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>
6 * gstutils.c: Utility functions
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
26 * @short_description: Various utility functions
30 #include "gst_private.h"
34 #include "gstghostpad.h"
40 #include "gst-i18n-lib.h"
41 #include "glib-compat-private.h"
46 * @mem: a pointer to the memory to dump
47 * @size: the size of the memory block to dump
49 * Dumps the memory block into a hex representation. Useful for debugging.
52 gst_util_dump_mem (const guchar * mem, guint size)
55 GString *string = g_string_sized_new (50);
56 GString *chars = g_string_sized_new (18);
60 if (g_ascii_isprint (mem[i]))
61 g_string_append_c (chars, mem[i]);
63 g_string_append_c (chars, '.');
65 g_string_append_printf (string, "%02x ", mem[i]);
70 if (j == 16 || i == size) {
71 g_print ("%08x (%p): %-48.48s %-16.16s\n", i - j, mem + i - j,
72 string->str, chars->str);
73 g_string_set_size (string, 0);
74 g_string_set_size (chars, 0);
78 g_string_free (string, TRUE);
79 g_string_free (chars, TRUE);
84 * gst_util_set_value_from_string:
85 * @value: (out caller-allocates): the value to set
86 * @value_str: the string to get the value from
88 * Converts the string to the type of the value and
89 * sets the value with it.
91 * Note that this function is dangerous as it does not return any indication
92 * if the conversion worked or not.
95 gst_util_set_value_from_string (GValue * value, const gchar * value_str)
99 g_return_if_fail (value != NULL);
100 g_return_if_fail (value_str != NULL);
102 GST_CAT_DEBUG (GST_CAT_PARAMS, "parsing '%s' to type %s", value_str,
103 g_type_name (G_VALUE_TYPE (value)));
105 res = gst_value_deserialize (value, value_str);
106 if (!res && G_VALUE_TYPE (value) == G_TYPE_BOOLEAN) {
107 /* backwards compat, all booleans that fail to parse are false */
108 g_value_set_boolean (value, FALSE);
111 g_return_if_fail (res);
115 * gst_util_set_object_arg:
116 * @object: the object to set the argument of
117 * @name: the name of the argument to set
118 * @value: the string value to set
120 * Converts the string value to the type of the objects argument and
121 * sets the argument with it.
123 * Note that this function silently returns if @object has no property named
124 * @name or when @value cannot be converted to the type of the property.
127 gst_util_set_object_arg (GObject * object, const gchar * name,
134 g_return_if_fail (G_IS_OBJECT (object));
135 g_return_if_fail (name != NULL);
136 g_return_if_fail (value != NULL);
138 pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (object), name);
142 value_type = pspec->value_type;
144 GST_DEBUG ("pspec->flags is %d, pspec->value_type is %s",
145 pspec->flags, g_type_name (value_type));
147 if (!(pspec->flags & G_PARAM_WRITABLE))
150 g_value_init (&v, value_type);
152 /* special case for element <-> xml (de)serialisation */
153 if (value_type == GST_TYPE_STRUCTURE && strcmp (value, "NULL") == 0) {
154 g_value_set_boxed (&v, NULL);
158 if (!gst_value_deserialize (&v, value))
163 g_object_set_property (object, pspec->name, &v);
167 /* work around error C2520: conversion from unsigned __int64 to double
168 * not implemented, use signed __int64
170 * These are implemented as functions because on some platforms a 64bit int to
171 * double conversion is not defined/implemented.
175 gst_util_guint64_to_gdouble (guint64 value)
177 if (value & G_GINT64_CONSTANT (0x8000000000000000))
178 return (gdouble) ((gint64) value) + (gdouble) 18446744073709551616.;
180 return (gdouble) ((gint64) value);
184 gst_util_gdouble_to_guint64 (gdouble value)
186 if (value < (gdouble) 9223372036854775808.) /* 1 << 63 */
187 return ((guint64) ((gint64) value));
189 value -= (gdouble) 18446744073709551616.;
190 return ((guint64) ((gint64) value));
193 #ifndef HAVE_UINT128_T
194 /* convenience struct for getting high and low uint32 parts of
201 #if G_BYTE_ORDER == G_BIG_ENDIAN
209 #if defined (__x86_64__) && defined (__GNUC__)
211 gst_util_uint64_mul_uint64 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
214 __asm__ __volatile__ ("mulq %3":"=a" (c0->ll), "=d" (c1->ll)
215 :"a" (arg1), "g" (arg2)
218 #else /* defined (__x86_64__) */
219 /* multiply two 64-bit unsigned ints into a 128-bit unsigned int. the high
220 * and low 64 bits of the product are placed in c1 and c0 respectively.
221 * this operation cannot overflow. */
223 gst_util_uint64_mul_uint64 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
233 /* do 128 bits multiply
241 * -------------------
244 * "a0" is optimized away, result is stored directly in c0. "b1" is
245 * optimized away, result is stored directly in c1.
247 c0->ll = (guint64) v.l.low * n.l.low;
248 a1.ll = (guint64) v.l.low * n.l.high;
249 b0.ll = (guint64) v.l.high * n.l.low;
251 /* add the high word of a0 to the low words of a1 and b0 using c1 as
252 * scrach space to capture the carry. the low word of the result becomes
253 * the final high word of c0 */
254 c1->ll = (guint64) c0->l.high + a1.l.low + b0.l.low;
255 c0->l.high = c1->l.low;
257 /* add the carry from the result above (found in the high word of c1) and
258 * the high words of a1 and b0 to b1, the result is c1. */
259 c1->ll = (guint64) v.l.high * n.l.high + c1->l.high + a1.l.high + b0.l.high;
261 #endif /* defined (__x86_64__) */
263 #if defined (__x86_64__) && defined (__GNUC__)
264 static inline guint64
265 gst_util_div128_64 (GstUInt64 c1, GstUInt64 c0, guint64 denom)
269 __asm__ __volatile__ ("divq %3":"=a" (res)
270 :"d" (c1.ll), "a" (c0.ll), "g" (denom)
276 /* count leading zeros */
278 gst_util_clz (guint32 val)
282 s = val | (val >> 1);
286 s = ~(s | (s >> 16));
287 s = s - ((s >> 1) & 0x55555555);
288 s = (s & 0x33333333) + ((s >> 2) & 0x33333333);
289 s = (s + (s >> 4)) & 0x0f0f0f0f;
291 s = (s + (s >> 16)) & 0x3f;
296 /* based on Hacker's Delight p152 */
297 static inline guint64
298 gst_util_div128_64 (GstUInt64 c1, GstUInt64 c0, guint64 denom)
300 GstUInt64 q1, q0, rhat;
301 GstUInt64 v, cmp1, cmp2;
306 /* count number of leading zeroes, we know they must be in the high
307 * part of denom since denom > G_MAXUINT32. */
308 s = gst_util_clz (v.l.high);
311 /* normalize divisor and dividend */
313 c1.ll = (c1.ll << s) | (c0.l.high >> (32 - s));
317 q1.ll = c1.ll / v.l.high;
318 rhat.ll = c1.ll - q1.ll * v.l.high;
320 cmp1.l.high = rhat.l.low;
321 cmp1.l.low = c0.l.high;
322 cmp2.ll = q1.ll * v.l.low;
324 while (q1.l.high || cmp2.ll > cmp1.ll) {
329 cmp1.l.high = rhat.l.low;
332 c1.l.high = c1.l.low;
333 c1.l.low = c0.l.high;
334 c1.ll -= q1.ll * v.ll;
335 q0.ll = c1.ll / v.l.high;
336 rhat.ll = c1.ll - q0.ll * v.l.high;
338 cmp1.l.high = rhat.l.low;
339 cmp1.l.low = c0.l.low;
340 cmp2.ll = q0.ll * v.l.low;
342 while (q0.l.high || cmp2.ll > cmp1.ll) {
347 cmp1.l.high = rhat.l.low;
350 q0.l.high += q1.l.low;
354 #endif /* defined (__GNUC__) */
356 /* This always gives the correct result because:
357 * a) val <= G_MAXUINT64-1
358 * b) (c0,c1) <= G_MAXUINT64 * (G_MAXUINT64-1)
360 * (c0,c1) == G_MAXUINT64 * G_MAXUINT64 and denom < G_MAXUINT64
361 * (note: num==denom case is handled by short path)
362 * This means that (c0,c1) either has enough space for val
363 * or that the overall result will overflow anyway.
366 /* add correction with carry */
367 #define CORRECT(c0,c1,val) \
369 if (G_MAXUINT64 - c0.ll < val) { \
370 if (G_UNLIKELY (c1.ll == G_MAXUINT64)) \
372 return G_MAXUINT64; \
379 gst_util_uint64_scale_uint64_unchecked (guint64 val, guint64 num,
380 guint64 denom, guint64 correct)
384 /* compute 128-bit numerator product */
385 gst_util_uint64_mul_uint64 (&c1, &c0, val, num);
387 /* perform rounding correction */
388 CORRECT (c0, c1, correct);
390 /* high word as big as or bigger than denom --> overflow */
391 if (G_UNLIKELY (c1.ll >= denom))
394 /* compute quotient, fits in 64 bits */
395 return gst_util_div128_64 (c1, c0, denom);
399 #define GST_MAXUINT128 ((__uint128_t) -1)
401 gst_util_uint64_scale_uint64_unchecked (guint64 val, guint64 num,
402 guint64 denom, guint64 correct)
406 /* Calculate val * num */
407 tmp = ((__uint128_t) val) * ((__uint128_t) num);
409 /* overflow checks */
410 if (G_UNLIKELY (GST_MAXUINT128 - correct < tmp))
413 /* perform rounding correction */
416 /* Divide by denom */
419 /* if larger than G_MAXUINT64 --> overflow */
420 if (G_UNLIKELY (tmp > G_MAXUINT64))
423 /* compute quotient, fits in 64 bits */
424 return (guint64) tmp;
429 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
431 gst_util_uint64_mul_uint32 (GstUInt64 * c1, GstUInt64 * c0, guint64 arg1,
438 c0->ll = (guint64) a.l.low * arg2;
439 c1->ll = (guint64) a.l.high * arg2 + c0->l.high;
443 /* divide a 96-bit unsigned int by a 32-bit unsigned int when we know the
444 * quotient fits into 64 bits. the high 64 bits and low 32 bits of the
445 * numerator are expected in c1 and c0 respectively. */
446 static inline guint64
447 gst_util_div96_32 (guint64 c1, guint64 c0, guint32 denom)
449 c0 += (c1 % denom) << 32;
450 return ((c1 / denom) << 32) + (c0 / denom);
453 static inline guint64
454 gst_util_uint64_scale_uint32_unchecked (guint64 val, guint32 num,
455 guint32 denom, guint32 correct)
459 /* compute 96-bit numerator product */
460 gst_util_uint64_mul_uint32 (&c1, &c0, val, num);
462 /* condition numerator based on rounding mode */
463 CORRECT (c0, c1, correct);
465 /* high 32 bits as big as or bigger than denom --> overflow */
466 if (G_UNLIKELY (c1.l.high >= denom))
469 /* compute quotient, fits in 64 bits */
470 return gst_util_div96_32 (c1.ll, c0.ll, denom);
474 /* the guts of the gst_util_uint64_scale() variants */
476 _gst_util_uint64_scale (guint64 val, guint64 num, guint64 denom,
479 g_return_val_if_fail (denom != 0, G_MAXUINT64);
481 if (G_UNLIKELY (num == 0))
484 if (G_UNLIKELY (num == denom))
487 /* on 64bits we always use a full 128bits multiply/division */
488 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
489 /* denom is low --> try to use 96 bit muldiv */
490 if (G_LIKELY (denom <= G_MAXUINT32)) {
491 /* num is low --> use 96 bit muldiv */
492 if (G_LIKELY (num <= G_MAXUINT32))
493 return gst_util_uint64_scale_uint32_unchecked (val, (guint32) num,
494 (guint32) denom, correct);
496 /* num is high but val is low --> swap and use 96-bit muldiv */
497 if (G_LIKELY (val <= G_MAXUINT32))
498 return gst_util_uint64_scale_uint32_unchecked (num, (guint32) val,
499 (guint32) denom, correct);
501 #endif /* !defined (__x86_64__) && !defined (HAVE_UINT128_T) */
503 /* val is high and num is high --> use 128-bit muldiv */
504 return gst_util_uint64_scale_uint64_unchecked (val, num, denom, correct);
508 * gst_util_uint64_scale:
509 * @val: the number to scale
510 * @num: the numerator of the scale ratio
511 * @denom: the denominator of the scale ratio
513 * Scale @val by the rational number @num / @denom, avoiding overflows and
514 * underflows and without loss of precision.
516 * This function can potentially be very slow if val and num are both
517 * greater than G_MAXUINT32.
519 * Returns: @val * @num / @denom. In the case of an overflow, this
520 * function returns G_MAXUINT64. If the result is not exactly
521 * representable as an integer it is truncated. See also
522 * gst_util_uint64_scale_round(), gst_util_uint64_scale_ceil(),
523 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
524 * gst_util_uint64_scale_int_ceil().
527 gst_util_uint64_scale (guint64 val, guint64 num, guint64 denom)
529 return _gst_util_uint64_scale (val, num, denom, 0);
533 * gst_util_uint64_scale_round:
534 * @val: the number to scale
535 * @num: the numerator of the scale ratio
536 * @denom: the denominator of the scale ratio
538 * Scale @val by the rational number @num / @denom, avoiding overflows and
539 * underflows and without loss of precision.
541 * This function can potentially be very slow if val and num are both
542 * greater than G_MAXUINT32.
544 * Returns: @val * @num / @denom. In the case of an overflow, this
545 * function returns G_MAXUINT64. If the result is not exactly
546 * representable as an integer, it is rounded to the nearest integer
547 * (half-way cases are rounded up). See also gst_util_uint64_scale(),
548 * gst_util_uint64_scale_ceil(), gst_util_uint64_scale_int(),
549 * gst_util_uint64_scale_int_round(), gst_util_uint64_scale_int_ceil().
552 gst_util_uint64_scale_round (guint64 val, guint64 num, guint64 denom)
554 return _gst_util_uint64_scale (val, num, denom, denom >> 1);
558 * gst_util_uint64_scale_ceil:
559 * @val: the number to scale
560 * @num: the numerator of the scale ratio
561 * @denom: the denominator of the scale ratio
563 * Scale @val by the rational number @num / @denom, avoiding overflows and
564 * underflows and without loss of precision.
566 * This function can potentially be very slow if val and num are both
567 * greater than G_MAXUINT32.
569 * Returns: @val * @num / @denom. In the case of an overflow, this
570 * function returns G_MAXUINT64. If the result is not exactly
571 * representable as an integer, it is rounded up. See also
572 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
573 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
574 * gst_util_uint64_scale_int_ceil().
577 gst_util_uint64_scale_ceil (guint64 val, guint64 num, guint64 denom)
579 return _gst_util_uint64_scale (val, num, denom, denom - 1);
582 /* the guts of the gst_util_uint64_scale_int() variants */
584 _gst_util_uint64_scale_int (guint64 val, gint num, gint denom, gint correct)
586 g_return_val_if_fail (denom > 0, G_MAXUINT64);
587 g_return_val_if_fail (num >= 0, G_MAXUINT64);
589 if (G_UNLIKELY (num == 0))
592 if (G_UNLIKELY (num == denom))
595 if (val <= G_MAXUINT32) {
596 /* simple case. num and denom are not negative so casts are OK. when
597 * not truncating, the additions to the numerator cannot overflow
598 * because val*num <= G_MAXUINT32 * G_MAXINT32 < G_MAXUINT64 -
599 * G_MAXINT32, so there's room to add another gint32. */
600 val *= (guint64) num;
601 /* add rounding correction */
604 return val / (guint64) denom;
606 #if !defined (__x86_64__) && !defined (HAVE_UINT128_T)
607 /* num and denom are not negative so casts are OK */
608 return gst_util_uint64_scale_uint32_unchecked (val, (guint32) num,
609 (guint32) denom, (guint32) correct);
611 /* always use full 128bits scale */
612 return gst_util_uint64_scale_uint64_unchecked (val, num, denom, correct);
617 * gst_util_uint64_scale_int:
618 * @val: guint64 (such as a #GstClockTime) to scale.
619 * @num: numerator of the scale factor.
620 * @denom: denominator of the scale factor.
622 * Scale @val by the rational number @num / @denom, avoiding overflows and
623 * underflows and without loss of precision. @num must be non-negative and
624 * @denom must be positive.
626 * Returns: @val * @num / @denom. In the case of an overflow, this
627 * function returns G_MAXUINT64. If the result is not exactly
628 * representable as an integer, it is truncated. See also
629 * gst_util_uint64_scale_int_round(), gst_util_uint64_scale_int_ceil(),
630 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
631 * gst_util_uint64_scale_ceil().
634 gst_util_uint64_scale_int (guint64 val, gint num, gint denom)
636 return _gst_util_uint64_scale_int (val, num, denom, 0);
640 * gst_util_uint64_scale_int_round:
641 * @val: guint64 (such as a #GstClockTime) to scale.
642 * @num: numerator of the scale factor.
643 * @denom: denominator of the scale factor.
645 * Scale @val by the rational number @num / @denom, avoiding overflows and
646 * underflows and without loss of precision. @num must be non-negative and
647 * @denom must be positive.
649 * Returns: @val * @num / @denom. In the case of an overflow, this
650 * function returns G_MAXUINT64. If the result is not exactly
651 * representable as an integer, it is rounded to the nearest integer
652 * (half-way cases are rounded up). See also gst_util_uint64_scale_int(),
653 * gst_util_uint64_scale_int_ceil(), gst_util_uint64_scale(),
654 * gst_util_uint64_scale_round(), gst_util_uint64_scale_ceil().
657 gst_util_uint64_scale_int_round (guint64 val, gint num, gint denom)
659 /* we can use a shift to divide by 2 because denom is required to be
661 return _gst_util_uint64_scale_int (val, num, denom, denom >> 1);
665 * gst_util_uint64_scale_int_ceil:
666 * @val: guint64 (such as a #GstClockTime) to scale.
667 * @num: numerator of the scale factor.
668 * @denom: denominator of the scale factor.
670 * Scale @val by the rational number @num / @denom, avoiding overflows and
671 * underflows and without loss of precision. @num must be non-negative and
672 * @denom must be positive.
674 * Returns: @val * @num / @denom. In the case of an overflow, this
675 * function returns G_MAXUINT64. If the result is not exactly
676 * representable as an integer, it is rounded up. See also
677 * gst_util_uint64_scale_int(), gst_util_uint64_scale_int_round(),
678 * gst_util_uint64_scale(), gst_util_uint64_scale_round(),
679 * gst_util_uint64_scale_ceil().
682 gst_util_uint64_scale_int_ceil (guint64 val, gint num, gint denom)
684 return _gst_util_uint64_scale_int (val, num, denom, denom - 1);
688 * gst_util_seqnum_next:
690 * Return a constantly incrementing sequence number.
692 * This function is used internally to GStreamer to be able to determine which
693 * events and messages are "the same". For example, elements may set the seqnum
694 * on a segment-done message to be the same as that of the last seek event, to
695 * indicate that event and the message correspond to the same segment.
697 * Returns: A constantly incrementing 32-bit unsigned integer, which might
698 * overflow back to 0 at some point. Use gst_util_seqnum_compare() to make sure
699 * you handle wraparound correctly.
702 gst_util_seqnum_next (void)
704 static gint counter = 0;
705 return g_atomic_int_add (&counter, 1);
709 * gst_util_seqnum_compare:
710 * @s1: A sequence number.
711 * @s2: Another sequence number.
713 * Compare two sequence numbers, handling wraparound.
715 * The current implementation just returns (gint32)(@s1 - @s2).
717 * Returns: A negative number if @s1 is before @s2, 0 if they are equal, or a
718 * positive number if @s1 is after @s2.
721 gst_util_seqnum_compare (guint32 s1, guint32 s2)
723 return (gint32) (s1 - s2);
726 /* -----------------------------------------------------
728 * The following code will be moved out of the main
729 * gstreamer library someday.
735 * gst_element_create_all_pads:
736 * @element: (transfer none): a #GstElement to create pads for
738 * Creates a pad for each pad template that is always available.
739 * This function is only useful during object initialization of
740 * subclasses of #GstElement.
743 gst_element_create_all_pads (GstElement * element)
747 /* FIXME: lock element */
750 gst_element_class_get_pad_template_list (GST_ELEMENT_CLASS
751 (G_OBJECT_GET_CLASS (element)));
754 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
756 if (padtempl->presence == GST_PAD_ALWAYS) {
759 pad = gst_pad_new_from_template (padtempl, padtempl->name_template);
761 gst_element_add_pad (element, pad);
763 padlist = padlist->next;
768 * gst_element_get_compatible_pad_template:
769 * @element: (transfer none): a #GstElement to get a compatible pad template for
770 * @compattempl: (transfer none): the #GstPadTemplate to find a compatible
773 * Retrieves a pad template from @element that is compatible with @compattempl.
774 * Pads from compatible templates can be linked together.
776 * Returns: (transfer none) (nullable): a compatible #GstPadTemplate,
777 * or %NULL if none was found. No unreferencing is necessary.
780 gst_element_get_compatible_pad_template (GstElement * element,
781 GstPadTemplate * compattempl)
783 GstPadTemplate *newtempl = NULL;
785 GstElementClass *class;
788 g_return_val_if_fail (element != NULL, NULL);
789 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
790 g_return_val_if_fail (compattempl != NULL, NULL);
792 class = GST_ELEMENT_GET_CLASS (element);
794 padlist = gst_element_class_get_pad_template_list (class);
796 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
797 "Looking for a suitable pad template in %s out of %d templates...",
798 GST_ELEMENT_NAME (element), g_list_length (padlist));
801 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
805 * Check direction (must be opposite)
808 GST_CAT_LOG (GST_CAT_CAPS,
809 "checking pad template %s", padtempl->name_template);
810 if (padtempl->direction != compattempl->direction) {
811 GST_CAT_DEBUG (GST_CAT_CAPS,
812 "compatible direction: found %s pad template \"%s\"",
813 padtempl->direction == GST_PAD_SRC ? "src" : "sink",
814 padtempl->name_template);
816 GST_CAT_DEBUG (GST_CAT_CAPS,
817 "intersecting %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (compattempl));
818 GST_CAT_DEBUG (GST_CAT_CAPS,
819 "..and %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (padtempl));
821 compatible = gst_caps_can_intersect (GST_PAD_TEMPLATE_CAPS (compattempl),
822 GST_PAD_TEMPLATE_CAPS (padtempl));
824 GST_CAT_DEBUG (GST_CAT_CAPS, "caps are %scompatible",
825 (compatible ? "" : "not "));
833 padlist = g_list_next (padlist);
836 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
837 "Returning new pad template %p", newtempl);
839 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "No compatible pad template found");
845 * gst_element_get_pad_from_template:
846 * @element: (transfer none): a #GstElement.
847 * @templ: (transfer none): a #GstPadTemplate belonging to @element.
849 * Gets a pad from @element described by @templ. If the presence of @templ is
850 * #GST_PAD_REQUEST, requests a new pad. Can return %NULL for #GST_PAD_SOMETIMES
853 * Returns: (transfer full) (nullable): the #GstPad, or %NULL if one
854 * could not be found or created.
857 gst_element_get_pad_from_template (GstElement * element, GstPadTemplate * templ)
860 GstPadPresence presence;
862 /* If this function is ever exported, we need check the validity of `element'
863 * and `templ', and to make sure the template actually belongs to the
866 presence = GST_PAD_TEMPLATE_PRESENCE (templ);
870 case GST_PAD_SOMETIMES:
871 ret = gst_element_get_static_pad (element, templ->name_template);
872 if (!ret && presence == GST_PAD_ALWAYS)
874 ("Element %s has an ALWAYS template %s, but no pad of the same name",
875 GST_OBJECT_NAME (element), templ->name_template);
878 case GST_PAD_REQUEST:
879 ret = gst_element_request_pad (element, templ, NULL, NULL);
887 * gst_element_request_compatible_pad:
888 * @element: a #GstElement.
889 * @templ: the #GstPadTemplate to which the new pad should be able to link.
891 * Requests a pad from @element. The returned pad should be unlinked and
892 * compatible with @templ. Might return an existing pad, or request a new one.
894 * Returns: (nullable): a #GstPad, or %NULL if one could not be found
898 gst_element_request_compatible_pad (GstElement * element,
899 GstPadTemplate * templ)
901 GstPadTemplate *templ_new;
904 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
905 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
907 /* FIXME: should really loop through the templates, testing each for
908 * compatibility and pad availability. */
909 templ_new = gst_element_get_compatible_pad_template (element, templ);
911 pad = gst_element_get_pad_from_template (element, templ_new);
913 /* This can happen for non-request pads. No need to unref. */
914 if (pad && GST_PAD_PEER (pad))
921 * Checks if the source pad and the sink pad can be linked.
922 * Both @srcpad and @sinkpad must be unlinked and have a parent.
925 gst_pad_check_link (GstPad * srcpad, GstPad * sinkpad)
928 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
929 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
931 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
932 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
934 if (GST_PAD_PEER (srcpad) != NULL) {
935 GST_CAT_INFO (GST_CAT_PADS, "Source pad %s:%s has a peer, failed",
936 GST_DEBUG_PAD_NAME (srcpad));
939 if (GST_PAD_PEER (sinkpad) != NULL) {
940 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has a peer, failed",
941 GST_DEBUG_PAD_NAME (sinkpad));
944 if (!GST_PAD_IS_SRC (srcpad)) {
945 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s is not source pad, failed",
946 GST_DEBUG_PAD_NAME (srcpad));
949 if (!GST_PAD_IS_SINK (sinkpad)) {
950 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s is not sink pad, failed",
951 GST_DEBUG_PAD_NAME (sinkpad));
954 if (GST_PAD_PARENT (srcpad) == NULL) {
955 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s has no parent, failed",
956 GST_DEBUG_PAD_NAME (srcpad));
959 if (GST_PAD_PARENT (sinkpad) == NULL) {
960 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has no parent, failed",
961 GST_DEBUG_PAD_NAME (srcpad));
969 * gst_element_get_compatible_pad:
970 * @element: (transfer none): a #GstElement in which the pad should be found.
971 * @pad: (transfer none): the #GstPad to find a compatible one for.
972 * @caps: (allow-none): the #GstCaps to use as a filter.
974 * Looks for an unlinked pad to which the given pad can link. It is not
975 * guaranteed that linking the pads will work, though it should work in most
978 * This function will first attempt to find a compatible unlinked ALWAYS pad,
979 * and if none can be found, it will request a compatible REQUEST pad by looking
980 * at the templates of @element.
982 * Returns: (transfer full) (nullable): the #GstPad to which a link
983 * can be made, or %NULL if one cannot be found. gst_object_unref()
987 gst_element_get_compatible_pad (GstElement * element, GstPad * pad,
991 GstPadTemplate *templ;
993 GstPad *foundpad = NULL;
995 GValue padptr = { 0, };
997 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
998 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1000 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1001 "finding pad in %s compatible with %s:%s",
1002 GST_ELEMENT_NAME (element), GST_DEBUG_PAD_NAME (pad));
1004 g_return_val_if_fail (GST_PAD_PEER (pad) == NULL, NULL);
1008 /* try to get an existing unlinked pad */
1009 if (GST_PAD_IS_SRC (pad)) {
1010 pads = gst_element_iterate_sink_pads (element);
1011 } else if (GST_PAD_IS_SINK (pad)) {
1012 pads = gst_element_iterate_src_pads (element);
1014 pads = gst_element_iterate_pads (element);
1018 switch (gst_iterator_next (pads, &padptr)) {
1019 case GST_ITERATOR_OK:
1026 current = g_value_get_object (&padptr);
1028 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
1029 GST_DEBUG_PAD_NAME (current));
1031 if (GST_PAD_IS_SRC (current)) {
1038 peer = gst_pad_get_peer (current);
1040 if (peer == NULL && gst_pad_check_link (srcpad, sinkpad)) {
1041 GstCaps *temp, *intersection;
1042 gboolean compatible;
1044 /* Now check if the two pads' caps are compatible */
1045 temp = gst_pad_query_caps (pad, NULL);
1047 intersection = gst_caps_intersect (temp, caps);
1048 gst_caps_unref (temp);
1050 intersection = temp;
1053 temp = gst_pad_query_caps (current, NULL);
1054 compatible = gst_caps_can_intersect (temp, intersection);
1055 gst_caps_unref (temp);
1056 gst_caps_unref (intersection);
1059 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1060 "found existing unlinked compatible pad %s:%s",
1061 GST_DEBUG_PAD_NAME (current));
1062 gst_iterator_free (pads);
1064 current = gst_object_ref (current);
1065 g_value_unset (&padptr);
1069 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "incompatible pads");
1072 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1073 "already linked or cannot be linked (peer = %p)", peer);
1075 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unreffing pads");
1077 g_value_reset (&padptr);
1079 gst_object_unref (peer);
1082 case GST_ITERATOR_DONE:
1085 case GST_ITERATOR_RESYNC:
1086 gst_iterator_resync (pads);
1088 case GST_ITERATOR_ERROR:
1089 g_assert_not_reached ();
1093 g_value_unset (&padptr);
1094 gst_iterator_free (pads);
1096 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
1097 "Could not find a compatible unlinked always pad to link to %s:%s, now checking request pads",
1098 GST_DEBUG_PAD_NAME (pad));
1100 /* try to create a new one */
1101 /* requesting is a little crazy, we need a template. Let's create one */
1102 templcaps = gst_pad_query_caps (pad, NULL);
1104 GstCaps *inter = gst_caps_intersect (templcaps, caps);
1106 gst_caps_unref (templcaps);
1109 templ = gst_pad_template_new ((gchar *) GST_PAD_NAME (pad),
1110 GST_PAD_DIRECTION (pad), GST_PAD_ALWAYS, templcaps);
1111 gst_caps_unref (templcaps);
1113 foundpad = gst_element_request_compatible_pad (element, templ);
1114 gst_object_unref (templ);
1117 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1118 "found existing request pad %s:%s", GST_DEBUG_PAD_NAME (foundpad));
1122 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element,
1123 "Could not find a compatible pad to link to %s:%s",
1124 GST_DEBUG_PAD_NAME (pad));
1129 * gst_element_state_get_name:
1130 * @state: a #GstState to get the name of.
1132 * Gets a string representing the given state.
1134 * Returns: (transfer none): a string with the name of the state.
1137 gst_element_state_get_name (GstState state)
1140 case GST_STATE_VOID_PENDING:
1141 return "VOID_PENDING";
1142 case GST_STATE_NULL:
1144 case GST_STATE_READY:
1146 case GST_STATE_PLAYING:
1148 case GST_STATE_PAUSED:
1151 /* This is a memory leak */
1152 return g_strdup_printf ("UNKNOWN!(%d)", state);
1157 * gst_element_state_change_return_get_name:
1158 * @state_ret: a #GstStateChangeReturn to get the name of.
1160 * Gets a string representing the given state change result.
1162 * Returns: (transfer none): a string with the name of the state
1166 gst_element_state_change_return_get_name (GstStateChangeReturn state_ret)
1168 switch (state_ret) {
1169 case GST_STATE_CHANGE_FAILURE:
1171 case GST_STATE_CHANGE_SUCCESS:
1173 case GST_STATE_CHANGE_ASYNC:
1175 case GST_STATE_CHANGE_NO_PREROLL:
1176 return "NO PREROLL";
1178 /* This is a memory leak */
1179 return g_strdup_printf ("UNKNOWN!(%d)", state_ret);
1185 gst_element_factory_can_accept_all_caps_in_direction (GstElementFactory *
1186 factory, const GstCaps * caps, GstPadDirection direction)
1190 g_return_val_if_fail (factory != NULL, FALSE);
1191 g_return_val_if_fail (caps != NULL, FALSE);
1193 templates = factory->staticpadtemplates;
1196 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1198 if (template->direction == direction) {
1199 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1201 if (gst_caps_is_always_compatible (caps, templcaps)) {
1202 gst_caps_unref (templcaps);
1205 gst_caps_unref (templcaps);
1207 templates = g_list_next (templates);
1214 gst_element_factory_can_accept_any_caps_in_direction (GstElementFactory *
1215 factory, const GstCaps * caps, GstPadDirection direction)
1219 g_return_val_if_fail (factory != NULL, FALSE);
1220 g_return_val_if_fail (caps != NULL, FALSE);
1222 templates = factory->staticpadtemplates;
1225 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1227 if (template->direction == direction) {
1228 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1230 if (gst_caps_can_intersect (caps, templcaps)) {
1231 gst_caps_unref (templcaps);
1234 gst_caps_unref (templcaps);
1236 templates = g_list_next (templates);
1243 * gst_element_factory_can_sink_all_caps:
1244 * @factory: factory to query
1245 * @caps: the caps to check
1247 * Checks if the factory can sink all possible capabilities.
1249 * Returns: %TRUE if the caps are fully compatible.
1252 gst_element_factory_can_sink_all_caps (GstElementFactory * factory,
1253 const GstCaps * caps)
1255 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1260 * gst_element_factory_can_src_all_caps:
1261 * @factory: factory to query
1262 * @caps: the caps to check
1264 * Checks if the factory can src all possible capabilities.
1266 * Returns: %TRUE if the caps are fully compatible.
1269 gst_element_factory_can_src_all_caps (GstElementFactory * factory,
1270 const GstCaps * caps)
1272 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1277 * gst_element_factory_can_sink_any_caps:
1278 * @factory: factory to query
1279 * @caps: the caps to check
1281 * Checks if the factory can sink any possible capability.
1283 * Returns: %TRUE if the caps have a common subset.
1286 gst_element_factory_can_sink_any_caps (GstElementFactory * factory,
1287 const GstCaps * caps)
1289 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1294 * gst_element_factory_can_src_any_caps:
1295 * @factory: factory to query
1296 * @caps: the caps to check
1298 * Checks if the factory can src any possible capability.
1300 * Returns: %TRUE if the caps have a common subset.
1303 gst_element_factory_can_src_any_caps (GstElementFactory * factory,
1304 const GstCaps * caps)
1306 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1310 /* if return val is true, *direct_child is a caller-owned ref on the direct
1311 * child of ancestor that is part of object's ancestry */
1313 object_has_ancestor (GstObject * object, GstObject * ancestor,
1314 GstObject ** direct_child)
1316 GstObject *child, *parent;
1319 *direct_child = NULL;
1321 child = gst_object_ref (object);
1322 parent = gst_object_get_parent (object);
1325 if (ancestor == parent) {
1327 *direct_child = child;
1329 gst_object_unref (child);
1330 gst_object_unref (parent);
1334 gst_object_unref (child);
1336 parent = gst_object_get_parent (parent);
1339 gst_object_unref (child);
1344 /* caller owns return */
1346 find_common_root (GstObject * o1, GstObject * o2)
1348 GstObject *top = o1;
1349 GstObject *kid1, *kid2;
1350 GstObject *root = NULL;
1352 while (GST_OBJECT_PARENT (top))
1353 top = GST_OBJECT_PARENT (top);
1355 /* the itsy-bitsy spider... */
1357 if (!object_has_ancestor (o2, top, &kid2))
1360 root = gst_object_ref (top);
1362 if (!object_has_ancestor (o1, kid2, &kid1)) {
1363 gst_object_unref (kid2);
1367 if (!object_has_ancestor (o2, kid1, &kid2)) {
1368 gst_object_unref (kid1);
1375 /* caller does not own return */
1377 ghost_up (GstElement * e, GstPad * pad)
1379 static gint ghost_pad_index = 0;
1384 GstObject *parent = GST_OBJECT_PARENT (e);
1386 name = g_strdup_printf ("ghost%d", ghost_pad_index++);
1387 gpad = gst_ghost_pad_new (name, pad);
1391 gst_element_get_state (e, ¤t, &next, 0);
1393 if (current > GST_STATE_READY || next == GST_STATE_PAUSED)
1394 gst_pad_set_active (gpad, TRUE);
1396 if (!gst_element_add_pad ((GstElement *) parent, gpad)) {
1397 g_warning ("Pad named %s already exists in element %s\n",
1398 GST_OBJECT_NAME (gpad), GST_OBJECT_NAME (parent));
1399 gst_object_unref ((GstObject *) gpad);
1400 GST_STATE_UNLOCK (e);
1403 GST_STATE_UNLOCK (e);
1409 remove_pad (gpointer ppad, gpointer unused)
1413 if (!gst_element_remove_pad ((GstElement *) GST_OBJECT_PARENT (pad), pad))
1414 g_warning ("Couldn't remove pad %s from element %s",
1415 GST_OBJECT_NAME (pad), GST_OBJECT_NAME (GST_OBJECT_PARENT (pad)));
1419 prepare_link_maybe_ghosting (GstPad ** src, GstPad ** sink,
1420 GSList ** pads_created)
1424 GSList *pads_created_local = NULL;
1426 g_assert (pads_created);
1428 e1 = GST_OBJECT_PARENT (*src);
1429 e2 = GST_OBJECT_PARENT (*sink);
1431 if (G_UNLIKELY (e1 == NULL)) {
1432 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1433 GST_PTR_FORMAT, *src);
1436 if (G_UNLIKELY (e2 == NULL)) {
1437 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1438 GST_PTR_FORMAT, *sink);
1442 if (GST_OBJECT_PARENT (e1) == GST_OBJECT_PARENT (e2)) {
1443 GST_CAT_INFO (GST_CAT_PADS, "%s and %s in same bin, no need for ghost pads",
1444 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1448 GST_CAT_INFO (GST_CAT_PADS, "%s and %s not in same bin, making ghost pads",
1449 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1451 /* we need to setup some ghost pads */
1452 root = find_common_root (e1, e2);
1454 if (GST_OBJECT_PARENT (e1) == NULL)
1455 g_warning ("Trying to link elements %s and %s that don't share a common "
1456 "ancestor: %s hasn't been added to a bin or pipeline, but %s is in %s",
1457 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1458 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1459 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1460 else if (GST_OBJECT_PARENT (e2) == NULL)
1461 g_warning ("Trying to link elements %s and %s that don't share a common "
1462 "ancestor: %s hasn't been added to a bin or pipeline, and %s is in %s",
1463 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1464 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (e1),
1465 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)));
1467 g_warning ("Trying to link elements %s and %s that don't share a common "
1468 "ancestor: %s is in %s, and %s is in %s",
1469 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1470 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)),
1471 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1475 while (GST_OBJECT_PARENT (e1) != root) {
1476 *src = ghost_up ((GstElement *) e1, *src);
1479 e1 = GST_OBJECT_PARENT (*src);
1480 pads_created_local = g_slist_prepend (pads_created_local, *src);
1482 while (GST_OBJECT_PARENT (e2) != root) {
1483 *sink = ghost_up ((GstElement *) e2, *sink);
1486 e2 = GST_OBJECT_PARENT (*sink);
1487 pads_created_local = g_slist_prepend (pads_created_local, *sink);
1490 gst_object_unref (root);
1491 *pads_created = g_slist_concat (*pads_created, pads_created_local);
1495 gst_object_unref (root);
1496 g_slist_foreach (pads_created_local, remove_pad, NULL);
1497 g_slist_free (pads_created_local);
1502 pad_link_maybe_ghosting (GstPad * src, GstPad * sink, GstPadLinkCheck flags)
1504 GSList *pads_created = NULL;
1507 if (!prepare_link_maybe_ghosting (&src, &sink, &pads_created)) {
1510 ret = (gst_pad_link_full (src, sink, flags) == GST_PAD_LINK_OK);
1514 g_slist_foreach (pads_created, remove_pad, NULL);
1516 g_slist_free (pads_created);
1522 release_and_unref_pad (GstElement * element, GstPad * pad, gboolean requestpad)
1526 gst_element_release_request_pad (element, pad);
1527 gst_object_unref (pad);
1532 * gst_element_link_pads_full:
1533 * @src: a #GstElement containing the source pad.
1534 * @srcpadname: (allow-none): the name of the #GstPad in source element
1535 * or %NULL for any pad.
1536 * @dest: (transfer none): the #GstElement containing the destination pad.
1537 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1538 * or %NULL for any pad.
1539 * @flags: the #GstPadLinkCheck to be performed when linking pads.
1541 * Links the two named pads of the source and destination elements.
1542 * Side effect is that if one of the pads has no parent, it becomes a
1543 * child of the parent of the other element. If they have different
1544 * parents, the link fails.
1546 * Calling gst_element_link_pads_full() with @flags == %GST_PAD_LINK_CHECK_DEFAULT
1547 * is the same as calling gst_element_link_pads() and the recommended way of
1548 * linking pads with safety checks applied.
1550 * This is a convenience function for gst_pad_link_full().
1552 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1555 gst_element_link_pads_full (GstElement * src, const gchar * srcpadname,
1556 GstElement * dest, const gchar * destpadname, GstPadLinkCheck flags)
1558 const GList *srcpads, *destpads, *srctempls, *desttempls, *l;
1559 GstPad *srcpad, *destpad;
1560 GstPadTemplate *srctempl, *desttempl;
1561 GstElementClass *srcclass, *destclass;
1562 gboolean srcrequest, destrequest;
1565 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1566 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1568 GST_CAT_INFO (GST_CAT_ELEMENT_PADS,
1569 "trying to link element %s:%s to element %s:%s", GST_ELEMENT_NAME (src),
1570 srcpadname ? srcpadname : "(any)", GST_ELEMENT_NAME (dest),
1571 destpadname ? destpadname : "(any)");
1574 destrequest = FALSE;
1578 /* name specified, look it up */
1579 if (!(srcpad = gst_element_get_static_pad (src, srcpadname))) {
1580 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
1584 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1585 GST_ELEMENT_NAME (src), srcpadname);
1588 if (!(GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC)) {
1589 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no src pad",
1590 GST_DEBUG_PAD_NAME (srcpad));
1591 release_and_unref_pad (src, srcpad, srcrequest);
1594 if (GST_PAD_PEER (srcpad) != NULL) {
1595 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1596 "pad %s:%s is already linked to %s:%s", GST_DEBUG_PAD_NAME (srcpad),
1597 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1598 /* already linked request pads look like static pads, so the request pad
1599 * was never requested a second time above, so no need to release it */
1600 gst_object_unref (srcpad);
1606 /* no name given, get the first available pad */
1607 GST_OBJECT_LOCK (src);
1608 srcpads = GST_ELEMENT_PADS (src);
1609 srcpad = srcpads ? GST_PAD_CAST (srcpads->data) : NULL;
1611 gst_object_ref (srcpad);
1612 GST_OBJECT_UNLOCK (src);
1615 /* get a destination pad */
1617 /* name specified, look it up */
1618 if (!(destpad = gst_element_get_static_pad (dest, destpadname))) {
1619 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
1623 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1624 GST_ELEMENT_NAME (dest), destpadname);
1625 release_and_unref_pad (src, srcpad, srcrequest);
1628 if (!(GST_PAD_DIRECTION (destpad) == GST_PAD_SINK)) {
1629 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no sink pad",
1630 GST_DEBUG_PAD_NAME (destpad));
1631 release_and_unref_pad (src, srcpad, srcrequest);
1632 release_and_unref_pad (dest, destpad, destrequest);
1635 if (GST_PAD_PEER (destpad) != NULL) {
1636 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1637 "pad %s:%s is already linked to %s:%s",
1638 GST_DEBUG_PAD_NAME (destpad),
1639 GST_DEBUG_PAD_NAME (GST_PAD_PEER (destpad)));
1640 release_and_unref_pad (src, srcpad, srcrequest);
1641 /* already linked request pads look like static pads, so the request pad
1642 * was never requested a second time above, so no need to release it */
1643 gst_object_unref (destpad);
1649 /* no name given, get the first available pad */
1650 GST_OBJECT_LOCK (dest);
1651 destpads = GST_ELEMENT_PADS (dest);
1652 destpad = destpads ? GST_PAD_CAST (destpads->data) : NULL;
1654 gst_object_ref (destpad);
1655 GST_OBJECT_UNLOCK (dest);
1658 if (srcpadname && destpadname) {
1661 /* two explicitly specified pads */
1662 result = pad_link_maybe_ghosting (srcpad, destpad, flags);
1665 gst_object_unref (srcpad);
1666 gst_object_unref (destpad);
1668 release_and_unref_pad (src, srcpad, srcrequest);
1669 release_and_unref_pad (dest, destpad, destrequest);
1675 /* loop through the allowed pads in the source, trying to find a
1676 * compatible destination pad */
1677 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1678 "looping through allowed src and dest pads");
1680 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying src pad %s:%s",
1681 GST_DEBUG_PAD_NAME (srcpad));
1682 if ((GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC) &&
1683 (GST_PAD_PEER (srcpad) == NULL)) {
1684 gboolean temprequest = FALSE;
1689 gst_object_ref (temp);
1691 temp = gst_element_get_compatible_pad (dest, srcpad, NULL);
1692 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1693 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
1699 if (temp && pad_link_maybe_ghosting (srcpad, temp, flags)) {
1700 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1701 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (temp));
1703 gst_object_unref (destpad);
1704 gst_object_unref (srcpad);
1705 gst_object_unref (temp);
1711 gst_element_release_request_pad (dest, temp);
1712 gst_object_unref (temp);
1715 /* find a better way for this mess */
1717 srcpads = g_list_next (srcpads);
1719 gst_object_unref (srcpad);
1720 srcpad = GST_PAD_CAST (srcpads->data);
1721 gst_object_ref (srcpad);
1727 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s:%s to %s",
1728 GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (dest));
1729 /* no need to release any request pad as both src- and destpadname must be
1730 * set to end up here, but this case has already been taken care of above */
1732 gst_object_unref (destpad);
1736 release_and_unref_pad (src, srcpad, srcrequest);
1741 /* loop through the existing pads in the destination */
1743 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying dest pad %s:%s",
1744 GST_DEBUG_PAD_NAME (destpad));
1745 if ((GST_PAD_DIRECTION (destpad) == GST_PAD_SINK) &&
1746 (GST_PAD_PEER (destpad) == NULL)) {
1747 GstPad *temp = gst_element_get_compatible_pad (src, destpad, NULL);
1748 gboolean temprequest = FALSE;
1750 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1751 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
1756 if (temp && pad_link_maybe_ghosting (temp, destpad, flags)) {
1757 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1758 GST_DEBUG_PAD_NAME (temp), GST_DEBUG_PAD_NAME (destpad));
1759 gst_object_unref (temp);
1760 gst_object_unref (destpad);
1764 release_and_unref_pad (src, temp, temprequest);
1767 destpads = g_list_next (destpads);
1769 gst_object_unref (destpad);
1770 destpad = GST_PAD_CAST (destpads->data);
1771 gst_object_ref (destpad);
1778 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s:%s",
1779 GST_ELEMENT_NAME (src), GST_DEBUG_PAD_NAME (destpad));
1780 release_and_unref_pad (dest, destpad, destrequest);
1783 /* no need to release any request pad as the case of unset destpatname and
1784 * destpad being a requst pad has already been taken care of when looking
1785 * though the destination pads above */
1787 gst_object_unref (destpad);
1792 srcclass = GST_ELEMENT_GET_CLASS (src);
1793 destclass = GST_ELEMENT_GET_CLASS (dest);
1795 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1796 "we might have request pads on both sides, checking...");
1797 srctempls = gst_element_class_get_pad_template_list (srcclass);
1798 desttempls = gst_element_class_get_pad_template_list (destclass);
1800 if (srctempls && desttempls) {
1802 srctempl = (GstPadTemplate *) srctempls->data;
1803 if (srctempl->presence == GST_PAD_REQUEST) {
1804 for (l = desttempls; l; l = l->next) {
1805 desttempl = (GstPadTemplate *) l->data;
1806 if (desttempl->presence == GST_PAD_REQUEST &&
1807 desttempl->direction != srctempl->direction) {
1808 GstCaps *srccaps, *destcaps;
1810 srccaps = gst_pad_template_get_caps (srctempl);
1811 destcaps = gst_pad_template_get_caps (desttempl);
1812 if (gst_caps_is_always_compatible (srccaps, destcaps)) {
1814 gst_element_request_pad (src, srctempl,
1815 srctempl->name_template, NULL);
1817 gst_element_request_pad (dest, desttempl,
1818 desttempl->name_template, NULL);
1819 if (srcpad && destpad
1820 && pad_link_maybe_ghosting (srcpad, destpad, flags)) {
1821 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1822 "linked pad %s:%s to pad %s:%s",
1823 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (destpad));
1824 gst_object_unref (srcpad);
1825 gst_object_unref (destpad);
1826 gst_caps_unref (srccaps);
1827 gst_caps_unref (destcaps);
1830 /* it failed, so we release the request pads */
1832 gst_element_release_request_pad (src, srcpad);
1833 gst_object_unref (srcpad);
1836 gst_element_release_request_pad (dest, destpad);
1837 gst_object_unref (destpad);
1840 gst_caps_unref (srccaps);
1841 gst_caps_unref (destcaps);
1845 srctempls = srctempls->next;
1849 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s",
1850 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
1855 * gst_element_link_pads:
1856 * @src: a #GstElement containing the source pad.
1857 * @srcpadname: (allow-none): the name of the #GstPad in source element
1858 * or %NULL for any pad.
1859 * @dest: (transfer none): the #GstElement containing the destination pad.
1860 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1861 * or %NULL for any pad.
1863 * Links the two named pads of the source and destination elements.
1864 * Side effect is that if one of the pads has no parent, it becomes a
1865 * child of the parent of the other element. If they have different
1866 * parents, the link fails.
1868 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1871 gst_element_link_pads (GstElement * src, const gchar * srcpadname,
1872 GstElement * dest, const gchar * destpadname)
1874 return gst_element_link_pads_full (src, srcpadname, dest, destpadname,
1875 GST_PAD_LINK_CHECK_DEFAULT);
1879 * gst_element_link_pads_filtered:
1880 * @src: a #GstElement containing the source pad.
1881 * @srcpadname: (allow-none): the name of the #GstPad in source element
1882 * or %NULL for any pad.
1883 * @dest: (transfer none): the #GstElement containing the destination pad.
1884 * @destpadname: (allow-none): the name of the #GstPad in destination element
1885 * or %NULL for any pad.
1886 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
1887 * or %NULL for no filter.
1889 * Links the two named pads of the source and destination elements. Side effect
1890 * is that if one of the pads has no parent, it becomes a child of the parent of
1891 * the other element. If they have different parents, the link fails. If @caps
1892 * is not %NULL, makes sure that the caps of the link is a subset of @caps.
1894 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1897 gst_element_link_pads_filtered (GstElement * src, const gchar * srcpadname,
1898 GstElement * dest, const gchar * destpadname, GstCaps * filter)
1901 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1902 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1903 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), FALSE);
1906 GstElement *capsfilter;
1908 GstState state, pending;
1911 capsfilter = gst_element_factory_make ("capsfilter", NULL);
1913 GST_ERROR ("Could not make a capsfilter");
1917 parent = gst_object_get_parent (GST_OBJECT (src));
1918 g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
1920 gst_element_get_state (GST_ELEMENT_CAST (parent), &state, &pending, 0);
1922 if (!gst_bin_add (GST_BIN (parent), capsfilter)) {
1923 GST_ERROR ("Could not add capsfilter");
1924 gst_object_unref (capsfilter);
1925 gst_object_unref (parent);
1929 if (pending != GST_STATE_VOID_PENDING)
1932 gst_element_set_state (capsfilter, state);
1934 gst_object_unref (parent);
1936 g_object_set (capsfilter, "caps", filter, NULL);
1938 lr1 = gst_element_link_pads (src, srcpadname, capsfilter, "sink");
1939 lr2 = gst_element_link_pads (capsfilter, "src", dest, destpadname);
1944 GST_INFO ("Could not link pads: %s:%s - capsfilter:sink",
1945 GST_ELEMENT_NAME (src), srcpadname);
1947 GST_INFO ("Could not link pads: capsfilter:src - %s:%s",
1948 GST_ELEMENT_NAME (dest), destpadname);
1950 gst_element_set_state (capsfilter, GST_STATE_NULL);
1951 /* this will unlink and unref as appropriate */
1952 gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (capsfilter)), capsfilter);
1956 if (gst_element_link_pads (src, srcpadname, dest, destpadname)) {
1959 GST_INFO ("Could not link pads: %s:%s - %s:%s", GST_ELEMENT_NAME (src),
1960 srcpadname, GST_ELEMENT_NAME (dest), destpadname);
1968 * @src: (transfer none): a #GstElement containing the source pad.
1969 * @dest: (transfer none): the #GstElement containing the destination pad.
1971 * Links @src to @dest. The link must be from source to
1972 * destination; the other direction will not be tried. The function looks for
1973 * existing pads that aren't linked yet. It will request new pads if necessary.
1974 * Such pads need to be released manually when unlinking.
1975 * If multiple links are possible, only one is established.
1977 * Make sure you have added your elements to a bin or pipeline with
1978 * gst_bin_add() before trying to link them.
1980 * Returns: %TRUE if the elements could be linked, %FALSE otherwise.
1983 gst_element_link (GstElement * src, GstElement * dest)
1985 return gst_element_link_pads (src, NULL, dest, NULL);
1989 * gst_element_link_many:
1990 * @element_1: (transfer none): the first #GstElement in the link chain.
1991 * @element_2: (transfer none): the second #GstElement in the link chain.
1992 * @...: the %NULL-terminated list of elements to link in order.
1994 * Chain together a series of elements. Uses gst_element_link().
1995 * Make sure you have added your elements to a bin or pipeline with
1996 * gst_bin_add() before trying to link them.
1998 * Returns: %TRUE on success, %FALSE otherwise.
2001 gst_element_link_many (GstElement * element_1, GstElement * element_2, ...)
2003 gboolean res = TRUE;
2006 g_return_val_if_fail (GST_IS_ELEMENT (element_1), FALSE);
2007 g_return_val_if_fail (GST_IS_ELEMENT (element_2), FALSE);
2009 va_start (args, element_2);
2012 if (!gst_element_link (element_1, element_2)) {
2017 element_1 = element_2;
2018 element_2 = va_arg (args, GstElement *);
2027 * gst_element_link_filtered:
2028 * @src: a #GstElement containing the source pad.
2029 * @dest: (transfer none): the #GstElement containing the destination pad.
2030 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
2031 * or %NULL for no filter.
2033 * Links @src to @dest using the given caps as filtercaps.
2034 * The link must be from source to
2035 * destination; the other direction will not be tried. The function looks for
2036 * existing pads that aren't linked yet. It will request new pads if necessary.
2037 * If multiple links are possible, only one is established.
2039 * Make sure you have added your elements to a bin or pipeline with
2040 * gst_bin_add() before trying to link them.
2042 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2045 gst_element_link_filtered (GstElement * src, GstElement * dest,
2048 return gst_element_link_pads_filtered (src, NULL, dest, NULL, filter);
2052 * gst_element_unlink_pads:
2053 * @src: a (transfer none): #GstElement containing the source pad.
2054 * @srcpadname: the name of the #GstPad in source element.
2055 * @dest: (transfer none): a #GstElement containing the destination pad.
2056 * @destpadname: the name of the #GstPad in destination element.
2058 * Unlinks the two named pads of the source and destination elements.
2060 * This is a convenience function for gst_pad_unlink().
2063 gst_element_unlink_pads (GstElement * src, const gchar * srcpadname,
2064 GstElement * dest, const gchar * destpadname)
2066 GstPad *srcpad, *destpad;
2067 gboolean srcrequest, destrequest;
2069 srcrequest = destrequest = FALSE;
2071 g_return_if_fail (src != NULL);
2072 g_return_if_fail (GST_IS_ELEMENT (src));
2073 g_return_if_fail (srcpadname != NULL);
2074 g_return_if_fail (dest != NULL);
2075 g_return_if_fail (GST_IS_ELEMENT (dest));
2076 g_return_if_fail (destpadname != NULL);
2078 /* obtain the pads requested */
2079 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
2080 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
2082 if (srcpad == NULL) {
2083 GST_WARNING_OBJECT (src, "source element has no pad \"%s\"", srcpadname);
2086 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
2087 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
2089 if (destpad == NULL) {
2090 GST_WARNING_OBJECT (dest, "destination element has no pad \"%s\"",
2095 /* we're satisfied they can be unlinked, let's do it */
2096 gst_pad_unlink (srcpad, destpad);
2099 gst_element_release_request_pad (dest, destpad);
2100 gst_object_unref (destpad);
2104 gst_element_release_request_pad (src, srcpad);
2105 gst_object_unref (srcpad);
2109 * gst_element_unlink_many:
2110 * @element_1: (transfer none): the first #GstElement in the link chain.
2111 * @element_2: (transfer none): the second #GstElement in the link chain.
2112 * @...: the %NULL-terminated list of elements to unlink in order.
2114 * Unlinks a series of elements. Uses gst_element_unlink().
2117 gst_element_unlink_many (GstElement * element_1, GstElement * element_2, ...)
2121 g_return_if_fail (element_1 != NULL && element_2 != NULL);
2122 g_return_if_fail (GST_IS_ELEMENT (element_1) && GST_IS_ELEMENT (element_2));
2124 va_start (args, element_2);
2127 gst_element_unlink (element_1, element_2);
2129 element_1 = element_2;
2130 element_2 = va_arg (args, GstElement *);
2137 * gst_element_unlink:
2138 * @src: (transfer none): the source #GstElement to unlink.
2139 * @dest: (transfer none): the sink #GstElement to unlink.
2141 * Unlinks all source pads of the source element with all sink pads
2142 * of the sink element to which they are linked.
2144 * If the link has been made using gst_element_link(), it could have created an
2145 * requestpad, which has to be released using gst_element_release_request_pad().
2148 gst_element_unlink (GstElement * src, GstElement * dest)
2151 gboolean done = FALSE;
2152 GValue data = { 0, };
2154 g_return_if_fail (GST_IS_ELEMENT (src));
2155 g_return_if_fail (GST_IS_ELEMENT (dest));
2157 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unlinking \"%s\" and \"%s\"",
2158 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2160 pads = gst_element_iterate_pads (src);
2162 switch (gst_iterator_next (pads, &data)) {
2163 case GST_ITERATOR_OK:
2165 GstPad *pad = g_value_get_object (&data);
2167 if (GST_PAD_IS_SRC (pad)) {
2168 GstPad *peerpad = gst_pad_get_peer (pad);
2170 /* see if the pad is linked and is really a pad of dest */
2172 GstElement *peerelem;
2174 peerelem = gst_pad_get_parent_element (peerpad);
2176 if (peerelem == dest) {
2177 gst_pad_unlink (pad, peerpad);
2180 gst_object_unref (peerelem);
2182 gst_object_unref (peerpad);
2185 g_value_reset (&data);
2188 case GST_ITERATOR_RESYNC:
2189 gst_iterator_resync (pads);
2191 case GST_ITERATOR_DONE:
2195 g_assert_not_reached ();
2199 g_value_unset (&data);
2200 gst_iterator_free (pads);
2204 * gst_element_query_position:
2205 * @element: a #GstElement to invoke the position query on.
2206 * @format: the #GstFormat requested
2207 * @cur: (out) (allow-none): a location in which to store the current
2208 * position, or %NULL.
2210 * Queries an element (usually top-level pipeline or playbin element) for the
2211 * stream position in nanoseconds. This will be a value between 0 and the
2212 * stream duration (if the stream duration is known). This query will usually
2213 * only work once the pipeline is prerolled (i.e. reached PAUSED or PLAYING
2214 * state). The application will receive an ASYNC_DONE message on the pipeline
2215 * bus when that is the case.
2217 * If one repeatedly calls this function one can also create a query and reuse
2218 * it in gst_element_query().
2220 * Returns: %TRUE if the query could be performed.
2223 gst_element_query_position (GstElement * element, GstFormat format,
2229 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2230 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2232 query = gst_query_new_position (format);
2233 ret = gst_element_query (element, query);
2236 gst_query_parse_position (query, NULL, cur);
2238 gst_query_unref (query);
2244 * gst_element_query_duration:
2245 * @element: a #GstElement to invoke the duration query on.
2246 * @format: the #GstFormat requested
2247 * @duration: (out) (allow-none): A location in which to store the total duration, or %NULL.
2249 * Queries an element (usually top-level pipeline or playbin element) for the
2250 * total stream duration in nanoseconds. This query will only work once the
2251 * pipeline is prerolled (i.e. reached PAUSED or PLAYING state). The application
2252 * will receive an ASYNC_DONE message on the pipeline bus when that is the case.
2254 * If the duration changes for some reason, you will get a DURATION_CHANGED
2255 * message on the pipeline bus, in which case you should re-query the duration
2256 * using this function.
2258 * Returns: %TRUE if the query could be performed.
2261 gst_element_query_duration (GstElement * element, GstFormat format,
2267 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2268 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2270 query = gst_query_new_duration (format);
2271 ret = gst_element_query (element, query);
2274 gst_query_parse_duration (query, NULL, duration);
2276 gst_query_unref (query);
2282 * gst_element_query_convert:
2283 * @element: a #GstElement to invoke the convert query on.
2284 * @src_format: a #GstFormat to convert from.
2285 * @src_val: a value to convert.
2286 * @dest_format: the #GstFormat to convert to.
2287 * @dest_val: (out): a pointer to the result.
2289 * Queries an element to convert @src_val in @src_format to @dest_format.
2291 * Returns: %TRUE if the query could be performed.
2294 gst_element_query_convert (GstElement * element, GstFormat src_format,
2295 gint64 src_val, GstFormat dest_format, gint64 * dest_val)
2300 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2301 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2302 g_return_val_if_fail (dest_val != NULL, FALSE);
2304 if (dest_format == src_format || src_val == -1) {
2305 *dest_val = src_val;
2309 query = gst_query_new_convert (src_format, src_val, dest_format);
2310 ret = gst_element_query (element, query);
2313 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2315 gst_query_unref (query);
2321 * gst_element_seek_simple:
2322 * @element: a #GstElement to seek on
2323 * @format: a #GstFormat to execute the seek in, such as #GST_FORMAT_TIME
2324 * @seek_flags: seek options; playback applications will usually want to use
2325 * GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT here
2326 * @seek_pos: position to seek to (relative to the start); if you are doing
2327 * a seek in #GST_FORMAT_TIME this value is in nanoseconds -
2328 * multiply with #GST_SECOND to convert seconds to nanoseconds or
2329 * with #GST_MSECOND to convert milliseconds to nanoseconds.
2331 * Simple API to perform a seek on the given element, meaning it just seeks
2332 * to the given position relative to the start of the stream. For more complex
2333 * operations like segment seeks (e.g. for looping) or changing the playback
2334 * rate or seeking relative to the last configured playback segment you should
2335 * use gst_element_seek().
2337 * In a completely prerolled PAUSED or PLAYING pipeline, seeking is always
2338 * guaranteed to return %TRUE on a seekable media type or %FALSE when the media
2339 * type is certainly not seekable (such as a live stream).
2341 * Some elements allow for seeking in the READY state, in this
2342 * case they will store the seek event and execute it when they are put to
2343 * PAUSED. If the element supports seek in READY, it will always return %TRUE when
2344 * it receives the event in the READY state.
2346 * Returns: %TRUE if the seek operation succeeded. Flushing seeks will trigger a
2347 * preroll, which will emit %GST_MESSAGE_ASYNC_DONE.
2350 gst_element_seek_simple (GstElement * element, GstFormat format,
2351 GstSeekFlags seek_flags, gint64 seek_pos)
2353 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2354 g_return_val_if_fail (seek_pos >= 0, FALSE);
2356 return gst_element_seek (element, 1.0, format, seek_flags,
2357 GST_SEEK_TYPE_SET, seek_pos, GST_SEEK_TYPE_NONE, 0);
2361 * gst_pad_use_fixed_caps:
2362 * @pad: the pad to use
2364 * A helper function you can use that sets the FIXED_CAPS flag
2365 * This way the default CAPS query will always return the negotiated caps
2366 * or in case the pad is not negotiated, the padtemplate caps.
2368 * The negotiated caps are the caps of the last CAPS event that passed on the
2369 * pad. Use this function on a pad that, once it negotiated to a CAPS, cannot
2370 * be renegotiated to something else.
2373 gst_pad_use_fixed_caps (GstPad * pad)
2375 GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FIXED_CAPS);
2379 * gst_pad_get_parent_element:
2382 * Gets the parent of @pad, cast to a #GstElement. If a @pad has no parent or
2383 * its parent is not an element, return %NULL.
2385 * Returns: (transfer full) (nullable): the parent of the pad. The
2386 * caller has a reference on the parent, so unref when you're finished
2392 gst_pad_get_parent_element (GstPad * pad)
2396 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2398 p = gst_object_get_parent (GST_OBJECT_CAST (pad));
2400 if (p && !GST_IS_ELEMENT (p)) {
2401 gst_object_unref (p);
2404 return GST_ELEMENT_CAST (p);
2408 * gst_object_default_error:
2409 * @source: the #GstObject that initiated the error.
2410 * @error: (in): the GError.
2411 * @debug: (in) (allow-none): an additional debug information string, or %NULL
2413 * A default error function that uses g_printerr() to display the error message
2414 * and the optional debug sting..
2416 * The default handler will simply print the error string using g_print.
2419 gst_object_default_error (GstObject * source, const GError * error,
2420 const gchar * debug)
2422 gchar *name = gst_object_get_path_string (source);
2424 g_printerr (_("ERROR: from element %s: %s\n"), name, error->message);
2426 g_printerr (_("Additional debug info:\n%s\n"), debug);
2434 * @element_1: (transfer full): the #GstElement element to add to the bin
2435 * @...: (transfer full): additional elements to add to the bin
2437 * Adds a %NULL-terminated list of elements to a bin. This function is
2438 * equivalent to calling gst_bin_add() for each member of the list. The return
2439 * value of each gst_bin_add() is ignored.
2442 gst_bin_add_many (GstBin * bin, GstElement * element_1, ...)
2446 g_return_if_fail (GST_IS_BIN (bin));
2447 g_return_if_fail (GST_IS_ELEMENT (element_1));
2449 va_start (args, element_1);
2452 gst_bin_add (bin, element_1);
2454 element_1 = va_arg (args, GstElement *);
2461 * gst_bin_remove_many:
2463 * @element_1: (transfer none): the first #GstElement to remove from the bin
2464 * @...: (transfer none): %NULL-terminated list of elements to remove from the bin
2466 * Remove a list of elements from a bin. This function is equivalent
2467 * to calling gst_bin_remove() with each member of the list.
2470 gst_bin_remove_many (GstBin * bin, GstElement * element_1, ...)
2474 g_return_if_fail (GST_IS_BIN (bin));
2475 g_return_if_fail (GST_IS_ELEMENT (element_1));
2477 va_start (args, element_1);
2480 gst_bin_remove (bin, element_1);
2482 element_1 = va_arg (args, GstElement *);
2492 } QueryAcceptCapsData;
2495 query_accept_caps_func (GstPad * pad, QueryAcceptCapsData * data)
2497 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2500 gst_query_parse_accept_caps_result (data->query, &result);
2501 data->ret &= result;
2507 * gst_pad_proxy_query_accept_caps:
2508 * @pad: a #GstPad to proxy.
2509 * @query: an ACCEPT_CAPS #GstQuery.
2511 * Checks if all internally linked pads of @pad accepts the caps in @query and
2512 * returns the intersection of the results.
2514 * This function is useful as a default accept caps query function for an element
2515 * that can handle any stream format, but requires caps that are acceptable for
2516 * all opposite pads.
2518 * Returns: %TRUE if @query could be executed
2521 gst_pad_proxy_query_accept_caps (GstPad * pad, GstQuery * query)
2523 QueryAcceptCapsData data;
2525 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2526 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2527 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS, FALSE);
2529 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2530 "proxying accept caps query for %s:%s", GST_DEBUG_PAD_NAME (pad));
2533 /* value to hold the return, by default it holds TRUE */
2534 /* FIXME: TRUE is wrong when there are no pads */
2537 gst_pad_forward (pad, (GstPadForwardFunction) query_accept_caps_func, &data);
2538 gst_query_set_accept_caps_result (query, data.ret);
2540 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying accept caps query: %d",
2553 query_caps_func (GstPad * pad, QueryCapsData * data)
2555 gboolean empty = FALSE;
2557 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2558 GstCaps *peercaps, *intersection;
2560 gst_query_parse_caps_result (data->query, &peercaps);
2561 GST_DEBUG_OBJECT (pad, "intersect with result %" GST_PTR_FORMAT, peercaps);
2562 intersection = gst_caps_intersect (data->ret, peercaps);
2563 GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, intersection);
2565 gst_caps_unref (data->ret);
2566 data->ret = intersection;
2568 /* stop when empty */
2569 empty = gst_caps_is_empty (intersection);
2575 * gst_pad_proxy_query_caps:
2576 * @pad: a #GstPad to proxy.
2577 * @query: a CAPS #GstQuery.
2579 * Calls gst_pad_query_caps() for all internally linked pads of @pad and returns
2580 * the intersection of the results.
2582 * This function is useful as a default caps query function for an element
2583 * that can handle any stream format, but requires all its pads to have
2584 * the same caps. Two such elements are tee and adder.
2586 * Returns: %TRUE if @query could be executed
2589 gst_pad_proxy_query_caps (GstPad * pad, GstQuery * query)
2591 GstCaps *filter, *templ, *result;
2594 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2595 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2596 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CAPS, FALSE);
2598 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying caps query for %s:%s",
2599 GST_DEBUG_PAD_NAME (pad));
2603 /* value to hold the return, by default it holds the filter or ANY */
2604 gst_query_parse_caps (query, &filter);
2605 data.ret = filter ? gst_caps_ref (filter) : gst_caps_new_any ();
2607 gst_pad_forward (pad, (GstPadForwardFunction) query_caps_func, &data);
2609 templ = gst_pad_get_pad_template_caps (pad);
2610 result = gst_caps_intersect (data.ret, templ);
2611 gst_caps_unref (data.ret);
2612 gst_caps_unref (templ);
2614 gst_query_set_caps_result (query, result);
2615 gst_caps_unref (result);
2617 /* FIXME: return something depending on the processing */
2622 * gst_pad_query_position:
2623 * @pad: a #GstPad to invoke the position query on.
2624 * @format: the #GstFormat requested
2625 * @cur: (out) (allow-none): A location in which to store the current position, or %NULL.
2627 * Queries a pad for the stream position.
2629 * Returns: %TRUE if the query could be performed.
2632 gst_pad_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2637 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2638 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2640 query = gst_query_new_position (format);
2641 if ((ret = gst_pad_query (pad, query)))
2642 gst_query_parse_position (query, NULL, cur);
2643 gst_query_unref (query);
2649 * gst_pad_peer_query_position:
2650 * @pad: a #GstPad on whose peer to invoke the position query on.
2651 * Must be a sink pad.
2652 * @format: the #GstFormat requested
2653 * @cur: (out) (allow-none): a location in which to store the current
2654 * position, or %NULL.
2656 * Queries the peer of a given sink pad for the stream position.
2658 * Returns: %TRUE if the query could be performed.
2661 gst_pad_peer_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2664 gboolean ret = FALSE;
2666 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2667 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2669 query = gst_query_new_position (format);
2670 if ((ret = gst_pad_peer_query (pad, query)))
2671 gst_query_parse_position (query, NULL, cur);
2672 gst_query_unref (query);
2678 * gst_pad_query_duration:
2679 * @pad: a #GstPad to invoke the duration query on.
2680 * @format: the #GstFormat requested
2681 * @duration: (out) (allow-none): a location in which to store the total
2682 * duration, or %NULL.
2684 * Queries a pad for the total stream duration.
2686 * Returns: %TRUE if the query could be performed.
2689 gst_pad_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2694 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2695 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2697 query = gst_query_new_duration (format);
2698 if ((ret = gst_pad_query (pad, query)))
2699 gst_query_parse_duration (query, NULL, duration);
2700 gst_query_unref (query);
2706 * gst_pad_peer_query_duration:
2707 * @pad: a #GstPad on whose peer pad to invoke the duration query on.
2708 * Must be a sink pad.
2709 * @format: the #GstFormat requested
2710 * @duration: (out) (allow-none): a location in which to store the total
2711 * duration, or %NULL.
2713 * Queries the peer pad of a given sink pad for the total stream duration.
2715 * Returns: %TRUE if the query could be performed.
2718 gst_pad_peer_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2721 gboolean ret = FALSE;
2723 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2724 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2725 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2727 query = gst_query_new_duration (format);
2728 if ((ret = gst_pad_peer_query (pad, query)))
2729 gst_query_parse_duration (query, NULL, duration);
2730 gst_query_unref (query);
2736 * gst_pad_query_convert:
2737 * @pad: a #GstPad to invoke the convert query on.
2738 * @src_format: a #GstFormat to convert from.
2739 * @src_val: a value to convert.
2740 * @dest_format: the #GstFormat to convert to.
2741 * @dest_val: (out): a pointer to the result.
2743 * Queries a pad to convert @src_val in @src_format to @dest_format.
2745 * Returns: %TRUE if the query could be performed.
2748 gst_pad_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2749 GstFormat dest_format, gint64 * dest_val)
2754 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2755 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2756 g_return_val_if_fail (dest_val != NULL, FALSE);
2758 if (dest_format == src_format || src_val == -1) {
2759 *dest_val = src_val;
2763 query = gst_query_new_convert (src_format, src_val, dest_format);
2764 if ((ret = gst_pad_query (pad, query)))
2765 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2766 gst_query_unref (query);
2772 * gst_pad_peer_query_convert:
2773 * @pad: a #GstPad, on whose peer pad to invoke the convert query on.
2774 * Must be a sink pad.
2775 * @src_format: a #GstFormat to convert from.
2776 * @src_val: a value to convert.
2777 * @dest_format: the #GstFormat to convert to.
2778 * @dest_val: (out): a pointer to the result.
2780 * Queries the peer pad of a given sink pad to convert @src_val in @src_format
2783 * Returns: %TRUE if the query could be performed.
2786 gst_pad_peer_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2787 GstFormat dest_format, gint64 * dest_val)
2790 gboolean ret = FALSE;
2792 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2793 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2794 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2795 g_return_val_if_fail (dest_val != NULL, FALSE);
2797 query = gst_query_new_convert (src_format, src_val, dest_format);
2798 if ((ret = gst_pad_peer_query (pad, query)))
2799 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2800 gst_query_unref (query);
2806 * gst_pad_query_caps:
2807 * @pad: a #GstPad to get the capabilities of.
2808 * @filter: (allow-none): suggested #GstCaps, or %NULL
2810 * Gets the capabilities this pad can produce or consume.
2811 * Note that this method doesn't necessarily return the caps set by sending a
2812 * gst_event_new_caps() - use gst_pad_get_current_caps() for that instead.
2813 * gst_pad_query_caps returns all possible caps a pad can operate with, using
2814 * the pad's CAPS query function, If the query fails, this function will return
2815 * @filter, if not %NULL, otherwise ANY.
2817 * When called on sinkpads @filter contains the caps that
2818 * upstream could produce in the order preferred by upstream. When
2819 * called on srcpads @filter contains the caps accepted by
2820 * downstream in the preferred order. @filter might be %NULL but
2821 * if it is not %NULL the returned caps will be a subset of @filter.
2823 * Note that this function does not return writable #GstCaps, use
2824 * gst_caps_make_writable() before modifying the caps.
2826 * Returns: (transfer full): the caps of the pad with incremented ref-count.
2829 gst_pad_query_caps (GstPad * pad, GstCaps * filter)
2831 GstCaps *result = NULL;
2834 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2835 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2837 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2838 "get pad caps with filter %" GST_PTR_FORMAT, filter);
2840 query = gst_query_new_caps (filter);
2841 if (gst_pad_query (pad, query)) {
2842 gst_query_parse_caps_result (query, &result);
2843 gst_caps_ref (result);
2844 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2845 "query returned %" GST_PTR_FORMAT, result);
2846 } else if (filter) {
2847 result = gst_caps_ref (filter);
2849 result = gst_caps_new_any ();
2851 gst_query_unref (query);
2857 * gst_pad_peer_query_caps:
2858 * @pad: a #GstPad to get the capabilities of.
2859 * @filter: (allow-none): a #GstCaps filter, or %NULL.
2861 * Gets the capabilities of the peer connected to this pad. Similar to
2862 * gst_pad_query_caps().
2864 * When called on srcpads @filter contains the caps that
2865 * upstream could produce in the order preferred by upstream. When
2866 * called on sinkpads @filter contains the caps accepted by
2867 * downstream in the preferred order. @filter might be %NULL but
2868 * if it is not %NULL the returned caps will be a subset of @filter.
2870 * Returns: the caps of the peer pad with incremented ref-count. When there is
2871 * no peer pad, this function returns @filter or, when @filter is %NULL, ANY
2875 gst_pad_peer_query_caps (GstPad * pad, GstCaps * filter)
2877 GstCaps *result = NULL;
2880 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2881 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2883 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2884 "get pad peer caps with filter %" GST_PTR_FORMAT, filter);
2886 query = gst_query_new_caps (filter);
2887 if (gst_pad_peer_query (pad, query)) {
2888 gst_query_parse_caps_result (query, &result);
2889 gst_caps_ref (result);
2890 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2891 "peer query returned %" GST_PTR_FORMAT, result);
2892 } else if (filter) {
2893 result = gst_caps_ref (filter);
2895 result = gst_caps_new_any ();
2897 gst_query_unref (query);
2903 * gst_pad_query_accept_caps:
2904 * @pad: a #GstPad to check
2905 * @caps: a #GstCaps to check on the pad
2907 * Check if the given pad accepts the caps.
2909 * Returns: %TRUE if the pad can accept the caps.
2912 gst_pad_query_accept_caps (GstPad * pad, GstCaps * caps)
2914 gboolean res = TRUE;
2917 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2918 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
2920 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %"
2921 GST_PTR_FORMAT, caps);
2923 query = gst_query_new_accept_caps (caps);
2924 if (gst_pad_query (pad, query)) {
2925 gst_query_parse_accept_caps_result (query, &res);
2926 GST_DEBUG_OBJECT (pad, "query returned %d", res);
2928 gst_query_unref (query);
2934 * gst_pad_peer_query_accept_caps:
2935 * @pad: a #GstPad to check the peer of
2936 * @caps: a #GstCaps to check on the pad
2938 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2941 * Returns: %TRUE if the peer of @pad can accept the caps or @pad has no peer.
2944 gst_pad_peer_query_accept_caps (GstPad * pad, GstCaps * caps)
2946 gboolean res = TRUE;
2949 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2950 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
2952 query = gst_query_new_accept_caps (caps);
2953 if (gst_pad_peer_query (pad, query)) {
2954 gst_query_parse_accept_caps_result (query, &res);
2955 GST_DEBUG_OBJECT (pad, "query returned %d", res);
2957 gst_query_unref (query);
2963 element_find_unlinked_pad (GstElement * element, GstPadDirection direction)
2966 GstPad *unlinked_pad = NULL;
2968 GValue data = { 0, };
2970 switch (direction) {
2972 iter = gst_element_iterate_src_pads (element);
2975 iter = gst_element_iterate_sink_pads (element);
2978 g_return_val_if_reached (NULL);
2983 switch (gst_iterator_next (iter, &data)) {
2984 case GST_ITERATOR_OK:{
2986 GstPad *pad = g_value_get_object (&data);
2988 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
2989 GST_DEBUG_PAD_NAME (pad));
2991 peer = gst_pad_get_peer (pad);
2993 unlinked_pad = gst_object_ref (pad);
2995 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
2996 "found existing unlinked pad %s:%s",
2997 GST_DEBUG_PAD_NAME (unlinked_pad));
2999 gst_object_unref (peer);
3001 g_value_reset (&data);
3004 case GST_ITERATOR_DONE:
3007 case GST_ITERATOR_RESYNC:
3008 gst_iterator_resync (iter);
3010 case GST_ITERATOR_ERROR:
3011 g_return_val_if_reached (NULL);
3015 g_value_unset (&data);
3016 gst_iterator_free (iter);
3018 return unlinked_pad;
3022 * gst_bin_find_unlinked_pad:
3023 * @bin: bin in which to look for elements with unlinked pads
3024 * @direction: whether to look for an unlinked source or sink pad
3026 * Recursively looks for elements with an unlinked pad of the given
3027 * direction within the specified bin and returns an unlinked pad
3028 * if one is found, or %NULL otherwise. If a pad is found, the caller
3029 * owns a reference to it and should use gst_object_unref() on the
3030 * pad when it is not needed any longer.
3032 * Returns: (transfer full) (nullable): unlinked pad of the given
3036 gst_bin_find_unlinked_pad (GstBin * bin, GstPadDirection direction)
3041 GValue data = { 0, };
3043 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3044 g_return_val_if_fail (direction != GST_PAD_UNKNOWN, NULL);
3047 iter = gst_bin_iterate_recurse (bin);
3049 switch (gst_iterator_next (iter, &data)) {
3050 case GST_ITERATOR_OK:{
3051 GstElement *element = g_value_get_object (&data);
3053 pad = element_find_unlinked_pad (element, direction);
3056 g_value_reset (&data);
3059 case GST_ITERATOR_DONE:
3062 case GST_ITERATOR_RESYNC:
3063 gst_iterator_resync (iter);
3065 case GST_ITERATOR_ERROR:
3066 g_return_val_if_reached (NULL);
3070 g_value_unset (&data);
3071 gst_iterator_free (iter);
3077 gst_bin_sync_children_states_foreach (const GValue * value, gpointer user_data)
3079 gboolean *success = user_data;
3080 GstElement *element = g_value_get_object (value);
3082 if (gst_element_is_locked_state (element)) {
3085 *success = *success && gst_element_sync_state_with_parent (element);
3087 if (GST_IS_BIN (element))
3089 && gst_bin_sync_children_states (GST_BIN_CAST (element));
3094 * gst_bin_sync_children_states:
3097 * Synchronizes the state of every child of @bin with the state
3098 * of @bin. See also gst_element_sync_state_with_parent().
3100 * Returns: %TRUE if syncing the state was successful for all children,
3106 gst_bin_sync_children_states (GstBin * bin)
3109 GstIteratorResult res = GST_ITERATOR_OK;
3110 gboolean success = TRUE;
3112 it = gst_bin_iterate_sorted (bin);
3115 if (res == GST_ITERATOR_RESYNC) {
3117 gst_iterator_resync (it);
3120 gst_iterator_foreach (it, gst_bin_sync_children_states_foreach,
3122 } while (res == GST_ITERATOR_RESYNC);
3123 gst_iterator_free (it);
3129 * gst_parse_bin_from_description:
3130 * @bin_description: command line describing the bin
3131 * @ghost_unlinked_pads: whether to automatically create ghost pads
3132 * for unlinked source or sink pads within the bin
3133 * @err: where to store the error message in case of an error, or %NULL
3135 * This is a convenience wrapper around gst_parse_launch() to create a
3136 * #GstBin from a gst-launch-style pipeline description. See
3137 * gst_parse_launch() and the gst-launch man page for details about the
3138 * syntax. Ghost pads on the bin for unlinked source or sink pads
3139 * within the bin can automatically be created (but only a maximum of
3140 * one ghost pad for each direction will be created; if you expect
3141 * multiple unlinked source pads or multiple unlinked sink pads
3142 * and want them all ghosted, you will have to create the ghost pads
3145 * Returns: (transfer floating) (type Gst.Bin) (nullable): a
3146 * newly-created bin, or %NULL if an error occurred.
3149 gst_parse_bin_from_description (const gchar * bin_description,
3150 gboolean ghost_unlinked_pads, GError ** err)
3152 return gst_parse_bin_from_description_full (bin_description,
3153 ghost_unlinked_pads, NULL, GST_PARSE_FLAG_NONE, err);
3157 * gst_parse_bin_from_description_full:
3158 * @bin_description: command line describing the bin
3159 * @ghost_unlinked_pads: whether to automatically create ghost pads
3160 * for unlinked source or sink pads within the bin
3161 * @context: (transfer none) (allow-none): a parse context allocated with
3162 * gst_parse_context_new(), or %NULL
3163 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
3164 * @err: where to store the error message in case of an error, or %NULL
3166 * This is a convenience wrapper around gst_parse_launch() to create a
3167 * #GstBin from a gst-launch-style pipeline description. See
3168 * gst_parse_launch() and the gst-launch man page for details about the
3169 * syntax. Ghost pads on the bin for unlinked source or sink pads
3170 * within the bin can automatically be created (but only a maximum of
3171 * one ghost pad for each direction will be created; if you expect
3172 * multiple unlinked source pads or multiple unlinked sink pads
3173 * and want them all ghosted, you will have to create the ghost pads
3176 * Returns: (transfer floating) (type Gst.Element): a newly-created
3177 * element, which is guaranteed to be a bin unless
3178 * GST_FLAG_NO_SINGLE_ELEMENT_BINS was passed, or %NULL if an error
3182 gst_parse_bin_from_description_full (const gchar * bin_description,
3183 gboolean ghost_unlinked_pads, GstParseContext * context,
3184 GstParseFlags flags, GError ** err)
3186 #ifndef GST_DISABLE_PARSE
3188 GstElement *element;
3192 g_return_val_if_fail (bin_description != NULL, NULL);
3193 g_return_val_if_fail (err == NULL || *err == NULL, NULL);
3195 GST_DEBUG ("Making bin from description '%s'", bin_description);
3197 /* parse the pipeline to a bin */
3198 if (flags & GST_PARSE_FLAG_NO_SINGLE_ELEMENT_BINS) {
3199 element = gst_parse_launch_full (bin_description, context, flags, err);
3201 desc = g_strdup_printf ("bin.( %s )", bin_description);
3202 element = gst_parse_launch_full (desc, context, flags, err);
3206 if (element == NULL || (err && *err != NULL)) {
3208 gst_object_unref (element);
3212 if (GST_IS_BIN (element)) {
3213 bin = GST_BIN (element);
3218 /* find pads and ghost them if necessary */
3219 if (ghost_unlinked_pads) {
3220 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SRC))) {
3221 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("src", pad));
3222 gst_object_unref (pad);
3224 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SINK))) {
3225 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("sink", pad));
3226 gst_object_unref (pad);
3230 return GST_ELEMENT (bin);
3234 GST_WARNING ("Disabled API called");
3236 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
3237 g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);
3245 * gst_util_get_timestamp:
3247 * Get a timestamp as GstClockTime to be used for interval measurements.
3248 * The timestamp should not be interpreted in any other way.
3250 * Returns: the timestamp
3253 gst_util_get_timestamp (void)
3255 #if defined (HAVE_POSIX_TIMERS) && defined(HAVE_MONOTONIC_CLOCK) &&\
3256 defined (HAVE_CLOCK_GETTIME)
3257 struct timespec now;
3259 clock_gettime (CLOCK_MONOTONIC, &now);
3260 return GST_TIMESPEC_TO_TIME (now);
3264 g_get_current_time (&now);
3265 return GST_TIMEVAL_TO_TIME (now);
3270 * gst_util_array_binary_search:
3271 * @array: the sorted input array
3272 * @num_elements: number of elements in the array
3273 * @element_size: size of every element in bytes
3274 * @search_func: (scope call): function to compare two elements, @search_data will always be passed as second argument
3275 * @mode: search mode that should be used
3276 * @search_data: element that should be found
3277 * @user_data: (closure): data to pass to @search_func
3279 * Searches inside @array for @search_data by using the comparison function
3280 * @search_func. @array must be sorted ascending.
3282 * As @search_data is always passed as second argument to @search_func it's
3283 * not required that @search_data has the same type as the array elements.
3285 * The complexity of this search function is O(log (num_elements)).
3287 * Returns: (transfer none) (nullable): The address of the found
3288 * element or %NULL if nothing was found
3291 gst_util_array_binary_search (gpointer array, guint num_elements,
3292 gsize element_size, GCompareDataFunc search_func, GstSearchMode mode,
3293 gconstpointer search_data, gpointer user_data)
3295 glong left = 0, right = num_elements - 1, m;
3297 guint8 *data = (guint8 *) array;
3299 g_return_val_if_fail (array != NULL, NULL);
3300 g_return_val_if_fail (element_size > 0, NULL);
3301 g_return_val_if_fail (search_func != NULL, NULL);
3303 /* 0. No elements => return NULL */
3304 if (num_elements == 0)
3307 /* 1. If search_data is before the 0th element return the 0th element */
3308 ret = search_func (data, search_data, user_data);
3309 if ((ret >= 0 && mode == GST_SEARCH_MODE_AFTER) || ret == 0)
3314 /* 2. If search_data is after the last element return the last element */
3316 search_func (data + (num_elements - 1) * element_size, search_data,
3318 if ((ret <= 0 && mode == GST_SEARCH_MODE_BEFORE) || ret == 0)
3319 return data + (num_elements - 1) * element_size;
3323 /* 3. else binary search */
3325 m = left + (right - left) / 2;
3327 ret = search_func (data + m * element_size, search_data, user_data);
3330 return data + m * element_size;
3331 } else if (ret < 0) {
3337 /* No exact match found */
3339 if (mode == GST_SEARCH_MODE_EXACT) {
3341 } else if (mode == GST_SEARCH_MODE_AFTER) {
3343 return (m < num_elements) ? data + (m + 1) * element_size : NULL;
3345 return data + m * element_size;
3348 return data + m * element_size;
3350 return (m > 0) ? data + (m - 1) * element_size : NULL;
3356 /* Finds the greatest common divisor.
3357 * Returns 1 if none other found.
3358 * This is Euclid's algorithm. */
3361 * gst_util_greatest_common_divisor:
3362 * @a: First value as #gint
3363 * @b: Second value as #gint
3365 * Calculates the greatest common divisor of @a
3368 * Returns: Greatest common divisor of @a and @b
3371 gst_util_greatest_common_divisor (gint a, gint b)
3384 * gst_util_greatest_common_divisor_int64:
3385 * @a: First value as #gint64
3386 * @b: Second value as #gint64
3388 * Calculates the greatest common divisor of @a
3391 * Returns: Greatest common divisor of @a and @b
3394 gst_util_greatest_common_divisor_int64 (gint64 a, gint64 b)
3408 * gst_util_fraction_to_double:
3409 * @src_n: Fraction numerator as #gint
3410 * @src_d: Fraction denominator #gint
3411 * @dest: (out): pointer to a #gdouble for the result
3413 * Transforms a fraction to a #gdouble.
3416 gst_util_fraction_to_double (gint src_n, gint src_d, gdouble * dest)
3418 g_return_if_fail (dest != NULL);
3419 g_return_if_fail (src_d != 0);
3421 *dest = ((gdouble) src_n) / ((gdouble) src_d);
3424 #define MAX_TERMS 30
3425 #define MIN_DIVISOR 1.0e-10
3426 #define MAX_ERROR 1.0e-20
3428 /* use continued fractions to transform a double into a fraction,
3429 * see http://mathforum.org/dr.math/faq/faq.fractions.html#decfrac.
3430 * This algorithm takes care of overflows.
3434 * gst_util_double_to_fraction:
3435 * @src: #gdouble to transform
3436 * @dest_n: (out): pointer to a #gint to hold the result numerator
3437 * @dest_d: (out): pointer to a #gint to hold the result denominator
3439 * Transforms a #gdouble to a fraction and simplifies
3443 gst_util_double_to_fraction (gdouble src, gint * dest_n, gint * dest_d)
3446 gdouble V, F; /* double being converted */
3447 gint N, D; /* will contain the result */
3448 gint A; /* current term in continued fraction */
3449 gint64 N1, D1; /* numerator, denominator of last approx */
3450 gint64 N2, D2; /* numerator, denominator of previous approx */
3453 gboolean negative = FALSE;
3455 g_return_if_fail (dest_n != NULL);
3456 g_return_if_fail (dest_d != NULL);
3458 /* initialize fraction being converted */
3466 /* initialize fractions with 1/0, 0/1 */
3474 for (i = 0; i < MAX_TERMS; i++) {
3476 A = (gint) F; /* no floor() needed, F is always >= 0 */
3477 /* get new divisor */
3480 /* calculate new fraction in temp */
3484 /* guard against overflow */
3485 if (N2 > G_MAXINT || D2 > G_MAXINT) {
3492 /* save last two fractions */
3498 /* quit if dividing by zero or close enough to target */
3499 if (F < MIN_DIVISOR || fabs (V - ((gdouble) N) / D) < MAX_ERROR) {
3503 /* Take reciprocal */
3506 /* fix for overflow */
3511 /* fix for negative */
3516 gcd = gst_util_greatest_common_divisor (N, D);
3528 * gst_util_fraction_multiply:
3529 * @a_n: Numerator of first value
3530 * @a_d: Denominator of first value
3531 * @b_n: Numerator of second value
3532 * @b_d: Denominator of second value
3533 * @res_n: (out): Pointer to #gint to hold the result numerator
3534 * @res_d: (out): Pointer to #gint to hold the result denominator
3536 * Multiplies the fractions @a_n/@a_d and @b_n/@b_d and stores
3537 * the result in @res_n and @res_d.
3539 * Returns: %FALSE on overflow, %TRUE otherwise.
3542 gst_util_fraction_multiply (gint a_n, gint a_d, gint b_n, gint b_d,
3543 gint * res_n, gint * res_d)
3547 g_return_val_if_fail (res_n != NULL, FALSE);
3548 g_return_val_if_fail (res_d != NULL, FALSE);
3549 g_return_val_if_fail (a_d != 0, FALSE);
3550 g_return_val_if_fail (b_d != 0, FALSE);
3552 /* early out if either is 0, as its gcd would be 0 */
3553 if (a_n == 0 || b_n == 0) {
3559 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3563 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3567 gcd = gst_util_greatest_common_divisor (a_n, b_d);
3571 gcd = gst_util_greatest_common_divisor (a_d, b_n);
3575 /* This would result in overflow */
3576 if (a_n != 0 && G_MAXINT / ABS (a_n) < ABS (b_n))
3578 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3584 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3592 * gst_util_fraction_add:
3593 * @a_n: Numerator of first value
3594 * @a_d: Denominator of first value
3595 * @b_n: Numerator of second value
3596 * @b_d: Denominator of second value
3597 * @res_n: (out): Pointer to #gint to hold the result numerator
3598 * @res_d: (out): Pointer to #gint to hold the result denominator
3600 * Adds the fractions @a_n/@a_d and @b_n/@b_d and stores
3601 * the result in @res_n and @res_d.
3603 * Returns: %FALSE on overflow, %TRUE otherwise.
3606 gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint * res_n,
3611 g_return_val_if_fail (res_n != NULL, FALSE);
3612 g_return_val_if_fail (res_d != NULL, FALSE);
3613 g_return_val_if_fail (a_d != 0, FALSE);
3614 g_return_val_if_fail (b_d != 0, FALSE);
3616 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3620 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3635 /* This would result in overflow */
3636 if (G_MAXINT / ABS (a_n) < ABS (b_n))
3638 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3641 *res_n = (a_n * b_d) + (a_d * b_n);
3644 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3657 * gst_util_fraction_compare:
3658 * @a_n: Numerator of first value
3659 * @a_d: Denominator of first value
3660 * @b_n: Numerator of second value
3661 * @b_d: Denominator of second value
3663 * Compares the fractions @a_n/@a_d and @b_n/@b_d and returns
3664 * -1 if a < b, 0 if a = b and 1 if a > b.
3666 * Returns: -1 if a < b; 0 if a = b; 1 if a > b.
3669 gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d)
3675 g_return_val_if_fail (a_d != 0 && b_d != 0, 0);
3678 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3682 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3686 /* fractions are reduced when set, so we can quickly see if they're equal */
3687 if (a_n == b_n && a_d == b_d)
3690 /* extend to 64 bits */
3691 new_num_1 = ((gint64) a_n) * b_d;
3692 new_num_2 = ((gint64) b_n) * a_d;
3693 if (new_num_1 < new_num_2)
3695 if (new_num_1 > new_num_2)
3698 /* Should not happen because a_d and b_d are not 0 */
3699 g_return_val_if_reached (0);
3703 gst_pad_create_stream_id_internal (GstPad * pad, GstElement * parent,
3704 const gchar * stream_id)
3706 GstEvent *upstream_event;
3707 gchar *upstream_stream_id = NULL, *new_stream_id;
3710 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3711 g_return_val_if_fail (GST_PAD_IS_SRC (pad), NULL);
3712 g_return_val_if_fail (GST_IS_ELEMENT (parent), NULL);
3714 g_return_val_if_fail (parent->numsinkpads <= 1, NULL);
3716 /* If the element has multiple source pads it must
3717 * provide a stream-id for every source pad, otherwise
3718 * all source pads will have the same and are not
3719 * distinguishable */
3720 g_return_val_if_fail (parent->numsrcpads <= 1 || stream_id, NULL);
3722 /* First try to get the upstream stream-start stream-id from the sinkpad.
3723 * This will only work for non-source elements */
3724 sinkpad = gst_element_get_static_pad (parent, "sink");
3727 gst_pad_get_sticky_event (sinkpad, GST_EVENT_STREAM_START, 0);
3728 if (upstream_event) {
3731 gst_event_parse_stream_start (upstream_event, &tmp);
3733 upstream_stream_id = g_strdup (tmp);
3734 gst_event_unref (upstream_event);
3736 gst_object_unref (sinkpad);
3739 /* The only case where we don't have an upstream start-start event
3740 * here is for source elements */
3741 if (!upstream_stream_id) {
3745 /* Try to generate one from the URI query and
3746 * if it fails take a random number instead */
3747 query = gst_query_new_uri ();
3748 if (gst_element_query (parent, query)) {
3749 gst_query_parse_uri (query, &uri);
3755 /* And then generate an SHA256 sum of the URI */
3756 cs = g_checksum_new (G_CHECKSUM_SHA256);
3757 g_checksum_update (cs, (const guchar *) uri, strlen (uri));
3759 upstream_stream_id = g_strdup (g_checksum_get_string (cs));
3760 g_checksum_free (cs);
3762 /* Just get some random number if the URI query fails */
3763 GST_FIXME_OBJECT (pad, "Creating random stream-id, consider "
3764 "implementing a deterministic way of creating a stream-id");
3765 upstream_stream_id =
3766 g_strdup_printf ("%08x%08x%08x%08x", g_random_int (), g_random_int (),
3767 g_random_int (), g_random_int ());
3770 gst_query_unref (query);
3774 new_stream_id = g_strconcat (upstream_stream_id, "/", stream_id, NULL);
3776 new_stream_id = g_strdup (upstream_stream_id);
3779 g_free (upstream_stream_id);
3781 return new_stream_id;
3785 * gst_pad_create_stream_id_printf_valist:
3786 * @pad: A source #GstPad
3787 * @parent: Parent #GstElement of @pad
3788 * @stream_id: (allow-none): The stream-id
3789 * @var_args: parameters for the @stream_id format string
3791 * Creates a stream-id for the source #GstPad @pad by combining the
3792 * upstream information with the optional @stream_id of the stream
3793 * of @pad. @pad must have a parent #GstElement and which must have zero
3794 * or one sinkpad. @stream_id can only be %NULL if the parent element
3795 * of @pad has only a single source pad.
3797 * This function generates an unique stream-id by getting the upstream
3798 * stream-start event stream ID and appending @stream_id to it. If the
3799 * element has no sinkpad it will generate an upstream stream-id by
3800 * doing an URI query on the element and in the worst case just uses
3801 * a random number. Source elements that don't implement the URI
3802 * handler interface should ideally generate a unique, deterministic
3803 * stream-id manually instead.
3805 * Returns: A stream-id for @pad. g_free() after usage.
3808 gst_pad_create_stream_id_printf_valist (GstPad * pad, GstElement * parent,
3809 const gchar * stream_id, va_list var_args)
3811 gchar *expanded = NULL, *new_stream_id;
3814 expanded = g_strdup_vprintf (stream_id, var_args);
3816 new_stream_id = gst_pad_create_stream_id_internal (pad, parent, expanded);
3820 return new_stream_id;
3824 * gst_pad_create_stream_id_printf:
3825 * @pad: A source #GstPad
3826 * @parent: Parent #GstElement of @pad
3827 * @stream_id: (allow-none): The stream-id
3828 * @...: parameters for the @stream_id format string
3830 * Creates a stream-id for the source #GstPad @pad by combining the
3831 * upstream information with the optional @stream_id of the stream
3832 * of @pad. @pad must have a parent #GstElement and which must have zero
3833 * or one sinkpad. @stream_id can only be %NULL if the parent element
3834 * of @pad has only a single source pad.
3836 * This function generates an unique stream-id by getting the upstream
3837 * stream-start event stream ID and appending @stream_id to it. If the
3838 * element has no sinkpad it will generate an upstream stream-id by
3839 * doing an URI query on the element and in the worst case just uses
3840 * a random number. Source elements that don't implement the URI
3841 * handler interface should ideally generate a unique, deterministic
3842 * stream-id manually instead.
3844 * Returns: A stream-id for @pad. g_free() after usage.
3847 gst_pad_create_stream_id_printf (GstPad * pad, GstElement * parent,
3848 const gchar * stream_id, ...)
3851 gchar *new_stream_id;
3853 va_start (var_args, stream_id);
3855 gst_pad_create_stream_id_printf_valist (pad, parent, stream_id, var_args);
3858 return new_stream_id;
3862 * gst_pad_create_stream_id:
3863 * @pad: A source #GstPad
3864 * @parent: Parent #GstElement of @pad
3865 * @stream_id: (allow-none): The stream-id
3867 * Creates a stream-id for the source #GstPad @pad by combining the
3868 * upstream information with the optional @stream_id of the stream
3869 * of @pad. @pad must have a parent #GstElement and which must have zero
3870 * or one sinkpad. @stream_id can only be %NULL if the parent element
3871 * of @pad has only a single source pad.
3873 * This function generates an unique stream-id by getting the upstream
3874 * stream-start event stream ID and appending @stream_id to it. If the
3875 * element has no sinkpad it will generate an upstream stream-id by
3876 * doing an URI query on the element and in the worst case just uses
3877 * a random number. Source elements that don't implement the URI
3878 * handler interface should ideally generate a unique, deterministic
3879 * stream-id manually instead.
3881 * Since stream IDs are sorted alphabetically, any numbers in the
3882 * stream ID should be printed with a fixed number of characters,
3883 * preceded by 0's, such as by using the format \%03u instead of \%u.
3885 * Returns: A stream-id for @pad. g_free() after usage.
3888 gst_pad_create_stream_id (GstPad * pad, GstElement * parent,
3889 const gchar * stream_id)
3891 return gst_pad_create_stream_id_internal (pad, parent, stream_id);
3895 * gst_pad_get_stream_id:
3896 * @pad: A source #GstPad
3898 * Returns the current stream-id for the @pad, or %NULL if none has been
3899 * set yet, i.e. the pad has not received a stream-start event yet.
3901 * This is a convenience wrapper around gst_pad_get_sticky_event() and
3902 * gst_event_parse_stream_start().
3904 * The returned stream-id string should be treated as an opaque string, its
3905 * contents should not be interpreted.
3907 * Returns: (nullable): a newly-allocated copy of the stream-id for
3908 * @pad, or %NULL. g_free() the returned string when no longer
3914 gst_pad_get_stream_id (GstPad * pad)
3916 const gchar *stream_id = NULL;
3920 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3922 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
3923 if (event != NULL) {
3924 gst_event_parse_stream_start (event, &stream_id);
3925 ret = g_strdup (stream_id);
3926 gst_event_unref (event);
3927 GST_LOG_OBJECT (pad, "pad has stream-id '%s'", ret);
3929 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");
3936 * gst_util_group_id_next:
3938 * Return a constantly incrementing group id.
3940 * This function is used to generate a new group-id for the
3941 * stream-start event.
3943 * Returns: A constantly incrementing unsigned integer, which might
3944 * overflow back to 0 at some point.
3947 gst_util_group_id_next (void)
3949 static gint counter = 0;
3950 return g_atomic_int_add (&counter, 1);