst_element_link (element_1, element_2)) {
2201 element_1 = element_2;
2202 element_2 = va_arg (args, GstElement *);
2211 * gst_element_link_filtered:
2212 * @src: a #GstElement containing the source pad.
2213 * @dest: (transfer none): the #GstElement containing the destination pad.
2214 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
2215 * or %NULL for no filter.
2217 * Links @src to @dest using the given caps as filtercaps.
2218 * 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 * If multiple links are possible, only one is established.
2223 * Make sure you have added your elements to a bin or pipeline with
2224 * gst_bin_add() before trying to link them.
2226 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2229 gst_element_link_filtered (GstElement * src, GstElement * dest,
2232 return gst_element_link_pads_filtered (src, NULL, dest, NULL, filter);
2236 * gst_element_unlink_pads:
2237 * @src: a (transfer none): #GstElement containing the source pad.
2238 * @srcpadname: the name of the #GstPad in source element.
2239 * @dest: (transfer none): a #GstElement containing the destination pad.
2240 * @destpadname: the name of the #GstPad in destination element.
2242 * Unlinks the two named pads of the source and destination elements.
2244 * This is a convenience function for gst_pad_unlink().
2247 gst_element_unlink_pads (GstElement * src, const gchar * srcpadname,
2248 GstElement * dest, const gchar * destpadname)
2250 GstPad *srcpad, *destpad;
2251 gboolean srcrequest, destrequest;
2253 srcrequest = destrequest = FALSE;
2255 g_return_if_fail (src != NULL);
2256 g_return_if_fail (GST_IS_ELEMENT (src));
2257 g_return_if_fail (srcpadname != NULL);
2258 g_return_if_fail (dest != NULL);
2259 g_return_if_fail (GST_IS_ELEMENT (dest));
2260 g_return_if_fail (destpadname != NULL);
2262 /* obtain the pads requested */
2263 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
2264 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
2266 if (srcpad == NULL) {
2267 GST_WARNING_OBJECT (src, "source element has no pad \"%s\"", srcpadname);
2270 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
2271 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
2273 if (destpad == NULL) {
2274 GST_WARNING_OBJECT (dest, "destination element has no pad \"%s\"",
2279 /* we're satisfied they can be unlinked, let's do it */
2280 gst_pad_unlink (srcpad, destpad);
2283 gst_element_release_request_pad (dest, destpad);
2284 gst_object_unref (destpad);
2288 gst_element_release_request_pad (src, srcpad);
2289 gst_object_unref (srcpad);
2293 * gst_element_unlink_many:
2294 * @element_1: (transfer none): the first #GstElement in the link chain.
2295 * @element_2: (transfer none): the second #GstElement in the link chain.
2296 * @...: the %NULL-terminated list of elements to unlink in order.
2298 * Unlinks a series of elements. Uses gst_element_unlink().
2301 gst_element_unlink_many (GstElement * element_1, GstElement * element_2, ...)
2305 g_return_if_fail (element_1 != NULL && element_2 != NULL);
2306 g_return_if_fail (GST_IS_ELEMENT (element_1) && GST_IS_ELEMENT (element_2));
2308 va_start (args, element_2);
2311 gst_element_unlink (element_1, element_2);
2313 element_1 = element_2;
2314 element_2 = va_arg (args, GstElement *);
2321 * gst_element_unlink:
2322 * @src: (transfer none): the source #GstElement to unlink.
2323 * @dest: (transfer none): the sink #GstElement to unlink.
2325 * Unlinks all source pads of the source element with all sink pads
2326 * of the sink element to which they are linked.
2328 * If the link has been made using gst_element_link(), it could have created an
2329 * requestpad, which has to be released using gst_element_release_request_pad().
2332 gst_element_unlink (GstElement * src, GstElement * dest)
2335 gboolean done = FALSE;
2336 GValue data = { 0, };
2338 g_return_if_fail (GST_IS_ELEMENT (src));
2339 g_return_if_fail (GST_IS_ELEMENT (dest));
2341 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unlinking \"%s\" and \"%s\"",
2342 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2344 pads = gst_element_iterate_pads (src);
2346 switch (gst_iterator_next (pads, &data)) {
2347 case GST_ITERATOR_OK:
2349 GstPad *pad = g_value_get_object (&data);
2351 if (GST_PAD_IS_SRC (pad)) {
2352 GstPad *peerpad = gst_pad_get_peer (pad);
2354 /* see if the pad is linked and is really a pad of dest */
2356 GstElement *peerelem;
2358 peerelem = gst_pad_get_parent_element (peerpad);
2360 if (peerelem == dest) {
2361 gst_pad_unlink (pad, peerpad);
2364 gst_object_unref (peerelem);
2366 gst_object_unref (peerpad);
2369 g_value_reset (&data);
2372 case GST_ITERATOR_RESYNC:
2373 gst_iterator_resync (pads);
2375 case GST_ITERATOR_DONE:
2379 g_assert_not_reached ();
2383 g_value_unset (&data);
2384 gst_iterator_free (pads);
2388 * gst_element_query_position:
2389 * @element: a #GstElement to invoke the position query on.
2390 * @format: the #GstFormat requested
2391 * @cur: (out) (allow-none): a location in which to store the current
2392 * position, or %NULL.
2394 * Queries an element (usually top-level pipeline or playbin element) for the
2395 * stream position in nanoseconds. This will be a value between 0 and the
2396 * stream duration (if the stream duration is known). This query will usually
2397 * only work once the pipeline is prerolled (i.e. reached PAUSED or PLAYING
2398 * state). The application will receive an ASYNC_DONE message on the pipeline
2399 * bus when that is the case.
2401 * If one repeatedly calls this function one can also create a query and reuse
2402 * it in gst_element_query().
2404 * Returns: %TRUE if the query could be performed.
2407 gst_element_query_position (GstElement * element, GstFormat format,
2413 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2414 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2416 query = gst_query_new_position (format);
2417 ret = gst_element_query (element, query);
2420 gst_query_parse_position (query, NULL, cur);
2422 gst_query_unref (query);
2428 * gst_element_query_duration:
2429 * @element: a #GstElement to invoke the duration query on.
2430 * @format: the #GstFormat requested
2431 * @duration: (out) (allow-none): A location in which to store the total duration, or %NULL.
2433 * Queries an element (usually top-level pipeline or playbin element) for the
2434 * total stream duration in nanoseconds. This query will only work once the
2435 * pipeline is prerolled (i.e. reached PAUSED or PLAYING state). The application
2436 * will receive an ASYNC_DONE message on the pipeline bus when that is the case.
2438 * If the duration changes for some reason, you will get a DURATION_CHANGED
2439 * message on the pipeline bus, in which case you should re-query the duration
2440 * using this function.
2442 * Returns: %TRUE if the query could be performed.
2445 gst_element_query_duration (GstElement * element, GstFormat format,
2451 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2452 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2454 query = gst_query_new_duration (format);
2455 ret = gst_element_query (element, query);
2458 gst_query_parse_duration (query, NULL, duration);
2460 gst_query_unref (query);
2466 * gst_element_query_convert:
2467 * @element: a #GstElement to invoke the convert query on.
2468 * @src_format: a #GstFormat to convert from.
2469 * @src_val: a value to convert.
2470 * @dest_format: the #GstFormat to convert to.
2471 * @dest_val: (out): a pointer to the result.
2473 * Queries an element to convert @src_val in @src_format to @dest_format.
2475 * Returns: %TRUE if the query could be performed.
2478 gst_element_query_convert (GstElement * element, GstFormat src_format,
2479 gint64 src_val, GstFormat dest_format, gint64 * dest_val)
2484 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2485 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2486 g_return_val_if_fail (dest_val != NULL, FALSE);
2488 if (dest_format == src_format || src_val == -1) {
2489 *dest_val = src_val;
2493 query = gst_query_new_convert (src_format, src_val, dest_format);
2494 ret = gst_element_query (element, query);
2497 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2499 gst_query_unref (query);
2505 * gst_element_seek_simple:
2506 * @element: a #GstElement to seek on
2507 * @format: a #GstFormat to execute the seek in, such as #GST_FORMAT_TIME
2508 * @seek_flags: seek options; playback applications will usually want to use
2509 * GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT here
2510 * @seek_pos: position to seek to (relative to the start); if you are doing
2511 * a seek in #GST_FORMAT_TIME this value is in nanoseconds -
2512 * multiply with #GST_SECOND to convert seconds to nanoseconds or
2513 * with #GST_MSECOND to convert milliseconds to nanoseconds.
2515 * Simple API to perform a seek on the given element, meaning it just seeks
2516 * to the given position relative to the start of the stream. For more complex
2517 * operations like segment seeks (e.g. for looping) or changing the playback
2518 * rate or seeking relative to the last configured playback segment you should
2519 * use gst_element_seek().
2521 * In a completely prerolled PAUSED or PLAYING pipeline, seeking is always
2522 * guaranteed to return %TRUE on a seekable media type or %FALSE when the media
2523 * type is certainly not seekable (such as a live stream).
2525 * Some elements allow for seeking in the READY state, in this
2526 * case they will store the seek event and execute it when they are put to
2527 * PAUSED. If the element supports seek in READY, it will always return %TRUE when
2528 * it receives the event in the READY state.
2530 * Returns: %TRUE if the seek operation succeeded. Flushing seeks will trigger a
2531 * preroll, which will emit %GST_MESSAGE_ASYNC_DONE.
2534 gst_element_seek_simple (GstElement * element, GstFormat format,
2535 GstSeekFlags seek_flags, gint64 seek_pos)
2537 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2538 g_return_val_if_fail (seek_pos >= 0, FALSE);
2540 return gst_element_seek (element, 1.0, format, seek_flags,
2541 GST_SEEK_TYPE_SET, seek_pos, GST_SEEK_TYPE_SET, GST_CLOCK_TIME_NONE);
2545 * gst_pad_use_fixed_caps:
2546 * @pad: the pad to use
2548 * A helper function you can use that sets the FIXED_CAPS flag
2549 * This way the default CAPS query will always return the negotiated caps
2550 * or in case the pad is not negotiated, the padtemplate caps.
2552 * The negotiated caps are the caps of the last CAPS event that passed on the
2553 * pad. Use this function on a pad that, once it negotiated to a CAPS, cannot
2554 * be renegotiated to something else.
2557 gst_pad_use_fixed_caps (GstPad * pad)
2559 GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FIXED_CAPS);
2563 * gst_pad_get_parent_element:
2566 * Gets the parent of @pad, cast to a #GstElement. If a @pad has no parent or
2567 * its parent is not an element, return %NULL.
2569 * Returns: (transfer full) (nullable): the parent of the pad. The
2570 * caller has a reference on the parent, so unref when you're finished
2576 gst_pad_get_parent_element (GstPad * pad)
2580 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2582 p = gst_object_get_parent (GST_OBJECT_CAST (pad));
2584 if (p && !GST_IS_ELEMENT (p)) {
2585 gst_object_unref (p);
2588 return GST_ELEMENT_CAST (p);
2592 * gst_object_default_error:
2593 * @source: the #GstObject that initiated the error.
2594 * @error: (in): the GError.
2595 * @debug: (in) (allow-none): an additional debug information string, or %NULL
2597 * A default error function that uses g_printerr() to display the error message
2598 * and the optional debug sting..
2600 * The default handler will simply print the error string using g_print.
2603 gst_object_default_error (GstObject * source, const GError * error,
2604 const gchar * debug)
2606 gchar *name = gst_object_get_path_string (source);
2608 g_printerr (_("ERROR: from element %s: %s\n"), name, error->message);
2610 g_printerr (_("Additional debug info:\n%s\n"), debug);
2616 * gst_bin_add_many: (skip)
2618 * @element_1: (transfer floating): the #GstElement element to add to the bin
2619 * @...: additional elements to add to the bin
2621 * Adds a %NULL-terminated list of elements to a bin. This function is
2622 * equivalent to calling gst_bin_add() for each member of the list. The return
2623 * value of each gst_bin_add() is ignored.
2626 gst_bin_add_many (GstBin * bin, GstElement * element_1, ...)
2630 g_return_if_fail (GST_IS_BIN (bin));
2631 g_return_if_fail (GST_IS_ELEMENT (element_1));
2633 va_start (args, element_1);
2636 gst_bin_add (bin, element_1);
2638 element_1 = va_arg (args, GstElement *);
2645 * gst_bin_remove_many: (skip)
2647 * @element_1: (transfer none): the first #GstElement to remove from the bin
2648 * @...: (transfer none): %NULL-terminated list of elements to remove from the bin
2650 * Remove a list of elements from a bin. This function is equivalent
2651 * to calling gst_bin_remove() with each member of the list.
2654 gst_bin_remove_many (GstBin * bin, GstElement * element_1, ...)
2658 g_return_if_fail (GST_IS_BIN (bin));
2659 g_return_if_fail (GST_IS_ELEMENT (element_1));
2661 va_start (args, element_1);
2664 gst_bin_remove (bin, element_1);
2666 element_1 = va_arg (args, GstElement *);
2676 } QueryAcceptCapsData;
2679 query_accept_caps_func (GstPad * pad, QueryAcceptCapsData * data)
2681 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2684 gst_query_parse_accept_caps_result (data->query, &result);
2685 data->ret &= result;
2691 * gst_pad_proxy_query_accept_caps:
2692 * @pad: a #GstPad to proxy.
2693 * @query: an ACCEPT_CAPS #GstQuery.
2695 * Checks if all internally linked pads of @pad accepts the caps in @query and
2696 * returns the intersection of the results.
2698 * This function is useful as a default accept caps query function for an element
2699 * that can handle any stream format, but requires caps that are acceptable for
2700 * all opposite pads.
2702 * Returns: %TRUE if @query could be executed
2705 gst_pad_proxy_query_accept_caps (GstPad * pad, GstQuery * query)
2707 QueryAcceptCapsData data;
2709 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2710 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2711 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS, FALSE);
2713 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2714 "proxying accept caps query for %s:%s", GST_DEBUG_PAD_NAME (pad));
2717 /* value to hold the return, by default it holds TRUE */
2718 /* FIXME: TRUE is wrong when there are no pads */
2721 gst_pad_forward (pad, (GstPadForwardFunction) query_accept_caps_func, &data);
2722 gst_query_set_accept_caps_result (query, data.ret);
2724 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying accept caps query: %d",
2737 query_caps_func (GstPad * pad, QueryCapsData * data)
2739 gboolean empty = FALSE;
2741 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2742 GstCaps *peercaps, *intersection;
2744 gst_query_parse_caps_result (data->query, &peercaps);
2745 GST_DEBUG_OBJECT (pad, "intersect with result %" GST_PTR_FORMAT, peercaps);
2746 intersection = gst_caps_intersect (data->ret, peercaps);
2747 GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, intersection);
2749 gst_caps_unref (data->ret);
2750 data->ret = intersection;
2752 /* stop when empty */
2753 empty = gst_caps_is_empty (intersection);
2759 * gst_pad_proxy_query_caps:
2760 * @pad: a #GstPad to proxy.
2761 * @query: a CAPS #GstQuery.
2763 * Calls gst_pad_query_caps() for all internally linked pads of @pad and returns
2764 * the intersection of the results.
2766 * This function is useful as a default caps query function for an element
2767 * that can handle any stream format, but requires all its pads to have
2768 * the same caps. Two such elements are tee and adder.
2770 * Returns: %TRUE if @query could be executed
2773 gst_pad_proxy_query_caps (GstPad * pad, GstQuery * query)
2775 GstCaps *filter, *templ, *result;
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_CAPS, FALSE);
2782 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying caps query for %s:%s",
2783 GST_DEBUG_PAD_NAME (pad));
2787 /* value to hold the return, by default it holds the filter or ANY */
2788 gst_query_parse_caps (query, &filter);
2789 data.ret = filter ? gst_caps_ref (filter) : gst_caps_new_any ();
2791 gst_pad_forward (pad, (GstPadForwardFunction) query_caps_func, &data);
2793 templ = gst_pad_get_pad_template_caps (pad);
2794 result = gst_caps_intersect (data.ret, templ);
2795 gst_caps_unref (data.ret);
2796 gst_caps_unref (templ);
2798 gst_query_set_caps_result (query, result);
2799 gst_caps_unref (result);
2801 /* FIXME: return something depending on the processing */
2806 * gst_pad_query_position:
2807 * @pad: a #GstPad to invoke the position query on.
2808 * @format: the #GstFormat requested
2809 * @cur: (out) (allow-none): A location in which to store the current position, or %NULL.
2811 * Queries a pad for the stream position.
2813 * Returns: %TRUE if the query could be performed.
2816 gst_pad_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2821 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2822 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2824 query = gst_query_new_position (format);
2825 if ((ret = gst_pad_query (pad, query)))
2826 gst_query_parse_position (query, NULL, cur);
2827 gst_query_unref (query);
2833 * gst_pad_peer_query_position:
2834 * @pad: a #GstPad on whose peer to invoke the position query on.
2835 * Must be a sink pad.
2836 * @format: the #GstFormat requested
2837 * @cur: (out) (allow-none): a location in which to store the current
2838 * position, or %NULL.
2840 * Queries the peer of a given sink pad for the stream position.
2842 * Returns: %TRUE if the query could be performed.
2845 gst_pad_peer_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2848 gboolean ret = FALSE;
2850 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2851 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2853 query = gst_query_new_position (format);
2854 if ((ret = gst_pad_peer_query (pad, query)))
2855 gst_query_parse_position (query, NULL, cur);
2856 gst_query_unref (query);
2862 * gst_pad_query_duration:
2863 * @pad: a #GstPad to invoke the duration query on.
2864 * @format: the #GstFormat requested
2865 * @duration: (out) (allow-none): a location in which to store the total
2866 * duration, or %NULL.
2868 * Queries a pad for the total stream duration.
2870 * Returns: %TRUE if the query could be performed.
2873 gst_pad_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2878 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2879 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2881 query = gst_query_new_duration (format);
2882 if ((ret = gst_pad_query (pad, query)))
2883 gst_query_parse_duration (query, NULL, duration);
2884 gst_query_unref (query);
2890 * gst_pad_peer_query_duration:
2891 * @pad: a #GstPad on whose peer pad to invoke the duration query on.
2892 * Must be a sink pad.
2893 * @format: the #GstFormat requested
2894 * @duration: (out) (allow-none): a location in which to store the total
2895 * duration, or %NULL.
2897 * Queries the peer pad of a given sink pad for the total stream duration.
2899 * Returns: %TRUE if the query could be performed.
2902 gst_pad_peer_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2905 gboolean ret = FALSE;
2907 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2908 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2909 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2911 query = gst_query_new_duration (format);
2912 if ((ret = gst_pad_peer_query (pad, query)))
2913 gst_query_parse_duration (query, NULL, duration);
2914 gst_query_unref (query);
2920 * gst_pad_query_convert:
2921 * @pad: a #GstPad to invoke the convert query on.
2922 * @src_format: a #GstFormat to convert from.
2923 * @src_val: a value to convert.
2924 * @dest_format: the #GstFormat to convert to.
2925 * @dest_val: (out): a pointer to the result.
2927 * Queries a pad to convert @src_val in @src_format to @dest_format.
2929 * Returns: %TRUE if the query could be performed.
2932 gst_pad_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2933 GstFormat dest_format, gint64 * dest_val)
2938 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2939 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2940 g_return_val_if_fail (dest_val != NULL, FALSE);
2942 if (dest_format == src_format || src_val == -1) {
2943 *dest_val = src_val;
2947 query = gst_query_new_convert (src_format, src_val, dest_format);
2948 if ((ret = gst_pad_query (pad, query)))
2949 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2950 gst_query_unref (query);
2956 * gst_pad_peer_query_convert:
2957 * @pad: a #GstPad, on whose peer pad to invoke the convert query on.
2958 * Must be a sink pad.
2959 * @src_format: a #GstFormat to convert from.
2960 * @src_val: a value to convert.
2961 * @dest_format: the #GstFormat to convert to.
2962 * @dest_val: (out): a pointer to the result.
2964 * Queries the peer pad of a given sink pad to convert @src_val in @src_format
2967 * Returns: %TRUE if the query could be performed.
2970 gst_pad_peer_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2971 GstFormat dest_format, gint64 * dest_val)
2974 gboolean ret = FALSE;
2976 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2977 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2978 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2979 g_return_val_if_fail (dest_val != NULL, FALSE);
2981 query = gst_query_new_convert (src_format, src_val, dest_format);
2982 if ((ret = gst_pad_peer_query (pad, query)))
2983 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2984 gst_query_unref (query);
2990 * gst_pad_query_caps:
2991 * @pad: a #GstPad to get the capabilities of.
2992 * @filter: (allow-none): suggested #GstCaps, or %NULL
2994 * Gets the capabilities this pad can produce or consume.
2995 * Note that this method doesn't necessarily return the caps set by sending a
2996 * gst_event_new_caps() - use gst_pad_get_current_caps() for that instead.
2997 * gst_pad_query_caps returns all possible caps a pad can operate with, using
2998 * the pad's CAPS query function, If the query fails, this function will return
2999 * @filter, if not %NULL, otherwise ANY.
3001 * When called on sinkpads @filter contains the caps that
3002 * upstream could produce in the order preferred by upstream. When
3003 * called on srcpads @filter contains the caps accepted by
3004 * downstream in the preferred order. @filter might be %NULL but
3005 * if it is not %NULL the returned caps will be a subset of @filter.
3007 * Note that this function does not return writable #GstCaps, use
3008 * gst_caps_make_writable() before modifying the caps.
3010 * Returns: (transfer full): the caps of the pad with incremented ref-count.
3013 gst_pad_query_caps (GstPad * pad, GstCaps * filter)
3015 GstCaps *result = NULL;
3018 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3019 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
3021 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3022 "get pad caps with filter %" GST_PTR_FORMAT, filter);
3024 query = gst_query_new_caps (filter);
3025 if (gst_pad_query (pad, query)) {
3026 gst_query_parse_caps_result (query, &result);
3027 gst_caps_ref (result);
3028 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3029 "query returned %" GST_PTR_FORMAT, result);
3030 } else if (filter) {
3031 result = gst_caps_ref (filter);
3033 result = gst_caps_new_any ();
3035 gst_query_unref (query);
3041 * gst_pad_peer_query_caps:
3042 * @pad: a #GstPad to get the capabilities of.
3043 * @filter: (allow-none): a #GstCaps filter, or %NULL.
3045 * Gets the capabilities of the peer connected to this pad. Similar to
3046 * gst_pad_query_caps().
3048 * When called on srcpads @filter contains the caps that
3049 * upstream could produce in the order preferred by upstream. When
3050 * called on sinkpads @filter contains the caps accepted by
3051 * downstream in the preferred order. @filter might be %NULL but
3052 * if it is not %NULL the returned caps will be a subset of @filter.
3054 * Returns: (transfer full): the caps of the peer pad with incremented
3055 * ref-count. When there is no peer pad, this function returns @filter or,
3056 * when @filter is %NULL, ANY caps.
3059 gst_pad_peer_query_caps (GstPad * pad, GstCaps * filter)
3061 GstCaps *result = NULL;
3064 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3065 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
3067 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3068 "get pad peer caps with filter %" GST_PTR_FORMAT, filter);
3070 query = gst_query_new_caps (filter);
3071 if (gst_pad_peer_query (pad, query)) {
3072 gst_query_parse_caps_result (query, &result);
3073 gst_caps_ref (result);
3074 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
3075 "peer query returned %" GST_PTR_FORMAT, result);
3076 } else if (filter) {
3077 result = gst_caps_ref (filter);
3079 result = gst_caps_new_any ();
3081 gst_query_unref (query);
3087 * gst_pad_query_accept_caps:
3088 * @pad: a #GstPad to check
3089 * @caps: a #GstCaps to check on the pad
3091 * Check if the given pad accepts the caps.
3093 * Returns: %TRUE if the pad can accept the caps.
3096 gst_pad_query_accept_caps (GstPad * pad, GstCaps * caps)
3098 gboolean res = TRUE;
3101 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3102 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
3104 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %"
3105 GST_PTR_FORMAT, caps);
3107 query = gst_query_new_accept_caps (caps);
3108 if (gst_pad_query (pad, query)) {
3109 gst_query_parse_accept_caps_result (query, &res);
3110 GST_DEBUG_OBJECT (pad, "query returned %d", res);
3112 gst_query_unref (query);
3118 * gst_pad_peer_query_accept_caps:
3119 * @pad: a #GstPad to check the peer of
3120 * @caps: a #GstCaps to check on the pad
3122 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
3125 * Returns: %TRUE if the peer of @pad can accept the caps or @pad has no peer.
3128 gst_pad_peer_query_accept_caps (GstPad * pad, GstCaps * caps)
3130 gboolean res = TRUE;
3133 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3134 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
3136 query = gst_query_new_accept_caps (caps);
3137 if (gst_pad_peer_query (pad, query)) {
3138 gst_query_parse_accept_caps_result (query, &res);
3139 GST_DEBUG_OBJECT (pad, "query returned %d", res);
3141 gst_query_unref (query);
3147 element_find_unlinked_pad (GstElement * element, GstPadDirection direction)
3150 GstPad *unlinked_pad = NULL;
3152 GValue data = { 0, };
3154 switch (direction) {
3156 iter = gst_element_iterate_src_pads (element);
3159 iter = gst_element_iterate_sink_pads (element);
3162 g_return_val_if_reached (NULL);
3167 switch (gst_iterator_next (iter, &data)) {
3168 case GST_ITERATOR_OK:{
3170 GstPad *pad = g_value_get_object (&data);
3172 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
3173 GST_DEBUG_PAD_NAME (pad));
3175 peer = gst_pad_get_peer (pad);
3177 unlinked_pad = gst_object_ref (pad);
3179 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
3180 "found existing unlinked pad %s:%s",
3181 GST_DEBUG_PAD_NAME (unlinked_pad));
3183 gst_object_unref (peer);
3185 g_value_reset (&data);
3188 case GST_ITERATOR_DONE:
3191 case GST_ITERATOR_RESYNC:
3192 gst_iterator_resync (iter);
3194 case GST_ITERATOR_ERROR:
3195 g_return_val_if_reached (NULL);
3199 g_value_unset (&data);
3200 gst_iterator_free (iter);
3202 return unlinked_pad;
3206 * gst_bin_find_unlinked_pad:
3207 * @bin: bin in which to look for elements with unlinked pads
3208 * @direction: whether to look for an unlinked source or sink pad
3210 * Recursively looks for elements with an unlinked pad of the given
3211 * direction within the specified bin and returns an unlinked pad
3212 * if one is found, or %NULL otherwise. If a pad is found, the caller
3213 * owns a reference to it and should use gst_object_unref() on the
3214 * pad when it is not needed any longer.
3216 * Returns: (transfer full) (nullable): unlinked pad of the given
3220 gst_bin_find_unlinked_pad (GstBin * bin, GstPadDirection direction)
3225 GValue data = { 0, };
3227 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3228 g_return_val_if_fail (direction != GST_PAD_UNKNOWN, NULL);
3231 iter = gst_bin_iterate_recurse (bin);
3233 switch (gst_iterator_next (iter, &data)) {
3234 case GST_ITERATOR_OK:{
3235 GstElement *element = g_value_get_object (&data);
3237 pad = element_find_unlinked_pad (element, direction);
3240 g_value_reset (&data);
3243 case GST_ITERATOR_DONE:
3246 case GST_ITERATOR_RESYNC:
3247 gst_iterator_resync (iter);
3249 case GST_ITERATOR_ERROR:
3250 g_return_val_if_reached (NULL);
3254 g_value_unset (&data);
3255 gst_iterator_free (iter);
3261 gst_bin_sync_children_states_foreach (const GValue * value, gpointer user_data)
3263 gboolean *success = user_data;
3264 GstElement *element = g_value_get_object (value);
3266 if (gst_element_is_locked_state (element)) {
3269 *success = *success && gst_element_sync_state_with_parent (element);
3271 if (GST_IS_BIN (element))
3273 && gst_bin_sync_children_states (GST_BIN_CAST (element));
3278 * gst_bin_sync_children_states:
3281 * Synchronizes the state of every child of @bin with the state
3282 * of @bin. See also gst_element_sync_state_with_parent().
3284 * Returns: %TRUE if syncing the state was successful for all children,
3290 gst_bin_sync_children_states (GstBin * bin)
3293 GstIteratorResult res = GST_ITERATOR_OK;
3294 gboolean success = TRUE;
3296 it = gst_bin_iterate_sorted (bin);
3299 if (res == GST_ITERATOR_RESYNC) {
3301 gst_iterator_resync (it);
3304 gst_iterator_foreach (it, gst_bin_sync_children_states_foreach,
3306 } while (res == GST_ITERATOR_RESYNC);
3307 gst_iterator_free (it);
3313 * gst_parse_bin_from_description:
3314 * @bin_description: command line describing the bin
3315 * @ghost_unlinked_pads: whether to automatically create ghost pads
3316 * for unlinked source or sink pads within the bin
3317 * @err: where to store the error message in case of an error, or %NULL
3319 * This is a convenience wrapper around gst_parse_launch() to create a
3320 * #GstBin from a gst-launch-style pipeline description. See
3321 * gst_parse_launch() and the gst-launch man page for details about the
3322 * syntax. Ghost pads on the bin for unlinked source or sink pads
3323 * within the bin can automatically be created (but only a maximum of
3324 * one ghost pad for each direction will be created; if you expect
3325 * multiple unlinked source pads or multiple unlinked sink pads
3326 * and want them all ghosted, you will have to create the ghost pads
3329 * Returns: (transfer floating) (type Gst.Bin) (nullable): a
3330 * newly-created bin, or %NULL if an error occurred.
3333 gst_parse_bin_from_description (const gchar * bin_description,
3334 gboolean ghost_unlinked_pads, GError ** err)
3336 return gst_parse_bin_from_description_full (bin_description,
3337 ghost_unlinked_pads, NULL, GST_PARSE_FLAG_NONE, err);
3341 * gst_parse_bin_from_description_full:
3342 * @bin_description: command line describing the bin
3343 * @ghost_unlinked_pads: whether to automatically create ghost pads
3344 * for unlinked source or sink pads within the bin
3345 * @context: (transfer none) (allow-none): a parse context allocated with
3346 * gst_parse_context_new(), or %NULL
3347 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
3348 * @err: where to store the error message in case of an error, or %NULL
3350 * This is a convenience wrapper around gst_parse_launch() to create a
3351 * #GstBin from a gst-launch-style pipeline description. See
3352 * gst_parse_launch() and the gst-launch man page for details about the
3353 * syntax. Ghost pads on the bin for unlinked source or sink pads
3354 * within the bin can automatically be created (but only a maximum of
3355 * one ghost pad for each direction will be created; if you expect
3356 * multiple unlinked source pads or multiple unlinked sink pads
3357 * and want them all ghosted, you will have to create the ghost pads
3360 * Returns: (transfer floating) (type Gst.Element): a newly-created
3361 * element, which is guaranteed to be a bin unless
3362 * GST_FLAG_NO_SINGLE_ELEMENT_BINS was passed, or %NULL if an error
3366 gst_parse_bin_from_description_full (const gchar * bin_description,
3367 gboolean ghost_unlinked_pads, GstParseContext * context,
3368 GstParseFlags flags, GError ** err)
3370 #ifndef GST_DISABLE_PARSE
3372 GstElement *element;
3376 g_return_val_if_fail (bin_description != NULL, NULL);
3377 g_return_val_if_fail (err == NULL || *err == NULL, NULL);
3379 GST_DEBUG ("Making bin from description '%s'", bin_description);
3381 /* parse the pipeline to a bin */
3382 if (flags & GST_PARSE_FLAG_NO_SINGLE_ELEMENT_BINS) {
3383 element = gst_parse_launch_full (bin_description, context, flags, err);
3385 desc = g_strdup_printf ("bin.( %s )", bin_description);
3386 element = gst_parse_launch_full (desc, context, flags, err);
3390 if (element == NULL || (err && *err != NULL)) {
3392 gst_object_unref (element);
3396 if (GST_IS_BIN (element)) {
3397 bin = GST_BIN (element);
3402 /* find pads and ghost them if necessary */
3403 if (ghost_unlinked_pads) {
3404 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SRC))) {
3405 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("src", pad));
3406 gst_object_unref (pad);
3408 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SINK))) {
3409 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("sink", pad));
3410 gst_object_unref (pad);
3414 return GST_ELEMENT (bin);
3418 GST_WARNING ("Disabled API called");
3420 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
3421 g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);
3429 * gst_util_get_timestamp:
3431 * Get a timestamp as GstClockTime to be used for interval measurements.
3432 * The timestamp should not be interpreted in any other way.
3434 * Returns: the timestamp
3437 gst_util_get_timestamp (void)
3439 #if defined (HAVE_POSIX_TIMERS) && defined(HAVE_MONOTONIC_CLOCK) &&\
3440 defined (HAVE_CLOCK_GETTIME)
3441 struct timespec now;
3443 clock_gettime (CLOCK_MONOTONIC, &now);
3444 return GST_TIMESPEC_TO_TIME (now);
3448 g_get_current_time (&now);
3449 return GST_TIMEVAL_TO_TIME (now);
3454 * gst_util_array_binary_search:
3455 * @array: the sorted input array
3456 * @num_elements: number of elements in the array
3457 * @element_size: size of every element in bytes
3458 * @search_func: (scope call): function to compare two elements, @search_data will always be passed as second argument
3459 * @mode: search mode that should be used
3460 * @search_data: element that should be found
3461 * @user_data: (closure): data to pass to @search_func
3463 * Searches inside @array for @search_data by using the comparison function
3464 * @search_func. @array must be sorted ascending.
3466 * As @search_data is always passed as second argument to @search_func it's
3467 * not required that @search_data has the same type as the array elements.
3469 * The complexity of this search function is O(log (num_elements)).
3471 * Returns: (transfer none) (nullable): The address of the found
3472 * element or %NULL if nothing was found
3475 gst_util_array_binary_search (gpointer array, guint num_elements,
3476 gsize element_size, GCompareDataFunc search_func, GstSearchMode mode,
3477 gconstpointer search_data, gpointer user_data)
3479 glong left = 0, right = num_elements - 1, m;
3481 guint8 *data = (guint8 *) array;
3483 g_return_val_if_fail (array != NULL, NULL);
3484 g_return_val_if_fail (element_size > 0, NULL);
3485 g_return_val_if_fail (search_func != NULL, NULL);
3487 /* 0. No elements => return NULL */
3488 if (num_elements == 0)
3491 /* 1. If search_data is before the 0th element return the 0th element */
3492 ret = search_func (data, search_data, user_data);
3493 if ((ret >= 0 && mode == GST_SEARCH_MODE_AFTER) || ret == 0)
3498 /* 2. If search_data is after the last element return the last element */
3500 search_func (data + (num_elements - 1) * element_size, search_data,
3502 if ((ret <= 0 && mode == GST_SEARCH_MODE_BEFORE) || ret == 0)
3503 return data + (num_elements - 1) * element_size;
3507 /* 3. else binary search */
3509 m = left + (right - left) / 2;
3511 ret = search_func (data + m * element_size, search_data, user_data);
3514 return data + m * element_size;
3515 } else if (ret < 0) {
3521 /* No exact match found */
3523 if (mode == GST_SEARCH_MODE_EXACT) {
3525 } else if (mode == GST_SEARCH_MODE_AFTER) {
3527 return (m < num_elements) ? data + (m + 1) * element_size : NULL;
3529 return data + m * element_size;
3532 return data + m * element_size;
3534 return (m > 0) ? data + (m - 1) * element_size : NULL;
3540 /* Finds the greatest common divisor.
3541 * Returns 1 if none other found.
3542 * This is Euclid's algorithm. */
3545 * gst_util_greatest_common_divisor:
3546 * @a: First value as #gint
3547 * @b: Second value as #gint
3549 * Calculates the greatest common divisor of @a
3552 * Returns: Greatest common divisor of @a and @b
3555 gst_util_greatest_common_divisor (gint a, gint b)
3568 * gst_util_greatest_common_divisor_int64:
3569 * @a: First value as #gint64
3570 * @b: Second value as #gint64
3572 * Calculates the greatest common divisor of @a
3575 * Returns: Greatest common divisor of @a and @b
3578 gst_util_greatest_common_divisor_int64 (gint64 a, gint64 b)
3592 * gst_util_fraction_to_double:
3593 * @src_n: Fraction numerator as #gint
3594 * @src_d: Fraction denominator #gint
3595 * @dest: (out): pointer to a #gdouble for the result
3597 * Transforms a fraction to a #gdouble.
3600 gst_util_fraction_to_double (gint src_n, gint src_d, gdouble * dest)
3602 g_return_if_fail (dest != NULL);
3603 g_return_if_fail (src_d != 0);
3605 *dest = ((gdouble) src_n) / ((gdouble) src_d);
3608 #define MAX_TERMS 30
3609 #define MIN_DIVISOR 1.0e-10
3610 #define MAX_ERROR 1.0e-20
3612 /* use continued fractions to transform a double into a fraction,
3613 * see http://mathforum.org/dr.math/faq/faq.fractions.html#decfrac.
3614 * This algorithm takes care of overflows.
3618 * gst_util_double_to_fraction:
3619 * @src: #gdouble to transform
3620 * @dest_n: (out): pointer to a #gint to hold the result numerator
3621 * @dest_d: (out): pointer to a #gint to hold the result denominator
3623 * Transforms a #gdouble to a fraction and simplifies
3627 gst_util_double_to_fraction (gdouble src, gint * dest_n, gint * dest_d)
3630 gdouble V, F; /* double being converted */
3631 gint N, D; /* will contain the result */
3632 gint A; /* current term in continued fraction */
3633 gint64 N1, D1; /* numerator, denominator of last approx */
3634 gint64 N2, D2; /* numerator, denominator of previous approx */
3637 gboolean negative = FALSE;
3639 g_return_if_fail (dest_n != NULL);
3640 g_return_if_fail (dest_d != NULL);
3642 /* initialize fraction being converted */
3650 /* initialize fractions with 1/0, 0/1 */
3658 for (i = 0; i < MAX_TERMS; i++) {
3660 A = (gint) F; /* no floor() needed, F is always >= 0 */
3661 /* get new divisor */
3664 /* calculate new fraction in temp */
3668 /* guard against overflow */
3669 if (N2 > G_MAXINT || D2 > G_MAXINT) {
3676 /* save last two fractions */
3682 /* quit if dividing by zero or close enough to target */
3683 if (F < MIN_DIVISOR || fabs (V - ((gdouble) N) / D) < MAX_ERROR) {
3687 /* Take reciprocal */
3690 /* fix for overflow */
3695 /* fix for negative */
3700 gcd = gst_util_greatest_common_divisor (N, D);
3712 * gst_util_fraction_multiply:
3713 * @a_n: Numerator of first value
3714 * @a_d: Denominator of first value
3715 * @b_n: Numerator of second value
3716 * @b_d: Denominator of second value
3717 * @res_n: (out): Pointer to #gint to hold the result numerator
3718 * @res_d: (out): Pointer to #gint to hold the result denominator
3720 * Multiplies the fractions @a_n/@a_d and @b_n/@b_d and stores
3721 * the result in @res_n and @res_d.
3723 * Returns: %FALSE on overflow, %TRUE otherwise.
3726 gst_util_fraction_multiply (gint a_n, gint a_d, gint b_n, gint b_d,
3727 gint * res_n, gint * res_d)
3731 g_return_val_if_fail (res_n != NULL, FALSE);
3732 g_return_val_if_fail (res_d != NULL, FALSE);
3733 g_return_val_if_fail (a_d != 0, FALSE);
3734 g_return_val_if_fail (b_d != 0, FALSE);
3736 /* early out if either is 0, as its gcd would be 0 */
3737 if (a_n == 0 || b_n == 0) {
3743 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3747 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3751 gcd = gst_util_greatest_common_divisor (a_n, b_d);
3755 gcd = gst_util_greatest_common_divisor (a_d, b_n);
3759 /* This would result in overflow */
3760 if (a_n != 0 && G_MAXINT / ABS (a_n) < ABS (b_n))
3762 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3768 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3776 * gst_util_fraction_add:
3777 * @a_n: Numerator of first value
3778 * @a_d: Denominator of first value
3779 * @b_n: Numerator of second value
3780 * @b_d: Denominator of second value
3781 * @res_n: (out): Pointer to #gint to hold the result numerator
3782 * @res_d: (out): Pointer to #gint to hold the result denominator
3784 * Adds the fractions @a_n/@a_d and @b_n/@b_d and stores
3785 * the result in @res_n and @res_d.
3787 * Returns: %FALSE on overflow, %TRUE otherwise.
3790 gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint * res_n,
3795 g_return_val_if_fail (res_n != NULL, FALSE);
3796 g_return_val_if_fail (res_d != NULL, FALSE);
3797 g_return_val_if_fail (a_d != 0, FALSE);
3798 g_return_val_if_fail (b_d != 0, FALSE);
3800 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3804 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3819 /* This would result in overflow */
3820 if (G_MAXINT / ABS (a_n) < ABS (b_n))
3822 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3825 *res_n = (a_n * b_d) + (a_d * b_n);
3828 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3841 * gst_util_fraction_compare:
3842 * @a_n: Numerator of first value
3843 * @a_d: Denominator of first value
3844 * @b_n: Numerator of second value
3845 * @b_d: Denominator of second value
3847 * Compares the fractions @a_n/@a_d and @b_n/@b_d and returns
3848 * -1 if a < b, 0 if a = b and 1 if a > b.
3850 * Returns: -1 if a < b; 0 if a = b; 1 if a > b.
3853 gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d)
3859 g_return_val_if_fail (a_d != 0 && b_d != 0, 0);
3862 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3866 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3870 /* fractions are reduced when set, so we can quickly see if they're equal */
3871 if (a_n == b_n && a_d == b_d)
3874 /* extend to 64 bits */
3875 new_num_1 = ((gint64) a_n) * b_d;
3876 new_num_2 = ((gint64) b_n) * a_d;
3877 if (new_num_1 < new_num_2)
3879 if (new_num_1 > new_num_2)
3882 /* Should not happen because a_d and b_d are not 0 */
3883 g_return_val_if_reached (0);
3887 gst_pad_create_stream_id_internal (GstPad * pad, GstElement * parent,
3888 const gchar * stream_id)
3890 GstEvent *upstream_event;
3891 gchar *upstream_stream_id = NULL, *new_stream_id;
3894 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3895 g_return_val_if_fail (GST_PAD_IS_SRC (pad), NULL);
3896 g_return_val_if_fail (GST_IS_ELEMENT (parent), NULL);
3898 g_return_val_if_fail (parent->numsinkpads <= 1, NULL);
3900 /* If the element has multiple source pads it must
3901 * provide a stream-id for every source pad, otherwise
3902 * all source pads will have the same and are not
3903 * distinguishable */
3904 g_return_val_if_fail (parent->numsrcpads <= 1 || stream_id, NULL);
3906 /* First try to get the upstream stream-start stream-id from the sinkpad.
3907 * This will only work for non-source elements */
3908 sinkpad = gst_element_get_static_pad (parent, "sink");
3911 gst_pad_get_sticky_event (sinkpad, GST_EVENT_STREAM_START, 0);
3912 if (upstream_event) {
3915 gst_event_parse_stream_start (upstream_event, &tmp);
3917 upstream_stream_id = g_strdup (tmp);
3918 gst_event_unref (upstream_event);
3920 gst_object_unref (sinkpad);
3923 /* The only case where we don't have an upstream start-start event
3924 * here is for source elements */
3925 if (!upstream_stream_id) {
3929 /* Try to generate one from the URI query and
3930 * if it fails take a random number instead */
3931 query = gst_query_new_uri ();
3932 if (gst_element_query (parent, query)) {
3933 gst_query_parse_uri (query, &uri);
3939 /* And then generate an SHA256 sum of the URI */
3940 cs = g_checksum_new (G_CHECKSUM_SHA256);
3941 g_checksum_update (cs, (const guchar *) uri, strlen (uri));
3943 upstream_stream_id = g_strdup (g_checksum_get_string (cs));
3944 g_checksum_free (cs);
3946 /* Just get some random number if the URI query fails */
3947 GST_FIXME_OBJECT (pad, "Creating random stream-id, consider "
3948 "implementing a deterministic way of creating a stream-id");
3949 upstream_stream_id =
3950 g_strdup_printf ("%08x%08x%08x%08x", g_random_int (), g_random_int (),
3951 g_random_int (), g_random_int ());
3954 gst_query_unref (query);
3958 new_stream_id = g_strconcat (upstream_stream_id, "/", stream_id, NULL);
3960 new_stream_id = g_strdup (upstream_stream_id);
3963 g_free (upstream_stream_id);
3965 return new_stream_id;
3969 * gst_pad_create_stream_id_printf_valist:
3970 * @pad: A source #GstPad
3971 * @parent: Parent #GstElement of @pad
3972 * @stream_id: (allow-none): The stream-id
3973 * @var_args: parameters for the @stream_id format string
3975 * Creates a stream-id for the source #GstPad @pad by combining the
3976 * upstream information with the optional @stream_id of the stream
3977 * of @pad. @pad must have a parent #GstElement and which must have zero
3978 * or one sinkpad. @stream_id can only be %NULL if the parent element
3979 * of @pad has only a single source pad.
3981 * This function generates an unique stream-id by getting the upstream
3982 * stream-start event stream ID and appending @stream_id to it. If the
3983 * element has no sinkpad it will generate an upstream stream-id by
3984 * doing an URI query on the element and in the worst case just uses
3985 * a random number. Source elements that don't implement the URI
3986 * handler interface should ideally generate a unique, deterministic
3987 * stream-id manually instead.
3989 * Returns: A stream-id for @pad. g_free() after usage.
3992 gst_pad_create_stream_id_printf_valist (GstPad * pad, GstElement * parent,
3993 const gchar * stream_id, va_list var_args)
3995 gchar *expanded = NULL, *new_stream_id;
3998 expanded = g_strdup_vprintf (stream_id, var_args);
4000 new_stream_id = gst_pad_create_stream_id_internal (pad, parent, expanded);
4004 return new_stream_id;
4008 * gst_pad_create_stream_id_printf:
4009 * @pad: A source #GstPad
4010 * @parent: Parent #GstElement of @pad
4011 * @stream_id: (allow-none): The stream-id
4012 * @...: parameters for the @stream_id format string
4014 * Creates a stream-id for the source #GstPad @pad by combining the
4015 * upstream information with the optional @stream_id of the stream
4016 * of @pad. @pad must have a parent #GstElement and which must have zero
4017 * or one sinkpad. @stream_id can only be %NULL if the parent element
4018 * of @pad has only a single source pad.
4020 * This function generates an unique stream-id by getting the upstream
4021 * stream-start event stream ID and appending @stream_id to it. If the
4022 * element has no sinkpad it will generate an upstream stream-id by
4023 * doing an URI query on the element and in the worst case just uses
4024 * a random number. Source elements that don't implement the URI
4025 * handler interface should ideally generate a unique, deterministic
4026 * stream-id manually instead.
4028 * Returns: A stream-id for @pad. g_free() after usage.
4031 gst_pad_create_stream_id_printf (GstPad * pad, GstElement * parent,
4032 const gchar * stream_id, ...)
4035 gchar *new_stream_id;
4037 va_start (var_args, stream_id);
4039 gst_pad_create_stream_id_printf_valist (pad, parent, stream_id, var_args);
4042 return new_stream_id;
4046 * gst_pad_create_stream_id:
4047 * @pad: A source #GstPad
4048 * @parent: Parent #GstElement of @pad
4049 * @stream_id: (allow-none): The stream-id
4051 * Creates a stream-id for the source #GstPad @pad by combining the
4052 * upstream information with the optional @stream_id of the stream
4053 * of @pad. @pad must have a parent #GstElement and which must have zero
4054 * or one sinkpad. @stream_id can only be %NULL if the parent element
4055 * of @pad has only a single source pad.
4057 * This function generates an unique stream-id by getting the upstream
4058 * stream-start event stream ID and appending @stream_id to it. If the
4059 * element has no sinkpad it will generate an upstream stream-id by
4060 * doing an URI query on the element and in the worst case just uses
4061 * a random number. Source elements that don't implement the URI
4062 * handler interface should ideally generate a unique, deterministic
4063 * stream-id manually instead.
4065 * Since stream IDs are sorted alphabetically, any numbers in the
4066 * stream ID should be printed with a fixed number of characters,
4067 * preceded by 0's, such as by using the format \%03u instead of \%u.
4069 * Returns: A stream-id for @pad. g_free() after usage.
4072 gst_pad_create_stream_id (GstPad * pad, GstElement * parent,
4073 const gchar * stream_id)
4075 return gst_pad_create_stream_id_internal (pad, parent, stream_id);
4079 * gst_pad_get_stream_id:
4080 * @pad: A source #GstPad
4082 * Returns the current stream-id for the @pad, or %NULL if none has been
4083 * set yet, i.e. the pad has not received a stream-start event yet.
4085 * This is a convenience wrapper around gst_pad_get_sticky_event() and
4086 * gst_event_parse_stream_start().
4088 * The returned stream-id string should be treated as an opaque string, its
4089 * contents should not be interpreted.
4091 * Returns: (nullable): a newly-allocated copy of the stream-id for
4092 * @pad, or %NULL. g_free() the returned string when no longer
4098 gst_pad_get_stream_id (GstPad * pad)
4100 const gchar *stream_id = NULL;
4104 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
4106 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
4107 if (event != NULL) {
4108 gst_event_parse_stream_start (event, &stream_id);
4109 ret = g_strdup (stream_id);
4110 gst_event_unref (event);
4111 GST_LOG_OBJECT (pad, "pad has stream-id '%s'", ret);
4113 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");
4120 * gst_pad_get_stream:
4121 * @pad: A source #GstPad
4123 * Returns the current #GstStream for the @pad, or %NULL if none has been
4124 * set yet, i.e. the pad has not received a stream-start event yet.
4126 * This is a convenience wrapper around gst_pad_get_sticky_event() and
4127 * gst_event_parse_stream().
4129 * Returns: (nullable) (transfer full): the current #GstStream for @pad, or %NULL.
4130 * unref the returned stream when no longer needed.
4135 gst_pad_get_stream (GstPad * pad)
4137 GstStream *stream = NULL;
4140 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
4142 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
4143 if (event != NULL) {
4144 gst_event_parse_stream (event, &stream);
4145 gst_event_unref (event);
4146 GST_LOG_OBJECT (pad, "pad has stream object %p", stream);
4148 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");
4155 * gst_util_group_id_next:
4157 * Return a constantly incrementing group id.
4159 * This function is used to generate a new group-id for the
4160 * stream-start event.
4162 * Returns: A constantly incrementing unsigned integer, which might
4163 * overflow back to 0 at some point.
4166 gst_util_group_id_next (void)
4168 static gint counter = 0;
4169 return g_atomic_int_add (&counter, 1);
4172 /* Compute log2 of the passed 64-bit number by finding the highest set bit */
4174 gst_log2 (GstClockTime in)
4177 { 0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000, 0xFFFFFFFF00000000LL };
4178 const guint64 S[] = { 1, 2, 4, 8, 16, 32 };
4182 for (i = 5; i >= 0; i--) {
4193 * gst_calculate_linear_regression: (skip)
4194 * @xy: Pairs of (x,y) values
4195 * @temp: Temporary scratch space used by the function
4196 * @n: number of (x,y) pairs
4197 * @m_num: (out): numerator of calculated slope
4198 * @m_denom: (out): denominator of calculated slope
4199 * @b: (out): Offset at Y-axis
4200 * @xbase: (out): Offset at X-axis
4201 * @r_squared: (out): R-squared
4203 * Calculates the linear regression of the values @xy and places the
4204 * result in @m_num, @m_denom, @b and @xbase, representing the function
4205 * y(x) = m_num/m_denom * (x - xbase) + b
4206 * that has the least-square distance from all points @x and @y.
4208 * @r_squared will contain the remaining error.
4210 * If @temp is not %NULL, it will be used as temporary space for the function,
4211 * in which case the function works without any allocation at all. If @temp is
4212 * %NULL, an allocation will take place. @temp should have at least the same
4213 * amount of memory allocated as @xy, i.e. 2*n*sizeof(GstClockTime).
4215 * > This function assumes (x,y) values with reasonable large differences
4216 * > between them. It will not calculate the exact results if the differences
4217 * > between neighbouring values are too small due to not being able to
4218 * > represent sub-integer values during the calculations.
4220 * Returns: %TRUE if the linear regression was successfully calculated
4224 /* http://mathworld.wolfram.com/LeastSquaresFitting.html
4228 gst_calculate_linear_regression (const GstClockTime * xy,
4229 GstClockTime * temp, guint n,
4230 GstClockTime * m_num, GstClockTime * m_denom,
4231 GstClockTime * b, GstClockTime * xbase, gdouble * r_squared)
4233 const GstClockTime *x, *y;
4234 GstClockTime *newx, *newy;
4235 GstClockTime xmin, ymin, xbar, ybar, xbar4, ybar4;
4236 GstClockTime xmax, ymax;
4237 GstClockTimeDiff sxx, sxy, syy;
4242 g_return_val_if_fail (xy != NULL, FALSE);
4243 g_return_val_if_fail (m_num != NULL, FALSE);
4244 g_return_val_if_fail (m_denom != NULL, FALSE);
4245 g_return_val_if_fail (b != NULL, FALSE);
4246 g_return_val_if_fail (xbase != NULL, FALSE);
4247 g_return_val_if_fail (r_squared != NULL, FALSE);
4252 xbar = ybar = sxx = syy = sxy = 0;
4254 xmin = ymin = G_MAXUINT64;
4256 for (i = j = 0; i < n; i++, j += 2) {
4257 xmin = MIN (xmin, x[j]);
4258 ymin = MIN (ymin, y[j]);
4260 xmax = MAX (xmax, x[j]);
4261 ymax = MAX (ymax, y[j]);
4265 /* Allocate up to 1kb on the stack, otherwise heap */
4266 newx = n > 64 ? g_new (GstClockTime, 2 * n) : g_newa (GstClockTime, 2 * n);
4273 /* strip off unnecessary bits of precision */
4274 for (i = j = 0; i < n; i++, j += 2) {
4275 newx[j] = x[j] - xmin;
4276 newy[j] = y[j] - ymin;
4279 #ifdef DEBUGGING_ENABLED
4280 GST_CAT_DEBUG (GST_CAT_CLOCK, "reduced numbers:");
4281 for (i = j = 0; i < n; i++, j += 2)
4282 GST_CAT_DEBUG (GST_CAT_CLOCK,
4283 " %" G_GUINT64_FORMAT " %" G_GUINT64_FORMAT, newx[j], newy[j]);
4286 /* have to do this precisely otherwise the results are pretty much useless.
4287 * should guarantee that none of these accumulators can overflow */
4289 /* quantities on the order of 1e10 to 1e13 -> 30-35 bits;
4290 * window size a max of 2^10, so
4291 this addition could end up around 2^45 or so -- ample headroom */
4292 for (i = j = 0; i < n; i++, j += 2) {
4293 /* Just in case assumptions about headroom prove false, let's check */
4294 if ((newx[j] > 0 && G_MAXUINT64 - xbar <= newx[j]) ||
4295 (newy[j] > 0 && G_MAXUINT64 - ybar <= newy[j])) {
4296 GST_CAT_WARNING (GST_CAT_CLOCK,
4297 "Regression overflowed in clock slaving! xbar %"
4298 G_GUINT64_FORMAT " newx[j] %" G_GUINT64_FORMAT " ybar %"
4299 G_GUINT64_FORMAT " newy[j] %" G_GUINT64_FORMAT, xbar, newx[j], ybar,
4301 if (temp == NULL && n > 64)
4312 /* multiplying directly would give quantities on the order of 1e20-1e26 ->
4313 * 60 bits to 70 bits times the window size that's 80 which is too much.
4314 * Instead we (1) subtract off the xbar*ybar in the loop instead of after,
4315 * to avoid accumulation; (2) shift off some estimated number of bits from
4316 * each multiplicand to limit the expected ceiling. For strange
4317 * distributions of input values, things can still overflow, in which
4318 * case we drop precision and retry - at most a few times, in practice rarely
4321 /* Guess how many bits we might need for the usual distribution of input,
4322 * with a fallback loop that drops precision if things go pear-shaped */
4323 max_bits = gst_log2 (MAX (xmax - xmin, ymax - ymin)) * 7 / 8 + gst_log2 (n);
4325 pshift = max_bits - 64;
4329 #ifdef DEBUGGING_ENABLED
4330 GST_CAT_DEBUG (GST_CAT_CLOCK,
4331 "Restarting regression with precision shift %u", pshift);
4334 xbar4 = xbar >> pshift;
4335 ybar4 = ybar >> pshift;
4336 sxx = syy = sxy = 0;
4337 for (i = j = 0; i < n; i++, j += 2) {
4338 GstClockTime newx4, newy4;
4339 GstClockTimeDiff tmp;
4341 newx4 = newx[j] >> pshift;
4342 newy4 = newy[j] >> pshift;
4344 tmp = (newx4 + xbar4) * (newx4 - xbar4);
4345 if (G_UNLIKELY (tmp > 0 && sxx > 0 && (G_MAXINT64 - sxx <= tmp))) {
4347 /* Drop some precision and restart */
4351 } while (G_MAXINT64 - sxx <= tmp);
4353 } else if (G_UNLIKELY (tmp < 0 && sxx < 0 && (G_MAXINT64 - sxx >= tmp))) {
4355 /* Drop some precision and restart */
4359 } while (G_MININT64 - sxx >= tmp);
4364 tmp = newy4 * newy4 - ybar4 * ybar4;
4365 if (G_UNLIKELY (tmp > 0 && syy > 0 && (G_MAXINT64 - syy <= tmp))) {
4370 } while (G_MAXINT64 - syy <= tmp);
4372 } else if (G_UNLIKELY (tmp < 0 && syy < 0 && (G_MAXINT64 - syy >= tmp))) {
4377 } while (G_MININT64 - syy >= tmp);
4382 tmp = newx4 * newy4 - xbar4 * ybar4;
4383 if (G_UNLIKELY (tmp > 0 && sxy > 0 && (G_MAXINT64 - sxy <= tmp))) {
4388 } while (G_MAXINT64 - sxy <= tmp);
4390 } else if (G_UNLIKELY (tmp < 0 && sxy < 0 && (G_MININT64 - sxy >= tmp))) {
4395 } while (G_MININT64 - sxy >= tmp);
4402 if (G_UNLIKELY (sxx == 0))
4407 *b = (ymin + ybar) - gst_util_uint64_scale_round (xbar, *m_num, *m_denom);
4408 /* Report base starting from the most recent observation */
4410 *b += gst_util_uint64_scale_round (xmax - xmin, *m_num, *m_denom);
4412 *r_squared = ((double) sxy * (double) sxy) / ((double) sxx * (double) syy);
4414 #ifdef DEBUGGING_ENABLED
4415 GST_CAT_DEBUG (GST_CAT_CLOCK, " m = %g", ((double) *m_num) / *m_denom);
4416 GST_CAT_DEBUG (GST_CAT_CLOCK, " b = %" G_GUINT64_FORMAT, *b);
4417 GST_CAT_DEBUG (GST_CAT_CLOCK, " xbase = %" G_GUINT64_FORMAT, *xbase);
4418 GST_CAT_DEBUG (GST_CAT_CLOCK, " r2 = %g", *r_squared);
4421 if (temp == NULL && n > 64)
4428 GST_CAT_DEBUG (GST_CAT_CLOCK, "sxx == 0, regression failed");
4429 if (temp == NULL && n > 64)