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., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, 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.
704 gst_util_seqnum_next (void)
706 static gint counter = 0;
707 return g_atomic_int_add (&counter, 1);
711 * gst_util_seqnum_compare:
712 * @s1: A sequence number.
713 * @s2: Another sequence number.
715 * Compare two sequence numbers, handling wraparound.
717 * The current implementation just returns (gint32)(@s1 - @s2).
719 * Returns: A negative number if @s1 is before @s2, 0 if they are equal, or a
720 * positive number if @s1 is after @s2.
725 gst_util_seqnum_compare (guint32 s1, guint32 s2)
727 return (gint32) (s1 - s2);
730 /* -----------------------------------------------------
732 * The following code will be moved out of the main
733 * gstreamer library someday.
739 * gst_element_create_all_pads:
740 * @element: (transfer none): a #GstElement to create pads for
742 * Creates a pad for each pad template that is always available.
743 * This function is only useful during object initialization of
744 * subclasses of #GstElement.
747 gst_element_create_all_pads (GstElement * element)
751 /* FIXME: lock element */
754 gst_element_class_get_pad_template_list (GST_ELEMENT_CLASS
755 (G_OBJECT_GET_CLASS (element)));
758 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
760 if (padtempl->presence == GST_PAD_ALWAYS) {
763 pad = gst_pad_new_from_template (padtempl, padtempl->name_template);
765 gst_element_add_pad (element, pad);
767 padlist = padlist->next;
772 * gst_element_get_compatible_pad_template:
773 * @element: (transfer none): a #GstElement to get a compatible pad template for
774 * @compattempl: (transfer none): the #GstPadTemplate to find a compatible
777 * Retrieves a pad template from @element that is compatible with @compattempl.
778 * Pads from compatible templates can be linked together.
780 * Returns: (transfer none): a compatible #GstPadTemplate, or NULL if none
781 * was found. No unreferencing is necessary.
784 gst_element_get_compatible_pad_template (GstElement * element,
785 GstPadTemplate * compattempl)
787 GstPadTemplate *newtempl = NULL;
789 GstElementClass *class;
792 g_return_val_if_fail (element != NULL, NULL);
793 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
794 g_return_val_if_fail (compattempl != NULL, NULL);
796 class = GST_ELEMENT_GET_CLASS (element);
798 padlist = gst_element_class_get_pad_template_list (class);
800 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
801 "Looking for a suitable pad template in %s out of %d templates...",
802 GST_ELEMENT_NAME (element), g_list_length (padlist));
805 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
809 * Check direction (must be opposite)
812 GST_CAT_LOG (GST_CAT_CAPS,
813 "checking pad template %s", padtempl->name_template);
814 if (padtempl->direction != compattempl->direction) {
815 GST_CAT_DEBUG (GST_CAT_CAPS,
816 "compatible direction: found %s pad template \"%s\"",
817 padtempl->direction == GST_PAD_SRC ? "src" : "sink",
818 padtempl->name_template);
820 GST_CAT_DEBUG (GST_CAT_CAPS,
821 "intersecting %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (compattempl));
822 GST_CAT_DEBUG (GST_CAT_CAPS,
823 "..and %" GST_PTR_FORMAT, GST_PAD_TEMPLATE_CAPS (padtempl));
825 compatible = gst_caps_can_intersect (GST_PAD_TEMPLATE_CAPS (compattempl),
826 GST_PAD_TEMPLATE_CAPS (padtempl));
828 GST_CAT_DEBUG (GST_CAT_CAPS, "caps are %scompatible",
829 (compatible ? "" : "not "));
837 padlist = g_list_next (padlist);
840 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
841 "Returning new pad template %p", newtempl);
843 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "No compatible pad template found");
849 * gst_element_get_pad_from_template:
850 * @element: (transfer none): a #GstElement.
851 * @templ: (transfer none): a #GstPadTemplate belonging to @element.
853 * Gets a pad from @element described by @templ. If the presence of @templ is
854 * #GST_PAD_REQUEST, requests a new pad. Can return %NULL for #GST_PAD_SOMETIMES
857 * Returns: (transfer full): the #GstPad, or NULL if one could not be found
861 gst_element_get_pad_from_template (GstElement * element, GstPadTemplate * templ)
864 GstPadPresence presence;
866 /* If this function is ever exported, we need check the validity of `element'
867 * and `templ', and to make sure the template actually belongs to the
870 presence = GST_PAD_TEMPLATE_PRESENCE (templ);
874 case GST_PAD_SOMETIMES:
875 ret = gst_element_get_static_pad (element, templ->name_template);
876 if (!ret && presence == GST_PAD_ALWAYS)
878 ("Element %s has an ALWAYS template %s, but no pad of the same name",
879 GST_OBJECT_NAME (element), templ->name_template);
882 case GST_PAD_REQUEST:
883 ret = gst_element_request_pad (element, templ, NULL, NULL);
891 * gst_element_request_compatible_pad:
892 * @element: a #GstElement.
893 * @templ: the #GstPadTemplate to which the new pad should be able to link.
895 * Requests a pad from @element. The returned pad should be unlinked and
896 * compatible with @templ. Might return an existing pad, or request a new one.
898 * Returns: a #GstPad, or %NULL if one could not be found or created.
901 gst_element_request_compatible_pad (GstElement * element,
902 GstPadTemplate * templ)
904 GstPadTemplate *templ_new;
907 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
908 g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
910 /* FIXME: should really loop through the templates, testing each for
911 * compatibility and pad availability. */
912 templ_new = gst_element_get_compatible_pad_template (element, templ);
914 pad = gst_element_get_pad_from_template (element, templ_new);
916 /* This can happen for non-request pads. No need to unref. */
917 if (pad && GST_PAD_PEER (pad))
924 * Checks if the source pad and the sink pad can be linked.
925 * Both @srcpad and @sinkpad must be unlinked and have a parent.
928 gst_pad_check_link (GstPad * srcpad, GstPad * sinkpad)
930 /* FIXME This function is gross. It's almost a direct copy of
931 * gst_pad_link_filtered(). Any decent programmer would attempt
932 * to merge the two functions, which I will do some day. --ds
936 g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
937 g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
939 GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
940 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
942 /* FIXME: shouldn't we convert this to g_return_val_if_fail? */
943 if (GST_PAD_PEER (srcpad) != NULL) {
944 GST_CAT_INFO (GST_CAT_PADS, "Source pad %s:%s has a peer, failed",
945 GST_DEBUG_PAD_NAME (srcpad));
948 if (GST_PAD_PEER (sinkpad) != NULL) {
949 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has a peer, failed",
950 GST_DEBUG_PAD_NAME (sinkpad));
953 if (!GST_PAD_IS_SRC (srcpad)) {
954 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s is not source pad, failed",
955 GST_DEBUG_PAD_NAME (srcpad));
958 if (!GST_PAD_IS_SINK (sinkpad)) {
959 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s is not sink pad, failed",
960 GST_DEBUG_PAD_NAME (sinkpad));
963 if (GST_PAD_PARENT (srcpad) == NULL) {
964 GST_CAT_INFO (GST_CAT_PADS, "Src pad %s:%s has no parent, failed",
965 GST_DEBUG_PAD_NAME (srcpad));
968 if (GST_PAD_PARENT (sinkpad) == NULL) {
969 GST_CAT_INFO (GST_CAT_PADS, "Sink pad %s:%s has no parent, failed",
970 GST_DEBUG_PAD_NAME (srcpad));
978 * gst_element_get_compatible_pad:
979 * @element: (transfer none): a #GstElement in which the pad should be found.
980 * @pad: (transfer none): the #GstPad to find a compatible one for.
981 * @caps: the #GstCaps to use as a filter.
983 * Looks for an unlinked pad to which the given pad can link. It is not
984 * guaranteed that linking the pads will work, though it should work in most
987 * This function will first attempt to find a compatible unlinked ALWAYS pad,
988 * and if none can be found, it will request a compatible REQUEST pad by looking
989 * at the templates of @element.
991 * Returns: (transfer full): the #GstPad to which a link can be made, or %NULL
992 * if one cannot be found. gst_object_unref() after usage.
995 gst_element_get_compatible_pad (GstElement * element, GstPad * pad,
999 GstPadTemplate *templ;
1001 GstPad *foundpad = NULL;
1003 GValue padptr = { 0, };
1005 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1006 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
1008 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1009 "finding pad in %s compatible with %s:%s",
1010 GST_ELEMENT_NAME (element), GST_DEBUG_PAD_NAME (pad));
1012 g_return_val_if_fail (GST_PAD_PEER (pad) == NULL, NULL);
1016 /* try to get an existing unlinked pad */
1017 if (GST_PAD_IS_SRC (pad)) {
1018 pads = gst_element_iterate_sink_pads (element);
1019 } else if (GST_PAD_IS_SINK (pad)) {
1020 pads = gst_element_iterate_src_pads (element);
1022 pads = gst_element_iterate_pads (element);
1026 switch (gst_iterator_next (pads, &padptr)) {
1027 case GST_ITERATOR_OK:
1034 current = g_value_get_object (&padptr);
1036 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
1037 GST_DEBUG_PAD_NAME (current));
1039 if (GST_PAD_IS_SRC (current)) {
1046 peer = gst_pad_get_peer (current);
1048 if (peer == NULL && gst_pad_check_link (srcpad, sinkpad)) {
1049 GstCaps *temp, *intersection;
1050 gboolean compatible;
1052 /* Now check if the two pads' caps are compatible */
1053 temp = gst_pad_query_caps (pad, NULL);
1055 intersection = gst_caps_intersect (temp, caps);
1056 gst_caps_unref (temp);
1058 intersection = temp;
1061 temp = gst_pad_query_caps (current, NULL);
1062 compatible = gst_caps_can_intersect (temp, intersection);
1063 gst_caps_unref (temp);
1064 gst_caps_unref (intersection);
1067 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1068 "found existing unlinked compatible pad %s:%s",
1069 GST_DEBUG_PAD_NAME (current));
1070 gst_iterator_free (pads);
1072 current = gst_object_ref (current);
1073 g_value_unset (&padptr);
1077 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "incompatible pads");
1080 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1081 "already linked or cannot be linked (peer = %p)", peer);
1083 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unreffing pads");
1085 g_value_reset (&padptr);
1087 gst_object_unref (peer);
1090 case GST_ITERATOR_DONE:
1093 case GST_ITERATOR_RESYNC:
1094 gst_iterator_resync (pads);
1096 case GST_ITERATOR_ERROR:
1097 g_assert_not_reached ();
1101 g_value_unset (&padptr);
1102 gst_iterator_free (pads);
1104 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
1105 "Could not find a compatible unlinked always pad to link to %s:%s, now checking request pads",
1106 GST_DEBUG_PAD_NAME (pad));
1108 /* try to create a new one */
1109 /* requesting is a little crazy, we need a template. Let's create one */
1110 /* FIXME: why not gst_pad_get_pad_template (pad); */
1111 templcaps = gst_pad_query_caps (pad, NULL);
1112 templ = gst_pad_template_new ((gchar *) GST_PAD_NAME (pad),
1113 GST_PAD_DIRECTION (pad), GST_PAD_ALWAYS, templcaps);
1114 gst_caps_unref (templcaps);
1116 foundpad = gst_element_request_compatible_pad (element, templ);
1117 gst_object_unref (templ);
1120 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1121 "found existing request pad %s:%s", GST_DEBUG_PAD_NAME (foundpad));
1125 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element,
1126 "Could not find a compatible pad to link to %s:%s",
1127 GST_DEBUG_PAD_NAME (pad));
1132 * gst_element_state_get_name:
1133 * @state: a #GstState to get the name of.
1135 * Gets a string representing the given state.
1137 * Returns: (transfer none): a string with the name of the state.
1140 gst_element_state_get_name (GstState state)
1143 case GST_STATE_VOID_PENDING:
1144 return "VOID_PENDING";
1145 case GST_STATE_NULL:
1147 case GST_STATE_READY:
1149 case GST_STATE_PLAYING:
1151 case GST_STATE_PAUSED:
1154 /* This is a memory leak */
1155 return g_strdup_printf ("UNKNOWN!(%d)", state);
1160 * gst_element_state_change_return_get_name:
1161 * @state_ret: a #GstStateChangeReturn to get the name of.
1163 * Gets a string representing the given state change result.
1165 * Returns: (transfer none): a string with the name of the state
1171 gst_element_state_change_return_get_name (GstStateChangeReturn state_ret)
1173 switch (state_ret) {
1174 case GST_STATE_CHANGE_FAILURE:
1176 case GST_STATE_CHANGE_SUCCESS:
1178 case GST_STATE_CHANGE_ASYNC:
1180 case GST_STATE_CHANGE_NO_PREROLL:
1181 return "NO PREROLL";
1183 /* This is a memory leak */
1184 return g_strdup_printf ("UNKNOWN!(%d)", state_ret);
1190 gst_element_factory_can_accept_all_caps_in_direction (GstElementFactory *
1191 factory, const GstCaps * caps, GstPadDirection direction)
1195 g_return_val_if_fail (factory != NULL, FALSE);
1196 g_return_val_if_fail (caps != NULL, FALSE);
1198 templates = factory->staticpadtemplates;
1201 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1203 if (template->direction == direction) {
1204 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1206 if (gst_caps_is_always_compatible (caps, templcaps)) {
1207 gst_caps_unref (templcaps);
1210 gst_caps_unref (templcaps);
1212 templates = g_list_next (templates);
1219 gst_element_factory_can_accept_any_caps_in_direction (GstElementFactory *
1220 factory, const GstCaps * caps, GstPadDirection direction)
1224 g_return_val_if_fail (factory != NULL, FALSE);
1225 g_return_val_if_fail (caps != NULL, FALSE);
1227 templates = factory->staticpadtemplates;
1230 GstStaticPadTemplate *template = (GstStaticPadTemplate *) templates->data;
1232 if (template->direction == direction) {
1233 GstCaps *templcaps = gst_static_caps_get (&template->static_caps);
1235 if (gst_caps_can_intersect (caps, templcaps)) {
1236 gst_caps_unref (templcaps);
1239 gst_caps_unref (templcaps);
1241 templates = g_list_next (templates);
1248 * gst_element_factory_can_sink_all_caps:
1249 * @factory: factory to query
1250 * @caps: the caps to check
1252 * Checks if the factory can sink all possible capabilities.
1254 * Returns: %TRUE if the caps are fully compatible.
1259 gst_element_factory_can_sink_all_caps (GstElementFactory * factory,
1260 const GstCaps * caps)
1262 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1267 * gst_element_factory_can_src_all_caps:
1268 * @factory: factory to query
1269 * @caps: the caps to check
1271 * Checks if the factory can src all possible capabilities.
1273 * Returns: %TRUE if the caps are fully compatible.
1278 gst_element_factory_can_src_all_caps (GstElementFactory * factory,
1279 const GstCaps * caps)
1281 return gst_element_factory_can_accept_all_caps_in_direction (factory, caps,
1286 * gst_element_factory_can_sink_any_caps:
1287 * @factory: factory to query
1288 * @caps: the caps to check
1290 * Checks if the factory can sink any possible capability.
1292 * Returns: %TRUE if the caps have a common subset.
1297 gst_element_factory_can_sink_any_caps (GstElementFactory * factory,
1298 const GstCaps * caps)
1300 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1305 * gst_element_factory_can_src_any_caps:
1306 * @factory: factory to query
1307 * @caps: the caps to check
1309 * Checks if the factory can src any possible capability.
1311 * Returns: %TRUE if the caps have a common subset.
1316 gst_element_factory_can_src_any_caps (GstElementFactory * factory,
1317 const GstCaps * caps)
1319 return gst_element_factory_can_accept_any_caps_in_direction (factory, caps,
1323 /* if return val is true, *direct_child is a caller-owned ref on the direct
1324 * child of ancestor that is part of object's ancestry */
1326 object_has_ancestor (GstObject * object, GstObject * ancestor,
1327 GstObject ** direct_child)
1329 GstObject *child, *parent;
1332 *direct_child = NULL;
1334 child = gst_object_ref (object);
1335 parent = gst_object_get_parent (object);
1338 if (ancestor == parent) {
1340 *direct_child = child;
1342 gst_object_unref (child);
1343 gst_object_unref (parent);
1347 gst_object_unref (child);
1349 parent = gst_object_get_parent (parent);
1352 gst_object_unref (child);
1357 /* caller owns return */
1359 find_common_root (GstObject * o1, GstObject * o2)
1361 GstObject *top = o1;
1362 GstObject *kid1, *kid2;
1363 GstObject *root = NULL;
1365 while (GST_OBJECT_PARENT (top))
1366 top = GST_OBJECT_PARENT (top);
1368 /* the itsy-bitsy spider... */
1370 if (!object_has_ancestor (o2, top, &kid2))
1373 root = gst_object_ref (top);
1375 if (!object_has_ancestor (o1, kid2, &kid1)) {
1376 gst_object_unref (kid2);
1380 if (!object_has_ancestor (o2, kid1, &kid2)) {
1381 gst_object_unref (kid1);
1388 /* caller does not own return */
1390 ghost_up (GstElement * e, GstPad * pad)
1392 static gint ghost_pad_index = 0;
1397 GstObject *parent = GST_OBJECT_PARENT (e);
1399 name = g_strdup_printf ("ghost%d", ghost_pad_index++);
1400 gpad = gst_ghost_pad_new (name, pad);
1404 gst_element_get_state (e, ¤t, &next, 0);
1406 if (current > GST_STATE_READY || next == GST_STATE_PAUSED)
1407 gst_pad_set_active (gpad, TRUE);
1409 if (!gst_element_add_pad ((GstElement *) parent, gpad)) {
1410 g_warning ("Pad named %s already exists in element %s\n",
1411 GST_OBJECT_NAME (gpad), GST_OBJECT_NAME (parent));
1412 gst_object_unref ((GstObject *) gpad);
1413 GST_STATE_UNLOCK (e);
1416 GST_STATE_UNLOCK (e);
1422 remove_pad (gpointer ppad, gpointer unused)
1426 if (!gst_element_remove_pad ((GstElement *) GST_OBJECT_PARENT (pad), pad))
1427 g_warning ("Couldn't remove pad %s from element %s",
1428 GST_OBJECT_NAME (pad), GST_OBJECT_NAME (GST_OBJECT_PARENT (pad)));
1432 prepare_link_maybe_ghosting (GstPad ** src, GstPad ** sink,
1433 GSList ** pads_created)
1437 GSList *pads_created_local = NULL;
1439 g_assert (pads_created);
1441 e1 = GST_OBJECT_PARENT (*src);
1442 e2 = GST_OBJECT_PARENT (*sink);
1444 if (G_UNLIKELY (e1 == NULL)) {
1445 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1446 GST_PTR_FORMAT, *src);
1449 if (G_UNLIKELY (e2 == NULL)) {
1450 GST_WARNING ("Trying to ghost a pad that doesn't have a parent: %"
1451 GST_PTR_FORMAT, *sink);
1455 if (GST_OBJECT_PARENT (e1) == GST_OBJECT_PARENT (e2)) {
1456 GST_CAT_INFO (GST_CAT_PADS, "%s and %s in same bin, no need for ghost pads",
1457 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1461 GST_CAT_INFO (GST_CAT_PADS, "%s and %s not in same bin, making ghost pads",
1462 GST_OBJECT_NAME (e1), GST_OBJECT_NAME (e2));
1464 /* we need to setup some ghost pads */
1465 root = find_common_root (e1, e2);
1467 g_warning ("Trying to connect elements that don't share a common "
1468 "ancestor: %s and %s", GST_ELEMENT_NAME (e1), GST_ELEMENT_NAME (e2));
1472 while (GST_OBJECT_PARENT (e1) != root) {
1473 *src = ghost_up ((GstElement *) e1, *src);
1476 e1 = GST_OBJECT_PARENT (*src);
1477 pads_created_local = g_slist_prepend (pads_created_local, *src);
1479 while (GST_OBJECT_PARENT (e2) != root) {
1480 *sink = ghost_up ((GstElement *) e2, *sink);
1483 e2 = GST_OBJECT_PARENT (*sink);
1484 pads_created_local = g_slist_prepend (pads_created_local, *sink);
1487 gst_object_unref (root);
1488 *pads_created = g_slist_concat (*pads_created, pads_created_local);
1492 gst_object_unref (root);
1493 g_slist_foreach (pads_created_local, remove_pad, NULL);
1494 g_slist_free (pads_created_local);
1499 pad_link_maybe_ghosting (GstPad * src, GstPad * sink, GstPadLinkCheck flags)
1501 GSList *pads_created = NULL;
1504 if (!prepare_link_maybe_ghosting (&src, &sink, &pads_created)) {
1507 ret = (gst_pad_link_full (src, sink, flags) == GST_PAD_LINK_OK);
1511 g_slist_foreach (pads_created, remove_pad, NULL);
1513 g_slist_free (pads_created);
1519 * gst_element_link_pads_full:
1520 * @src: a #GstElement containing the source pad.
1521 * @srcpadname: (allow-none): the name of the #GstPad in source element
1522 * or NULL for any pad.
1523 * @dest: (transfer none): the #GstElement containing the destination pad.
1524 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1525 * or NULL for any pad.
1526 * @flags: the #GstPadLinkCheck to be performed when linking pads.
1528 * Links the two named pads of the source and destination elements.
1529 * Side effect is that if one of the pads has no parent, it becomes a
1530 * child of the parent of the other element. If they have different
1531 * parents, the link fails.
1533 * Calling gst_element_link_pads_full() with @flags == %GST_PAD_LINK_CHECK_DEFAULT
1534 * is the same as calling gst_element_link_pads() and the recommended way of
1535 * linking pads with safety checks applied.
1537 * This is a convenience function for gst_pad_link_full().
1539 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1544 gst_element_link_pads_full (GstElement * src, const gchar * srcpadname,
1545 GstElement * dest, const gchar * destpadname, GstPadLinkCheck flags)
1547 const GList *srcpads, *destpads, *srctempls, *desttempls, *l;
1548 GstPad *srcpad, *destpad;
1549 GstPadTemplate *srctempl, *desttempl;
1550 GstElementClass *srcclass, *destclass;
1553 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1554 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1556 GST_CAT_INFO (GST_CAT_ELEMENT_PADS,
1557 "trying to link element %s:%s to element %s:%s", GST_ELEMENT_NAME (src),
1558 srcpadname ? srcpadname : "(any)", GST_ELEMENT_NAME (dest),
1559 destpadname ? destpadname : "(any)");
1563 /* name specified, look it up */
1564 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
1565 srcpad = gst_element_get_request_pad (src, srcpadname);
1567 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1568 GST_ELEMENT_NAME (src), srcpadname);
1571 if (!(GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC)) {
1572 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no src pad",
1573 GST_DEBUG_PAD_NAME (srcpad));
1574 gst_object_unref (srcpad);
1577 if (GST_PAD_PEER (srcpad) != NULL) {
1578 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1579 "pad %s:%s is already linked to %s:%s", GST_DEBUG_PAD_NAME (srcpad),
1580 GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
1581 gst_object_unref (srcpad);
1587 /* no name given, get the first available pad */
1588 GST_OBJECT_LOCK (src);
1589 srcpads = GST_ELEMENT_PADS (src);
1590 srcpad = srcpads ? GST_PAD_CAST (srcpads->data) : NULL;
1592 gst_object_ref (srcpad);
1593 GST_OBJECT_UNLOCK (src);
1596 /* get a destination pad */
1598 /* name specified, look it up */
1599 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
1600 destpad = gst_element_get_request_pad (dest, destpadname);
1602 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no pad %s:%s",
1603 GST_ELEMENT_NAME (dest), destpadname);
1606 if (!(GST_PAD_DIRECTION (destpad) == GST_PAD_SINK)) {
1607 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is no sink pad",
1608 GST_DEBUG_PAD_NAME (destpad));
1609 gst_object_unref (destpad);
1612 if (GST_PAD_PEER (destpad) != NULL) {
1613 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1614 "pad %s:%s is already linked to %s:%s",
1615 GST_DEBUG_PAD_NAME (destpad),
1616 GST_DEBUG_PAD_NAME (GST_PAD_PEER (destpad)));
1617 gst_object_unref (destpad);
1623 /* no name given, get the first available pad */
1624 GST_OBJECT_LOCK (dest);
1625 destpads = GST_ELEMENT_PADS (dest);
1626 destpad = destpads ? GST_PAD_CAST (destpads->data) : NULL;
1628 gst_object_ref (destpad);
1629 GST_OBJECT_UNLOCK (dest);
1632 if (srcpadname && destpadname) {
1635 /* two explicitly specified pads */
1636 result = pad_link_maybe_ghosting (srcpad, destpad, flags);
1638 gst_object_unref (srcpad);
1639 gst_object_unref (destpad);
1645 /* loop through the allowed pads in the source, trying to find a
1646 * compatible destination pad */
1647 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1648 "looping through allowed src and dest pads");
1650 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying src pad %s:%s",
1651 GST_DEBUG_PAD_NAME (srcpad));
1652 if ((GST_PAD_DIRECTION (srcpad) == GST_PAD_SRC) &&
1653 (GST_PAD_PEER (srcpad) == NULL)) {
1658 gst_object_ref (temp);
1660 temp = gst_element_get_compatible_pad (dest, srcpad, NULL);
1663 if (temp && pad_link_maybe_ghosting (srcpad, temp, flags)) {
1664 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1665 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (temp));
1667 gst_object_unref (destpad);
1668 gst_object_unref (srcpad);
1669 gst_object_unref (temp);
1674 gst_object_unref (temp);
1677 /* find a better way for this mess */
1679 srcpads = g_list_next (srcpads);
1681 gst_object_unref (srcpad);
1682 srcpad = GST_PAD_CAST (srcpads->data);
1683 gst_object_ref (srcpad);
1689 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s:%s to %s",
1690 GST_DEBUG_PAD_NAME (srcpad), GST_ELEMENT_NAME (dest));
1692 gst_object_unref (destpad);
1696 gst_object_unref (srcpad);
1700 /* loop through the existing pads in the destination */
1702 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "trying dest pad %s:%s",
1703 GST_DEBUG_PAD_NAME (destpad));
1704 if ((GST_PAD_DIRECTION (destpad) == GST_PAD_SINK) &&
1705 (GST_PAD_PEER (destpad) == NULL)) {
1706 GstPad *temp = gst_element_get_compatible_pad (src, destpad, NULL);
1708 if (temp && pad_link_maybe_ghosting (temp, destpad, flags)) {
1709 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "linked pad %s:%s to pad %s:%s",
1710 GST_DEBUG_PAD_NAME (temp), GST_DEBUG_PAD_NAME (destpad));
1711 gst_object_unref (temp);
1712 gst_object_unref (destpad);
1716 gst_object_unref (temp);
1720 destpads = g_list_next (destpads);
1722 gst_object_unref (destpad);
1723 destpad = GST_PAD_CAST (destpads->data);
1724 gst_object_ref (destpad);
1731 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s:%s",
1732 GST_ELEMENT_NAME (src), GST_DEBUG_PAD_NAME (destpad));
1733 gst_object_unref (destpad);
1737 gst_object_unref (destpad);
1741 srcclass = GST_ELEMENT_GET_CLASS (src);
1742 destclass = GST_ELEMENT_GET_CLASS (dest);
1744 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1745 "we might have request pads on both sides, checking...");
1746 srctempls = gst_element_class_get_pad_template_list (srcclass);
1747 desttempls = gst_element_class_get_pad_template_list (destclass);
1749 if (srctempls && desttempls) {
1751 srctempl = (GstPadTemplate *) srctempls->data;
1752 if (srctempl->presence == GST_PAD_REQUEST) {
1753 for (l = desttempls; l; l = l->next) {
1754 desttempl = (GstPadTemplate *) l->data;
1755 if (desttempl->presence == GST_PAD_REQUEST &&
1756 desttempl->direction != srctempl->direction) {
1757 GstCaps *srccaps, *destcaps;
1759 srccaps = gst_pad_template_get_caps (srctempl);
1760 destcaps = gst_pad_template_get_caps (desttempl);
1761 if (gst_caps_is_always_compatible (srccaps, destcaps)) {
1763 gst_element_request_pad (src, srctempl,
1764 srctempl->name_template, NULL);
1766 gst_element_request_pad (dest, desttempl,
1767 desttempl->name_template, NULL);
1768 if (srcpad && destpad
1769 && pad_link_maybe_ghosting (srcpad, destpad, flags)) {
1770 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1771 "linked pad %s:%s to pad %s:%s",
1772 GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (destpad));
1773 gst_object_unref (srcpad);
1774 gst_object_unref (destpad);
1775 gst_caps_unref (srccaps);
1776 gst_caps_unref (destcaps);
1779 /* it failed, so we release the request pads */
1781 gst_element_release_request_pad (src, srcpad);
1783 gst_element_release_request_pad (dest, destpad);
1785 gst_caps_unref (srccaps);
1786 gst_caps_unref (destcaps);
1790 srctempls = srctempls->next;
1794 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "no link possible from %s to %s",
1795 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
1800 * gst_element_link_pads:
1801 * @src: a #GstElement containing the source pad.
1802 * @srcpadname: (allow-none): the name of the #GstPad in source element
1803 * or NULL for any pad.
1804 * @dest: (transfer none): the #GstElement containing the destination pad.
1805 * @destpadname: (allow-none): the name of the #GstPad in destination element,
1806 * or NULL for any pad.
1808 * Links the two named pads of the source and destination elements.
1809 * Side effect is that if one of the pads has no parent, it becomes a
1810 * child of the parent of the other element. If they have different
1811 * parents, the link fails.
1813 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1816 gst_element_link_pads (GstElement * src, const gchar * srcpadname,
1817 GstElement * dest, const gchar * destpadname)
1819 return gst_element_link_pads_full (src, srcpadname, dest, destpadname,
1820 GST_PAD_LINK_CHECK_DEFAULT);
1824 * gst_element_link_pads_filtered:
1825 * @src: a #GstElement containing the source pad.
1826 * @srcpadname: (allow-none): the name of the #GstPad in source element
1827 * or NULL for any pad.
1828 * @dest: (transfer none): the #GstElement containing the destination pad.
1829 * @destpadname: (allow-none): the name of the #GstPad in destination element
1830 * or NULL for any pad.
1831 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
1832 * or #NULL for no filter.
1834 * Links the two named pads of the source and destination elements. Side effect
1835 * is that if one of the pads has no parent, it becomes a child of the parent of
1836 * the other element. If they have different parents, the link fails. If @caps
1837 * is not #NULL, makes sure that the caps of the link is a subset of @caps.
1839 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1842 gst_element_link_pads_filtered (GstElement * src, const gchar * srcpadname,
1843 GstElement * dest, const gchar * destpadname, GstCaps * filter)
1846 g_return_val_if_fail (GST_IS_ELEMENT (src), FALSE);
1847 g_return_val_if_fail (GST_IS_ELEMENT (dest), FALSE);
1848 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), FALSE);
1851 GstElement *capsfilter;
1853 GstState state, pending;
1856 capsfilter = gst_element_factory_make ("capsfilter", NULL);
1858 GST_ERROR ("Could not make a capsfilter");
1862 parent = gst_object_get_parent (GST_OBJECT (src));
1863 g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
1865 gst_element_get_state (GST_ELEMENT_CAST (parent), &state, &pending, 0);
1867 if (!gst_bin_add (GST_BIN (parent), capsfilter)) {
1868 GST_ERROR ("Could not add capsfilter");
1869 gst_object_unref (capsfilter);
1870 gst_object_unref (parent);
1874 if (pending != GST_STATE_VOID_PENDING)
1877 gst_element_set_state (capsfilter, state);
1879 gst_object_unref (parent);
1881 g_object_set (capsfilter, "caps", filter, NULL);
1883 lr1 = gst_element_link_pads (src, srcpadname, capsfilter, "sink");
1884 lr2 = gst_element_link_pads (capsfilter, "src", dest, destpadname);
1889 GST_INFO ("Could not link pads: %s:%s - capsfilter:sink",
1890 GST_ELEMENT_NAME (src), srcpadname);
1892 GST_INFO ("Could not link pads: capsfilter:src - %s:%s",
1893 GST_ELEMENT_NAME (dest), destpadname);
1895 gst_element_set_state (capsfilter, GST_STATE_NULL);
1896 /* this will unlink and unref as appropriate */
1897 gst_bin_remove (GST_BIN (GST_OBJECT_PARENT (capsfilter)), capsfilter);
1901 if (gst_element_link_pads (src, srcpadname, dest, destpadname)) {
1904 GST_INFO ("Could not link pads: %s:%s - %s:%s", GST_ELEMENT_NAME (src),
1905 srcpadname, GST_ELEMENT_NAME (dest), destpadname);
1913 * @src: (transfer none): a #GstElement containing the source pad.
1914 * @dest: (transfer none): the #GstElement containing the destination pad.
1916 * Links @src to @dest. The link must be from source to
1917 * destination; the other direction will not be tried. The function looks for
1918 * existing pads that aren't linked yet. It will request new pads if necessary.
1919 * Such pads need to be released manually when unlinking.
1920 * If multiple links are possible, only one is established.
1922 * Make sure you have added your elements to a bin or pipeline with
1923 * gst_bin_add() before trying to link them.
1925 * Returns: TRUE if the elements could be linked, FALSE otherwise.
1928 gst_element_link (GstElement * src, GstElement * dest)
1930 return gst_element_link_pads (src, NULL, dest, NULL);
1934 * gst_element_link_many:
1935 * @element_1: (transfer none): the first #GstElement in the link chain.
1936 * @element_2: (transfer none): the second #GstElement in the link chain.
1937 * @...: the NULL-terminated list of elements to link in order.
1939 * Chain together a series of elements. Uses gst_element_link().
1940 * Make sure you have added your elements to a bin or pipeline with
1941 * gst_bin_add() before trying to link them.
1943 * Returns: TRUE on success, FALSE otherwise.
1946 gst_element_link_many (GstElement * element_1, GstElement * element_2, ...)
1948 gboolean res = TRUE;
1951 g_return_val_if_fail (GST_IS_ELEMENT (element_1), FALSE);
1952 g_return_val_if_fail (GST_IS_ELEMENT (element_2), FALSE);
1954 va_start (args, element_2);
1957 if (!gst_element_link (element_1, element_2)) {
1962 element_1 = element_2;
1963 element_2 = va_arg (args, GstElement *);
1972 * gst_element_link_filtered:
1973 * @src: a #GstElement containing the source pad.
1974 * @dest: (transfer none): the #GstElement containing the destination pad.
1975 * @filter: (transfer none) (allow-none): the #GstCaps to filter the link,
1976 * or #NULL for no filter.
1978 * Links @src to @dest using the given caps as filtercaps.
1979 * The link must be from source to
1980 * destination; the other direction will not be tried. The function looks for
1981 * existing pads that aren't linked yet. It will request new pads if necessary.
1982 * If multiple links are possible, only one is established.
1984 * Make sure you have added your elements to a bin or pipeline with
1985 * gst_bin_add() before trying to link them.
1987 * Returns: TRUE if the pads could be linked, FALSE otherwise.
1990 gst_element_link_filtered (GstElement * src, GstElement * dest,
1993 return gst_element_link_pads_filtered (src, NULL, dest, NULL, filter);
1997 * gst_element_unlink_pads:
1998 * @src: a (transfer none): #GstElement containing the source pad.
1999 * @srcpadname: the name of the #GstPad in source element.
2000 * @dest: (transfer none): a #GstElement containing the destination pad.
2001 * @destpadname: the name of the #GstPad in destination element.
2003 * Unlinks the two named pads of the source and destination elements.
2005 * This is a convenience function for gst_pad_unlink().
2008 gst_element_unlink_pads (GstElement * src, const gchar * srcpadname,
2009 GstElement * dest, const gchar * destpadname)
2011 GstPad *srcpad, *destpad;
2012 gboolean srcrequest, destrequest;
2014 srcrequest = destrequest = FALSE;
2016 g_return_if_fail (src != NULL);
2017 g_return_if_fail (GST_IS_ELEMENT (src));
2018 g_return_if_fail (srcpadname != NULL);
2019 g_return_if_fail (dest != NULL);
2020 g_return_if_fail (GST_IS_ELEMENT (dest));
2021 g_return_if_fail (destpadname != NULL);
2023 /* obtain the pads requested */
2024 if (!(srcpad = gst_element_get_static_pad (src, srcpadname)))
2025 if ((srcpad = gst_element_get_request_pad (src, srcpadname)))
2027 if (srcpad == NULL) {
2028 GST_WARNING_OBJECT (src, "source element has no pad \"%s\"", srcpadname);
2031 if (!(destpad = gst_element_get_static_pad (dest, destpadname)))
2032 if ((destpad = gst_element_get_request_pad (dest, destpadname)))
2034 if (destpad == NULL) {
2035 GST_WARNING_OBJECT (dest, "destination element has no pad \"%s\"",
2040 /* we're satisfied they can be unlinked, let's do it */
2041 gst_pad_unlink (srcpad, destpad);
2044 gst_element_release_request_pad (dest, destpad);
2045 gst_object_unref (destpad);
2049 gst_element_release_request_pad (src, srcpad);
2050 gst_object_unref (srcpad);
2054 * gst_element_unlink_many:
2055 * @element_1: (transfer none): the first #GstElement in the link chain.
2056 * @element_2: (transfer none): the second #GstElement in the link chain.
2057 * @...: the NULL-terminated list of elements to unlink in order.
2059 * Unlinks a series of elements. Uses gst_element_unlink().
2062 gst_element_unlink_many (GstElement * element_1, GstElement * element_2, ...)
2066 g_return_if_fail (element_1 != NULL && element_2 != NULL);
2067 g_return_if_fail (GST_IS_ELEMENT (element_1) && GST_IS_ELEMENT (element_2));
2069 va_start (args, element_2);
2072 gst_element_unlink (element_1, element_2);
2074 element_1 = element_2;
2075 element_2 = va_arg (args, GstElement *);
2082 * gst_element_unlink:
2083 * @src: (transfer none): the source #GstElement to unlink.
2084 * @dest: (transfer none): the sink #GstElement to unlink.
2086 * Unlinks all source pads of the source element with all sink pads
2087 * of the sink element to which they are linked.
2089 * If the link has been made using gst_element_link(), it could have created an
2090 * requestpad, which has to be released using gst_element_release_request_pad().
2093 gst_element_unlink (GstElement * src, GstElement * dest)
2096 gboolean done = FALSE;
2097 GValue data = { 0, };
2099 g_return_if_fail (GST_IS_ELEMENT (src));
2100 g_return_if_fail (GST_IS_ELEMENT (dest));
2102 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "unlinking \"%s\" and \"%s\"",
2103 GST_ELEMENT_NAME (src), GST_ELEMENT_NAME (dest));
2105 pads = gst_element_iterate_pads (src);
2107 switch (gst_iterator_next (pads, &data)) {
2108 case GST_ITERATOR_OK:
2110 GstPad *pad = g_value_get_object (&data);
2112 if (GST_PAD_IS_SRC (pad)) {
2113 GstPad *peerpad = gst_pad_get_peer (pad);
2115 /* see if the pad is linked and is really a pad of dest */
2117 GstElement *peerelem;
2119 peerelem = gst_pad_get_parent_element (peerpad);
2121 if (peerelem == dest) {
2122 gst_pad_unlink (pad, peerpad);
2125 gst_object_unref (peerelem);
2127 gst_object_unref (peerpad);
2130 g_value_reset (&data);
2133 case GST_ITERATOR_RESYNC:
2134 gst_iterator_resync (pads);
2136 case GST_ITERATOR_DONE:
2140 g_assert_not_reached ();
2144 g_value_unset (&data);
2145 gst_iterator_free (pads);
2149 * gst_element_query_position:
2150 * @element: a #GstElement to invoke the position query on.
2151 * @format: the #GstFormat requested
2152 * @cur: (out) (allow-none): a location in which to store the current
2153 * position, or NULL.
2155 * Queries an element for the stream position. If one repeatedly calls this
2156 * function one can also create and reuse it in gst_element_query().
2158 * Returns: TRUE if the query could be performed.
2161 gst_element_query_position (GstElement * element, GstFormat format,
2167 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2168 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2170 query = gst_query_new_position (format);
2171 ret = gst_element_query (element, query);
2174 gst_query_parse_position (query, NULL, cur);
2176 gst_query_unref (query);
2182 * gst_element_query_duration:
2183 * @element: a #GstElement to invoke the duration query on.
2184 * @format: the #GstFormat requested
2185 * @duration: (out): A location in which to store the total duration, or NULL.
2187 * Queries an element for the total stream duration.
2189 * Returns: TRUE if the query could be performed.
2192 gst_element_query_duration (GstElement * element, GstFormat format,
2198 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2199 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2201 query = gst_query_new_duration (format);
2202 ret = gst_element_query (element, query);
2205 gst_query_parse_duration (query, NULL, duration);
2207 gst_query_unref (query);
2213 * gst_element_query_convert:
2214 * @element: a #GstElement to invoke the convert query on.
2215 * @src_format: (inout): a #GstFormat to convert from.
2216 * @src_val: a value to convert.
2217 * @dest_format: the #GstFormat to convert to.
2218 * @dest_val: (out): a pointer to the result.
2220 * Queries an element to convert @src_val in @src_format to @dest_format.
2222 * Returns: TRUE if the query could be performed.
2225 gst_element_query_convert (GstElement * element, GstFormat src_format,
2226 gint64 src_val, GstFormat dest_format, gint64 * dest_val)
2231 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2232 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2233 g_return_val_if_fail (dest_val != NULL, FALSE);
2235 if (dest_format == src_format || src_val == -1) {
2236 *dest_val = src_val;
2240 query = gst_query_new_convert (src_format, src_val, dest_format);
2241 ret = gst_element_query (element, query);
2244 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2246 gst_query_unref (query);
2252 * gst_element_seek_simple:
2253 * @element: a #GstElement to seek on
2254 * @format: a #GstFormat to execute the seek in, such as #GST_FORMAT_TIME
2255 * @seek_flags: seek options; playback applications will usually want to use
2256 * GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT here
2257 * @seek_pos: position to seek to (relative to the start); if you are doing
2258 * a seek in #GST_FORMAT_TIME this value is in nanoseconds -
2259 * multiply with #GST_SECOND to convert seconds to nanoseconds or
2260 * with #GST_MSECOND to convert milliseconds to nanoseconds.
2262 * Simple API to perform a seek on the given element, meaning it just seeks
2263 * to the given position relative to the start of the stream. For more complex
2264 * operations like segment seeks (e.g. for looping) or changing the playback
2265 * rate or seeking relative to the last configured playback segment you should
2266 * use gst_element_seek().
2268 * In a completely prerolled PAUSED or PLAYING pipeline, seeking is always
2269 * guaranteed to return %TRUE on a seekable media type or %FALSE when the media
2270 * type is certainly not seekable (such as a live stream).
2272 * Some elements allow for seeking in the READY state, in this
2273 * case they will store the seek event and execute it when they are put to
2274 * PAUSED. If the element supports seek in READY, it will always return %TRUE when
2275 * it receives the event in the READY state.
2277 * Returns: %TRUE if the seek operation succeeded. Flushing seeks will trigger a
2278 * preroll, which will emit %GST_MESSAGE_ASYNC_DONE.
2283 gst_element_seek_simple (GstElement * element, GstFormat format,
2284 GstSeekFlags seek_flags, gint64 seek_pos)
2286 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2287 g_return_val_if_fail (seek_pos >= 0, FALSE);
2289 return gst_element_seek (element, 1.0, format, seek_flags,
2290 GST_SEEK_TYPE_SET, seek_pos, GST_SEEK_TYPE_NONE, 0);
2294 * gst_pad_use_fixed_caps:
2295 * @pad: the pad to use
2297 * A helper function you can use that sets the FIXED_CAPS flag
2298 * This way the default CAPS query will always return the negotiated caps
2299 * or in case the pad is not negotiated, the padtemplate caps.
2301 * The negotiated caps are the caps of the last CAPS event that passed on the
2302 * pad. Use this function on a pad that, once it negotiated to a CAPS, cannot
2303 * be renegotiated to something else.
2306 gst_pad_use_fixed_caps (GstPad * pad)
2308 GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_FIXED_CAPS);
2312 * gst_pad_get_parent_element:
2315 * Gets the parent of @pad, cast to a #GstElement. If a @pad has no parent or
2316 * its parent is not an element, return NULL.
2318 * Returns: (transfer full): the parent of the pad. The caller has a
2319 * reference on the parent, so unref when you're finished with it.
2324 gst_pad_get_parent_element (GstPad * pad)
2328 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2330 p = gst_object_get_parent (GST_OBJECT_CAST (pad));
2332 if (p && !GST_IS_ELEMENT (p)) {
2333 gst_object_unref (p);
2336 return GST_ELEMENT_CAST (p);
2340 * gst_object_default_error:
2341 * @source: the #GstObject that initiated the error.
2342 * @error: (in): the GError.
2343 * @debug: (in) (allow-none): an additional debug information string, or NULL
2345 * A default error function that uses g_printerr() to display the error message
2346 * and the optional debug sting..
2348 * The default handler will simply print the error string using g_print.
2351 gst_object_default_error (GstObject * source, const GError * error,
2352 const gchar * debug)
2354 gchar *name = gst_object_get_path_string (source);
2356 g_printerr (_("ERROR: from element %s: %s\n"), name, error->message);
2358 g_printerr (_("Additional debug info:\n%s\n"), debug);
2366 * @element_1: (transfer full): the #GstElement element to add to the bin
2367 * @...: (transfer full): additional elements to add to the bin
2369 * Adds a NULL-terminated list of elements to a bin. This function is
2370 * equivalent to calling gst_bin_add() for each member of the list. The return
2371 * value of each gst_bin_add() is ignored.
2374 gst_bin_add_many (GstBin * bin, GstElement * element_1, ...)
2378 g_return_if_fail (GST_IS_BIN (bin));
2379 g_return_if_fail (GST_IS_ELEMENT (element_1));
2381 va_start (args, element_1);
2384 gst_bin_add (bin, element_1);
2386 element_1 = va_arg (args, GstElement *);
2393 * gst_bin_remove_many:
2395 * @element_1: (transfer none): the first #GstElement to remove from the bin
2396 * @...: (transfer none): NULL-terminated list of elements to remove from the bin
2398 * Remove a list of elements from a bin. This function is equivalent
2399 * to calling gst_bin_remove() with each member of the list.
2402 gst_bin_remove_many (GstBin * bin, GstElement * element_1, ...)
2406 g_return_if_fail (GST_IS_BIN (bin));
2407 g_return_if_fail (GST_IS_ELEMENT (element_1));
2409 va_start (args, element_1);
2412 gst_bin_remove (bin, element_1);
2414 element_1 = va_arg (args, GstElement *);
2424 } QueryAcceptCapsData;
2427 query_accept_caps_func (GstPad * pad, QueryAcceptCapsData * data)
2429 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2432 gst_query_parse_accept_caps_result (data->query, &result);
2433 data->ret &= result;
2439 * gst_pad_proxy_query_accept_caps:
2440 * @pad: a #GstPad to proxy.
2441 * @query: an ACCEPT_CAPS #GstQuery.
2443 * Calls gst_pad_accept_caps() for all internally linked pads of @pad and
2444 * returns the intersection of the results.
2446 * This function is useful as a default accept caps query function for an element
2447 * that can handle any stream format, but requires caps that are acceptable for
2450 * Returns: TRUE if @query could be executed
2453 gst_pad_proxy_query_accept_caps (GstPad * pad, GstQuery * query)
2455 QueryAcceptCapsData data;
2457 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2458 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2459 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS, FALSE);
2461 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
2462 "proxying accept caps query for %s:%s", GST_DEBUG_PAD_NAME (pad));
2465 /* value to hold the return, by default it holds TRUE */
2468 gst_pad_forward (pad, (GstPadForwardFunction) query_accept_caps_func, &data);
2469 gst_query_set_accept_caps_result (query, data.ret);
2481 query_caps_func (GstPad * pad, QueryCapsData * data)
2483 gboolean empty = FALSE;
2485 if (G_LIKELY (gst_pad_peer_query (pad, data->query))) {
2486 GstCaps *peercaps, *intersection;
2488 gst_query_parse_caps_result (data->query, &peercaps);
2489 GST_DEBUG_OBJECT (pad, "intersect with result %" GST_PTR_FORMAT, peercaps);
2490 intersection = gst_caps_intersect (data->ret, peercaps);
2491 GST_DEBUG_OBJECT (pad, "intersected %" GST_PTR_FORMAT, intersection);
2493 gst_caps_unref (data->ret);
2494 data->ret = intersection;
2496 /* stop when empty */
2497 empty = gst_caps_is_empty (intersection);
2503 * gst_pad_proxy_query_caps:
2504 * @pad: a #GstPad to proxy.
2505 * @query: a CAPS #GstQuery.
2507 * Calls gst_pad_query_caps() for all internally linked pads fof @pad and returns
2508 * the intersection of the results.
2510 * This function is useful as a default caps query function for an element
2511 * that can handle any stream format, but requires all its pads to have
2512 * the same caps. Two such elements are tee and adder.
2514 * Returns: TRUE if @query could be executed
2517 gst_pad_proxy_query_caps (GstPad * pad, GstQuery * query)
2519 GstCaps *templ, *intersected;
2522 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2523 g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
2524 g_return_val_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CAPS, FALSE);
2526 GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "proxying caps query for %s:%s",
2527 GST_DEBUG_PAD_NAME (pad));
2530 /* value to hold the return, by default it holds ANY */
2531 data.ret = gst_caps_new_any ();
2533 gst_pad_forward (pad, (GstPadForwardFunction) query_caps_func, &data);
2535 templ = gst_pad_get_pad_template_caps (pad);
2536 intersected = gst_caps_intersect (data.ret, templ);
2537 gst_caps_unref (data.ret);
2538 gst_caps_unref (templ);
2540 gst_query_set_caps_result (query, intersected);
2541 gst_caps_unref (intersected);
2547 * gst_pad_query_position:
2548 * @pad: a #GstPad to invoke the position query on.
2549 * @format: the #GstFormat requested
2550 * @cur: (out): A location in which to store the current position, or NULL.
2552 * Queries a pad for the stream position.
2554 * Returns: TRUE if the query could be performed.
2557 gst_pad_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2562 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2563 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2565 query = gst_query_new_position (format);
2566 if ((ret = gst_pad_query (pad, query)))
2567 gst_query_parse_position (query, NULL, cur);
2568 gst_query_unref (query);
2574 * gst_pad_peer_query_position:
2575 * @pad: a #GstPad on whose peer to invoke the position query on.
2576 * Must be a sink pad.
2577 * @format: the #GstFormat requested
2578 * @cur: (out) (allow-none): a location in which to store the current
2579 * position, or NULL.
2581 * Queries the peer of a given sink pad for the stream position.
2583 * Returns: TRUE if the query could be performed.
2586 gst_pad_peer_query_position (GstPad * pad, GstFormat format, gint64 * cur)
2589 gboolean ret = FALSE;
2591 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2592 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2593 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2595 query = gst_query_new_position (format);
2596 if ((ret = gst_pad_peer_query (pad, query)))
2597 gst_query_parse_position (query, NULL, cur);
2598 gst_query_unref (query);
2604 * gst_pad_query_duration:
2605 * @pad: a #GstPad to invoke the duration query on.
2606 * @format: the #GstFormat requested
2607 * @duration: (out) (allow-none): a location in which to store the total
2608 * duration, or NULL.
2610 * Queries a pad for the total stream duration.
2612 * Returns: TRUE if the query could be performed.
2615 gst_pad_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2620 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2621 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2623 query = gst_query_new_duration (format);
2624 if ((ret = gst_pad_query (pad, query)))
2625 gst_query_parse_duration (query, NULL, duration);
2626 gst_query_unref (query);
2632 * gst_pad_peer_query_duration:
2633 * @pad: a #GstPad on whose peer pad to invoke the duration query on.
2634 * Must be a sink pad.
2635 * @format: the #GstFormat requested
2636 * @duration: (out) (allow-none): a location in which to store the total
2637 * duration, or NULL.
2639 * Queries the peer pad of a given sink pad for the total stream duration.
2641 * Returns: TRUE if the query could be performed.
2644 gst_pad_peer_query_duration (GstPad * pad, GstFormat format, gint64 * duration)
2647 gboolean ret = FALSE;
2649 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2650 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2651 g_return_val_if_fail (format != GST_FORMAT_UNDEFINED, FALSE);
2653 query = gst_query_new_duration (format);
2654 if ((ret = gst_pad_peer_query (pad, query)))
2655 gst_query_parse_duration (query, NULL, duration);
2656 gst_query_unref (query);
2662 * gst_pad_query_convert:
2663 * @pad: a #GstPad to invoke the convert query on.
2664 * @src_format: a #GstFormat to convert from.
2665 * @src_val: a value to convert.
2666 * @dest_format: the #GstFormat to convert to.
2667 * @dest_val: (out): a pointer to the result.
2669 * Queries a pad to convert @src_val in @src_format to @dest_format.
2671 * Returns: TRUE if the query could be performed.
2674 gst_pad_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2675 GstFormat dest_format, gint64 * dest_val)
2680 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2681 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2682 g_return_val_if_fail (dest_val != NULL, FALSE);
2684 if (dest_format == src_format || src_val == -1) {
2685 *dest_val = src_val;
2689 query = gst_query_new_convert (src_format, src_val, dest_format);
2690 if ((ret = gst_pad_query (pad, query)))
2691 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2692 gst_query_unref (query);
2698 * gst_pad_peer_query_convert:
2699 * @pad: a #GstPad, on whose peer pad to invoke the convert query on.
2700 * Must be a sink pad.
2701 * @src_format: a #GstFormat to convert from.
2702 * @src_val: a value to convert.
2703 * @dest_format: the #GstFormat to convert to.
2704 * @dest_val: (out): a pointer to the result.
2706 * Queries the peer pad of a given sink pad to convert @src_val in @src_format
2709 * Returns: TRUE if the query could be performed.
2712 gst_pad_peer_query_convert (GstPad * pad, GstFormat src_format, gint64 src_val,
2713 GstFormat dest_format, gint64 * dest_val)
2716 gboolean ret = FALSE;
2718 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2719 g_return_val_if_fail (GST_PAD_IS_SINK (pad), FALSE);
2720 g_return_val_if_fail (dest_format != GST_FORMAT_UNDEFINED, FALSE);
2721 g_return_val_if_fail (dest_val != NULL, FALSE);
2723 query = gst_query_new_convert (src_format, src_val, dest_format);
2724 if ((ret = gst_pad_peer_query (pad, query)))
2725 gst_query_parse_convert (query, NULL, NULL, NULL, dest_val);
2726 gst_query_unref (query);
2732 * gst_pad_query_caps:
2733 * @pad: a #GstPad to get the capabilities of.
2734 * @filter: (allow-none): suggested #GstCaps, or NULL
2736 * Gets the capabilities this pad can produce or consume.
2737 * Note that this method doesn't necessarily return the caps set by
2738 * gst_pad_set_caps() - use gst_pad_get_current_caps() for that instead.
2739 * gst_pad_query_caps returns all possible caps a pad can operate with, using
2740 * the pad's CAPS query function, If the query fails, this function will return
2741 * @filter, if not #NULL, otherwise ANY.
2743 * When called on sinkpads @filter contains the caps that
2744 * upstream could produce in the order preferred by upstream. When
2745 * called on srcpads @filter contains the caps accepted by
2746 * downstream in the preffered order. @filter might be %NULL but
2747 * if it is not %NULL the returned caps will be a subset of @filter.
2749 * Note that this function does not return writable #GstCaps, use
2750 * gst_caps_make_writable() before modifying the caps.
2752 * Returns: (transfer full): the caps of the pad with incremented ref-count.
2755 gst_pad_query_caps (GstPad * pad, GstCaps * filter)
2757 GstCaps *result = NULL;
2760 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2761 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2763 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2764 "get pad caps with filter %" GST_PTR_FORMAT, filter);
2766 query = gst_query_new_caps (filter);
2767 if (gst_pad_query (pad, query)) {
2768 gst_query_parse_caps_result (query, &result);
2769 gst_caps_ref (result);
2770 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2771 "query returned %" GST_PTR_FORMAT, result);
2772 } else if (filter) {
2773 result = gst_caps_ref (filter);
2775 result = gst_caps_new_any ();
2777 gst_query_unref (query);
2783 * gst_pad_peer_query_caps:
2784 * @pad: a #GstPad to get the capabilities of.
2785 * @filter: (allow-none): a #GstCaps filter, or NULL.
2787 * Gets the capabilities of the peer connected to this pad. Similar to
2788 * gst_pad_query_caps().
2790 * When called on srcpads @filter contains the caps that
2791 * upstream could produce in the order preferred by upstream. When
2792 * called on sinkpads @filter contains the caps accepted by
2793 * downstream in the preffered order. @filter might be %NULL but
2794 * if it is not %NULL the returned caps will be a subset of @filter.
2796 * Returns: the caps of the peer pad with incremented ref-count. This function
2797 * returns %NULL when there is no peer pad.
2800 gst_pad_peer_query_caps (GstPad * pad, GstCaps * filter)
2802 GstCaps *result = NULL;
2805 g_return_val_if_fail (GST_IS_PAD (pad), NULL);
2806 g_return_val_if_fail (filter == NULL || GST_IS_CAPS (filter), NULL);
2808 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2809 "get pad peer caps with filter %" GST_PTR_FORMAT, filter);
2811 query = gst_query_new_caps (filter);
2812 if (gst_pad_peer_query (pad, query)) {
2813 gst_query_parse_caps_result (query, &result);
2814 gst_caps_ref (result);
2815 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
2816 "peer query returned %" GST_PTR_FORMAT, result);
2817 } else if (filter) {
2818 result = gst_caps_ref (filter);
2820 result = gst_caps_new_any ();
2822 gst_query_unref (query);
2828 * gst_pad_query_accept_caps:
2829 * @pad: a #GstPad to check
2830 * @caps: a #GstCaps to check on the pad
2832 * Check if the given pad accepts the caps.
2834 * Returns: TRUE if the pad can accept the caps.
2837 gst_pad_query_accept_caps (GstPad * pad, GstCaps * caps)
2839 gboolean res = TRUE;
2842 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2843 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
2845 GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %"
2846 GST_PTR_FORMAT, caps);
2848 query = gst_query_new_accept_caps (caps);
2849 if (gst_pad_query (pad, query)) {
2850 gst_query_parse_accept_caps_result (query, &res);
2851 GST_DEBUG_OBJECT (pad, "query returned %d", res);
2853 gst_query_unref (query);
2859 * gst_pad_peer_query_accept_caps:
2860 * @pad: a #GstPad to check the peer of
2861 * @caps: a #GstCaps to check on the pad
2863 * Check if the peer of @pad accepts @caps. If @pad has no peer, this function
2866 * Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
2869 gst_pad_peer_query_accept_caps (GstPad * pad, GstCaps * caps)
2871 gboolean res = TRUE;
2874 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
2875 g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
2877 query = gst_query_new_accept_caps (caps);
2878 if (gst_pad_peer_query (pad, query)) {
2879 gst_query_parse_accept_caps_result (query, &res);
2880 GST_DEBUG_OBJECT (pad, "query returned %d", res);
2882 gst_query_unref (query);
2888 element_find_unlinked_pad (GstElement * element, GstPadDirection direction)
2891 GstPad *unlinked_pad = NULL;
2893 GValue data = { 0, };
2895 switch (direction) {
2897 iter = gst_element_iterate_src_pads (element);
2900 iter = gst_element_iterate_sink_pads (element);
2903 g_return_val_if_reached (NULL);
2908 switch (gst_iterator_next (iter, &data)) {
2909 case GST_ITERATOR_OK:{
2911 GstPad *pad = g_value_get_object (&data);
2913 GST_CAT_LOG (GST_CAT_ELEMENT_PADS, "examining pad %s:%s",
2914 GST_DEBUG_PAD_NAME (pad));
2916 peer = gst_pad_get_peer (pad);
2918 unlinked_pad = gst_object_ref (pad);
2920 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
2921 "found existing unlinked pad %s:%s",
2922 GST_DEBUG_PAD_NAME (unlinked_pad));
2924 gst_object_unref (peer);
2926 g_value_reset (&data);
2929 case GST_ITERATOR_DONE:
2932 case GST_ITERATOR_RESYNC:
2933 gst_iterator_resync (iter);
2935 case GST_ITERATOR_ERROR:
2936 g_return_val_if_reached (NULL);
2940 g_value_unset (&data);
2941 gst_iterator_free (iter);
2943 return unlinked_pad;
2947 * gst_bin_find_unlinked_pad:
2948 * @bin: bin in which to look for elements with unlinked pads
2949 * @direction: whether to look for an unlinked source or sink pad
2951 * Recursively looks for elements with an unlinked pad of the given
2952 * direction within the specified bin and returns an unlinked pad
2953 * if one is found, or NULL otherwise. If a pad is found, the caller
2954 * owns a reference to it and should use gst_object_unref() on the
2955 * pad when it is not needed any longer.
2957 * Returns: (transfer full): unlinked pad of the given direction, or NULL.
2962 gst_bin_find_unlinked_pad (GstBin * bin, GstPadDirection direction)
2967 GValue data = { 0, };
2969 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2970 g_return_val_if_fail (direction != GST_PAD_UNKNOWN, NULL);
2973 iter = gst_bin_iterate_recurse (bin);
2975 switch (gst_iterator_next (iter, &data)) {
2976 case GST_ITERATOR_OK:{
2977 GstElement *element = g_value_get_object (&data);
2979 pad = element_find_unlinked_pad (element, direction);
2982 g_value_reset (&data);
2985 case GST_ITERATOR_DONE:
2988 case GST_ITERATOR_RESYNC:
2989 gst_iterator_resync (iter);
2991 case GST_ITERATOR_ERROR:
2992 g_return_val_if_reached (NULL);
2996 g_value_unset (&data);
2997 gst_iterator_free (iter);
3003 * gst_parse_bin_from_description:
3004 * @bin_description: command line describing the bin
3005 * @ghost_unlinked_pads: whether to automatically create ghost pads
3006 * for unlinked source or sink pads within the bin
3007 * @err: where to store the error message in case of an error, or NULL
3009 * This is a convenience wrapper around gst_parse_launch() to create a
3010 * #GstBin from a gst-launch-style pipeline description. See
3011 * gst_parse_launch() and the gst-launch man page for details about the
3012 * syntax. Ghost pads on the bin for unlinked source or sink pads
3013 * within the bin can automatically be created (but only a maximum of
3014 * one ghost pad for each direction will be created; if you expect
3015 * multiple unlinked source pads or multiple unlinked sink pads
3016 * and want them all ghosted, you will have to create the ghost pads
3019 * Returns: (transfer floating): a newly-created bin, or NULL if an error occurred.
3024 gst_parse_bin_from_description (const gchar * bin_description,
3025 gboolean ghost_unlinked_pads, GError ** err)
3027 return gst_parse_bin_from_description_full (bin_description,
3028 ghost_unlinked_pads, NULL, GST_PARSE_FLAG_NONE, err);
3032 * gst_parse_bin_from_description_full:
3033 * @bin_description: command line describing the bin
3034 * @ghost_unlinked_pads: whether to automatically create ghost pads
3035 * for unlinked source or sink pads within the bin
3036 * @context: (transfer none) (allow-none): a parse context allocated with
3037 * gst_parse_context_new(), or %NULL
3038 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
3039 * @err: where to store the error message in case of an error, or NULL
3041 * This is a convenience wrapper around gst_parse_launch() to create a
3042 * #GstBin from a gst-launch-style pipeline description. See
3043 * gst_parse_launch() and the gst-launch man page for details about the
3044 * syntax. Ghost pads on the bin for unlinked source or sink pads
3045 * within the bin can automatically be created (but only a maximum of
3046 * one ghost pad for each direction will be created; if you expect
3047 * multiple unlinked source pads or multiple unlinked sink pads
3048 * and want them all ghosted, you will have to create the ghost pads
3051 * Returns: (transfer full): a newly-created bin, or NULL if an error occurred.
3056 gst_parse_bin_from_description_full (const gchar * bin_description,
3057 gboolean ghost_unlinked_pads, GstParseContext * context,
3058 GstParseFlags flags, GError ** err)
3060 #ifndef GST_DISABLE_PARSE
3065 g_return_val_if_fail (bin_description != NULL, NULL);
3066 g_return_val_if_fail (err == NULL || *err == NULL, NULL);
3068 GST_DEBUG ("Making bin from description '%s'", bin_description);
3070 /* parse the pipeline to a bin */
3071 desc = g_strdup_printf ("bin.( %s )", bin_description);
3072 bin = (GstBin *) gst_parse_launch_full (desc, context, flags, err);
3075 if (bin == NULL || (err && *err != NULL)) {
3077 gst_object_unref (bin);
3081 /* find pads and ghost them if necessary */
3082 if (ghost_unlinked_pads) {
3083 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SRC))) {
3084 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("src", pad));
3085 gst_object_unref (pad);
3087 if ((pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SINK))) {
3088 gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new ("sink", pad));
3089 gst_object_unref (pad);
3093 return GST_ELEMENT (bin);
3097 GST_WARNING ("Disabled API called");
3099 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
3100 g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);
3108 * gst_util_get_timestamp:
3110 * Get a timestamp as GstClockTime to be used for interval measurements.
3111 * The timestamp should not be interpreted in any other way.
3113 * Returns: the timestamp
3118 gst_util_get_timestamp (void)
3120 #if defined (HAVE_POSIX_TIMERS) && defined(HAVE_MONOTONIC_CLOCK)
3121 struct timespec now;
3123 clock_gettime (CLOCK_MONOTONIC, &now);
3124 return GST_TIMESPEC_TO_TIME (now);
3128 g_get_current_time (&now);
3129 return GST_TIMEVAL_TO_TIME (now);
3134 * gst_util_array_binary_search:
3135 * @array: the sorted input array
3136 * @num_elements: number of elements in the array
3137 * @element_size: size of every element in bytes
3138 * @search_func: (scope call): function to compare two elements, @search_data will always be passed as second argument
3139 * @mode: search mode that should be used
3140 * @search_data: element that should be found
3141 * @user_data: (closure): data to pass to @search_func
3143 * Searches inside @array for @search_data by using the comparison function
3144 * @search_func. @array must be sorted ascending.
3146 * As @search_data is always passed as second argument to @search_func it's
3147 * not required that @search_data has the same type as the array elements.
3149 * The complexity of this search function is O(log (num_elements)).
3151 * Returns: (transfer none): The address of the found element or %NULL if nothing was found
3156 gst_util_array_binary_search (gpointer array, guint num_elements,
3157 gsize element_size, GCompareDataFunc search_func, GstSearchMode mode,
3158 gconstpointer search_data, gpointer user_data)
3160 glong left = 0, right = num_elements - 1, m;
3162 guint8 *data = (guint8 *) array;
3164 g_return_val_if_fail (array != NULL, NULL);
3165 g_return_val_if_fail (element_size > 0, NULL);
3166 g_return_val_if_fail (search_func != NULL, NULL);
3168 /* 0. No elements => return NULL */
3169 if (num_elements == 0)
3172 /* 1. If search_data is before the 0th element return the 0th element */
3173 ret = search_func (data, search_data, user_data);
3174 if ((ret >= 0 && mode == GST_SEARCH_MODE_AFTER) || ret == 0)
3179 /* 2. If search_data is after the last element return the last element */
3181 search_func (data + (num_elements - 1) * element_size, search_data,
3183 if ((ret <= 0 && mode == GST_SEARCH_MODE_BEFORE) || ret == 0)
3184 return data + (num_elements - 1) * element_size;
3188 /* 3. else binary search */
3190 m = left + (right - left) / 2;
3192 ret = search_func (data + m * element_size, search_data, user_data);
3195 return data + m * element_size;
3196 } else if (ret < 0) {
3202 /* No exact match found */
3204 if (mode == GST_SEARCH_MODE_EXACT) {
3206 } else if (mode == GST_SEARCH_MODE_AFTER) {
3208 return (m < num_elements) ? data + (m + 1) * element_size : NULL;
3210 return data + m * element_size;
3213 return data + m * element_size;
3215 return (m > 0) ? data + (m - 1) * element_size : NULL;
3221 /* Finds the greatest common divisor.
3222 * Returns 1 if none other found.
3223 * This is Euclid's algorithm. */
3226 * gst_util_greatest_common_divisor:
3227 * @a: First value as #gint
3228 * @b: Second value as #gint
3230 * Calculates the greatest common divisor of @a
3233 * Returns: Greatest common divisor of @a and @b
3238 gst_util_greatest_common_divisor (gint a, gint b)
3251 * gst_util_greatest_common_divisor_int64:
3252 * @a: First value as #gint64
3253 * @b: Second value as #gint64
3255 * Calculates the greatest common divisor of @a
3258 * Returns: Greatest common divisor of @a and @b
3263 gst_util_greatest_common_divisor_int64 (gint64 a, gint64 b)
3277 * gst_util_fraction_to_double:
3278 * @src_n: Fraction numerator as #gint
3279 * @src_d: Fraction denominator #gint
3280 * @dest: (out): pointer to a #gdouble for the result
3282 * Transforms a fraction to a #gdouble.
3287 gst_util_fraction_to_double (gint src_n, gint src_d, gdouble * dest)
3289 g_return_if_fail (dest != NULL);
3290 g_return_if_fail (src_d != 0);
3292 *dest = ((gdouble) src_n) / ((gdouble) src_d);
3295 #define MAX_TERMS 30
3296 #define MIN_DIVISOR 1.0e-10
3297 #define MAX_ERROR 1.0e-20
3299 /* use continued fractions to transform a double into a fraction,
3300 * see http://mathforum.org/dr.math/faq/faq.fractions.html#decfrac.
3301 * This algorithm takes care of overflows.
3305 * gst_util_double_to_fraction:
3306 * @src: #gdouble to transform
3307 * @dest_n: (out): pointer to a #gint to hold the result numerator
3308 * @dest_d: (out): pointer to a #gint to hold the result denominator
3310 * Transforms a #gdouble to a fraction and simplifies
3316 gst_util_double_to_fraction (gdouble src, gint * dest_n, gint * dest_d)
3319 gdouble V, F; /* double being converted */
3320 gint N, D; /* will contain the result */
3321 gint A; /* current term in continued fraction */
3322 gint64 N1, D1; /* numerator, denominator of last approx */
3323 gint64 N2, D2; /* numerator, denominator of previous approx */
3326 gboolean negative = FALSE;
3328 g_return_if_fail (dest_n != NULL);
3329 g_return_if_fail (dest_d != NULL);
3331 /* initialize fraction being converted */
3339 /* initialize fractions with 1/0, 0/1 */
3347 for (i = 0; i < MAX_TERMS; i++) {
3349 A = (gint) F; /* no floor() needed, F is always >= 0 */
3350 /* get new divisor */
3353 /* calculate new fraction in temp */
3357 /* guard against overflow */
3358 if (N2 > G_MAXINT || D2 > G_MAXINT) {
3365 /* save last two fractions */
3371 /* quit if dividing by zero or close enough to target */
3372 if (F < MIN_DIVISOR || fabs (V - ((gdouble) N) / D) < MAX_ERROR) {
3376 /* Take reciprocal */
3379 /* fix for overflow */
3384 /* fix for negative */
3389 gcd = gst_util_greatest_common_divisor (N, D);
3401 * gst_util_fraction_multiply:
3402 * @a_n: Numerator of first value
3403 * @a_d: Denominator of first value
3404 * @b_n: Numerator of second value
3405 * @b_d: Denominator of second value
3406 * @res_n: (out): Pointer to #gint to hold the result numerator
3407 * @res_d: (out): Pointer to #gint to hold the result denominator
3409 * Multiplies the fractions @a_n/@a_d and @b_n/@b_d and stores
3410 * the result in @res_n and @res_d.
3412 * Returns: %FALSE on overflow, %TRUE otherwise.
3417 gst_util_fraction_multiply (gint a_n, gint a_d, gint b_n, gint b_d,
3418 gint * res_n, gint * res_d)
3422 g_return_val_if_fail (res_n != NULL, FALSE);
3423 g_return_val_if_fail (res_d != NULL, FALSE);
3424 g_return_val_if_fail (a_d != 0, FALSE);
3425 g_return_val_if_fail (b_d != 0, FALSE);
3427 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3431 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3435 gcd = gst_util_greatest_common_divisor (a_n, b_d);
3439 gcd = gst_util_greatest_common_divisor (a_d, b_n);
3443 /* This would result in overflow */
3444 if (a_n != 0 && G_MAXINT / ABS (a_n) < ABS (b_n))
3446 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3452 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3460 * gst_util_fraction_add:
3461 * @a_n: Numerator of first value
3462 * @a_d: Denominator of first value
3463 * @b_n: Numerator of second value
3464 * @b_d: Denominator of second value
3465 * @res_n: (out): Pointer to #gint to hold the result numerator
3466 * @res_d: (out): Pointer to #gint to hold the result denominator
3468 * Adds the fractions @a_n/@a_d and @b_n/@b_d and stores
3469 * the result in @res_n and @res_d.
3471 * Returns: %FALSE on overflow, %TRUE otherwise.
3476 gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint * res_n,
3481 g_return_val_if_fail (res_n != NULL, FALSE);
3482 g_return_val_if_fail (res_d != NULL, FALSE);
3483 g_return_val_if_fail (a_d != 0, FALSE);
3484 g_return_val_if_fail (b_d != 0, FALSE);
3486 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3490 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3505 /* This would result in overflow */
3506 if (G_MAXINT / ABS (a_n) < ABS (b_n))
3508 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3510 if (G_MAXINT / ABS (a_d) < ABS (b_d))
3513 *res_n = (a_n * b_d) + (a_d * b_n);
3516 gcd = gst_util_greatest_common_divisor (*res_n, *res_d);
3529 * gst_util_fraction_compare:
3530 * @a_n: Numerator of first value
3531 * @a_d: Denominator of first value
3532 * @b_n: Numerator of second value
3533 * @b_d: Denominator of second value
3535 * Compares the fractions @a_n/@a_d and @b_n/@b_d and returns
3536 * -1 if a < b, 0 if a = b and 1 if a > b.
3538 * Returns: -1 if a < b; 0 if a = b; 1 if a > b.
3543 gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d)
3549 g_return_val_if_fail (a_d != 0 && b_d != 0, 0);
3552 gcd = gst_util_greatest_common_divisor (a_n, a_d);
3556 gcd = gst_util_greatest_common_divisor (b_n, b_d);
3560 /* fractions are reduced when set, so we can quickly see if they're equal */
3561 if (a_n == b_n && a_d == b_d)
3564 /* extend to 64 bits */
3565 new_num_1 = ((gint64) a_n) * b_d;
3566 new_num_2 = ((gint64) b_n) * a_d;
3567 if (new_num_1 < new_num_2)
3569 if (new_num_1 > new_num_2)
3572 /* Should not happen because a_d and b_d are not 0 */
3573 g_return_val_if_reached (0);