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 * Convertes 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 (GST_VALUE_HOLDS_STRUCTURE (&v) && 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): a compatible #GstPadTemplate, or NULL if none
777 * 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): the #GstPad, or NULL if one could not be found
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: a #GstPad, or %NULL if one could not be found or created.
897 gst_element_request_compatible_pad (GstElement * element,
898 GstPadTemplate * templ)
900 GstPadTemplate *templ_new;
903 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
904 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
906 /* FIXME: should really loop through the templates, testing each for
907 * compatibility and pad availability. */
908 templ_new = gst_element_get_compatible_pad_template (element, templ);
910 pad = gst_element_get_pad_from_template (element, templ_new);
912 /* This can happen for non-request pads. No need to unref. */
913 if (pad && GST_PAD_PEER (pad))
920 * Checks if the source pad and the sink pad can be linked.
921 * Both @srcpad and @sinkpad must be unlinked and have a parent.
924 gst_pad_check_link (GstPad * srcpad, GstPad * sinkpad)
926 /* FIXME This function is gross. It's almost a direct copy of
927 * gst_pad_link_filtered(). Any decent programmer would attempt
928 * to merge the two functions, which I will do some day. --ds
932 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
933 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
935 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
936 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
938 /* FIXME: shouldn't we convert this to g_return_val_if_fail? */
939 if (GST_PAD_PEER (srcpad) != NULL) {
940 GST_CAT_INFO (GST_CAT_PADS, "Source pad %s:%s has a peer, failed",
941 GST_DEBUG_PAD_NAME (srcpad));
944 if (GST_PAD_PEER (sinkpad) != NULL) {
945 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has a peer, failed",
946 GST_DEBUG_PAD_NAME (sinkpad));
949 if (!GST_PAD_IS_SRC (srcpad)) {
950 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s is not source pad, failed",
951 GST_DEBUG_PAD_NAME (srcpad));
954 if (!GST_PAD_IS_SINK (sinkpad)) {
955 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s is not sink pad, failed",
956 GST_DEBUG_PAD_NAME (sinkpad));
959 if (GST_PAD_PARENT (srcpad) == NULL) {
960 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s has no parent, failed",
961 GST_DEBUG_PAD_NAME (srcpad));
964 if (GST_PAD_PARENT (sinkpad) == NULL) {
965 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has no parent, failed",
966 GST_DEBUG_PAD_NAME (srcpad));
974 * gst_element_get_compatible_pad:
975 * @element: (transfer none): a #GstElement in which the pad should be found.
976 * @pad: (transfer none): the #GstPad to find a compatible one for.
977 * @caps: (allow-none): the #GstCaps to use as a filter.
979 * Looks for an unlinked pad to which the given pad can link. It is not
980 * guaranteed that linking the pads will work, though it should work in most
983 * This function will first attempt to find a compatible unlinked ALWAYS pad,
984 * and if none can be found, it will request a compatible REQUEST pad by looking
985 * at the templates of @element.
987 * Returns: (transfer full): the #GstPad to which a link can be made, or %NULL
988 * if one cannot be found. gst_object_unref() after usage.
991 gst_element_get_compatible_pad (GstElement * element, GstPad * pad,
995 GstPadTemplate *templ;
996 GstPad *foundpad = NULL;
998 GValue padptr = { 0, };
1000 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1001 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1003 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1004 "finding pad in %s compatible with %s:%s",
1005 GST_ELEMENT_NAME (element), GST_DEBUG_PAD_NAME (pad));
1007 g_return_val_if_fail (GST_PAD_PEER (pad) == NULL, NULL);
1011 /* try to get an existing unlinked pad */
1012 if (GST_PAD_IS_SRC (pad)) {
1013 pads = gst_element_iterate_sink_pads (element);
1014 } else if (GST_PAD_IS_SINK (pad)) {
1015 pads = gst_element_iterate_src_pads (element);
1017 pads = gst_element_iterate_pads (element);
1021 switch (gst_iterator_next (pads, &padptr)) {
1022 case GST_ITERATOR_OK:
1029 current = g_value_get_object (&padptr);
1031 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
1032 GST_DEBUG_PAD_NAME (current));
1034 if (GST_PAD_IS_SRC (current)) {
1041 peer = gst_pad_get_peer (current);
1043 if (peer == NULL && gst_pad_check_link (srcpad, sinkpad)) {
1044 GstCaps *temp, *intersection;
1045 gboolean compatible;
1047 /* Now check if the two pads' caps are compatible */
1048 temp = gst_pad_query_caps (pad, NULL);
1050 intersection = gst_caps_intersect (temp, caps);
1051 gst_caps_unref (temp);
1053 intersection = temp;
1056 temp = gst_pad_query_caps (current, NULL);
1057 compatible = gst_caps_can_intersect (temp, intersection);
1058 gst_caps_unref (temp);
1059 gst_caps_unref (intersection);
1062 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1063 "found existing unlinked compatible pad %s:%s",
1064 GST_DEBUG_PAD_NAME (current));
1065 gst_iterator_free (pads);
1067 current = gst_object_ref (current);
1068 g_value_unset (&padptr);
1072 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "incompatible pads");
1075 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1076 "already linked or cannot be linked (peer = %p)", peer);
1078 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unreffing pads");
1080 g_value_reset (&padptr);
1082 gst_object_unref (peer);
1085 case GST_ITERATOR_DONE:
1088 case GST_ITERATOR_RESYNC:
1089 gst_iterator_resync (pads);
1091 case GST_ITERATOR_ERROR:
1092 g_assert_not_reached ();
1096 g_value_unset (&padptr);
1097 gst_iterator_free (pads);
1099 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
1100 "Could not find a compatible unlinked always pad to link to %s:%s, now checking request pads",
1101 GST_DEBUG_PAD_NAME (pad));
1103 /* requesting is a little crazy, we need a template. Let's get the one in that pad */
1104 templ = gst_pad_get_pad_template (pad);
1106 /* that failed, try to create a new one */
1109 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
1110 "Couldn't extract template from pad %s:%s creating a new one",
1111 GST_DEBUG_PAD_NAME (pad));
1113 templcaps = gst_pad_query_caps (pad, NULL);
1114 templ = gst_pad_template_new ((gchar *) GST_PAD_NAME (pad),
1115 GST_PAD_DIRECTION (pad), GST_PAD_ALWAYS, templcaps);
1116 gst_caps_unref (templcaps);
1119 foundpad = gst_element_request_compatible_pad (element, templ);
1120 gst_object_unref (templ);
1123 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1124 "found existing request pad %s:%s", GST_DEBUG_PAD_NAME (foundpad));
1128 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element,
1129 "Could not find a compatible pad to link to %s:%s",
1130 GST_DEBUG_PAD_NAME (pad));
1135 * gst_element_state_get_name:
1136 * @state: a #GstState to get the name of.
1138 * Gets a string representing the given state.
1140 * Returns: (transfer none): a string with the name of the state.
1143 gst_element_state_get_name (GstState state)
1146 case GST_STATE_VOID_PENDING:
1147 return "VOID_PENDING";
1148 case GST_STATE_NULL:
1150 case GST_STATE_READY:
1152 case GST_STATE_PLAYING:
1154 case GST_STATE_PAUSED:
1157 /* This is a memory leak */
1158 return g_strdup_printf ("UNKNOWN!(%d)", state);
1163 * gst_element_state_change_return_get_name:
1164 * @state_ret: a #GstStateChangeReturn to get the name of.
1166 * Gets a string representing the given state change result.
1168 * Returns: (transfer none): a string with the name of the state
1172 gst_element_state_change_return_get_name (GstStateChangeReturn state_ret)
1174 switch (state_ret) {
1175 case GST_STATE_CHANGE_FAILURE:
1177 case GST_STATE_CHANGE_SUCCESS:
1179 case GST_STATE_CHANGE_ASYNC:
1181 case GST_STATE_CHANGE_NO_PREROLL:
1182 return "NO PREROLL";
1184 /* This is a memory leak */
1185 return g_strdup_printf ("UNKNOWN!(%d)", state_ret);
1191 gst_element_factory_can_accept_all_caps_in_direction (GstElementFactory *
1192 factory, const GstCaps * caps, GstPadDirection direction)
1196 g_return_val_if_fail (factory != NULL, FALSE);
1197 g_return_val_if_fail (caps != NULL, FALSE);
1199 templates = factory->staticpadtemplates;
1202 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1204 if (template->direction == direction) {
1205 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1207 if (gst_caps_is_always_compatible (caps, templcaps)) {
1208 gst_caps_unref (templcaps);
1211 gst_caps_unref (templcaps);
1213 templates = g_list_next (templates);
1220 gst_element_factory_can_accept_any_caps_in_direction (GstElementFactory *
1221 factory, const GstCaps * caps, GstPadDirection direction)
1225 g_return_val_if_fail (factory != NULL, FALSE);
1226 g_return_val_if_fail (caps != NULL, FALSE);
1228 templates = factory->staticpadtemplates;
1231 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1233 if (template->direction == direction) {
1234 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1236 if (gst_caps_can_intersect (caps, templcaps)) {
1237 gst_caps_unref (templcaps);
1240 gst_caps_unref (templcaps);
1242 templates = g_list_next (templates);
1249 * gst_element_factory_can_sink_all_caps:
1250 * @factory: factory to query
1251 * @caps: the caps to check
1253 * Checks if the factory can sink all possible capabilities.
1255 * Returns: %TRUE if the caps are fully compatible.
1258 gst_element_factory_can_sink_all_caps (GstElementFactory * factory,
1259 const GstCaps * caps)
1261 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1266 * gst_element_factory_can_src_all_caps:
1267 * @factory: factory to query
1268 * @caps: the caps to check
1270 * Checks if the factory can src all possible capabilities.
1272 * Returns: %TRUE if the caps are fully compatible.
1275 gst_element_factory_can_src_all_caps (GstElementFactory * factory,
1276 const GstCaps * caps)
1278 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1283 * gst_element_factory_can_sink_any_caps:
1284 * @factory: factory to query
1285 * @caps: the caps to check
1287 * Checks if the factory can sink any possible capability.
1289 * Returns: %TRUE if the caps have a common subset.
1292 gst_element_factory_can_sink_any_caps (GstElementFactory * factory,
1293 const GstCaps * caps)
1295 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1300 * gst_element_factory_can_src_any_caps:
1301 * @factory: factory to query
1302 * @caps: the caps to check
1304 * Checks if the factory can src any possible capability.
1306 * Returns: %TRUE if the caps have a common subset.
1309 gst_element_factory_can_src_any_caps (GstElementFactory * factory,
1310 const GstCaps * caps)
1312 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1316 /* if return val is true, *direct_child is a caller-owned ref on the direct
1317 * child of ancestor that is part of object's ancestry */
1319 object_has_ancestor (GstObject * object, GstObject * ancestor,
1320 GstObject ** direct_child)
1322 GstObject *child, *parent;
1325 *direct_child = NULL;
1327 child = gst_object_ref (object);
1328 parent = gst_object_get_parent (object);
1331 if (ancestor == parent) {
1333 *direct_child = child;
1335 gst_object_unref (child);
1336 gst_object_unref (parent);
1340 gst_object_unref (child);
1342 parent = gst_object_get_parent (parent);
1345 gst_object_unref (child);
1350 /* caller owns return */
1352 find_common_root (GstObject * o1, GstObject * o2)
1354 GstObject *top = o1;
1355 GstObject *kid1, *kid2;
1356 GstObject *root = NULL;
1358 while (GST_OBJECT_PARENT (top))
1359 top = GST_OBJECT_PARENT (top);
1361 /* the itsy-bitsy spider... */
1363 if (!object_has_ancestor (o2, top, &kid2))
1366 root = gst_object_ref (top);
1368 if (!object_has_ancestor (o1, kid2, &kid1)) {
1369 gst_object_unref (kid2);
1373 if (!object_has_ancestor (o2, kid1, &kid2)) {
1374 gst_object_unref (kid1);
1381 /* caller does not own return */
1383 ghost_up (GstElement * e, GstPad * pad)
1385 static gint ghost_pad_index = 0;
1390 GstObject *parent = GST_OBJECT_PARENT (e);
1392 name = g_strdup_printf ("ghost%d", ghost_pad_index++);
1393 gpad = gst_ghost_pad_new (name, pad);
1397 gst_element_get_state (e, ¤t, &next, 0);
1399 if (current > GST_STATE_READY || next == GST_STATE_PAUSED)
1400 gst_pad_set_active (gpad, TRUE);
1402 if (!gst_element_add_pad ((GstElement *) parent, gpad)) {
1403 g_warning ("Pad named %s already exists in element %s\n",
1404 GST_OBJECT_NAME (gpad), GST_OBJECT_NAME (parent));
1405 gst_object_unref ((GstObject *) gpad);
1406 GST_STATE_UNLOCK (e);
1409 GST_STATE_UNLOCK (e);
1415 remove_pad (gpointer ppad, gpointer unused)
1419 if (!gst_element_remove_pad ((GstElement *) GST_OBJECT_PARENT (pad), pad))
1420 g_warning ("Couldn't remove pad %s from element %s",
1421 GST_OBJECT_NAME (pad), GST_OBJECT_NAME (GST_OBJECT_PARENT (pad)));
1425 prepare_link_maybe_ghosting (GstPad ** src, GstPad ** sink,
1426 GSList ** pads_created)
1430 GSList *pads_created_local = NULL;
1432 g_assert (pads_created);
1434 e1 = GST_OBJECT_PARENT (*src);
1435 e2 = GST_OBJECT_PARENT (*sink);
1437 if (G_UNLIKELY (e1 == NULL)) {
1438 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1439 GST_PTR_FORMAT, *src);
1442 if (G_UNLIKELY (e2 == NULL)) {
1443 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1444 GST_PTR_FORMAT, *sink);
1448 if (GST_OBJECT_PARENT (e1) == GST_OBJECT_PARENT (e2)) {
1449 GST_CAT_INFO (GST_CAT_PADS, "%s and %s in same bin, no need for ghost pads",
1450 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1454 GST_CAT_INFO (GST_CAT_PADS, "%s and %s not in same bin, making ghost pads",
1455 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1457 /* we need to setup some ghost pads */
1458 root = find_common_root (e1, e2);
1460 g_warning ("Trying to connect elements that don't share a common "
1461 "ancestor: %s and %s", GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2));
1465 while (GST_OBJECT_PARENT (e1) != root) {
1466 *src = ghost_up ((GstElement *) e1, *src);
1469 e1 = GST_OBJECT_PARENT (*src);
1470 pads_created_local = g_slist_prepend (pads_created_local, *src);
1472 while (GST_OBJECT_PARENT (e2) != root) {
1473 *sink = ghost_up ((GstElement *) e2, *sink);
1476 e2 = GST_OBJECT_PARENT (*sink);
1477 pads_created_local = g_slist_prepend (pads_created_local, *sink);
1480 gst_object_unref (root);
1481 *pads_created = g_slist_concat (*pads_created, pads_created_local);
1485 gst_object_unref (root);
1486 g_slist_foreach (pads_created_local, remove_pad, NULL);
1487 g_slist_free (pads_created_local);
1492 pad_link_maybe_ghosting (GstPad * src, GstPad * sink, GstPadLinkCheck flags)
1494 GSList *pads_created = NULL;
1497 if (!prepare_link_maybe_ghosting (&src, &sink, &pads_created)) {
1500 ret = (gst_pad_link_full (src, sink, flags) == GST_PAD_LINK_OK);
1504 g_slist_foreach (pads_created, remove_pad, NULL);
1506 g_slist_free (pads_created);
1512 * gst_element_link_pads_full:
1513 * @src: a #GstElement containing the source pad.
1514 * @srcpadname: (allow-none): the name of the #GstPad in source element
1515 * or NULL for any pad.
1516 * @dest: (transfer none): the #GstElement containing the destination pad.
1517 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1518 * or NULL for any pad.
1519 * @flags: the #GstPadLinkCheck to be performed when linking pads.
1521 * Links the two named pads of the source and destination elements.
1522 * Side effect is that if one of the pads has no parent, it becomes a
1523 * child of the parent of the other element. If they have different
1524 * parents, the link fails.
1526 * Calling gst_element_link_pads_full() with @flags == %GST_PAD_LINK_CHECK_DEFAULT
1527 * is the same as calling gst_element_link_pads() and the recommended way of
1528 * linking pads with safety checks applied.
1530 * This is a convenience function for gst_pad_link_full().
1532 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1535 gst_element_link_pads_full (GstElement * src, const gchar * srcpadname,
1536 GstElement * dest, const gchar * destpadname, GstPadLinkCheck flags)
1538 const GList *srcpads, *destpads, *srctempls, *desttempls, *l;
1539 GstPad *srcpad, *destpad;
1540 GstPadTemplate *srctempl, *desttempl;
1541 GstElementClass *srcclass, *destclass;
1544 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1545 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1547 GST_CAT_INFO (GST_CAT_ELEMENT_PADS,
1548 "trying to link element %s:%s to element %s:%s", GST_ELEMENT_NAME (src),
1549 srcpadname ? srcpadname : "(any)", GST_ELEMENT_NAME (dest),
1550 destpadname ? destpadname : "(any)");
1554 /* name specified, look it up */
1555 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
1556 srcpad = gst_element_get_request_pad (src, srcpadname);
1558 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1559 GST_ELEMENT_NAME (src), srcpadname);
1562 if (!(GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC)) {
1563 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no src pad",
1564 GST_DEBUG_PAD_NAME (srcpad));
1565 gst_object_unref (srcpad);
1568 if (GST_PAD_PEER (srcpad) != NULL) {
1569 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1570 "pad %s:%s is already linked to %s:%s", GST_DEBUG_PAD_NAME (srcpad),
1571 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1572 gst_object_unref (srcpad);
1578 /* no name given, get the first available pad */
1579 GST_OBJECT_LOCK (src);
1580 srcpads = GST_ELEMENT_PADS (src);
1581 srcpad = srcpads ? GST_PAD_CAST (srcpads->data) : NULL;
1583 gst_object_ref (srcpad);
1584 GST_OBJECT_UNLOCK (src);
1587 /* get a destination pad */
1589 /* name specified, look it up */
1590 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
1591 destpad = gst_element_get_request_pad (dest, destpadname);
1593 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1594 GST_ELEMENT_NAME (dest), destpadname);
1597 if (!(GST_PAD_DIRECTION (destpad) == GST_PAD_SINK)) {
1598 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no sink pad",
1599 GST_DEBUG_PAD_NAME (destpad));
1600 gst_object_unref (destpad);
1603 if (GST_PAD_PEER (destpad) != NULL) {
1604 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1605 "pad %s:%s is already linked to %s:%s",
1606 GST_DEBUG_PAD_NAME (destpad),
1607 GST_DEBUG_PAD_NAME (GST_PAD_PEER (destpad)));
1608 gst_object_unref (destpad);
1614 /* no name given, get the first available pad */
1615 GST_OBJECT_LOCK (dest);
1616 destpads = GST_ELEMENT_PADS (dest);
1617 destpad = destpads ? GST_PAD_CAST (destpads->data) : NULL;
1619 gst_object_ref (destpad);
1620 GST_OBJECT_UNLOCK (dest);
1623 if (srcpadname && destpadname) {
1626 /* two explicitly specified pads */
1627 result = pad_link_maybe_ghosting (srcpad, destpad, flags);
1629 gst_object_unref (srcpad);
1630 gst_object_unref (destpad);
1636 /* loop through the allowed pads in the source, trying to find a
1637 * compatible destination pad */
1638 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1639 "looping through allowed src and dest pads");
1641 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying src pad %s:%s",
1642 GST_DEBUG_PAD_NAME (srcpad));
1643 if ((GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC) &&
1644 (GST_PAD_PEER (srcpad) == NULL)) {
1649 gst_object_ref (temp);
1651 temp = gst_element_get_compatible_pad (dest, srcpad, NULL);
1654 if (temp && pad_link_maybe_ghosting (srcpad, temp, flags)) {
1655 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1656 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (temp));
1658 gst_object_unref (destpad);
1659 gst_object_unref (srcpad);
1660 gst_object_unref (temp);
1665 gst_object_unref (temp);
1668 /* find a better way for this mess */
1670 srcpads = g_list_next (srcpads);
1672 gst_object_unref (srcpad);
1673 srcpad = GST_PAD_CAST (srcpads->data);
1674 gst_object_ref (srcpad);
1680 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s:%s to %s",
1681 GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (dest));
1683 gst_object_unref (destpad);
1687 gst_object_unref (srcpad);
1691 /* loop through the existing pads in the destination */
1693 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying dest pad %s:%s",
1694 GST_DEBUG_PAD_NAME (destpad));
1695 if ((GST_PAD_DIRECTION (destpad) == GST_PAD_SINK) &&
1696 (GST_PAD_PEER (destpad) == NULL)) {
1697 GstPad *temp = gst_element_get_compatible_pad (src, destpad, NULL);
1699 if (temp && pad_link_maybe_ghosting (temp, destpad, flags)) {
1700 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1701 GST_DEBUG_PAD_NAME (temp), GST_DEBUG_PAD_NAME (destpad));
1702 gst_object_unref (temp);
1703 gst_object_unref (destpad);
1707 gst_object_unref (temp);
1711 destpads = g_list_next (destpads);
1713 gst_object_unref (destpad);
1714 destpad = GST_PAD_CAST (destpads->data);
1715 gst_object_ref (destpad);
1722 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s:%s",
1723 GST_ELEMENT_NAME (src), GST_DEBUG_PAD_NAME (destpad));
1724 gst_object_unref (destpad);
1728 gst_object_unref (destpad);
1732 srcclass = GST_ELEMENT_GET_CLASS (src);
1733 destclass = GST_ELEMENT_GET_CLASS (dest);
1735 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1736 "we might have request pads on both sides, checking...");
1737 srctempls = gst_element_class_get_pad_template_list (srcclass);
1738 desttempls = gst_element_class_get_pad_template_list (destclass);
1740 if (srctempls && desttempls) {
1742 srctempl = (GstPadTemplate *) srctempls->data;
1743 if (srctempl->presence == GST_PAD_REQUEST) {
1744 for (l = desttempls; l; l = l->next) {
1745 desttempl = (GstPadTemplate *) l->data;
1746 if (desttempl->presence == GST_PAD_REQUEST &&
1747 desttempl->direction != srctempl->direction) {
1748 GstCaps *srccaps, *destcaps;
1750 srccaps = gst_pad_template_get_caps (srctempl);
1751 destcaps = gst_pad_template_get_caps (desttempl);
1752 if (gst_caps_is_always_compatible (srccaps, destcaps)) {
1754 gst_element_request_pad (src, srctempl,
1755 srctempl->name_template, NULL);
1757 gst_element_request_pad (dest, desttempl,
1758 desttempl->name_template, NULL);
1759 if (srcpad && destpad
1760 && pad_link_maybe_ghosting (srcpad, destpad, flags)) {
1761 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1762 "linked pad %s:%s to pad %s:%s",
1763 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (destpad));
1764 gst_object_unref (srcpad);
1765 gst_object_unref (destpad);
1766 gst_caps_unref (srccaps);
1767 gst_caps_unref (destcaps);
1770 /* it failed, so we release the request pads */
1772 gst_element_release_request_pad (src, srcpad);
1774 gst_element_release_request_pad (dest, destpad);
1776 gst_caps_unref (srccaps);
1777 gst_caps_unref (destcaps);
1781 srctempls = srctempls->next;
1785 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s",
1786 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
1791 * gst_element_link_pads:
1792 * @src: a #GstElement containing the source pad.
1793 * @srcpadname: (allow-none): the name of the #GstPad in source element
1794 * or NULL for any pad.
1795 * @dest: (transfer none): the #GstElement containing the destination pad.
1796 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1797 * or NULL for any pad.
1799 * Links the two named pads of the source and destination elements.
1800 * Side effect is that if one of the pads has no parent, it becomes a
1801 * child of the parent of the other element. If they have different
1802 * parents, the link fails.
1804 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1807 gst_element_link_pads (GstElement * src, const gchar * srcpadname,
1808 GstElement * dest, const gchar * destpadname)
1810 return gst_element_link_pads_full (src, srcpadname, dest, destpadname,
1811 GST_PAD_LINK_CHECK_DEFAULT);
1815 * gst_element_link_pads_filtered:
1816 * @src: a #GstElement containing the source pad.
1817 * @srcpadname: (allow-none): the name of the #GstPad in source element
1818 * or NULL for any pad.
1819 * @dest: (transfer none): the #GstElement containing the destination pad.
1820 * @destpadname: (allow-none): the name of the #GstPad in destination element
1821 * or NULL for any pad.
1822 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
1823 * or #NULL for no filter.
1825 * Links the two named pads of the source and destination elements. Side effect
1826 * is that if one of the pads has no parent, it becomes a child of the parent of
1827 * the other element. If they have different parents, the link fails. If @caps
1828 * is not #NULL, makes sure that the caps of the link is a subset of @caps.
1830 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1833 gst_element_link_pads_filtered (GstElement * src, const gchar * srcpadname,
1834 GstElement * dest, const gchar * destpadname, GstCaps * filter)
1837 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1838 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1839 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), FALSE);
1842 GstElement *capsfilter;
1844 GstState state, pending;
1847 capsfilter = gst_element_factory_make ("capsfilter", NULL);
1849 GST_ERROR ("Could not make a capsfilter");
1853 parent = gst_object_get_parent (GST_OBJECT (src));
1854 g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
1856 gst_element_get_state (GST_ELEMENT_CAST (parent), &state, &pending, 0);
1858 if (!gst_bin_add (GST_BIN (parent), capsfilter)) {
1859 GST_ERROR ("Could not add capsfilter");
1860 gst_object_unref (capsfilter);
1861 gst_object_unref (parent);
1865 if (pending != GST_STATE_VOID_PENDING)
1868 gst_element_set_state (capsfilter, state);
1870 gst_object_unref (parent);
1872 g_object_set (capsfilter, "caps", filter, NULL);
1874 lr1 = gst_element_link_pads (src, srcpadname, capsfilter, "sink");
1875 lr2 = gst_element_link_pads (capsfilter, "src", dest, destpadname);
1880 GST_INFO ("Could not link pads: %s:%s - capsfilter:sink",
1881 GST_ELEMENT_NAME (src), srcpadname);
1883 GST_INFO ("Could not link pads: capsfilter:src - %s:%s",
1884 GST_ELEMENT_NAME (dest), destpadname);
1886 gst_element_set_state (capsfilter, GST_STATE_NULL);
1887 /* this will unlink and unref as appropriate */
1888 gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (capsfilter)), capsfilter);
1892 if (gst_element_link_pads (src, srcpadname, dest, destpadname)) {
1895 GST_INFO ("Could not link pads: %s:%s - %s:%s", GST_ELEMENT_NAME (src),
1896 srcpadname, GST_ELEMENT_NAME (dest), destpadname);
1904 * @src: (transfer none): a #GstElement containing the source pad.
1905 * @dest: (transfer none): the #GstElement containing the destination pad.
1907 * Links @src to @dest. The link must be from source to
1908 * destination; the other direction will not be tried. The function looks for
1909 * existing pads that aren't linked yet. It will request new pads if necessary.
1910 * Such pads need to be released manually when unlinking.
1911 * If multiple links are possible, only one is established.
1913 * Make sure you have added your elements to a bin or pipeline with
1914 * gst_bin_add() before trying to link them.
1916 * Returns: TRUE if the elements could be linked, FALSE otherwise.
1919 gst_element_link (GstElement * src, GstElement * dest)
1921 return gst_element_link_pads (src, NULL, dest, NULL);
1925 * gst_element_link_many:
1926 * @element_1: (transfer none): the first #GstElement in the link chain.
1927 * @element_2: (transfer none): the second #GstElement in the link chain.
1928 * @...: the NULL-terminated list of elements to link in order.
1930 * Chain together a series of elements. Uses gst_element_link().
1931 * Make sure you have added your elements to a bin or pipeline with
1932 * gst_bin_add() before trying to link them.
1934 * Returns: TRUE on success, FALSE otherwise.
1937 gst_element_link_many (GstElement * element_1, GstElement * element_2, ...)
1939 gboolean res = TRUE;
1942 g_return_val_if_fail (GST_IS_ELEMENT (element_1), FALSE);
1943 g_return_val_if_fail (GST_IS_ELEMENT (element_2), FALSE);
1945 va_start (args, element_2);
1948 if (!gst_element_link (element_1, element_2)) {
1953 element_1 = element_2;
1954 element_2 = va_arg (args, GstElement *);
1963 * gst_element_link_filtered:
1964 * @src: a #GstElement containing the source pad.
1965 * @dest: (transfer none): the #GstElement containing the destination pad.
1966 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
1967 * or #NULL for no filter.
1969 * Links @src to @dest using the given caps as filtercaps.
1970 * The link must be from source to
1971 * destination; the other direction will not be tried. The function looks for
1972 * existing pads that aren't linked yet. It will request new pads if necessary.
1973 * If multiple links are possible, only one is established.
1975 * Make sure you have added your elements to a bin or pipeline with
1976 * gst_bin_add() before trying to link them.
1978 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1981 gst_element_link_filtered (GstElement * src, GstElement * dest,
1984 return gst_element_link_pads_filtered (src, NULL, dest, NULL, filter);
1988 * gst_element_unlink_pads:
1989 * @src: a (transfer none): #GstElement containing the source pad.
1990 * @srcpadname: the name of the #GstPad in source element.
1991 * @dest: (transfer none): a #GstElement containing the destination pad.
1992 * @destpadname: the name of the #GstPad in destination element.
1994 * Unlinks the two named pads of the source and destination elements.
1996 * This is a convenience function for gst_pad_unlink().
1999 gst_element_unlink_pads (GstElement * src, const gchar * srcpadname,
2000 GstElement * dest, const gchar * destpadname)
2002 GstPad *srcpad, *destpad;
2003 gboolean srcrequest, destrequest;
2005 srcrequest = destrequest = FALSE;
2007 g_return_if_fail (src != NULL);
2008 g_return_if_fail (GST_IS_ELEMENT (src));
2009 g_return_if_fail (srcpadname != NULL);
2010 g_return_if_fail (dest != NULL);
2011 g_return_if_fail (GST_IS_ELEMENT (dest));
2012 g_return_if_fail (destpadname != NULL);
2014 /* obtain the pads requested */
2015 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
2016 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
2018 if (srcpad == NULL) {
2019 GST_WARNING_OBJECT (src, "source element has no pad \"%s\"", srcpadname);
2022 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
2023 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
2025 if (destpad == NULL) {
2026 GST_WARNING_OBJECT (dest, "destination element has no pad \"%s\"",
2031 /* we're satisfied they can be unlinked, let's do it */
2032 gst_pad_unlink (srcpad, destpad);
2035 gst_element_release_request_pad (dest, destpad);
2036 gst_object_unref (destpad);
2040 gst_element_release_request_pad (src, srcpad);
2041 gst_object_unref (srcpad);
2045 * gst_element_unlink_many:
2046 * @element_1: (transfer none): the first #GstElement in the link chain.
2047 * @element_2: (transfer none): the second #GstElement in the link chain.
2048 * @...: the NULL-terminated list of elements to unlink in order.
2050 * Unlinks a series of elements. Uses gst_element_unlink().
2053 gst_element_unlink_many (GstElement * element_1, GstElement * element_2, ...)
2057 g_return_if_fail (element_1 != NULL && element_2 != NULL);
2058 g_return_if_fail (GST_IS_ELEMENT (element_1) && GST_IS_ELEMENT (element_2));
2060 va_start (args, element_2);
2063 gst_element_unlink (element_1, element_2);
2065 element_1 = element_2;
2066 element_2 = va_arg (args, GstElement *);
2073 * gst_element_unlink:
2074 * @src: (transfer none): the source #GstElement to unlink.
2075 * @dest: (transfer none): the sink #GstElement to unlink.
2077 * Unlinks all source pads of the source element with all sink pads
2078 * of the sink element to which they are linked.
2080 * If the link has been made using gst_element_link(), it could have created an
2081 * requestpad, which has to be released using gst_element_release_request_pad().
2084 gst_element_unlink (GstElement * src, GstElement * dest)
2087 gboolean done = FALSE;
2088 GValue data = { 0, };
2090 g_return_if_fail (GST_IS_ELEMENT (src));
2091 g_return_if_fail (GST_IS_ELEMENT (dest));
2093 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unlinking \"%s\" and \"%s\"",
2094 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2096 pads = gst_element_iterate_pads (src);
2098 switch (gst_iterator_next (pads, &data)) {
2099 case GST_ITERATOR_OK:
2101 GstPad *pad = g_value_get_object (&data);
2103 if (GST_PAD_IS_SRC (pad)) {
2104 GstPad *peerpad = gst_pad_get_peer (pad);
2106 /* see if the pad is linked and is really a pad of dest */
2108 GstElement *peerelem;
2110 peerelem = gst_pad_get_parent_element (peerpad);
2112 if (peerelem == dest) {
2113 gst_pad_unlink (pad, peerpad);
2116 gst_object_unref (peerelem);
2118 gst_object_unref (peerpad);
2121 g_value_reset (&data);
2124 case GST_ITERATOR_RESYNC:
2125 gst_iterator_resync (pads);
2127 case GST_ITERATOR_DONE:
2131 g_assert_not_reached ();
2135 g_value_unset (&data);
2136 gst_iterator_free (pads);
2140 * gst_element_query_position:
2141 * @element: a #GstElement to invoke the position query on.
2142 * @format: the #GstFormat requested
2143 * @cur: (out) (allow-none): a location in which to store the current
2144 * position, or NULL.
2146 * Queries an element for the stream position. If one repeatedly calls this
2147 * function one can also create and reuse it in gst_element_query().
2149 * Returns: TRUE if the query could be performed.
2152 gst_element_query_position (GstElement * element, GstFormat format,
2158 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2159 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2161 query = gst_query_new_position (format);
2162 ret = gst_element_query (element, query);
2165 gst_query_parse_position (query, NULL, cur);
2167 gst_query_unref (query);
2173 * gst_element_query_duration:
2174 * @element: a #GstElement to invoke the duration query on.
2175 * @format: the #GstFormat requested
2176 * @duration: (out): A location in which to store the total duration, or NULL.
2178 * Queries an element for the total stream duration.
2180 * Returns: TRUE if the query could be performed.
2183 gst_element_query_duration (GstElement * element, GstFormat format,
2189 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2190 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2192 query = gst_query_new_duration (format);
2193 ret = gst_element_query (element, query);
2196 gst_query_parse_duration (query, NULL, duration);
2198 gst_query_unref (query);
2204 * gst_element_query_convert:
2205 * @element: a #GstElement to invoke the convert query on.
2206 * @src_format: (inout): a #GstFormat to convert from.
2207 * @src_val: a value to convert.
2208 * @dest_format: the #GstFormat to convert to.
2209 * @dest_val: (out): a pointer to the result.
2211 * Queries an element to convert @src_val in @src_format to @dest_format.
2213 * Returns: TRUE if the query could be performed.
2216 gst_element_query_convert (GstElement * element, GstFormat src_format,
2217 gint64 src_val, GstFormat dest_format, gint64 * dest_val)
2222 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2223 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2224 g_return_val_if_fail (dest_val != NULL, FALSE);
2226 if (dest_format == src_format || src_val == -1) {
2227 *dest_val = src_val;
2231 query = gst_query_new_convert (src_format, src_val, dest_format);
2232 ret = gst_element_query (element, query);
2235 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2237 gst_query_unref (query);
2243 * gst_element_seek_simple:
2244 * @element: a #GstElement to seek on
2245 * @format: a #GstFormat to execute the seek in, such as #GST_FORMAT_TIME
2246 * @seek_flags: seek options; playback applications will usually want to use
2247 * GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT here
2248 * @seek_pos: position to seek to (relative to the start); if you are doing
2249 * a seek in #GST_FORMAT_TIME this value is in nanoseconds -
2250 * multiply with #GST_SECOND to convert seconds to nanoseconds or
2251 * with #GST_MSECOND to convert milliseconds to nanoseconds.
2253 * Simple API to perform a seek on the given element, meaning it just seeks
2254 * to the given position relative to the start of the stream. For more complex
2255 * operations like segment seeks (e.g. for looping) or changing the playback
2256 * rate or seeking relative to the last configured playback segment you should
2257 * use gst_element_seek().
2259 * In a completely prerolled PAUSED or PLAYING pipeline, seeking is always
2260 * guaranteed to return %TRUE on a seekable media type or %FALSE when the media
2261 * type is certainly not seekable (such as a live stream).
2263 * Some elements allow for seeking in the READY state, in this
2264 * case they will store the seek event and execute it when they are put to
2265 * PAUSED. If the element supports seek in READY, it will always return %TRUE when
2266 * it receives the event in the READY state.
2268 * Returns: %TRUE if the seek operation succeeded. Flushing seeks will trigger a
2269 * preroll, which will emit %GST_MESSAGE_ASYNC_DONE.
2272 gst_element_seek_simple (GstElement * element, GstFormat format,
2273 GstSeekFlags seek_flags, gint64 seek_pos)
2275 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2276 g_return_val_if_fail (seek_pos >= 0, FALSE);
2278 return gst_element_seek (element, 1.0, format, seek_flags,
2279 GST_SEEK_TYPE_SET, seek_pos, GST_SEEK_TYPE_NONE, 0);
2283 * gst_pad_use_fixed_caps:
2284 * @pad: the pad to use
2286 * A helper function you can use that sets the FIXED_CAPS flag
2287 * This way the default CAPS query will always return the negotiated caps
2288 * or in case the pad is not negotiated, the padtemplate caps.
2290 * The negotiated caps are the caps of the last CAPS event that passed on the
2291 * pad. Use this function on a pad that, once it negotiated to a CAPS, cannot
2292 * be renegotiated to something else.
2295 gst_pad_use_fixed_caps (GstPad * pad)
2297 GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FIXED_CAPS);
2301 * gst_pad_get_parent_element:
2304 * Gets the parent of @pad, cast to a #GstElement. If a @pad has no parent or
2305 * its parent is not an element, return NULL.
2307 * Returns: (transfer full): the parent of the pad. The caller has a
2308 * reference on the parent, so unref when you're finished with it.
2313 gst_pad_get_parent_element (GstPad * pad)
2317 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2319 p = gst_object_get_parent (GST_OBJECT_CAST (pad));
2321 if (p && !GST_IS_ELEMENT (p)) {
2322 gst_object_unref (p);
2325 return GST_ELEMENT_CAST (p);
2329 * gst_object_default_error:
2330 * @source: the #GstObject that initiated the error.
2331 * @error: (in): the GError.
2332 * @debug: (in) (allow-none): an additional debug information string, or NULL
2334 * A default error function that uses g_printerr() to display the error message
2335 * and the optional debug sting..
2337 * The default handler will simply print the error string using g_print.
2340 gst_object_default_error (GstObject * source, const GError * error,
2341 const gchar * debug)
2343 gchar *name = gst_object_get_path_string (source);
2345 g_printerr (_("ERROR: from element %s: %s\n"), name, error->message);
2347 g_printerr (_("Additional debug info:\n%s\n"), debug);
2355 * @element_1: (transfer full): the #GstElement element to add to the bin
2356 * @...: (transfer full): additional elements to add to the bin
2358 * Adds a NULL-terminated list of elements to a bin. This function is
2359 * equivalent to calling gst_bin_add() for each member of the list. The return
2360 * value of each gst_bin_add() is ignored.
2363 gst_bin_add_many (GstBin * bin, GstElement * element_1, ...)
2367 g_return_if_fail (GST_IS_BIN (bin));
2368 g_return_if_fail (GST_IS_ELEMENT (element_1));
2370 va_start (args, element_1);
2373 gst_bin_add (bin, element_1);
2375 element_1 = va_arg (args, GstElement *);
2382 * gst_bin_remove_many:
2384 * @element_1: (transfer none): the first #GstElement to remove from the bin
2385 * @...: (transfer none): NULL-terminated list of elements to remove from the bin
2387 * Remove a list of elements from a bin. This function is equivalent
2388 * to calling gst_bin_remove() with each member of the list.
2391 gst_bin_remove_many (GstBin * bin, GstElement * element_1, ...)
2395 g_return_if_fail (GST_IS_BIN (bin));
2396 g_return_if_fail (GST_IS_ELEMENT (element_1));
2398 va_start (args, element_1);
2401 gst_bin_remove (bin, element_1);
2403 element_1 = va_arg (args, GstElement *);
2413 } QueryAcceptCapsData;
2416 query_accept_caps_func (GstPad * pad, QueryAcceptCapsData * data)
2418 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2421 gst_query_parse_accept_caps_result (data->query, &result);
2422 data->ret &= result;
2428 * gst_pad_proxy_query_accept_caps:
2429 * @pad: a #GstPad to proxy.
2430 * @query: an ACCEPT_CAPS #GstQuery.
2432 * Calls gst_pad_accept_caps() for all internally linked pads of @pad and
2433 * returns the intersection of the results.
2435 * This function is useful as a default accept caps query function for an element
2436 * that can handle any stream format, but requires caps that are acceptable for
2439 * Returns: TRUE if @query could be executed
2442 gst_pad_proxy_query_accept_caps (GstPad * pad, GstQuery * query)
2444 QueryAcceptCapsData data;
2446 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2447 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2448 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS, FALSE);
2450 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2451 "proxying accept caps query for %s:%s", GST_DEBUG_PAD_NAME (pad));
2454 /* value to hold the return, by default it holds TRUE */
2457 gst_pad_forward (pad, (GstPadForwardFunction) query_accept_caps_func, &data);
2458 gst_query_set_accept_caps_result (query, data.ret);
2470 query_caps_func (GstPad * pad, QueryCapsData * data)
2472 gboolean empty = FALSE;
2474 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2475 GstCaps *peercaps, *intersection;
2477 gst_query_parse_caps_result (data->query, &peercaps);
2478 GST_DEBUG_OBJECT (pad, "intersect with result %" GST_PTR_FORMAT, peercaps);
2479 intersection = gst_caps_intersect (data->ret, peercaps);
2480 GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, intersection);
2482 gst_caps_unref (data->ret);
2483 data->ret = intersection;
2485 /* stop when empty */
2486 empty = gst_caps_is_empty (intersection);
2492 * gst_pad_proxy_query_caps:
2493 * @pad: a #GstPad to proxy.
2494 * @query: a CAPS #GstQuery.
2496 * Calls gst_pad_query_caps() for all internally linked pads fof @pad and returns
2497 * the intersection of the results.
2499 * This function is useful as a default caps query function for an element
2500 * that can handle any stream format, but requires all its pads to have
2501 * the same caps. Two such elements are tee and adder.
2503 * Returns: TRUE if @query could be executed
2506 gst_pad_proxy_query_caps (GstPad * pad, GstQuery * query)
2508 GstCaps *filter, *templ, *result;
2511 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2512 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2513 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CAPS, FALSE);
2515 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying caps query for %s:%s",
2516 GST_DEBUG_PAD_NAME (pad));
2520 /* value to hold the return, by default it holds the filter or ANY */
2521 gst_query_parse_caps (query, &filter);
2522 data.ret = filter ? gst_caps_ref (filter) : gst_caps_new_any ();
2524 gst_pad_forward (pad, (GstPadForwardFunction) query_caps_func, &data);
2526 templ = gst_pad_get_pad_template_caps (pad);
2527 result = gst_caps_intersect (data.ret, templ);
2528 gst_caps_unref (data.ret);
2529 gst_caps_unref (templ);
2531 gst_query_set_caps_result (query, result);
2532 gst_caps_unref (result);
2538 * gst_pad_query_position:
2539 * @pad: a #GstPad to invoke the position query on.
2540 * @format: the #GstFormat requested
2541 * @cur: (out): A location in which to store the current position, or NULL.
2543 * Queries a pad for the stream position.
2545 * Returns: TRUE if the query could be performed.
2548 gst_pad_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2553 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2554 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2556 query = gst_query_new_position (format);
2557 if ((ret = gst_pad_query (pad, query)))
2558 gst_query_parse_position (query, NULL, cur);
2559 gst_query_unref (query);
2565 * gst_pad_peer_query_position:
2566 * @pad: a #GstPad on whose peer to invoke the position query on.
2567 * Must be a sink pad.
2568 * @format: the #GstFormat requested
2569 * @cur: (out) (allow-none): a location in which to store the current
2570 * position, or NULL.
2572 * Queries the peer of a given sink pad for the stream position.
2574 * Returns: TRUE if the query could be performed.
2577 gst_pad_peer_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2580 gboolean ret = FALSE;
2582 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2583 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2584 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2586 query = gst_query_new_position (format);
2587 if ((ret = gst_pad_peer_query (pad, query)))
2588 gst_query_parse_position (query, NULL, cur);
2589 gst_query_unref (query);
2595 * gst_pad_query_duration:
2596 * @pad: a #GstPad to invoke the duration query on.
2597 * @format: the #GstFormat requested
2598 * @duration: (out) (allow-none): a location in which to store the total
2599 * duration, or NULL.
2601 * Queries a pad for the total stream duration.
2603 * Returns: TRUE if the query could be performed.
2606 gst_pad_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2611 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2612 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2614 query = gst_query_new_duration (format);
2615 if ((ret = gst_pad_query (pad, query)))
2616 gst_query_parse_duration (query, NULL, duration);
2617 gst_query_unref (query);
2623 * gst_pad_peer_query_duration:
2624 * @pad: a #GstPad on whose peer pad to invoke the duration query on.
2625 * Must be a sink pad.
2626 * @format: the #GstFormat requested
2627 * @duration: (out) (allow-none): a location in which to store the total
2628 * duration, or NULL.
2630 * Queries the peer pad of a given sink pad for the total stream duration.
2632 * Returns: TRUE if the query could be performed.
2635 gst_pad_peer_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2638 gboolean ret = FALSE;
2640 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2641 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2642 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2644 query = gst_query_new_duration (format);
2645 if ((ret = gst_pad_peer_query (pad, query)))
2646 gst_query_parse_duration (query, NULL, duration);
2647 gst_query_unref (query);
2653 * gst_pad_query_convert:
2654 * @pad: a #GstPad to invoke the convert query on.
2655 * @src_format: a #GstFormat to convert from.
2656 * @src_val: a value to convert.
2657 * @dest_format: the #GstFormat to convert to.
2658 * @dest_val: (out): a pointer to the result.
2660 * Queries a pad to convert @src_val in @src_format to @dest_format.
2662 * Returns: TRUE if the query could be performed.
2665 gst_pad_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2666 GstFormat dest_format, gint64 * dest_val)
2671 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2672 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2673 g_return_val_if_fail (dest_val != NULL, FALSE);
2675 if (dest_format == src_format || src_val == -1) {
2676 *dest_val = src_val;
2680 query = gst_query_new_convert (src_format, src_val, dest_format);
2681 if ((ret = gst_pad_query (pad, query)))
2682 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2683 gst_query_unref (query);
2689 * gst_pad_peer_query_convert:
2690 * @pad: a #GstPad, on whose peer pad to invoke the convert query on.
2691 * Must be a sink pad.
2692 * @src_format: a #GstFormat to convert from.
2693 * @src_val: a value to convert.
2694 * @dest_format: the #GstFormat to convert to.
2695 * @dest_val: (out): a pointer to the result.
2697 * Queries the peer pad of a given sink pad to convert @src_val in @src_format
2700 * Returns: TRUE if the query could be performed.
2703 gst_pad_peer_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2704 GstFormat dest_format, gint64 * dest_val)
2707 gboolean ret = FALSE;
2709 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2710 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2711 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2712 g_return_val_if_fail (dest_val != NULL, FALSE);
2714 query = gst_query_new_convert (src_format, src_val, dest_format);
2715 if ((ret = gst_pad_peer_query (pad, query)))
2716 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2717 gst_query_unref (query);
2723 * gst_pad_query_caps:
2724 * @pad: a #GstPad to get the capabilities of.
2725 * @filter: (allow-none): suggested #GstCaps, or NULL
2727 * Gets the capabilities this pad can produce or consume.
2728 * Note that this method doesn't necessarily return the caps set by sending a
2729 * gst_event_new_caps() - use gst_pad_get_current_caps() for that instead.
2730 * gst_pad_query_caps returns all possible caps a pad can operate with, using
2731 * the pad's CAPS query function, If the query fails, this function will return
2732 * @filter, if not #NULL, otherwise ANY.
2734 * When called on sinkpads @filter contains the caps that
2735 * upstream could produce in the order preferred by upstream. When
2736 * called on srcpads @filter contains the caps accepted by
2737 * downstream in the preffered order. @filter might be %NULL but
2738 * if it is not %NULL the returned caps will be a subset of @filter.
2740 * Note that this function does not return writable #GstCaps, use
2741 * gst_caps_make_writable() before modifying the caps.
2743 * Returns: (transfer full): the caps of the pad with incremented ref-count.
2746 gst_pad_query_caps (GstPad * pad, GstCaps * filter)
2748 GstCaps *result = NULL;
2751 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2752 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2754 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2755 "get pad caps with filter %" GST_PTR_FORMAT, filter);
2757 query = gst_query_new_caps (filter);
2758 if (gst_pad_query (pad, query)) {
2759 gst_query_parse_caps_result (query, &result);
2760 gst_caps_ref (result);
2761 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2762 "query returned %" GST_PTR_FORMAT, result);
2763 } else if (filter) {
2764 result = gst_caps_ref (filter);
2766 result = gst_caps_new_any ();
2768 gst_query_unref (query);
2774 * gst_pad_peer_query_caps:
2775 * @pad: a #GstPad to get the capabilities of.
2776 * @filter: (allow-none): a #GstCaps filter, or NULL.
2778 * Gets the capabilities of the peer connected to this pad. Similar to
2779 * gst_pad_query_caps().
2781 * When called on srcpads @filter contains the caps that
2782 * upstream could produce in the order preferred by upstream. When
2783 * called on sinkpads @filter contains the caps accepted by
2784 * downstream in the preffered order. @filter might be %NULL but
2785 * if it is not %NULL the returned caps will be a subset of @filter.
2787 * Returns: the caps of the peer pad with incremented ref-count. When there is
2788 * no peer pad, this function returns @filter or, when @filter is %NULL, ANY
2792 gst_pad_peer_query_caps (GstPad * pad, GstCaps * filter)
2794 GstCaps *result = NULL;
2797 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2798 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2800 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2801 "get pad peer caps with filter %" GST_PTR_FORMAT, filter);
2803 query = gst_query_new_caps (filter);
2804 if (gst_pad_peer_query (pad, query)) {
2805 gst_query_parse_caps_result (query, &result);
2806 gst_caps_ref (result);
2807 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2808 "peer query returned %" GST_PTR_FORMAT, result);
2809 } else if (filter) {
2810 result = gst_caps_ref (filter);
2812 result = gst_caps_new_any ();
2814 gst_query_unref (query);
2820 * gst_pad_query_accept_caps:
2821 * @pad: a #GstPad to check
2822 * @caps: a #GstCaps to check on the pad
2824 * Check if the given pad accepts the caps.
2826 * Returns: TRUE if the pad can accept the caps.
2829 gst_pad_query_accept_caps (GstPad * pad, GstCaps * caps)
2831 gboolean res = TRUE;
2834 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2835 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
2837 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %"
2838 GST_PTR_FORMAT, caps);
2840 query = gst_query_new_accept_caps (caps);
2841 if (gst_pad_query (pad, query)) {
2842 gst_query_parse_accept_caps_result (query, &res);
2843 GST_DEBUG_OBJECT (pad, "query returned %d", res);
2845 gst_query_unref (query);
2851 * gst_pad_peer_query_accept_caps:
2852 * @pad: a #GstPad to check the peer of
2853 * @caps: a #GstCaps to check on the pad
2855 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2858 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2861 gst_pad_peer_query_accept_caps (GstPad * pad, GstCaps * caps)
2863 gboolean res = TRUE;
2866 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2867 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
2869 query = gst_query_new_accept_caps (caps);
2870 if (gst_pad_peer_query (pad, query)) {
2871 gst_query_parse_accept_caps_result (query, &res);
2872 GST_DEBUG_OBJECT (pad, "query returned %d", res);
2874 gst_query_unref (query);
2880 element_find_unlinked_pad (GstElement * element, GstPadDirection direction)
2883 GstPad *unlinked_pad = NULL;
2885 GValue data = { 0, };
2887 switch (direction) {
2889 iter = gst_element_iterate_src_pads (element);
2892 iter = gst_element_iterate_sink_pads (element);
2895 g_return_val_if_reached (NULL);
2900 switch (gst_iterator_next (iter, &data)) {
2901 case GST_ITERATOR_OK:{
2903 GstPad *pad = g_value_get_object (&data);
2905 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
2906 GST_DEBUG_PAD_NAME (pad));
2908 peer = gst_pad_get_peer (pad);
2910 unlinked_pad = gst_object_ref (pad);
2912 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
2913 "found existing unlinked pad %s:%s",
2914 GST_DEBUG_PAD_NAME (unlinked_pad));
2916 gst_object_unref (peer);
2918 g_value_reset (&data);
2921 case GST_ITERATOR_DONE:
2924 case GST_ITERATOR_RESYNC:
2925 gst_iterator_resync (iter);
2927 case GST_ITERATOR_ERROR:
2928 g_return_val_if_reached (NULL);
2932 g_value_unset (&data);
2933 gst_iterator_free (iter);
2935 return unlinked_pad;
2939 * gst_bin_find_unlinked_pad:
2940 * @bin: bin in which to look for elements with unlinked pads
2941 * @direction: whether to look for an unlinked source or sink pad
2943 * Recursively looks for elements with an unlinked pad of the given
2944 * direction within the specified bin and returns an unlinked pad
2945 * if one is found, or NULL otherwise. If a pad is found, the caller
2946 * owns a reference to it and should use gst_object_unref() on the
2947 * pad when it is not needed any longer.
2949 * Returns: (transfer full): unlinked pad of the given direction, or NULL.
2952 gst_bin_find_unlinked_pad (GstBin * bin, GstPadDirection direction)
2957 GValue data = { 0, };
2959 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2960 g_return_val_if_fail (direction != GST_PAD_UNKNOWN, NULL);
2963 iter = gst_bin_iterate_recurse (bin);
2965 switch (gst_iterator_next (iter, &data)) {
2966 case GST_ITERATOR_OK:{
2967 GstElement *element = g_value_get_object (&data);
2969 pad = element_find_unlinked_pad (element, direction);
2972 g_value_reset (&data);
2975 case GST_ITERATOR_DONE:
2978 case GST_ITERATOR_RESYNC:
2979 gst_iterator_resync (iter);
2981 case GST_ITERATOR_ERROR:
2982 g_return_val_if_reached (NULL);
2986 g_value_unset (&data);
2987 gst_iterator_free (iter);
2993 * gst_parse_bin_from_description:
2994 * @bin_description: command line describing the bin
2995 * @ghost_unlinked_pads: whether to automatically create ghost pads
2996 * for unlinked source or sink pads within the bin
2997 * @err: where to store the error message in case of an error, or NULL
2999 * This is a convenience wrapper around gst_parse_launch() to create a
3000 * #GstBin from a gst-launch-style pipeline description. See
3001 * gst_parse_launch() and the gst-launch man page for details about the
3002 * syntax. Ghost pads on the bin for unlinked source or sink pads
3003 * within the bin can automatically be created (but only a maximum of
3004 * one ghost pad for each direction will be created; if you expect
3005 * multiple unlinked source pads or multiple unlinked sink pads
3006 * and want them all ghosted, you will have to create the ghost pads
3009 * Returns: (transfer floating) (type Gst.Bin): a newly-created bin,
3010 * or %NULL if an error occurred.
3013 gst_parse_bin_from_description (const gchar * bin_description,
3014 gboolean ghost_unlinked_pads, GError ** err)
3016 return gst_parse_bin_from_description_full (bin_description,
3017 ghost_unlinked_pads, NULL, GST_PARSE_FLAG_NONE, err);
3021 * gst_parse_bin_from_description_full:
3022 * @bin_description: command line describing the bin
3023 * @ghost_unlinked_pads: whether to automatically create ghost pads
3024 * for unlinked source or sink pads within the bin
3025 * @context: (transfer none) (allow-none): a parse context allocated with
3026 * gst_parse_context_new(), or %NULL
3027 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
3028 * @err: where to store the error message in case of an error, or NULL
3030 * This is a convenience wrapper around gst_parse_launch() to create a
3031 * #GstBin from a gst-launch-style pipeline description. See
3032 * gst_parse_launch() and the gst-launch man page for details about the
3033 * syntax. Ghost pads on the bin for unlinked source or sink pads
3034 * within the bin can automatically be created (but only a maximum of
3035 * one ghost pad for each direction will be created; if you expect
3036 * multiple unlinked source pads or multiple unlinked sink pads
3037 * and want them all ghosted, you will have to create the ghost pads
3040 * Returns: (transfer full) (type Gst.Bin): a newly-created bin, or
3041 * %NULL if an error occurred.
3044 gst_parse_bin_from_description_full (const gchar * bin_description,
3045 gboolean ghost_unlinked_pads, GstParseContext * context,
3046 GstParseFlags flags, GError ** err)
3048 #ifndef GST_DISABLE_PARSE
3053 g_return_val_if_fail (bin_description != NULL, NULL);
3054 g_return_val_if_fail (err == NULL || *err == NULL, NULL);
3056 GST_DEBUG ("Making bin from description '%s'", bin_description);
3058 /* parse the pipeline to a bin */
3059 desc = g_strdup_printf ("bin.( %s )", bin_description);
3060 bin = (GstBin *) gst_parse_launch_full (desc, context, flags, err);
3063 if (bin == NULL || (err && *err != NULL)) {
3065 gst_object_unref (bin);
3069 /* find pads and ghost them if necessary */
3070 if (ghost_unlinked_pads) {
3071 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SRC))) {
3072 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("src", pad));
3073 gst_object_unref (pad);
3075 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SINK))) {
3076 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("sink", pad));
3077 gst_object_unref (pad);
3081 return GST_ELEMENT (bin);
3085 GST_WARNING ("Disabled API called");
3087 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
3088 g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);
3096 * gst_util_get_timestamp:
3098 * Get a timestamp as GstClockTime to be used for interval measurements.
3099 * The timestamp should not be interpreted in any other way.
3101 * Returns: the timestamp
3104 gst_util_get_timestamp (void)
3106 #if defined (HAVE_POSIX_TIMERS) && defined(HAVE_MONOTONIC_CLOCK)
3107 struct timespec now;
3109 clock_gettime (CLOCK_MONOTONIC, &now);
3110 return GST_TIMESPEC_TO_TIME (now);
3114 g_get_current_time (&now);
3115 return GST_TIMEVAL_TO_TIME (now);
3120 * gst_util_array_binary_search:
3121 * @array: the sorted input array
3122 * @num_elements: number of elements in the array
3123 * @element_size: size of every element in bytes
3124 * @search_func: (scope call): function to compare two elements, @search_data will always be passed as second argument
3125 * @mode: search mode that should be used
3126 * @search_data: element that should be found
3127 * @user_data: (closure): data to pass to @search_func
3129 * Searches inside @array for @search_data by using the comparison function
3130 * @search_func. @array must be sorted ascending.
3132 * As @search_data is always passed as second argument to @search_func it's
3133 * not required that @search_data has the same type as the array elements.
3135 * The complexity of this search function is O(log (num_elements)).
3137 * Returns: (transfer none): The address of the found element or %NULL if nothing was found
3140 gst_util_array_binary_search (gpointer array, guint num_elements,
3141 gsize element_size, GCompareDataFunc search_func, GstSearchMode mode,
3142 gconstpointer search_data, gpointer user_data)
3144 glong left = 0, right = num_elements - 1, m;
3146 guint8 *data = (guint8 *) array;
3148 g_return_val_if_fail (array != NULL, NULL);
3149 g_return_val_if_fail (element_size > 0, NULL);
3150 g_return_val_if_fail (search_func != NULL, NULL);
3152 /* 0. No elements => return NULL */
3153 if (num_elements == 0)
3156 /* 1. If search_data is before the 0th element return the 0th element */
3157 ret = search_func (data, search_data, user_data);
3158 if ((ret >= 0 && mode == GST_SEARCH_MODE_AFTER) || ret == 0)
3163 /* 2. If search_data is after the last element return the last element */
3165 search_func (data + (num_elements - 1) * element_size, search_data,
3167 if ((ret <= 0 && mode == GST_SEARCH_MODE_BEFORE) || ret == 0)
3168 return data + (num_elements - 1) * element_size;
3172 /* 3. else binary search */
3174 m = left + (right - left) / 2;
3176 ret = search_func (data + m * element_size, search_data, user_data);
3179 return data + m * element_size;
3180 } else if (ret < 0) {
3186 /* No exact match found */
3188 if (mode == GST_SEARCH_MODE_EXACT) {
3190 } else if (mode == GST_SEARCH_MODE_AFTER) {
3192 return (m < num_elements) ? data + (m + 1) * element_size : NULL;
3194 return data + m * element_size;
3197 return data + m * element_size;
3199 return (m > 0) ? data + (m - 1) * element_size : NULL;
3205 /* Finds the greatest common divisor.
3206 * Returns 1 if none other found.
3207 * This is Euclid's algorithm. */
3210 * gst_util_greatest_common_divisor:
3211 * @a: First value as #gint
3212 * @b: Second value as #gint
3214 * Calculates the greatest common divisor of @a
3217 * Returns: Greatest common divisor of @a and @b
3220 gst_util_greatest_common_divisor (gint a, gint b)
3233 * gst_util_greatest_common_divisor_int64:
3234 * @a: First value as #gint64
3235 * @b: Second value as #gint64
3237 * Calculates the greatest common divisor of @a
3240 * Returns: Greatest common divisor of @a and @b
3243 gst_util_greatest_common_divisor_int64 (gint64 a, gint64 b)
3257 * gst_util_fraction_to_double:
3258 * @src_n: Fraction numerator as #gint
3259 * @src_d: Fraction denominator #gint
3260 * @dest: (out): pointer to a #gdouble for the result
3262 * Transforms a fraction to a #gdouble.
3265 gst_util_fraction_to_double (gint src_n, gint src_d, gdouble * dest)
3267 g_return_if_fail (dest != NULL);
3268 g_return_if_fail (src_d != 0);
3270 *dest = ((gdouble) src_n) / ((gdouble) src_d);
3273 #define MAX_TERMS 30
3274 #define MIN_DIVISOR 1.0e-10
3275 #define MAX_ERROR 1.0e-20
3277 /* use continued fractions to transform a double into a fraction,
3278 * see http://mathforum.org/dr.math/faq/faq.fractions.html#decfrac.
3279 * This algorithm takes care of overflows.
3283 * gst_util_double_to_fraction:
3284 * @src: #gdouble to transform
3285 * @dest_n: (out): pointer to a #gint to hold the result numerator
3286 * @dest_d: (out): pointer to a #gint to hold the result denominator
3288 * Transforms a #gdouble to a fraction and simplifies
3292 gst_util_double_to_fraction (gdouble src, gint * dest_n, gint * dest_d)
3295 gdouble V, F; /* double being converted */
3296 gint N, D; /* will contain the result */
3297 gint A; /* current term in continued fraction */
3298 gint64 N1, D1; /* numerator, denominator of last approx */
3299 gint64 N2, D2; /* numerator, denominator of previous approx */
3302 gboolean negative = FALSE;
3304 g_return_if_fail (dest_n != NULL);
3305 g_return_if_fail (dest_d != NULL);
3307 /* initialize fraction being converted */
3315 /* initialize fractions with 1/0, 0/1 */
3323 for (i = 0; i < MAX_TERMS; i++) {
3325 A = (gint) F; /* no floor() needed, F is always >= 0 */
3326 /* get new divisor */
3329 /* calculate new fraction in temp */
3333 /* guard against overflow */
3334 if (N2 > G_MAXINT || D2 > G_MAXINT) {
3341 /* save last two fractions */
3347 /* quit if dividing by zero or close enough to target */
3348 if (F < MIN_DIVISOR || fabs (V - ((gdouble) N) / D) < MAX_ERROR) {
3352 /* Take reciprocal */
3355 /* fix for overflow */
3360 /* fix for negative */
3365 gcd = gst_util_greatest_common_divisor (N, D);
3377 * gst_util_fraction_multiply:
3378 * @a_n: Numerator of first value
3379 * @a_d: Denominator of first value
3380 * @b_n: Numerator of second value
3381 * @b_d: Denominator of second value
3382 * @res_n: (out): Pointer to #gint to hold the result numerator
3383 * @res_d: (out): Pointer to #gint to hold the result denominator
3385 * Multiplies the fractions @a_n/@a_d and @b_n/@b_d and stores
3386 * the result in @res_n and @res_d.
3388 * Returns: %FALSE on overflow, %TRUE otherwise.
3391 gst_util_fraction_multiply (gint a_n, gint a_d, gint b_n, gint b_d,
3392 gint * res_n, gint * res_d)
3396 g_return_val_if_fail (res_n != NULL, FALSE);
3397 g_return_val_if_fail (res_d != NULL, FALSE);
3398 g_return_val_if_fail (a_d != 0, FALSE);
3399 g_return_val_if_fail (b_d != 0, FALSE);
3401 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3405 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3409 gcd = gst_util_greatest_common_divisor (a_n, b_d);
3413 gcd = gst_util_greatest_common_divisor (a_d, b_n);
3417 /* This would result in overflow */
3418 if (a_n != 0 && G_MAXINT / ABS (a_n) < ABS (b_n))
3420 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3426 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3434 * gst_util_fraction_add:
3435 * @a_n: Numerator of first value
3436 * @a_d: Denominator of first value
3437 * @b_n: Numerator of second value
3438 * @b_d: Denominator of second value
3439 * @res_n: (out): Pointer to #gint to hold the result numerator
3440 * @res_d: (out): Pointer to #gint to hold the result denominator
3442 * Adds the fractions @a_n/@a_d and @b_n/@b_d and stores
3443 * the result in @res_n and @res_d.
3445 * Returns: %FALSE on overflow, %TRUE otherwise.
3448 gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint * res_n,
3453 g_return_val_if_fail (res_n != NULL, FALSE);
3454 g_return_val_if_fail (res_d != NULL, FALSE);
3455 g_return_val_if_fail (a_d != 0, FALSE);
3456 g_return_val_if_fail (b_d != 0, FALSE);
3458 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3462 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3477 /* This would result in overflow */
3478 if (G_MAXINT / ABS (a_n) < ABS (b_n))
3480 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3482 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3485 *res_n = (a_n * b_d) + (a_d * b_n);
3488 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3501 * gst_util_fraction_compare:
3502 * @a_n: Numerator of first value
3503 * @a_d: Denominator of first value
3504 * @b_n: Numerator of second value
3505 * @b_d: Denominator of second value
3507 * Compares the fractions @a_n/@a_d and @b_n/@b_d and returns
3508 * -1 if a < b, 0 if a = b and 1 if a > b.
3510 * Returns: -1 if a < b; 0 if a = b; 1 if a > b.
3513 gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d)
3519 g_return_val_if_fail (a_d != 0 && b_d != 0, 0);
3522 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3526 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3530 /* fractions are reduced when set, so we can quickly see if they're equal */
3531 if (a_n == b_n && a_d == b_d)
3534 /* extend to 64 bits */
3535 new_num_1 = ((gint64) a_n) * b_d;
3536 new_num_2 = ((gint64) b_n) * a_d;
3537 if (new_num_1 < new_num_2)
3539 if (new_num_1 > new_num_2)
3542 /* Should not happen because a_d and b_d are not 0 */
3543 g_return_val_if_reached (0);
3547 * gst_pad_create_stream_id_printf_valist:
3548 * @pad: A source #GstPad
3549 * @parent: Parent #GstElement of @pad
3550 * @stream_id: (allow-none): The stream-id
3551 * @var_args: parameters for the @stream_id format string
3553 * Creates a stream-id for the source #GstPad @pad by combining the
3554 * upstream information with the optional @stream_id of the stream
3555 * of @pad. @pad must have a parent #GstElement and which must have zero
3556 * or one sinkpad. @stream_id can only be %NULL if the parent element
3557 * of @pad has only a single source pad.
3559 * This function generates an unique stream-id by getting the upstream
3560 * stream-start event stream ID and appending @stream_id to it. If the
3561 * element has no sinkpad it will generate an upstream stream-id by
3562 * doing an URI query on the element and in the worst case just uses
3563 * a random number. Source elements that don't implement the URI
3564 * handler interface should ideally generate a unique, deterministic
3565 * stream-id manually instead.
3567 * Returns: A stream-id for @pad. g_free() after usage.
3570 gst_pad_create_stream_id_printf_valist (GstPad * pad, GstElement * parent,
3571 const gchar * stream_id, va_list var_args)
3573 GstEvent *upstream_event;
3574 gchar *upstream_stream_id = NULL, *new_stream_id;
3577 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3578 g_return_val_if_fail (GST_PAD_IS_SRC (pad), NULL);
3579 g_return_val_if_fail (GST_IS_ELEMENT (parent), NULL);
3581 g_return_val_if_fail (parent->numsinkpads <= 1, NULL);
3583 /* If the element has multiple source pads it must
3584 * provide a stream-id for every source pad, otherwise
3585 * all source pads will have the same and are not
3586 * distinguishable */
3587 g_return_val_if_fail (parent->numsrcpads <= 1 || stream_id, NULL);
3589 /* First try to get the upstream stream-start stream-id from the sinkpad.
3590 * This will only work for non-source elements */
3591 sinkpad = gst_element_get_static_pad (parent, "sink");
3594 gst_pad_get_sticky_event (sinkpad, GST_EVENT_STREAM_START, 0);
3595 if (upstream_event) {
3598 gst_event_parse_stream_start (upstream_event, &tmp);
3600 upstream_stream_id = g_strdup (tmp);
3601 gst_event_unref (upstream_event);
3603 gst_object_unref (sinkpad);
3606 /* The only case where we don't have an upstream start-start event
3607 * here is for source elements */
3608 if (!upstream_stream_id) {
3611 /* Try to generate one from the URI query and
3612 * if it fails take a random number instead */
3613 query = gst_query_new_uri ();
3614 if (gst_element_query (parent, query)) {
3618 gst_query_parse_uri (query, &uri);
3620 /* And then generate an SHA256 sum of the URI */
3621 cs = g_checksum_new (G_CHECKSUM_SHA256);
3622 g_checksum_update (cs, (const guchar *) uri, strlen (uri));
3624 upstream_stream_id = g_strdup (g_checksum_get_string (cs));
3625 g_checksum_free (cs);
3627 /* Just get some random number if the URI query fails */
3628 GST_FIXME_OBJECT (pad, "Creating random stream-id, consider "
3629 "implementing a deterministic way of creating a stream-id");
3630 upstream_stream_id =
3631 g_strdup_printf ("%08x%08x%08x%08x", g_random_int (), g_random_int (),
3632 g_random_int (), g_random_int ());
3635 gst_query_unref (query);
3639 gchar *expanded = g_strdup_vprintf (stream_id, var_args);
3640 new_stream_id = g_strconcat (upstream_stream_id, "/", expanded, NULL);
3643 new_stream_id = g_strdup (upstream_stream_id);
3646 g_free (upstream_stream_id);
3648 return new_stream_id;
3652 * gst_pad_create_stream_id_printf:
3653 * @pad: A source #GstPad
3654 * @parent: Parent #GstElement of @pad
3655 * @stream_id: (allow-none): The stream-id
3656 * @...: parameters for the @stream_id format string
3658 * Creates a stream-id for the source #GstPad @pad by combining the
3659 * upstream information with the optional @stream_id of the stream
3660 * of @pad. @pad must have a parent #GstElement and which must have zero
3661 * or one sinkpad. @stream_id can only be %NULL if the parent element
3662 * of @pad has only a single source pad.
3664 * This function generates an unique stream-id by getting the upstream
3665 * stream-start event stream ID and appending @stream_id to it. If the
3666 * element has no sinkpad it will generate an upstream stream-id by
3667 * doing an URI query on the element and in the worst case just uses
3668 * a random number. Source elements that don't implement the URI
3669 * handler interface should ideally generate a unique, deterministic
3670 * stream-id manually instead.
3672 * Returns: A stream-id for @pad. g_free() after usage.
3675 gst_pad_create_stream_id_printf (GstPad * pad, GstElement * parent,
3676 const gchar * stream_id, ...)
3679 gchar *new_stream_id;
3681 va_start (var_args, stream_id);
3683 gst_pad_create_stream_id_printf_valist (pad, parent, stream_id, var_args);
3686 return new_stream_id;
3690 * gst_pad_create_stream_id:
3691 * @pad: A source #GstPad
3692 * @parent: Parent #GstElement of @pad
3693 * @stream_id: (allow-none): The stream-id
3695 * Creates a stream-id for the source #GstPad @pad by combining the
3696 * upstream information with the optional @stream_id of the stream
3697 * of @pad. @pad must have a parent #GstElement and which must have zero
3698 * or one sinkpad. @stream_id can only be %NULL if the parent element
3699 * of @pad has only a single source pad.
3701 * This function generates an unique stream-id by getting the upstream
3702 * stream-start event stream ID and appending @stream_id to it. If the
3703 * element has no sinkpad it will generate an upstream stream-id by
3704 * doing an URI query on the element and in the worst case just uses
3705 * a random number. Source elements that don't implement the URI
3706 * handler interface should ideally generate a unique, deterministic
3707 * stream-id manually instead.
3709 * Returns: A stream-id for @pad. g_free() after usage.
3712 gst_pad_create_stream_id (GstPad * pad, GstElement * parent,
3713 const gchar * stream_id)
3715 return gst_pad_create_stream_id_printf (pad, parent, stream_id, NULL);
3719 * gst_pad_get_stream_id:
3720 * @pad: A source #GstPad
3722 * Returns the current stream-id for the @pad, or %NULL if none has been
3723 * set yet, i.e. the pad has not received a stream-start event yet.
3725 * This is a convenience wrapper around gst_pad_get_sticky_event() and
3726 * gst_event_parse_stream_start().
3728 * The returned stream-id string should be treated as an opaque string, its
3729 * contents should not be interpreted.
3731 * Returns: a newly-allocated copy of the stream-idfor @pad, or %NULL.
3732 * g_free() the returned string when no longer needed.
3737 gst_pad_get_stream_id (GstPad * pad)
3739 const gchar *stream_id = NULL;
3743 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
3745 event = gst_pad_get_sticky_event (pad, GST_EVENT_STREAM_START, 0);
3746 if (event != NULL) {
3747 gst_event_parse_stream_start (event, &stream_id);
3748 ret = g_strdup (stream_id);
3749 gst_event_unref (event);
3750 GST_LOG_OBJECT (pad, "pad has stream-id '%s'", ret);
3752 GST_DEBUG_OBJECT (pad, "pad has not received a stream-start event yet");