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);
1366 gst_object_unref (root);
1368 if (!object_has_ancestor (o2, kid1, &kid2)) {
1369 gst_object_unref (kid1);
1372 gst_object_unref (root);
1377 /* caller does not own return */
1379 ghost_up (GstElement * e, GstPad * pad)
1381 static gint ghost_pad_index = 0;
1386 GstObject *parent = GST_OBJECT_PARENT (e);
1388 name = g_strdup_printf ("ghost%d", ghost_pad_index++);
1389 gpad = gst_ghost_pad_new (name, pad);
1392 GST_STATE_LOCK (parent);
1393 gst_element_get_state (GST_ELEMENT (parent), ¤t, &next, 0);
1395 if (current > GST_STATE_READY || next >= GST_STATE_PAUSED)
1396 gst_pad_set_active (gpad, TRUE);
1398 if (!gst_element_add_pad ((GstElement *) parent, gpad)) {
1399 g_warning ("Pad named %s already exists in element %s\n",
1400 GST_OBJECT_NAME (gpad), GST_OBJECT_NAME (parent));
1401 gst_object_unref ((GstObject *) gpad);
1402 GST_STATE_UNLOCK (parent);
1405 GST_STATE_UNLOCK (parent);
1411 remove_pad (gpointer ppad, gpointer unused)
1415 if (!gst_element_remove_pad ((GstElement *) GST_OBJECT_PARENT (pad), pad))
1416 g_warning ("Couldn't remove pad %s from element %s",
1417 GST_OBJECT_NAME (pad), GST_OBJECT_NAME (GST_OBJECT_PARENT (pad)));
1421 prepare_link_maybe_ghosting (GstPad ** src, GstPad ** sink,
1422 GSList ** pads_created)
1426 GSList *pads_created_local = NULL;
1428 g_assert (pads_created);
1430 e1 = GST_OBJECT_PARENT (*src);
1431 e2 = GST_OBJECT_PARENT (*sink);
1433 if (G_UNLIKELY (e1 == NULL)) {
1434 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1435 GST_PTR_FORMAT, *src);
1438 if (G_UNLIKELY (e2 == NULL)) {
1439 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1440 GST_PTR_FORMAT, *sink);
1444 if (GST_OBJECT_PARENT (e1) == GST_OBJECT_PARENT (e2)) {
1445 GST_CAT_INFO (GST_CAT_PADS, "%s and %s in same bin, no need for ghost pads",
1446 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1450 GST_CAT_INFO (GST_CAT_PADS, "%s and %s not in same bin, making ghost pads",
1451 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1453 /* we need to setup some ghost pads */
1454 root = find_common_root (e1, e2);
1456 if (GST_OBJECT_PARENT (e1) == NULL)
1457 g_warning ("Trying to link elements %s and %s that don't share a common "
1458 "ancestor: %s hasn't been added to a bin or pipeline, but %s is in %s",
1459 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1460 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1461 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1462 else if (GST_OBJECT_PARENT (e2) == NULL)
1463 g_warning ("Trying to link elements %s and %s that don't share a common "
1464 "ancestor: %s hasn't been added to a bin or pipeline, and %s is in %s",
1465 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1466 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (e1),
1467 GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)));
1469 g_warning ("Trying to link elements %s and %s that don't share a common "
1470 "ancestor: %s is in %s, and %s is in %s",
1471 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2),
1472 GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e1)),
1473 GST_ELEMENT_NAME (e2), GST_ELEMENT_NAME (GST_OBJECT_PARENT (e2)));
1477 while (GST_OBJECT_PARENT (e1) != root) {
1478 *src = ghost_up ((GstElement *) e1, *src);
1481 e1 = GST_OBJECT_PARENT (*src);
1482 pads_created_local = g_slist_prepend (pads_created_local, *src);
1484 while (GST_OBJECT_PARENT (e2) != root) {
1485 *sink = ghost_up ((GstElement *) e2, *sink);
1488 e2 = GST_OBJECT_PARENT (*sink);
1489 pads_created_local = g_slist_prepend (pads_created_local, *sink);
1492 gst_object_unref (root);
1493 *pads_created = g_slist_concat (*pads_created, pads_created_local);
1497 gst_object_unref (root);
1498 g_slist_foreach (pads_created_local, remove_pad, NULL);
1499 g_slist_free (pads_created_local);
1504 pad_link_maybe_ghosting (GstPad * src, GstPad * sink, GstPadLinkCheck flags)
1506 GSList *pads_created = NULL;
1509 if (!prepare_link_maybe_ghosting (&src, &sink, &pads_created)) {
1512 ret = (gst_pad_link_full (src, sink, flags) == GST_PAD_LINK_OK);
1516 g_slist_foreach (pads_created, remove_pad, NULL);
1518 g_slist_free (pads_created);
1524 * gst_pad_link_maybe_ghosting_full:
1527 * @flags: some #GstPadLinkCheck flags
1529 * Links @src to @sink, creating any #GstGhostPad's in between as necessary.
1531 * This is a convenience function to save having to create and add intermediate
1532 * #GstGhostPad's as required for linking across #GstBin boundaries.
1534 * If @src or @sink pads don't have parent elements or do not share a common
1535 * ancestor, the link will fail.
1537 * Calling gst_pad_link_maybe_ghosting_full() with
1538 * @flags == %GST_PAD_LINK_CHECK_DEFAULT is the recommended way of linking
1539 * pads with safety checks applied.
1541 * Returns: whether the link succeeded.
1546 gst_pad_link_maybe_ghosting_full (GstPad * src, GstPad * sink,
1547 GstPadLinkCheck flags)
1549 g_return_val_if_fail (GST_IS_PAD (src), FALSE);
1550 g_return_val_if_fail (GST_IS_PAD (sink), FALSE);
1552 return pad_link_maybe_ghosting (src, sink, flags);
1556 * gst_pad_link_maybe_ghosting:
1560 * Links @src to @sink, creating any #GstGhostPad's in between as necessary.
1562 * This is a convenience function to save having to create and add intermediate
1563 * #GstGhostPad's as required for linking across #GstBin boundaries.
1565 * If @src or @sink pads don't have parent elements or do not share a common
1566 * ancestor, the link will fail.
1568 * Returns: whether the link succeeded.
1573 gst_pad_link_maybe_ghosting (GstPad * src, GstPad * sink)
1575 g_return_val_if_fail (GST_IS_PAD (src), FALSE);
1576 g_return_val_if_fail (GST_IS_PAD (sink), FALSE);
1578 return gst_pad_link_maybe_ghosting_full (src, sink,
1579 GST_PAD_LINK_CHECK_DEFAULT);
1583 release_and_unref_pad (GstElement * element, GstPad * pad, gboolean requestpad)
1587 gst_element_release_request_pad (element, pad);
1588 gst_object_unref (pad);
1593 * gst_element_link_pads_full:
1594 * @src: a #GstElement containing the source pad.
1595 * @srcpadname: (allow-none): the name of the #GstPad in source element
1596 * or %NULL for any pad.
1597 * @dest: (transfer none): the #GstElement containing the destination pad.
1598 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1599 * or %NULL for any pad.
1600 * @flags: the #GstPadLinkCheck to be performed when linking pads.
1602 * Links the two named pads of the source and destination elements.
1603 * Side effect is that if one of the pads has no parent, it becomes a
1604 * child of the parent of the other element. If they have different
1605 * parents, the link fails.
1607 * Calling gst_element_link_pads_full() with @flags == %GST_PAD_LINK_CHECK_DEFAULT
1608 * is the same as calling gst_element_link_pads() and the recommended way of
1609 * linking pads with safety checks applied.
1611 * This is a convenience function for gst_pad_link_full().
1613 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1616 gst_element_link_pads_full (GstElement * src, const gchar * srcpadname,
1617 GstElement * dest, const gchar * destpadname, GstPadLinkCheck flags)
1619 const GList *srcpads, *destpads, *srctempls, *desttempls, *l;
1620 GstPad *srcpad, *destpad;
1621 GstPadTemplate *srctempl, *desttempl;
1622 GstElementClass *srcclass, *destclass;
1623 gboolean srcrequest, destrequest;
1626 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1627 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1629 GST_CAT_INFO (GST_CAT_ELEMENT_PADS,
1630 "trying to link element %s:%s to element %s:%s", GST_ELEMENT_NAME (src),
1631 srcpadname ? srcpadname : "(any)", GST_ELEMENT_NAME (dest),
1632 destpadname ? destpadname : "(any)");
1635 destrequest = FALSE;
1639 /* name specified, look it up */
1640 if (!(srcpad = gst_element_get_static_pad (src, srcpadname))) {
1641 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
1645 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1646 GST_ELEMENT_NAME (src), srcpadname);
1649 if (!(GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC)) {
1650 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no src pad",
1651 GST_DEBUG_PAD_NAME (srcpad));
1652 release_and_unref_pad (src, srcpad, srcrequest);
1655 if (GST_PAD_PEER (srcpad) != NULL) {
1656 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1657 "pad %s:%s is already linked to %s:%s", GST_DEBUG_PAD_NAME (srcpad),
1658 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1659 /* already linked request pads look like static pads, so the request pad
1660 * was never requested a second time above, so no need to release it */
1661 gst_object_unref (srcpad);
1667 /* no name given, get the first available pad */
1668 GST_OBJECT_LOCK (src);
1669 srcpads = GST_ELEMENT_PADS (src);
1670 srcpad = srcpads ? GST_PAD_CAST (srcpads->data) : NULL;
1672 gst_object_ref (srcpad);
1673 GST_OBJECT_UNLOCK (src);
1676 /* get a destination pad */
1678 /* name specified, look it up */
1679 if (!(destpad = gst_element_get_static_pad (dest, destpadname))) {
1680 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
1684 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1685 GST_ELEMENT_NAME (dest), destpadname);
1686 release_and_unref_pad (src, srcpad, srcrequest);
1689 if (!(GST_PAD_DIRECTION (destpad) == GST_PAD_SINK)) {
1690 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no sink pad",
1691 GST_DEBUG_PAD_NAME (destpad));
1692 release_and_unref_pad (src, srcpad, srcrequest);
1693 release_and_unref_pad (dest, destpad, destrequest);
1696 if (GST_PAD_PEER (destpad) != NULL) {
1697 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1698 "pad %s:%s is already linked to %s:%s",
1699 GST_DEBUG_PAD_NAME (destpad),
1700 GST_DEBUG_PAD_NAME (GST_PAD_PEER (destpad)));
1701 release_and_unref_pad (src, srcpad, srcrequest);
1702 /* already linked request pads look like static pads, so the request pad
1703 * was never requested a second time above, so no need to release it */
1704 gst_object_unref (destpad);
1710 /* no name given, get the first available pad */
1711 GST_OBJECT_LOCK (dest);
1712 destpads = GST_ELEMENT_PADS (dest);
1713 destpad = destpads ? GST_PAD_CAST (destpads->data) : NULL;
1715 gst_object_ref (destpad);
1716 GST_OBJECT_UNLOCK (dest);
1719 if (srcpadname && destpadname) {
1722 /* two explicitly specified pads */
1723 result = pad_link_maybe_ghosting (srcpad, destpad, flags);
1726 gst_object_unref (srcpad);
1727 gst_object_unref (destpad);
1729 release_and_unref_pad (src, srcpad, srcrequest);
1730 release_and_unref_pad (dest, destpad, destrequest);
1736 /* loop through the allowed pads in the source, trying to find a
1737 * compatible destination pad */
1738 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1739 "looping through allowed src and dest pads");
1741 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying src pad %s:%s",
1742 GST_DEBUG_PAD_NAME (srcpad));
1743 if ((GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC) &&
1744 (GST_PAD_PEER (srcpad) == NULL)) {
1745 gboolean temprequest = FALSE;
1750 gst_object_ref (temp);
1752 temp = gst_element_get_compatible_pad (dest, srcpad, NULL);
1753 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1754 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
1760 if (temp && pad_link_maybe_ghosting (srcpad, temp, flags)) {
1761 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1762 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (temp));
1764 gst_object_unref (destpad);
1765 gst_object_unref (srcpad);
1766 gst_object_unref (temp);
1772 gst_element_release_request_pad (dest, temp);
1773 gst_object_unref (temp);
1776 /* find a better way for this mess */
1778 srcpads = g_list_next (srcpads);
1780 gst_object_unref (srcpad);
1781 srcpad = GST_PAD_CAST (srcpads->data);
1782 gst_object_ref (srcpad);
1788 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s:%s to %s",
1789 GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (dest));
1790 /* no need to release any request pad as both src- and destpadname must be
1791 * set to end up here, but this case has already been taken care of above */
1793 gst_object_unref (destpad);
1797 release_and_unref_pad (src, srcpad, srcrequest);
1802 /* loop through the existing pads in the destination */
1804 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying dest pad %s:%s",
1805 GST_DEBUG_PAD_NAME (destpad));
1806 if ((GST_PAD_DIRECTION (destpad) == GST_PAD_SINK) &&
1807 (GST_PAD_PEER (destpad) == NULL)) {
1808 GstPad *temp = gst_element_get_compatible_pad (src, destpad, NULL);
1809 gboolean temprequest = FALSE;
1811 if (temp && GST_PAD_PAD_TEMPLATE (temp)
1812 && GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (temp)) ==
1817 if (temp && pad_link_maybe_ghosting (temp, destpad, flags)) {
1818 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1819 GST_DEBUG_PAD_NAME (temp), GST_DEBUG_PAD_NAME (destpad));
1820 gst_object_unref (temp);
1821 gst_object_unref (destpad);
1825 release_and_unref_pad (src, temp, temprequest);
1828 destpads = g_list_next (destpads);
1830 gst_object_unref (destpad);
1831 destpad = GST_PAD_CAST (destpads->data);
1832 gst_object_ref (destpad);
1839 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s:%s",
1840 GST_ELEMENT_NAME (src), GST_DEBUG_PAD_NAME (destpad));
1841 release_and_unref_pad (dest, destpad, destrequest);
1844 /* no need to release any request pad as the case of unset destpatname and
1845 * destpad being a requst pad has already been taken care of when looking
1846 * though the destination pads above */
1848 gst_object_unref (destpad);
1853 srcclass = GST_ELEMENT_GET_CLASS (src);
1854 destclass = GST_ELEMENT_GET_CLASS (dest);
1856 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1857 "we might have request pads on both sides, checking...");
1858 srctempls = gst_element_class_get_pad_template_list (srcclass);
1859 desttempls = gst_element_class_get_pad_template_list (destclass);
1861 if (srctempls && desttempls) {
1863 srctempl = (GstPadTemplate *) srctempls->data;
1864 if (srctempl->presence == GST_PAD_REQUEST) {
1865 for (l = desttempls; l; l = l->next) {
1866 desttempl = (GstPadTemplate *) l->data;
1867 if (desttempl->presence == GST_PAD_REQUEST &&
1868 desttempl->direction != srctempl->direction) {
1869 GstCaps *srccaps, *destcaps;
1871 srccaps = gst_pad_template_get_caps (srctempl);
1872 destcaps = gst_pad_template_get_caps (desttempl);
1873 if (gst_caps_is_always_compatible (srccaps, destcaps)) {
1875 gst_element_request_pad (src, srctempl,
1876 srctempl->name_template, NULL);
1878 gst_element_request_pad (dest, desttempl,
1879 desttempl->name_template, NULL);
1880 if (srcpad && destpad
1881 && pad_link_maybe_ghosting (srcpad, destpad, flags)) {
1882 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1883 "linked pad %s:%s to pad %s:%s",
1884 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (destpad));
1885 gst_object_unref (srcpad);
1886 gst_object_unref (destpad);
1887 gst_caps_unref (srccaps);
1888 gst_caps_unref (destcaps);
1891 /* it failed, so we release the request pads */
1893 gst_element_release_request_pad (src, srcpad);
1894 gst_object_unref (srcpad);
1897 gst_element_release_request_pad (dest, destpad);
1898 gst_object_unref (destpad);
1901 gst_caps_unref (srccaps);
1902 gst_caps_unref (destcaps);
1906 srctempls = srctempls->next;
1910 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s",
1911 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
1916 * gst_element_link_pads:
1917 * @src: a #GstElement containing the source pad.
1918 * @srcpadname: (allow-none): the name of the #GstPad in source element
1919 * or %NULL for any pad.
1920 * @dest: (transfer none): the #GstElement containing the destination pad.
1921 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1922 * or %NULL for any pad.
1924 * Links the two named pads of the source and destination elements.
1925 * Side effect is that if one of the pads has no parent, it becomes a
1926 * child of the parent of the other element. If they have different
1927 * parents, the link fails.
1929 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1932 gst_element_link_pads (GstElement * src, const gchar * srcpadname,
1933 GstElement * dest, const gchar * destpadname)
1935 return gst_element_link_pads_full (src, srcpadname, dest, destpadname,
1936 GST_PAD_LINK_CHECK_DEFAULT);
1940 * gst_element_link_pads_filtered:
1941 * @src: a #GstElement containing the source pad.
1942 * @srcpadname: (allow-none): the name of the #GstPad in source element
1943 * or %NULL for any pad.
1944 * @dest: (transfer none): the #GstElement containing the destination pad.
1945 * @destpadname: (allow-none): the name of the #GstPad in destination element
1946 * or %NULL for any pad.
1947 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
1948 * or %NULL for no filter.
1950 * Links the two named pads of the source and destination elements. Side effect
1951 * is that if one of the pads has no parent, it becomes a child of the parent of
1952 * the other element. If they have different parents, the link fails. If @caps
1953 * is not %NULL, makes sure that the caps of the link is a subset of @caps.
1955 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
1958 gst_element_link_pads_filtered (GstElement * src, const gchar * srcpadname,
1959 GstElement * dest, const gchar * destpadname, GstCaps * filter)
1962 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1963 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1964 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), FALSE);
1967 GstElement *capsfilter;
1969 GstState state, pending;
1972 capsfilter = gst_element_factory_make ("capsfilter", NULL);
1974 GST_ERROR ("Could not make a capsfilter");
1978 parent = gst_object_get_parent (GST_OBJECT (src));
1979 g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
1981 gst_element_get_state (GST_ELEMENT_CAST (parent), &state, &pending, 0);
1983 if (!gst_bin_add (GST_BIN (parent), capsfilter)) {
1984 GST_ERROR ("Could not add capsfilter");
1985 gst_object_unref (capsfilter);
1986 gst_object_unref (parent);
1990 if (pending != GST_STATE_VOID_PENDING)
1993 gst_element_set_state (capsfilter, state);
1995 gst_object_unref (parent);
1997 g_object_set (capsfilter, "caps", filter, NULL);
1999 lr1 = gst_element_link_pads (src, srcpadname, capsfilter, "sink");
2000 lr2 = gst_element_link_pads (capsfilter, "src", dest, destpadname);
2005 GST_INFO ("Could not link pads: %s:%s - capsfilter:sink",
2006 GST_ELEMENT_NAME (src), srcpadname);
2008 GST_INFO ("Could not link pads: capsfilter:src - %s:%s",
2009 GST_ELEMENT_NAME (dest), destpadname);
2011 gst_element_set_state (capsfilter, GST_STATE_NULL);
2012 /* this will unlink and unref as appropriate */
2013 gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (capsfilter)), capsfilter);
2017 if (gst_element_link_pads (src, srcpadname, dest, destpadname)) {
2020 GST_INFO ("Could not link pads: %s:%s - %s:%s", GST_ELEMENT_NAME (src),
2021 srcpadname, GST_ELEMENT_NAME (dest), destpadname);
2029 * @src: (transfer none): a #GstElement containing the source pad.
2030 * @dest: (transfer none): the #GstElement containing the destination pad.
2032 * Links @src to @dest. The link must be from source to
2033 * destination; the other direction will not be tried. The function looks for
2034 * existing pads that aren't linked yet. It will request new pads if necessary.
2035 * Such pads need to be released manually when unlinking.
2036 * If multiple links are possible, only one is established.
2038 * Make sure you have added your elements to a bin or pipeline with
2039 * gst_bin_add() before trying to link them.
2041 * Returns: %TRUE if the elements could be linked, %FALSE otherwise.
2044 gst_element_link (GstElement * src, GstElement * dest)
2046 return gst_element_link_pads (src, NULL, dest, NULL);
2050 * gst_element_link_many:
2051 * @element_1: (transfer none): the first #GstElement in the link chain.
2052 * @element_2: (transfer none): the second #GstElement in the link chain.
2053 * @...: the %NULL-terminated list of elements to link in order.
2055 * Chain together a series of elements. Uses gst_element_link().
2056 * Make sure you have added your elements to a bin or pipeline with
2057 * gst_bin_add() before trying to link them.
2059 * Returns: %TRUE on success, %FALSE otherwise.
2062 gst_element_link_many (GstElement * element_1, GstElement * element_2, ...)
2064 gboolean res = TRUE;
2067 g_return_val_if_fail (GST_IS_ELEMENT (element_1), FALSE);
2068 g_return_val_if_fail (GST_IS_ELEMENT (element_2), FALSE);
2070 va_start (args, element_2);
2073 if (!gst_element_link (element_1, element_2)) {
2078 element_1 = element_2;
2079 element_2 = va_arg (args, GstElement *);
2088 * gst_element_link_filtered:
2089 * @src: a #GstElement containing the source pad.
2090 * @dest: (transfer none): the #GstElement containing the destination pad.
2091 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
2092 * or %NULL for no filter.
2094 * Links @src to @dest using the given caps as filtercaps.
2095 * The link must be from source to
2096 * destination; the other direction will not be tried. The function looks for
2097 * existing pads that aren't linked yet. It will request new pads if necessary.
2098 * If multiple links are possible, only one is established.
2100 * Make sure you have added your elements to a bin or pipeline with
2101 * gst_bin_add() before trying to link them.
2103 * Returns: %TRUE if the pads could be linked, %FALSE otherwise.
2106 gst_element_link_filtered (GstElement * src, GstElement * dest,
2109 return gst_element_link_pads_filtered (src, NULL, dest, NULL, filter);
2113 * gst_element_unlink_pads:
2114 * @src: a (transfer none): #GstElement containing the source pad.
2115 * @srcpadname: the name of the #GstPad in source element.
2116 * @dest: (transfer none): a #GstElement containing the destination pad.
2117 * @destpadname: the name of the #GstPad in destination element.
2119 * Unlinks the two named pads of the source and destination elements.
2121 * This is a convenience function for gst_pad_unlink().
2124 gst_element_unlink_pads (GstElement * src, const gchar * srcpadname,
2125 GstElement * dest, const gchar * destpadname)
2127 GstPad *srcpad, *destpad;
2128 gboolean srcrequest, destrequest;
2130 srcrequest = destrequest = FALSE;
2132 g_return_if_fail (src != NULL);
2133 g_return_if_fail (GST_IS_ELEMENT (src));
2134 g_return_if_fail (srcpadname != NULL);
2135 g_return_if_fail (dest != NULL);
2136 g_return_if_fail (GST_IS_ELEMENT (dest));
2137 g_return_if_fail (destpadname != NULL);
2139 /* obtain the pads requested */
2140 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
2141 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
2143 if (srcpad == NULL) {
2144 GST_WARNING_OBJECT (src, "source element has no pad \"%s\"", srcpadname);
2147 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
2148 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
2150 if (destpad == NULL) {
2151 GST_WARNING_OBJECT (dest, "destination element has no pad \"%s\"",
2156 /* we're satisfied they can be unlinked, let's do it */
2157 gst_pad_unlink (srcpad, destpad);
2160 gst_element_release_request_pad (dest, destpad);
2161 gst_object_unref (destpad);
2165 gst_element_release_request_pad (src, srcpad);
2166 gst_object_unref (srcpad);
2170 * gst_element_unlink_many:
2171 * @element_1: (transfer none): the first #GstElement in the link chain.
2172 * @element_2: (transfer none): the second #GstElement in the link chain.
2173 * @...: the %NULL-terminated list of elements to unlink in order.
2175 * Unlinks a series of elements. Uses gst_element_unlink().
2178 gst_element_unlink_many (GstElement * element_1, GstElement * element_2, ...)
2182 g_return_if_fail (element_1 != NULL && element_2 != NULL);
2183 g_return_if_fail (GST_IS_ELEMENT (element_1) && GST_IS_ELEMENT (element_2));
2185 va_start (args, element_2);
2188 gst_element_unlink (element_1, element_2);
2190 element_1 = element_2;
2191 element_2 = va_arg (args, GstElement *);
2198 * gst_element_unlink:
2199 * @src: (transfer none): the source #GstElement to unlink.
2200 * @dest: (transfer none): the sink #GstElement to unlink.
2202 * Unlinks all source pads of the source element with all sink pads
2203 * of the sink element to which they are linked.
2205 * If the link has been made using gst_element_link(), it could have created an
2206 * requestpad, which has to be released using gst_element_release_request_pad().
2209 gst_element_unlink (GstElement * src, GstElement * dest)
2212 gboolean done = FALSE;
2213 GValue data = { 0, };
2215 g_return_if_fail (GST_IS_ELEMENT (src));
2216 g_return_if_fail (GST_IS_ELEMENT (dest));
2218 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unlinking \"%s\" and \"%s\"",
2219 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2221 pads = gst_element_iterate_pads (src);
2223 switch (gst_iterator_next (pads, &data)) {
2224 case GST_ITERATOR_OK:
2226 GstPad *pad = g_value_get_object (&data);
2228 if (GST_PAD_IS_SRC (pad)) {
2229 GstPad *peerpad = gst_pad_get_peer (pad);
2231 /* see if the pad is linked and is really a pad of dest */
2233 GstElement *peerelem;
2235 peerelem = gst_pad_get_parent_element (peerpad);
2237 if (peerelem == dest) {
2238 gst_pad_unlink (pad, peerpad);
2241 gst_object_unref (peerelem);
2243 gst_object_unref (peerpad);
2246 g_value_reset (&data);
2249 case GST_ITERATOR_RESYNC:
2250 gst_iterator_resync (pads);
2252 case GST_ITERATOR_DONE:
2256 g_assert_not_reached ();
2260 g_value_unset (&data);
2261 gst_iterator_free (pads);
2265 * gst_element_query_position:
2266 * @element: a #GstElement to invoke the position query on.
2267 * @format: the #GstFormat requested
2268 * @cur: (out) (allow-none): a location in which to store the current
2269 * position, or %NULL.
2271 * Queries an element (usually top-level pipeline or playbin element) for the
2272 * stream position in nanoseconds. This will be a value between 0 and the
2273 * stream duration (if the stream duration is known). This query will usually
2274 * only work once the pipeline is prerolled (i.e. reached PAUSED or PLAYING
2275 * state). The application will receive an ASYNC_DONE message on the pipeline
2276 * bus when that is the case.
2278 * If one repeatedly calls this function one can also create a query and reuse
2279 * it in gst_element_query().
2281 * Returns: %TRUE if the query could be performed.
2284 gst_element_query_position (GstElement * element, GstFormat format,
2290 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2291 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2293 query = gst_query_new_position (format);
2294 ret = gst_element_query (element, query);
2297 gst_query_parse_position (query, NULL, cur);
2299 gst_query_unref (query);
2305 * gst_element_query_duration:
2306 * @element: a #GstElement to invoke the duration query on.
2307 * @format: the #GstFormat requested
2308 * @duration: (out) (allow-none): A location in which to store the total duration, or %NULL.
2310 * Queries an element (usually top-level pipeline or playbin element) for the
2311 * total stream duration in nanoseconds. This query will only work once the
2312 * pipeline is prerolled (i.e. reached PAUSED or PLAYING state). The application
2313 * will receive an ASYNC_DONE message on the pipeline bus when that is the case.
2315 * If the duration changes for some reason, you will get a DURATION_CHANGED
2316 * message on the pipeline bus, in which case you should re-query the duration
2317 * using this function.
2319 * Returns: %TRUE if the query could be performed.
2322 gst_element_query_duration (GstElement * element, GstFormat format,
2328 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2329 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2331 query = gst_query_new_duration (format);
2332 ret = gst_element_query (element, query);
2335 gst_query_parse_duration (query, NULL, duration);
2337 gst_query_unref (query);
2343 * gst_element_query_convert:
2344 * @element: a #GstElement to invoke the convert query on.
2345 * @src_format: a #GstFormat to convert from.
2346 * @src_val: a value to convert.
2347 * @dest_format: the #GstFormat to convert to.
2348 * @dest_val: (out): a pointer to the result.
2350 * Queries an element to convert @src_val in @src_format to @dest_format.
2352 * Returns: %TRUE if the query could be performed.
2355 gst_element_query_convert (GstElement * element, GstFormat src_format,
2356 gint64 src_val, GstFormat dest_format, gint64 * dest_val)
2361 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2362 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2363 g_return_val_if_fail (dest_val != NULL, FALSE);
2365 if (dest_format == src_format || src_val == -1) {
2366 *dest_val = src_val;
2370 query = gst_query_new_convert (src_format, src_val, dest_format);
2371 ret = gst_element_query (element, query);
2374 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2376 gst_query_unref (query);
2382 * gst_element_seek_simple:
2383 * @element: a #GstElement to seek on
2384 * @format: a #GstFormat to execute the seek in, such as #GST_FORMAT_TIME
2385 * @seek_flags: seek options; playback applications will usually want to use
2386 * GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT here
2387 * @seek_pos: position to seek to (relative to the start); if you are doing
2388 * a seek in #GST_FORMAT_TIME this value is in nanoseconds -
2389 * multiply with #GST_SECOND to convert seconds to nanoseconds or
2390 * with #GST_MSECOND to convert milliseconds to nanoseconds.
2392 * Simple API to perform a seek on the given element, meaning it just seeks
2393 * to the given position relative to the start of the stream. For more complex
2394 * operations like segment seeks (e.g. for looping) or changing the playback
2395 * rate or seeking relative to the last configured playback segment you should
2396 * use gst_element_seek().
2398 * In a completely prerolled PAUSED or PLAYING pipeline, seeking is always
2399 * guaranteed to return %TRUE on a seekable media type or %FALSE when the media
2400 * type is certainly not seekable (such as a live stream).
2402 * Some elements allow for seeking in the READY state, in this
2403 * case they will store the seek event and execute it when they are put to
2404 * PAUSED. If the element supports seek in READY, it will always return %TRUE when
2405 * it receives the event in the READY state.
2407 * Returns: %TRUE if the seek operation succeeded. Flushing seeks will trigger a
2408 * preroll, which will emit %GST_MESSAGE_ASYNC_DONE.
2411 gst_element_seek_simple (GstElement * element, GstFormat format,
2412 GstSeekFlags seek_flags, gint64 seek_pos)
2414 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2415 g_return_val_if_fail (seek_pos >= 0, FALSE);
2417 return gst_element_seek (element, 1.0, format, seek_flags,
2418 GST_SEEK_TYPE_SET, seek_pos, GST_SEEK_TYPE_SET, GST_CLOCK_TIME_NONE);
2422 * gst_pad_use_fixed_caps:
2423 * @pad: the pad to use
2425 * A helper function you can use that sets the FIXED_CAPS flag
2426 * This way the default CAPS query will always return the negotiated caps
2427 * or in case the pad is not negotiated, the padtemplate caps.
2429 * The negotiated caps are the caps of the last CAPS event that passed on the
2430 * pad. Use this function on a pad that, once it negotiated to a CAPS, cannot
2431 * be renegotiated to something else.
2434 gst_pad_use_fixed_caps (GstPad * pad)
2436 GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FIXED_CAPS);
2440 * gst_pad_get_parent_element:
2443 * Gets the parent of @pad, cast to a #GstElement. If a @pad has no parent or
2444 * its parent is not an element, return %NULL.
2446 * Returns: (transfer full) (nullable): the parent of the pad. The
2447 * caller has a reference on the parent, so unref when you're finished
2453 gst_pad_get_parent_element (GstPad * pad)
2457 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2459 p = gst_object_get_parent (GST_OBJECT_CAST (pad));
2461 if (p && !GST_IS_ELEMENT (p)) {
2462 gst_object_unref (p);
2465 return GST_ELEMENT_CAST (p);
2469 * gst_object_default_error:
2470 * @source: the #GstObject that initiated the error.
2471 * @error: (in): the GError.
2472 * @debug: (in) (allow-none): an additional debug information string, or %NULL
2474 * A default error function that uses g_printerr() to display the error message
2475 * and the optional debug sting..
2477 * The default handler will simply print the error string using g_print.
2480 gst_object_default_error (GstObject * source, const GError * error,
2481 const gchar * debug)
2483 gchar *name = gst_object_get_path_string (source);
2485 g_printerr (_("ERROR: from element %s: %s\n"), name, error->message);
2487 g_printerr (_("Additional debug info:\n%s\n"), debug);
2495 * @element_1: (transfer full): the #GstElement element to add to the bin
2496 * @...: (transfer full): additional elements to add to the bin
2498 * Adds a %NULL-terminated list of elements to a bin. This function is
2499 * equivalent to calling gst_bin_add() for each member of the list. The return
2500 * value of each gst_bin_add() is ignored.
2503 gst_bin_add_many (GstBin * bin, GstElement * element_1, ...)
2507 g_return_if_fail (GST_IS_BIN (bin));
2508 g_return_if_fail (GST_IS_ELEMENT (element_1));
2510 va_start (args, element_1);
2513 gst_bin_add (bin, element_1);
2515 element_1 = va_arg (args, GstElement *);
2522 * gst_bin_remove_many:
2524 * @element_1: (transfer none): the first #GstElement to remove from the bin
2525 * @...: (transfer none): %NULL-terminated list of elements to remove from the bin
2527 * Remove a list of elements from a bin. This function is equivalent
2528 * to calling gst_bin_remove() with each member of the list.
2531 gst_bin_remove_many (GstBin * bin, GstElement * element_1, ...)
2535 g_return_if_fail (GST_IS_BIN (bin));
2536 g_return_if_fail (GST_IS_ELEMENT (element_1));
2538 va_start (args, element_1);
2541 gst_bin_remove (bin, element_1);
2543 element_1 = va_arg (args, GstElement *);
2553 } QueryAcceptCapsData;
2556 query_accept_caps_func (GstPad * pad, QueryAcceptCapsData * data)
2558 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2561 gst_query_parse_accept_caps_result (data->query, &result);
2562 data->ret &= result;
2568 * gst_pad_proxy_query_accept_caps:
2569 * @pad: a #GstPad to proxy.
2570 * @query: an ACCEPT_CAPS #GstQuery.
2572 * Checks if all internally linked pads of @pad accepts the caps in @query and
2573 * returns the intersection of the results.
2575 * This function is useful as a default accept caps query function for an element
2576 * that can handle any stream format, but requires caps that are acceptable for
2577 * all opposite pads.
2579 * Returns: %TRUE if @query could be executed
2582 gst_pad_proxy_query_accept_caps (GstPad * pad, GstQuery * query)
2584 QueryAcceptCapsData data;
2586 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2587 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2588 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS, FALSE);
2590 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2591 "proxying accept caps query for %s:%s", GST_DEBUG_PAD_NAME (pad));
2594 /* value to hold the return, by default it holds TRUE */
2595 /* FIXME: TRUE is wrong when there are no pads */
2598 gst_pad_forward (pad, (GstPadForwardFunction) query_accept_caps_func, &data);
2599 gst_query_set_accept_caps_result (query, data.ret);
2601 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying accept caps query: %d",
2614 query_caps_func (GstPad * pad, QueryCapsData * data)
2616 gboolean empty = FALSE;
2618 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2619 GstCaps *peercaps, *intersection;
2621 gst_query_parse_caps_result (data->query, &peercaps);
2622 GST_DEBUG_OBJECT (pad, "intersect with result %" GST_PTR_FORMAT, peercaps);
2623 intersection = gst_caps_intersect (data->ret, peercaps);
2624 GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, intersection);
2626 gst_caps_unref (data->ret);
2627 data->ret = intersection;
2629 /* stop when empty */
2630 empty = gst_caps_is_empty (intersection);
2636 * gst_pad_proxy_query_caps:
2637 * @pad: a #GstPad to proxy.
2638 * @query: a CAPS #GstQuery.
2640 * Calls gst_pad_query_caps() for all internally linked pads of @pad and returns
2641 * the intersection of the results.
2643 * This function is useful as a default caps query function for an element
2644 * that can handle any stream format, but requires all its pads to have
2645 * the same caps. Two such elements are tee and adder.
2647 * Returns: %TRUE if @query could be executed
2650 gst_pad_proxy_query_caps (GstPad * pad, GstQuery * query)
2652 GstCaps *filter, *templ, *result;
2655 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2656 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2657 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CAPS, FALSE);
2659 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying caps query for %s:%s",
2660 GST_DEBUG_PAD_NAME (pad));
2664 /* value to hold the return, by default it holds the filter or ANY */
2665 gst_query_parse_caps (query, &filter);
2666 data.ret = filter ? gst_caps_ref (filter) : gst_caps_new_any ();
2668 gst_pad_forward (pad, (GstPadForwardFunction) query_caps_func, &data);
2670 templ = gst_pad_get_pad_template_caps (pad);
2671 result = gst_caps_intersect (data.ret, templ);
2672 gst_caps_unref (data.ret);
2673 gst_caps_unref (templ);
2675 gst_query_set_caps_result (query, result);
2676 gst_caps_unref (result);
2678 /* FIXME: return something depending on the processing */
2683 * gst_pad_query_position:
2684 * @pad: a #GstPad to invoke the position query on.
2685 * @format: the #GstFormat requested
2686 * @cur: (out) (allow-none): A location in which to store the current position, or %NULL.
2688 * Queries a pad for the stream position.
2690 * Returns: %TRUE if the query could be performed.
2693 gst_pad_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2698 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2699 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2701 query = gst_query_new_position (format);
2702 if ((ret = gst_pad_query (pad, query)))
2703 gst_query_parse_position (query, NULL, cur);
2704 gst_query_unref (query);
2710 * gst_pad_peer_query_position:
2711 * @pad: a #GstPad on whose peer to invoke the position query on.
2712 * Must be a sink pad.
2713 * @format: the #GstFormat requested
2714 * @cur: (out) (allow-none): a location in which to store the current
2715 * position, or %NULL.
2717 * Queries the peer of a given sink pad for the stream position.
2719 * Returns: %TRUE if the query could be performed.
2722 gst_pad_peer_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2725 gboolean ret = FALSE;
2727 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2728 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2730 query = gst_query_new_position (format);
2731 if ((ret = gst_pad_peer_query (pad, query)))
2732 gst_query_parse_position (query, NULL, cur);
2733 gst_query_unref (query);
2739 * gst_pad_query_duration:
2740 * @pad: a #GstPad to invoke the duration query on.
2741 * @format: the #GstFormat requested
2742 * @duration: (out) (allow-none): a location in which to store the total
2743 * duration, or %NULL.
2745 * Queries a pad for the total stream duration.
2747 * Returns: %TRUE if the query could be performed.
2750 gst_pad_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2755 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2756 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2758 query = gst_query_new_duration (format);
2759 if ((ret = gst_pad_query (pad, query)))
2760 gst_query_parse_duration (query, NULL, duration);
2761 gst_query_unref (query);
2767 * gst_pad_peer_query_duration:
2768 * @pad: a #GstPad on whose peer pad to invoke the duration query on.
2769 * Must be a sink pad.
2770 * @format: the #GstFormat requested
2771 * @duration: (out) (allow-none): a location in which to store the total
2772 * duration, or %NULL.
2774 * Queries the peer pad of a given sink pad for the total stream duration.
2776 * Returns: %TRUE if the query could be performed.
2779 gst_pad_peer_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2782 gboolean ret = FALSE;
2784 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2785 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2786 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2788 query = gst_query_new_duration (format);
2789 if ((ret = gst_pad_peer_query (pad, query)))
2790 gst_query_parse_duration (query, NULL, duration);
2791 gst_query_unref (query);
2797 * gst_pad_query_convert:
2798 * @pad: a #GstPad to invoke the convert query on.
2799 * @src_format: a #GstFormat to convert from.
2800 * @src_val: a value to convert.
2801 * @dest_format: the #GstFormat to convert to.
2802 * @dest_val: (out): a pointer to the result.
2804 * Queries a pad to convert @src_val in @src_format to @dest_format.
2806 * Returns: %TRUE if the query could be performed.
2809 gst_pad_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2810 GstFormat dest_format, gint64 * dest_val)
2815 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2816 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2817 g_return_val_if_fail (dest_val != NULL, FALSE);
2819 if (dest_format == src_format || src_val == -1) {
2820 *dest_val = src_val;
2824 query = gst_query_new_convert (src_format, src_val, dest_format);
2825 if ((ret = gst_pad_query (pad, query)))
2826 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2827 gst_query_unref (query);
2833 * gst_pad_peer_query_convert:
2834 * @pad: a #GstPad, on whose peer pad to invoke the convert query on.
2835 * Must be a sink pad.
2836 * @src_format: a #GstFormat to convert from.
2837 * @src_val: a value to convert.
2838 * @dest_format: the #GstFormat to convert to.
2839 * @dest_val: (out): a pointer to the result.
2841 * Queries the peer pad of a given sink pad to convert @src_val in @src_format
2844 * Returns: %TRUE if the query could be performed.
2847 gst_pad_peer_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2848 GstFormat dest_format, gint64 * dest_val)
2851 gboolean ret = FALSE;
2853 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2854 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2855 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2856 g_return_val_if_fail (dest_val != NULL, FALSE);
2858 query = gst_query_new_convert (src_format, src_val, dest_format);
2859 if ((ret = gst_pad_peer_query (pad, query)))
2860 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2861 gst_query_unref (query);
2867 * gst_pad_query_caps:
2868 * @pad: a #GstPad to get the capabilities of.
2869 * @filter: (allow-none): suggested #GstCaps, or %NULL
2871 * Gets the capabilities this pad can produce or consume.
2872 * Note that this method doesn't necessarily return the caps set by sending a
2873 * gst_event_new_caps() - use gst_pad_get_current_caps() for that instead.
2874 * gst_pad_query_caps returns all possible caps a pad can operate with, using
2875 * the pad's CAPS query function, If the query fails, this function will return
2876 * @filter, if not %NULL, otherwise ANY.
2878 * When called on sinkpads @filter contains the caps that
2879 * upstream could produce in the order preferred by upstream. When
2880 * called on srcpads @filter contains the caps accepted by
2881 * downstream in the preferred order. @filter might be %NULL but
2882 * if it is not %NULL the returned caps will be a subset of @filter.
2884 * Note that this function does not return writable #GstCaps, use
2885 * gst_caps_make_writable() before modifying the caps.
2887 * Returns: (transfer full): the caps of the pad with incremented ref-count.
2890 gst_pad_query_caps (GstPad * pad, GstCaps * filter)
2892 GstCaps *result = NULL;
2895 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2896 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2898 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2899 "get pad caps with filter %" GST_PTR_FORMAT, filter);
2901 query = gst_query_new_caps (filter);
2902 if (gst_pad_query (pad, query)) {
2903 gst_query_parse_caps_result (query, &result);
2904 gst_caps_ref (result);
2905 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2906 "query returned %" GST_PTR_FORMAT, result);
2907 } else if (filter) {
2908 result = gst_caps_ref (filter);
2910 result = gst_caps_new_any ();
2912 gst_query_unref (query);
2918 * gst_pad_peer_query_caps:
2919 * @pad: a #GstPad to get the capabilities of.
2920 * @filter: (allow-none): a #GstCaps filter, or %NULL.
2922 * Gets the capabilities of the peer connected to this pad. Similar to
2923 * gst_pad_query_caps().
2925 * When called on srcpads @filter contains the caps that
2926 * upstream could produce in the order preferred by upstream. When
2927 * called on sinkpads @filter contains the caps accepted by
2928 * downstream in the preferred order. @filter might be %NULL but
2929 * if it is not %NULL the returned caps will be a subset of @filter.
2931 * Returns: (transfer full): the caps of the peer pad with incremented
2932 * ref-count. When there is no peer pad, this function returns @filter or,
2933 * when @filter is %NULL, ANY caps.
2936 gst_pad_peer_query_caps (GstPad * pad, GstCaps * filter)
2938 GstCaps *result = NULL;
2941 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2942 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2944 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2945 "get pad peer caps with filter %" GST_PTR_FORMAT, filter);
2947 query = gst_query_new_caps (filter);
2948 if (gst_pad_peer_query (pad, query)) {
2949 gst_query_parse_caps_result (query, &result);
2950 gst_caps_ref (result);
2951 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2952 "peer query returned %" GST_PTR_FORMAT, result);
2953 } else if (filter) {
2954 result = gst_caps_ref (filter);
2956 result = gst_caps_new_any ();
2958 gst_query_unref (query);
2964 * gst_pad_query_accept_caps:
2965 * @pad: a #GstPad to check
2966 * @caps: a #GstCaps to check on the pad
2968 * Check if the given pad accepts the caps.
2970 * Returns: %TRUE if the pad can accept the caps.
2973 gst_pad_query_accept_caps (GstPad * pad, GstCaps * caps)
2975 gboolean res = TRUE;
2978 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2979 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
2981 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %"
2982 GST_PTR_FORMAT, caps);
2984 query = gst_query_new_accept_caps (caps);
2985 if (gst_pad_query (pad, query)) {
2986 gst_query_parse_accept_caps_result (query, &res);
2987 GST_DEBUG_OBJECT (pad, "query returned %d", res);
2989 gst_query_unref (query);
2995 * gst_pad_peer_query_accept_caps:
2996 * @pad: a #GstPad to check the peer of
2997 * @caps: a #GstCaps to check on the pad
2999 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
3002 * Returns: %TRUE if the peer of @pad can accept the caps or @pad has no peer.
3005 gst_pad_peer_query_accept_caps (GstPad * pad, GstCaps * caps)
3007 gboolean res = TRUE;
3010 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
3011 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
3013 query = gst_query_new_accept_caps (caps);
3014 if (gst_pad_peer_query (pad, query)) {
3015 gst_query_parse_accept_caps_result (query, &res);
3016 GST_DEBUG_OBJECT (pad, "query returned %d", res);
3018 gst_query_unref (query);
3024 element_find_unlinked_pad (GstElement * element, GstPadDirection direction)
3027 GstPad *unlinked_pad = NULL;
3029 GValue data = { 0, };
3031 switch (direction) {
3033 iter = gst_element_iterate_src_pads (element);
3036 iter = gst_element_iterate_sink_pads (element);
3039 g_return_val_if_reached (NULL);
3044 switch (gst_iterator_next (iter, &data)) {
3045 case GST_ITERATOR_OK:{
3047 GstPad *pad = g_value_get_object (&data);
3049 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
3050 GST_DEBUG_PAD_NAME (pad));
3052 peer = gst_pad_get_peer (pad);
3054 unlinked_pad = gst_object_ref (pad);
3056 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
3057 "found existing unlinked pad %s:%s",
3058 GST_DEBUG_PAD_NAME (unlinked_pad));
3060 gst_object_unref (peer);
3062 g_value_reset (&data);
3065 case GST_ITERATOR_DONE:
3068 case GST_ITERATOR_RESYNC:
3069 gst_iterator_resync (iter);
3071 case GST_ITERATOR_ERROR:
3072 g_return_val_if_reached (NULL);
3076 g_value_unset (&data);
3077 gst_iterator_free (iter);
3079 return unlinked_pad;
3083 * gst_bin_find_unlinked_pad:
3084 * @bin: bin in which to look for elements with unlinked pads
3085 * @direction: whether to look for an unlinked source or sink pad
3087 * Recursively looks for elements with an unlinked pad of the given
3088 * direction within the specified bin and returns an unlinked pad
3089 * if one is found, or %NULL otherwise. If a pad is found, the caller
3090 * owns a reference to it and should use gst_object_unref() on the
3091 * pad when it is not needed any longer.
3093 * Returns: (transfer full) (nullable): unlinked pad of the given
3097 gst_bin_find_unlinked_pad (GstBin * bin, GstPadDirection direction)
3102 GValue data = { 0, };
3104 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3105 g_return_val_if_fail (direction != GST_PAD_UNKNOWN, NULL);
3108 iter = gst_bin_iterate_recurse (bin);
3110 switch (gst_iterator_next (iter, &data)) {
3111 case GST_ITERATOR_OK:{
3112 GstElement *element = g_value_get_object (&data);
3114 pad = element_find_unlinked_pad (element, direction);
3117 g_value_reset (&data);
3120 case GST_ITERATOR_DONE:
3123 case GST_ITERATOR_RESYNC:
3124 gst_iterator_resync (iter);
3126 case GST_ITERATOR_ERROR:
3127 g_return_val_if_reached (NULL);
3131 g_value_unset (&data);
3132 gst_iterator_free (iter);
3138 gst_bin_sync_children_states_foreach (const GValue * value, gpointer user_data)
3140 gboolean *success = user_data;
3141 GstElement *element = g_value_get_object (value);
3143 if (gst_element_is_locked_state (element)) {
3146 *success = *success && gst_element_sync_state_with_parent (element);
3148 if (GST_IS_BIN (element))
3150 && gst_bin_sync_children_states (GST_BIN_CAST (element));
3155 * gst_bin_sync_children_states:
3158 * Synchronizes the state of every child of @bin with the state
3159 * of @bin. See also gst_element_sync_state_with_parent().
3161 * Returns: %TRUE if syncing the state was successful for all children,
3167 gst_bin_sync_children_states (GstBin * bin)
3170 GstIteratorResult res = GST_ITERATOR_OK;
3171 gboolean success = TRUE;
3173 it = gst_bin_iterate_sorted (bin);
3176 if (res == GST_ITERATOR_RESYNC) {
3178 gst_iterator_resync (it);
3181 gst_iterator_foreach (it, gst_bin_sync_children_states_foreach,
3183 } while (res == GST_ITERATOR_RESYNC);
3184 gst_iterator_free (it);
3190 * gst_parse_bin_from_description:
3191 * @bin_description: command line describing the bin
3192 * @ghost_unlinked_pads: whether to automatically create ghost pads
3193 * for unlinked source or sink pads within the bin
3194 * @err: where to store the error message in case of an error, or %NULL
3196 * This is a convenience wrapper around gst_parse_launch() to create a
3197 * #GstBin from a gst-launch-style pipeline description. See
3198 * gst_parse_launch() and the gst-launch man page for details about the
3199 * syntax. Ghost pads on the bin for unlinked source or sink pads
3200 * within the bin can automatically be created (but only a maximum of
3201 * one ghost pad for each direction will be created; if you expect
3202 * multiple unlinked source pads or multiple unlinked sink pads
3203 * and want them all ghosted, you will have to create the ghost pads
3206 * Returns: (transfer floating) (type Gst.Bin) (nullable): a
3207 * newly-created bin, or %NULL if an error occurred.
3210 gst_parse_bin_from_description (const gchar * bin_description,
3211 gboolean ghost_unlinked_pads, GError ** err)
3213 return gst_parse_bin_from_description_full (bin_description,
3214 ghost_unlinked_pads, NULL, GST_PARSE_FLAG_NONE, err);
3218 * gst_parse_bin_from_description_full:
3219 * @bin_description: command line describing the bin
3220 * @ghost_unlinked_pads: whether to automatically create ghost pads
3221 * for unlinked source or sink pads within the bin
3222 * @context: (transfer none) (allow-none): a parse context allocated with
3223 * gst_parse_context_new(), or %NULL
3224 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
3225 * @err: where to store the error message in case of an error, or %NULL
3227 * This is a convenience wrapper around gst_parse_launch() to create a
3228 * #GstBin from a gst-launch-style pipeline description. See
3229 * gst_parse_launch() and the gst-launch man page for details about the
3230 * syntax. Ghost pads on the bin for unlinked source or sink pads
3231 * within the bin can automatically be created (but only a maximum of
3232 * one ghost pad for each direction will be created; if you expect
3233 * multiple unlinked source pads or multiple unlinked sink pads
3234 * and want them all ghosted, you will have to create the ghost pads
3237 * Returns: (transfer floating) (type Gst.Element): a newly-created
3238 * element, which is guaranteed to be a bin unless
3239 * GST_FLAG_NO_SINGLE_ELEMENT_BINS was passed, or %NULL if an error
3243 gst_parse_bin_from_description_full (const gchar * bin_description,
3244 gboolean ghost_unlinked_pads, GstParseContext * context,
3245 GstParseFlags flags, GError ** err)
3247 #ifndef GST_DISABLE_PARSE
3249 GstElement *element;
3253 g_return_val_if_fail (bin_description != NULL, NULL);
3254 g_return_val_if_fail (err == NULL || *err == NULL, NULL);
3256 GST_DEBUG ("Making bin from description '%s'", bin_description);
3258 /* parse the pipeline to a bin */
3259 if (flags & GST_PARSE_FLAG_NO_SINGLE_ELEMENT_BINS) {
3260 element = gst_parse_launch_full (bin_description, context, flags, err);
3262 desc = g_strdup_printf ("bin.( %s )", bin_description);
3263 element = gst_parse_launch_full (desc, context, flags, err);
3267 if (element == NULL || (err && *err != NULL)) {
3269 gst_object_unref (element);
3273 if (GST_IS_BIN (element)) {
3274 bin = GST_BIN (element);
3279 /* find pads and ghost them if necessary */
3280 if (ghost_unlinked_pads) {
3281 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SRC))) {
3282 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("src", pad));
3283 gst_object_unref (pad);
3285 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SINK))) {
3286 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("sink", pad));
3287 gst_object_unref (pad);
3291 return GST_ELEMENT (bin);
3295 GST_WARNING ("Disabled API called");
3297 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
3298 g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);
3306 * gst_util_get_timestamp:
3308 * Get a timestamp as GstClockTime to be used for interval measurements.
3309 * The timestamp should not be interpreted in any other way.
3311 * Returns: the timestamp
3314 gst_util_get_timestamp (void)
3316 #if defined (HAVE_POSIX_TIMERS) && defined(HAVE_MONOTONIC_CLOCK) &&\
3317 defined (HAVE_CLOCK_GETTIME)
3318 struct timespec now;
3320 clock_gettime (CLOCK_MONOTONIC, &now);
3321 return GST_TIMESPEC_TO_TIME (now);
3325 g_get_current_time (&now);
3326 return GST_TIMEVAL_TO_TIME (now);
3331 * gst_util_array_binary_search:
3332 * @array: the sorted input array
3333 * @num_elements: number of elements in the array
3334 * @element_size: size of every element in bytes
3335 * @search_func: (scope call): function to compare two elements, @search_data will always be passed as second argument
3336 * @mode: search mode that should be used
3337 * @search_data: element that should be found
3338 * @user_data: (closure): data to pass to @search_func
3340 * Searches inside @array for @search_data by using the comparison function
3341 * @search_func. @array must be sorted ascending.
3343 * As @search_data is always passed as second argument to @search_func it's
3344 * not required that @search_data has the same type as the array elements.
3346 * The complexity of this search function is O(log (num_elements)).
3348 * Returns: (transfer none) (nullable): The address of the found
3349 * element or %NULL if nothing was found
3352 gst_util_array_binary_search (gpointer array, guint num_elements,
3353 gsize element_size, GCompareDataFunc search_func, GstSearchMode mode,
3354 gconstpointer search_data, gpointer user_data)
3356 glong left = 0, right = num_elements - 1, m;
3358 guint8 *data = (guint8 *) array;
3360 g_return_val_if_fail (array != NULL, NULL);
3361 g_return_val_if_fail (element_size > 0, NULL);
3362 g_return_val_if_fail (search_func != NULL, NULL);
3364 /* 0. No elements => return NULL */
3365 if (num_elements == 0)
3368 /* 1. If search_data is before the 0th element return the 0th element */
3369 ret = search_func (data, search_data, user_data);
3370 if ((ret >= 0 && mode == GST_SEARCH_MODE_AFTER) || ret == 0)
3375 /* 2. If search_data is after the last element return the last element */
3377 search_func (data + (num_elements - 1) * element_size, search_data,
3379 if ((ret <= 0 && mode == GST_SEARCH_MODE_BEFORE) || ret == 0)
3380 return data + (num_elements - 1) * element_size;
3384 /* 3. else binary search */
3386 m = left + (right - left) / 2;
3388 ret = search_func (data + m * element_size, search_data, user_data);
3391 return data + m * element_size;
3392 } else if (ret < 0) {
3398 /* No exact match found */
3400 if (mode == GST_SEARCH_MODE_EXACT) {
3402 } else if (mode == GST_SEARCH_MODE_AFTER) {
3404 return (m < num_elements) ? data + (m + 1) * element_size : NULL;
3406 return data + m * element_size;
3409 return data + m * element_size;
3411 return (m > 0) ? data + (m - 1) * element_size : NULL;
3417 /* Finds the greatest common divisor.
3418 * Returns 1 if none other found.
3419 * This is Euclid's algorithm. */
3422 * gst_util_greatest_common_divisor:
3423 * @a: First value as #gint
3424 * @b: Second value as #gint
3426 * Calculates the greatest common divisor of @a
3429 * Returns: Greatest common divisor of @a and @b
3432 gst_util_greatest_common_divisor (gint a, gint b)
3445 * gst_util_greatest_common_divisor_int64:
3446 * @a: First value as #gint64
3447 * @b: Second value as #gint64
3449 * Calculates the greatest common divisor of @a
3452 * Returns: Greatest common divisor of @a and @b
3455 gst_util_greatest_common_divisor_int64 (gint64 a, gint64 b)
3469 * gst_util_fraction_to_double:
3470 * @src_n: Fraction numerator as #gint
3471 * @src_d: Fraction denominator #gint
3472 * @dest: (out): pointer to a #gdouble for the result
3474 * Transforms a fraction to a #gdouble.
3477 gst_util_fraction_to_double (gint src_n, gint src_d, gdouble * dest)
3479 g_return_if_fail (dest != NULL);
3480 g_return_if_fail (src_d != 0);
3482 *dest = ((gdouble) src_n) / ((gdouble) src_d);
3485 #define MAX_TERMS 30
3486 #define MIN_DIVISOR 1.0e-10
3487 #define MAX_ERROR 1.0e-20
3489 /* use continued fractions to transform a double into a fraction,
3490 * see http://mathforum.org/dr.math/faq/faq.fractions.html#decfrac.
3491 * This algorithm takes care of overflows.
3495 * gst_util_double_to_fraction:
3496 * @src: #gdouble to transform
3497 * @dest_n: (out): pointer to a #gint to hold the result numerator
3498 * @dest_d: (out): pointer to a #gint to hold the result denominator
3500 * Transforms a #gdouble to a fraction and simplifies
3504 gst_util_double_to_fraction (gdouble src, gint * dest_n, gint * dest_d)
3507 gdouble V, F; /* double being converted */
3508 gint N, D; /* will contain the result */
3509 gint A; /* current term in continued fraction */
3510 gint64 N1, D1; /* numerator, denominator of last approx */
3511 gint64 N2, D2; /* numerator, denominator of previous approx */
3514 gboolean negative = FALSE;
3516 g_return_if_fail (dest_n != NULL);
3517 g_return_if_fail (dest_d != NULL);
3519 /* initialize fraction being converted */
3527 /* initialize fractions with 1/0, 0/1 */
3535 for (i = 0; i < MAX_TERMS; i++) {
3537 A = (gint) F; /* no floor() needed, F is always >= 0 */
3538 /* get new divisor */
3541 /* calculate new fraction in temp */
3545 /* guard against overflow */
3546 if (N2 > G_MAXINT || D2 > G_MAXINT) {
3553 /* save last two fractions */
3559 /* quit if dividing by zero or close enough to target */
3560 if (F < MIN_DIVISOR || fabs (V - ((gdouble) N) / D) < MAX_ERROR) {
3564 /* Take reciprocal */
3567 /* fix for overflow */
3572 /* fix for negative */
3577 gcd = gst_util_greatest_common_divisor (N, D);
3589 * gst_util_fraction_multiply:
3590 * @a_n: Numerator of first value
3591 * @a_d: Denominator of first value
3592 * @b_n: Numerator of second value
3593 * @b_d: Denominator of second value
3594 * @res_n: (out): Pointer to #gint to hold the result numerator
3595 * @res_d: (out): Pointer to #gint to hold the result denominator
3597 * Multiplies the fractions @a_n/@a_d and @b_n/@b_d and stores
3598 * the result in @res_n and @res_d.
3600 * Returns: %FALSE on overflow, %TRUE otherwise.
3603 gst_util_fraction_multiply (gint a_n, gint a_d, gint b_n, gint b_d,
3604 gint * res_n, gint * res_d)
3608 g_return_val_if_fail (res_n != NULL, FALSE);
3609 g_return_val_if_fail (res_d != NULL, FALSE);
3610 g_return_val_if_fail (a_d != 0, FALSE);
3611 g_return_val_if_fail (b_d != 0, FALSE);
3613 /* early out if either is 0, as its gcd would be 0 */
3614 if (a_n == 0 || b_n == 0) {
3620 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3624 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3628 gcd = gst_util_greatest_common_divisor (a_n, b_d);
3632 gcd = gst_util_greatest_common_divisor (a_d, b_n);
3636 /* This would result in overflow */
3637 if (a_n != 0 && G_MAXINT / ABS (a_n) < ABS (b_n))
3639 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3645 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3653 * gst_util_fraction_add:
3654 * @a_n: Numerator of first value
3655 * @a_d: Denominator of first value
3656 * @b_n: Numerator of second value
3657 * @b_d: Denominator of second value
3658 * @res_n: (out): Pointer to #gint to hold the result numerator
3659 * @res_d: (out): Pointer to #gint to hold the result denominator
3661 * Adds the fractions @a_n/@a_d and @b_n/@b_d and stores
3662 * the result in @res_n and @res_d.
3664 * Returns: %FALSE on overflow, %TRUE otherwise.
3667 gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint * res_n,
3672 g_return_val_if_fail (res_n != NULL, FALSE);
3673 g_return_val_if_fail (res_d != NULL, FALSE);
3674 g_return_val_if_fail (a_d != 0, FALSE);
3675 g_return_val_if_fail (b_d != 0, FALSE);
3677 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3681 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3696 /* This would result in overflow */
3697 if (G_MAXINT / ABS (a_n) < ABS (b_n))
3699 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3702 *res_n = (a_n * b_d) + (a_d * b_n);
3705 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3718 * gst_util_fraction_compare:
3719 * @a_n: Numerator of first value
3720 * @a_d: Denominator of first value
3721 * @b_n: Numerator of second value
3722 * @b_d: Denominator of second value
3724 * Compares the fractions @a_n/@a_d and @b_n/@b_d and returns
3725 * -1 if a < b, 0 if a = b and 1 if a > b.
3727 * Returns: -1 if a < b; 0 if a = b; 1 if a > b.
3730 gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d)
3736 g_return_val_if_fail (a_d != 0 && b_d != 0, 0);
3739 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3743 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3747 /* fractions are reduced when set, so we can quickly see if they're equal */
3748 if (a_n == b_n && a_d == b_d)
3751 /* extend to 64 bits */
3752 new_num_1 = ((gint64) a_n) * b_d;
3753 new_num_2 = ((gint64) b_n) * a_d;
3754 if (new_num_1 < new_num_2)
3756 if (new_num_1 > new_num_2)
3759 /* Should not happen because a_d and b_d are not 0 */
3760 g_return_val_if_reached (0);
3764 gst_pad_create_stream_id_internal (GstPad * pad, GstElement * parent,
3765 const gchar * stream_id)
3767 GstEvent *upstream_event;
3768 gchar *upstream_stream_id = NULL, *new_stream_id;
3771 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3772 g_return_val_if_fail (GST_PAD_IS_SRC (pad), NULL);
3773 g_return_val_if_fail (GST_IS_ELEMENT (parent), NULL);
3775 g_return_val_if_fail (parent->numsinkpads <= 1, NULL);
3777 /* If the element has multiple source pads it must
3778 * provide a stream-id for every source pad, otherwise
3779 * all source pads will have the same and are not
3780 * distinguishable */
3781 g_return_val_if_fail (parent->numsrcpads <= 1 || stream_id, NULL);
3783 /* First try to get the upstream stream-start stream-id from the sinkpad.
3784 * This will only work for non-source elements */
3785 sinkpad = gst_element_get_static_pad (parent, "sink");
3788 gst_pad_get_sticky_event (sinkpad, GST_EVENT_STREAM_START, 0);
3789 if (upstream_event) {
3792 gst_event_parse_stream_start (upstream_event, &tmp);
3794 upstream_stream_id = g_strdup (tmp);
3795 gst_event_unref (upstream_event);
3797 gst_object_unref (sinkpad);
3800 /* The only case where we don't have an upstream start-start event
3801 * here is for source elements */
3802 if (!upstream_stream_id) {
3806 /* Try to generate one from the URI query and
3807 * if it fails take a random number instead */
3808 query = gst_query_new_uri ();
3809 if (gst_element_query (parent, query)) {
3810 gst_query_parse_uri (query, &uri);
3816 /* And then generate an SHA256 sum of the URI */
3817 cs = g_checksum_new (G_CHECKSUM_SHA256);
3818 g_checksum_update (cs, (const guchar *) uri, strlen (uri));
3820 upstream_stream_id = g_strdup (g_checksum_get_string (cs));
3821 g_checksum_free (cs);
3823 /* Just get some random number if the URI query fails */
3824 GST_FIXME_OBJECT (pad, "Creating random stream-id, consider "
3825 "implementing a deterministic way of creating a stream-id");
3826 upstream_stream_id =
3827 g_strdup_printf ("%08x%08x%08x%08x", g_random_int (), g_random_int (),
3828 g_random_int (), g_random_int ());
3831 gst_query_unref (query);
3835 new_stream_id = g_strconcat (upstream_stream_id, "/", stream_id, NULL);
3837 new_stream_id = g_strdup (upstream_stream_id);
3840 g_free (upstream_stream_id);
3842 return new_stream_id;
3846 * gst_pad_create_stream_id_printf_valist:
3847 * @pad: A source #GstPad
3848 * @parent: Parent #GstElement of @pad
3849 * @stream_id: (allow-none): The stream-id
3850 * @var_args: parameters for the @stream_id format string
3852 * Creates a stream-id for the source #GstPad @pad by combining the
3853 * upstream information with the optional @stream_id of the stream
3854 * of @pad. @pad must have a parent #GstElement and which must have zero
3855 * or one sinkpad. @stream_id can only be %NULL if the parent element
3856 * of @pad has only a single source pad.
3858 * This function generates an unique stream-id by getting the upstream
3859 * stream-start event stream ID and appending @stream_id to it. If the
3860 * element has no sinkpad it will generate an upstream stream-id by
3861 * doing an URI query on the element and in the worst case just uses
3862 * a random number. Source elements that don't implement the URI
3863 * handler interface should ideally generate a unique, deterministic
3864 * stream-id manually instead.
3866 * Returns: A stream-id for @pad. g_free() after usage.
3869 gst_pad_create_stream_id_printf_valist (GstPad * pad, GstElement * parent,
3870 const gchar * stream_id, va_list var_args)
3872 gchar *expanded = NULL, *new_stream_id;
3875 expanded = g_strdup_vprintf (stream_id, var_args);
3877 new_stream_id = gst_pad_create_stream_id_internal (pad, parent, expanded);
3881 return new_stream_id;
3885 * gst_pad_create_stream_id_printf:
3886 * @pad: A source #GstPad
3887 * @parent: Parent #GstElement of @pad
3888 * @stream_id: (allow-none): The stream-id
3889 * @...: parameters for the @stream_id format string
3891 * Creates a stream-id for the source #GstPad @pad by combining the
3892 * upstream information with the optional @stream_id of the stream
3893 * of @pad. @pad must have a parent #GstElement and which must have zero
3894 * or one sinkpad. @stream_id can only be %NULL if the parent element
3895 * of @pad has only a single source pad.
3897 * This function generates an unique stream-id by getting the upstream
3898 * stream-start event stream ID and appending @stream_id to it. If the
3899 * element has no sinkpad it will generate an upstream stream-id by
3900 * doing an URI query on the element and in the worst case just uses
3901 * a random number. Source elements that don't implement the URI
3902 * handler interface should ideally generate a unique, deterministic
3903 * stream-id manually instead.
3905 * Returns: A stream-id for @pad. g_free() after usage.
3908 gst_pad_create_stream_id_printf (GstPad * pad, GstElement * parent,
3909 const gchar * stream_id, ...)
3912 gchar *new_stream_id;
3914 va_start (var_args, stream_id);
3916 gst_pad_create_stream_id_printf_valist (pad, parent, stream_id, var_args);
3919 return new_stream_id;
3923 * gst_pad_create_stream_id:
3924 * @pad: A source #GstPad
3925 * @parent: Parent #GstElement of @pad
3926 * @stream_id: (allow-none): The stream-id
3928 * Creates a stream-id for the source #GstPad @pad by combining the
3929 * upstream information with the optional @stream_id of the stream
3930 * of @pad. @pad must have a parent #GstElement and which must have zero
3931 * or one sinkpad. @stream_id can only be %NULL if the parent element
3932 * of @pad has only a single source pad.
3934 * This function generates an unique stream-id by getting the upstream
3935 * stream-start event stream ID and appending @stream_id to it. If the
3936 * element has no sinkpad it will generate an upstream stream-id by
3937 * doing an URI query on the element and in the worst case just uses
3938 * a random number. Source elements that don't implement the URI
3939 * handler interface should ideally generate a unique, deterministic
3940 * stream-id manually instead.
3942 * Since stream IDs are sorted alphabetically, any numbers in the
3943 * stream ID should be printed with a fixed number of characters,
3944 * preceded by 0's, such as by using the format \%03u instead of \%u.
3946 * Returns: A stream-id for @pad. g_free() after usage.
3949 gst_pad_create_stream_id (GstPad * pad, GstElement * parent,
3950 const gchar * stream_id)
3952 return gst_pad_create_stream_id_internal (pad, parent, stream_id);
3956 * gst_pad_get_stream_id:
3957 * @pad: A source #GstPad
3959 * Returns the current stream-id for the @pad, or %NULL if none has been
3960 * set yet, i.e. the pad has not received a stream-start event yet.
3962 * This is a convenience wrapper around gst_pad_get_sticky_event() and
3963 * gst_event_parse_stream_start().
3965 * The returned stream-id string should be treated as an opaque string, its
3966 * contents should not be interpreted.
3968 * Returns: (nullable): a newly-allocated copy of the stream-id for
3969 * @pad, or %NULL. g_free() the returned string when no longer
3975 gst_pad_get_stream_id (GstPad * pad)
3977 const gchar *stream_id = NULL;
3981 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3983 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
3984 if (event != NULL) {
3985 gst_event_parse_stream_start (event, &stream_id);
3986 ret = g_strdup (stream_id);
3987 gst_event_unref (event);
3988 GST_LOG_OBJECT (pad, "pad has stream-id '%s'", ret);
3990 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");
3997 * gst_pad_get_stream:
3998 * @pad: A source #GstPad
4000 * Returns the current #GstStream for the @pad, or %NULL if none has been
4001 * set yet, i.e. the pad has not received a stream-start event yet.
4003 * This is a convenience wrapper around gst_pad_get_sticky_event() and
4004 * gst_event_parse_stream().
4006 * Returns: (nullable) (transfer full): the current #GstStream for @pad, or %NULL.
4007 * unref the returned stream when no longer needed.
4012 gst_pad_get_stream (GstPad * pad)
4014 GstStream *stream = NULL;
4017 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
4019 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
4020 if (event != NULL) {
4021 gst_event_parse_stream (event, &stream);
4022 gst_event_unref (event);
4023 GST_LOG_OBJECT (pad, "pad has stream object %p", stream);
4025 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");
4032 * gst_util_group_id_next:
4034 * Return a constantly incrementing group id.
4036 * This function is used to generate a new group-id for the
4037 * stream-start event.
4039 * Returns: A constantly incrementing unsigned integer, which might
4040 * overflow back to 0 at some point.
4043 gst_util_group_id_next (void)
4045 static gint counter = 0;
4046 return g_atomic_int_add (&counter, 1);