2 * Copyright (C) 2010 Wim Taymans <wim.taymans@gmail.com>
4 * gstbufferpool.c: GstBufferPool baseclass
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
23 * SECTION:gstbufferpool
24 * @short_description: Pool for buffers
25 * @see_also: #GstBuffer
29 #include "gst_private.h"
30 #include "glib-compat-private.h"
36 #include <sys/types.h>
38 #include "gstatomicqueue.h"
44 #include "gstbufferpool.h"
46 GST_DEBUG_CATEGORY_STATIC (gst_buffer_pool_debug);
47 #define GST_CAT_DEFAULT gst_buffer_pool_debug
49 #define GST_BUFFER_POOL_GET_PRIVATE(obj) \
50 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BUFFER_POOL, GstBufferPoolPrivate))
52 #define GST_BUFFER_POOL_LOCK(pool) (g_rec_mutex_lock(&pool->priv->rec_lock))
53 #define GST_BUFFER_POOL_UNLOCK(pool) (g_rec_mutex_unlock(&pool->priv->rec_lock))
55 struct _GstBufferPoolPrivate
57 GstAtomicQueue *queue;
82 static void gst_buffer_pool_finalize (GObject * object);
84 G_DEFINE_TYPE (GstBufferPool, gst_buffer_pool, GST_TYPE_OBJECT);
86 static gboolean default_start (GstBufferPool * pool);
87 static gboolean default_stop (GstBufferPool * pool);
88 static gboolean default_set_config (GstBufferPool * pool,
89 GstStructure * config);
90 static GstFlowReturn default_alloc_buffer (GstBufferPool * pool,
91 GstBuffer ** buffer, GstBufferPoolParams * params);
92 static GstFlowReturn default_acquire_buffer (GstBufferPool * pool,
93 GstBuffer ** buffer, GstBufferPoolParams * params);
94 static void default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer,
95 GstBufferPoolParams * params);
96 static void default_free_buffer (GstBufferPool * pool, GstBuffer * buffer);
97 static void default_release_buffer (GstBufferPool * pool, GstBuffer * buffer);
100 gst_buffer_pool_class_init (GstBufferPoolClass * klass)
102 GObjectClass *gobject_class = (GObjectClass *) klass;
104 g_type_class_add_private (klass, sizeof (GstBufferPoolPrivate));
106 gobject_class->finalize = gst_buffer_pool_finalize;
108 klass->start = default_start;
109 klass->stop = default_stop;
110 klass->set_config = default_set_config;
111 klass->acquire_buffer = default_acquire_buffer;
112 klass->reset_buffer = default_reset_buffer;
113 klass->alloc_buffer = default_alloc_buffer;
114 klass->release_buffer = default_release_buffer;
115 klass->free_buffer = default_free_buffer;
117 GST_DEBUG_CATEGORY_INIT (gst_buffer_pool_debug, "bufferpool", 0,
122 gst_buffer_pool_init (GstBufferPool * pool)
124 pool->priv = GST_BUFFER_POOL_GET_PRIVATE (pool);
126 g_rec_mutex_init (&pool->priv->rec_lock);
128 pool->priv->poll = gst_poll_new_timer ();
129 pool->priv->queue = gst_atomic_queue_new (10);
131 pool->priv->active = FALSE;
132 pool->priv->configured = FALSE;
133 pool->priv->started = FALSE;
135 gst_structure_new_id_empty (GST_QUARK (BUFFER_POOL_CONFIG));
136 gst_buffer_pool_config_set (pool->priv->config, NULL, 0, 0, 0, 0, 0);
137 gst_poll_write_control (pool->priv->poll);
139 GST_DEBUG_OBJECT (pool, "created");
143 gst_buffer_pool_finalize (GObject * object)
147 pool = GST_BUFFER_POOL_CAST (object);
149 GST_DEBUG_OBJECT (pool, "finalize");
151 gst_buffer_pool_set_active (pool, FALSE);
152 gst_atomic_queue_unref (pool->priv->queue);
153 gst_poll_free (pool->priv->poll);
154 gst_structure_free (pool->priv->config);
155 g_rec_mutex_clear (&pool->priv->rec_lock);
157 G_OBJECT_CLASS (gst_buffer_pool_parent_class)->finalize (object);
161 * gst_buffer_pool_new:
163 * Creates a new #GstBufferPool instance.
165 * Returns: (transfer full): a new #GstBufferPool instance
168 gst_buffer_pool_new (void)
170 GstBufferPool *result;
172 result = g_object_newv (GST_TYPE_BUFFER_POOL, 0, NULL);
173 GST_DEBUG_OBJECT (result, "created new buffer pool");
179 default_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
180 GstBufferPoolParams * params)
182 GstBufferPoolPrivate *priv = pool->priv;
185 *buffer = gst_buffer_new ();
187 mem = gst_allocator_alloc (NULL, priv->size + priv->prefix, priv->align);
188 gst_memory_resize (mem, priv->prefix, priv->size);
189 gst_buffer_take_memory (*buffer, -1, mem);
195 mark_meta_pooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
197 GstBufferPool *pool = user_data;
199 GST_DEBUG_OBJECT (pool, "marking meta %p as POOLED in buffer %p", *meta,
201 GST_META_FLAG_SET (*meta, GST_META_FLAG_POOLED);
206 /* the default implementation for preallocating the buffers
209 default_start (GstBufferPool * pool)
212 GstBufferPoolPrivate *priv = pool->priv;
213 GstBufferPoolClass *pclass;
215 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
217 /* no alloc function, error */
218 if (G_UNLIKELY (pclass->alloc_buffer == NULL))
221 /* we need to prealloc buffers */
222 for (i = 0; i < priv->min_buffers; i++) {
225 if (pclass->alloc_buffer (pool, &buffer, NULL) != GST_FLOW_OK)
228 gst_buffer_foreach_meta (buffer, mark_meta_pooled, pool);
229 GST_LOG_OBJECT (pool, "prealloced buffer %d: %p", i, buffer);
230 /* release to the queue, we call the vmethod directly, we don't need to do
231 * the other refcount handling right now. */
232 if (G_LIKELY (pclass->release_buffer))
233 pclass->release_buffer (pool, buffer);
240 GST_WARNING_OBJECT (pool, "no alloc function");
245 GST_WARNING_OBJECT (pool, "alloc function failed");
250 /* must be called with the lock */
252 do_start (GstBufferPool * pool)
254 if (!pool->priv->started) {
255 GstBufferPoolClass *pclass;
257 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
259 GST_LOG_OBJECT (pool, "starting");
260 /* start the pool, subclasses should allocate buffers and put them
262 if (G_LIKELY (pclass->start)) {
263 if (!pclass->start (pool))
266 pool->priv->started = TRUE;
273 default_free_buffer (GstBufferPool * pool, GstBuffer * buffer)
275 gst_buffer_unref (buffer);
278 /* must be called with the lock */
280 default_stop (GstBufferPool * pool)
283 GstBufferPoolClass *pclass;
285 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
288 while ((buffer = gst_atomic_queue_pop (pool->priv->queue))) {
289 GST_LOG_OBJECT (pool, "freeing %p", buffer);
290 gst_poll_read_control (pool->priv->poll);
292 if (G_LIKELY (pclass->free_buffer))
293 pclass->free_buffer (pool, buffer);
298 /* must be called with the lock */
300 do_stop (GstBufferPool * pool)
302 if (pool->priv->started) {
303 GstBufferPoolClass *pclass;
305 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
307 GST_LOG_OBJECT (pool, "stopping");
308 if (G_LIKELY (pclass->stop)) {
309 if (!pclass->stop (pool))
312 pool->priv->started = FALSE;
318 * gst_buffer_pool_set_active:
319 * @pool: a #GstBufferPool
320 * @active: the new active state
322 * Control the active state of @pool. When the pool is active, new calls to
323 * gst_buffer_pool_acquire_buffer() will return with GST_FLOW_FLUSHING.
325 * Activating the bufferpool will preallocate all resources in the pool based on
326 * the configuration of the pool.
328 * Deactivating will free the resources again when there are no outstanding
329 * buffers. When there are outstanding buffers, they will be freed as soon as
330 * they are all returned to the pool.
332 * Returns: %FALSE when the pool was not configured or when preallocation of the
336 gst_buffer_pool_set_active (GstBufferPool * pool, gboolean active)
340 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
342 GST_LOG_OBJECT (pool, "active %d", active);
344 GST_BUFFER_POOL_LOCK (pool);
345 /* just return if we are already in the right state */
346 if (pool->priv->active == active)
349 /* we need to be configured */
350 if (!pool->priv->configured)
354 if (!do_start (pool))
357 /* unset the flushing state now */
358 gst_poll_read_control (pool->priv->poll);
359 g_atomic_int_set (&pool->flushing, 0);
363 /* set to flushing first */
364 g_atomic_int_set (&pool->flushing, 1);
365 gst_poll_write_control (pool->priv->poll);
367 /* when all buffers are in the pool, free them. Else they will be
368 * freed when they are released */
369 outstanding = g_atomic_int_get (&pool->priv->outstanding);
370 GST_LOG_OBJECT (pool, "outstanding buffers %d", outstanding);
371 if (outstanding == 0) {
376 pool->priv->active = active;
377 GST_BUFFER_POOL_UNLOCK (pool);
383 GST_DEBUG_OBJECT (pool, "pool was in the right state");
384 GST_BUFFER_POOL_UNLOCK (pool);
389 GST_ERROR_OBJECT (pool, "pool was not configured");
390 GST_BUFFER_POOL_UNLOCK (pool);
395 GST_ERROR_OBJECT (pool, "start failed");
396 GST_BUFFER_POOL_UNLOCK (pool);
401 GST_WARNING_OBJECT (pool, "stop failed");
402 GST_BUFFER_POOL_UNLOCK (pool);
408 * gst_buffer_pool_is_active:
409 * @pool: a #GstBufferPool
411 * Check if @pool is active. A pool can be activated with the
412 * gst_buffer_pool_set_active() call.
414 * Returns: %TRUE when the pool is active.
417 gst_buffer_pool_is_active (GstBufferPool * pool)
421 GST_BUFFER_POOL_LOCK (pool);
422 res = pool->priv->active;
423 GST_BUFFER_POOL_UNLOCK (pool);
429 default_set_config (GstBufferPool * pool, GstStructure * config)
431 GstBufferPoolPrivate *priv = pool->priv;
433 guint size, min_buffers, max_buffers;
436 /* parse the config and keep around */
437 if (!gst_buffer_pool_config_get (config, &caps, &size, &min_buffers,
438 &max_buffers, &prefix, &align))
441 GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config);
444 priv->min_buffers = min_buffers;
445 priv->max_buffers = max_buffers;
446 priv->prefix = prefix;
453 GST_WARNING_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
459 * gst_buffer_pool_set_config:
460 * @pool: a #GstBufferPool
461 * @config: (transfer full): a #GstStructure
463 * Set the configuration of the pool. The pool must be inactive and all buffers
464 * allocated form this pool must be returned or else this function will do
465 * nothing and return FALSE.
467 * @config is a #GstStructure that contains the configuration parameters for
468 * the pool. A default and mandatory set of parameters can be configured with
469 * gst_buffer_pool_config_set(). This function takes ownership of @config.
471 * Returns: TRUE when the configuration could be set.
474 gst_buffer_pool_set_config (GstBufferPool * pool, GstStructure * config)
477 GstBufferPoolClass *pclass;
479 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
480 g_return_val_if_fail (config != NULL, FALSE);
482 GST_BUFFER_POOL_LOCK (pool);
483 /* can't change the settings when active */
484 if (pool->priv->active)
487 /* we can't change when outstanding buffers */
488 if (g_atomic_int_get (&pool->priv->outstanding) != 0)
489 goto have_outstanding;
491 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
493 /* set the new config */
494 if (G_LIKELY (pclass->set_config))
495 result = pclass->set_config (pool, config);
500 if (pool->priv->config)
501 gst_structure_free (pool->priv->config);
502 pool->priv->config = config;
504 /* now we are configured */
505 pool->priv->configured = TRUE;
507 GST_BUFFER_POOL_UNLOCK (pool);
514 GST_WARNING_OBJECT (pool, "can't change config, we are active");
515 GST_BUFFER_POOL_UNLOCK (pool);
520 GST_WARNING_OBJECT (pool, "can't change config, have outstanding buffers");
521 GST_BUFFER_POOL_UNLOCK (pool);
527 * gst_buffer_pool_get_config:
528 * @pool: a #GstBufferPool
530 * Get a copy of the current configuration of the pool. This configuration
531 * can either be modified and used for the gst_buffer_pool_set_config() call
532 * or it must be freed after usage.
534 * Returns: (transfer full): a copy of the current configuration of @pool. use
535 * gst_structure_free() after usage or gst_buffer_pool_set_config().
538 gst_buffer_pool_get_config (GstBufferPool * pool)
540 GstStructure *result;
542 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
544 GST_BUFFER_POOL_UNLOCK (pool);
545 result = gst_structure_copy (pool->priv->config);
546 GST_BUFFER_POOL_UNLOCK (pool);
551 static const gchar *empty_option[] = { NULL };
554 * gst_buffer_pool_get_options:
555 * @pool: a #GstBufferPool
557 * Get a NULL terminated array of string with supported bufferpool options for
558 * @pool. An option would typically be enabled with
559 * gst_buffer_pool_config_add_option().
561 * Returns: (array zero-terminated=1) (transfer none): a NULL terminated array of strings.
564 gst_buffer_pool_get_options (GstBufferPool * pool)
566 GstBufferPoolClass *pclass;
567 const gchar **result;
569 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
571 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
573 if (G_LIKELY (pclass->get_options)) {
574 if ((result = pclass->get_options (pool)) == NULL)
577 result = empty_option;
584 g_warning ("bufferpool subclass returned NULL options");
590 * gst_buffer_pool_has_option:
591 * @pool: a #GstBufferPool
594 * Check if the bufferpool supports @option.
596 * Returns: a NULL terminated array of strings.
599 gst_buffer_pool_has_option (GstBufferPool * pool, const gchar * option)
602 const gchar **options;
604 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
605 g_return_val_if_fail (option != NULL, FALSE);
607 options = gst_buffer_pool_get_options (pool);
609 for (i = 0; options[i]; i++) {
610 if (g_str_equal (options[i], option))
617 * gst_buffer_pool_config_set:
618 * @config: a #GstBufferPool configuration
619 * @caps: caps for the buffers
620 * @size: the size of each buffer, not including prefix
621 * @min_buffers: the minimum amount of buffers to allocate.
622 * @max_buffers: the maximum amount of buffers to allocate or 0 for unlimited.
623 * @prefix: prefix each buffer with this many bytes
624 * @align: alignment of the buffer data.
626 * Configure @config with the given parameters.
629 gst_buffer_pool_config_set (GstStructure * config, const GstCaps * caps,
630 guint size, guint min_buffers, guint max_buffers, guint prefix, guint align)
632 g_return_if_fail (config != NULL);
634 gst_structure_id_set (config,
635 GST_QUARK (CAPS), GST_TYPE_CAPS, caps,
636 GST_QUARK (SIZE), G_TYPE_UINT, size,
637 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
638 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers,
639 GST_QUARK (PREFIX), G_TYPE_UINT, prefix,
640 GST_QUARK (ALIGN), G_TYPE_UINT, align, NULL);
644 * gst_buffer_pool_config_add_option:
645 * @config: a #GstBufferPool configuration
646 * @option: an option to add
648 * Enabled the option in @config. This will instruct the @bufferpool to enable
649 * the specified option on the buffers that it allocates.
651 * The supported options by @pool can be retrieved with gst_buffer_pool_get_options().
654 gst_buffer_pool_config_add_option (GstStructure * config, const gchar * option)
657 GValue option_value = { 0, };
660 g_return_if_fail (config != NULL);
662 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
664 len = gst_value_array_get_size (value);
665 for (i = 0; i < len; ++i) {
666 const GValue *nth_val = gst_value_array_get_value (value, i);
668 if (g_str_equal (option, g_value_get_string (nth_val)))
672 GValue new_array_val = { 0, };
674 g_value_init (&new_array_val, GST_TYPE_ARRAY);
675 gst_structure_id_take_value (config, GST_QUARK (OPTIONS), &new_array_val);
676 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
678 g_value_init (&option_value, G_TYPE_STRING);
679 g_value_set_string (&option_value, option);
680 gst_value_array_append_value ((GValue *) value, &option_value);
681 g_value_unset (&option_value);
685 * gst_buffer_pool_config_n_options:
686 * @config: a #GstBufferPool configuration
688 * Retrieve the number of values currently stored in the
689 * options array of the @config structure.
691 * Returns: the options array size as a #guint.
694 gst_buffer_pool_config_n_options (GstStructure * config)
699 g_return_val_if_fail (config != NULL, 0);
701 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
703 size = gst_value_array_get_size (value);
709 * gst_buffer_pool_config_get_option:
710 * @config: a #GstBufferPool configuration
711 * @index: position in the option array to read
713 * Parse an available @config and get the option
714 * at @index of the options API array.
716 * Returns: a #gchar of the option at @index.
719 gst_buffer_pool_config_get_option (GstStructure * config, guint index)
722 const gchar *ret = NULL;
724 g_return_val_if_fail (config != NULL, 0);
726 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
728 const GValue *option_value;
730 option_value = gst_value_array_get_value (value, index);
732 ret = g_value_get_string (option_value);
738 * gst_buffer_pool_config_has_option:
739 * @config: a #GstBufferPool configuration
742 * Check if @config contains @option
744 * Returns: TRUE if the options array contains @option.
747 gst_buffer_pool_config_has_option (GstStructure * config, const gchar * option)
752 g_return_val_if_fail (config != NULL, 0);
754 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
756 len = gst_value_array_get_size (value);
757 for (i = 0; i < len; ++i) {
758 const GValue *nth_val = gst_value_array_get_value (value, i);
760 if (g_str_equal (option, g_value_get_string (nth_val)))
768 * gst_buffer_pool_config_get:
769 * @config: (transfer none): a #GstBufferPool configuration
770 * @caps: (out): the caps of buffers
771 * @size: (out): the size of each buffer, not including prefix
772 * @min_buffers: (out): the minimum amount of buffers to allocate.
773 * @max_buffers: (out): the maximum amount of buffers to allocate or 0 for unlimited.
774 * @prefix: (out): prefix each buffer with this many bytes
775 * @align: (out): alignment of the buffer data.
777 * Get the configuration values from @config.
780 gst_buffer_pool_config_get (GstStructure * config, const GstCaps ** caps,
781 guint * size, guint * min_buffers, guint * max_buffers, guint * prefix,
784 g_return_val_if_fail (config != NULL, FALSE);
786 return gst_structure_id_get (config,
787 GST_QUARK (CAPS), GST_TYPE_CAPS, caps,
788 GST_QUARK (SIZE), G_TYPE_UINT, size,
789 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
790 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers,
791 GST_QUARK (PREFIX), G_TYPE_UINT, prefix,
792 GST_QUARK (ALIGN), G_TYPE_UINT, align, NULL);
796 default_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
797 GstBufferPoolParams * params)
799 GstFlowReturn result;
800 GstBufferPoolClass *pclass;
801 GstBufferPoolPrivate *priv = pool->priv;
803 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
806 if (G_UNLIKELY (GST_BUFFER_POOL_IS_FLUSHING (pool)))
809 /* try to get a buffer from the queue */
810 *buffer = gst_atomic_queue_pop (pool->priv->queue);
811 if (G_LIKELY (*buffer)) {
812 gst_poll_read_control (pool->priv->poll);
813 result = GST_FLOW_OK;
814 GST_LOG_OBJECT (pool, "acquired buffer %p", *buffer);
819 if (priv->max_buffers == 0) {
820 /* no max_buffers, we allocate some more */
821 if (G_LIKELY (pclass->alloc_buffer)) {
822 result = pclass->alloc_buffer (pool, buffer, params);
823 if (result == GST_FLOW_OK && *buffer)
824 gst_buffer_foreach_meta (*buffer, mark_meta_pooled, pool);
826 result = GST_FLOW_ERROR;
828 result = GST_FLOW_NOT_SUPPORTED;
829 GST_LOG_OBJECT (pool, "alloc buffer %p", *buffer);
833 /* check if we need to wait */
834 if (params && (params->flags & GST_BUFFER_POOL_FLAG_DONTWAIT)) {
835 GST_LOG_OBJECT (pool, "no more buffers");
836 result = GST_FLOW_EOS;
841 GST_LOG_OBJECT (pool, "waiting for free buffers");
842 gst_poll_wait (pool->priv->poll, GST_CLOCK_TIME_NONE);
850 GST_DEBUG_OBJECT (pool, "we are flushing");
851 return GST_FLOW_FLUSHING;
856 dec_outstanding (GstBufferPool * pool)
858 if (g_atomic_int_dec_and_test (&pool->priv->outstanding)) {
859 /* all buffers are returned to the pool, see if we need to free them */
860 if (GST_BUFFER_POOL_IS_FLUSHING (pool)) {
861 /* take the lock so that set_active is not run concurrently */
862 GST_BUFFER_POOL_LOCK (pool);
863 /* recheck the flushing state in the lock, the pool could have been
864 * set to active again */
865 if (GST_BUFFER_POOL_IS_FLUSHING (pool))
868 GST_BUFFER_POOL_UNLOCK (pool);
874 remove_meta_unpooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
876 if (!GST_META_FLAG_IS_SET (*meta, GST_META_FLAG_POOLED))
882 default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer,
883 GstBufferPoolParams * params)
885 GST_BUFFER_FLAGS (buffer) = 0;
887 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
888 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
889 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
890 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
891 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
893 /* remove all metadata without the POOLED flag */
894 gst_buffer_foreach_meta (buffer, remove_meta_unpooled, pool);
898 * gst_buffer_pool_acquire_buffer:
899 * @pool: a #GstBufferPool
900 * @buffer: (out): a location for a #GstBuffer
901 * @params: (transfer none) (allow-none) parameters.
903 * Acquire a buffer from @pool. @buffer should point to a memory location that
904 * can hold a pointer to the new buffer.
906 * @params can be NULL or contain optional parameters to influence the allocation.
908 * Returns: a #GstFlowReturn such as GST_FLOW_FLUSHING when the pool is
912 gst_buffer_pool_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
913 GstBufferPoolParams * params)
915 GstBufferPoolClass *pclass;
916 GstFlowReturn result;
918 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), GST_FLOW_ERROR);
919 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
921 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
923 /* assume we'll have one more outstanding buffer we need to do that so
924 * that concurrent set_active doesn't clear the buffers */
925 g_atomic_int_inc (&pool->priv->outstanding);
927 if (G_LIKELY (pclass->acquire_buffer))
928 result = pclass->acquire_buffer (pool, buffer, params);
930 result = GST_FLOW_NOT_SUPPORTED;
932 if (G_LIKELY (result == GST_FLOW_OK)) {
933 /* all buffers from the pool point to the pool and have the refcount of the
934 * pool incremented */
935 (*buffer)->pool = gst_object_ref (pool);
936 /* now reset the buffer when needed */
937 if (G_LIKELY (pclass->reset_buffer))
938 pclass->reset_buffer (pool, *buffer, params);
940 dec_outstanding (pool);
947 default_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
949 /* keep it around in our queue */
950 GST_LOG_OBJECT (pool, "released buffer %p", buffer);
951 gst_atomic_queue_push (pool->priv->queue, buffer);
952 gst_poll_write_control (pool->priv->poll);
956 * gst_buffer_pool_release_buffer:
957 * @pool: a #GstBufferPool
958 * @buffer: (transfer none): a #GstBuffer
960 * Release @buffer to @pool. @buffer should have previously been allocated from
961 * @pool with gst_buffer_pool_acquire_buffer().
963 * This function is usually called automatically when the last ref on @buffer
967 gst_buffer_pool_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
969 GstBufferPoolClass *pclass;
971 g_return_if_fail (GST_IS_BUFFER_POOL (pool));
972 g_return_if_fail (buffer != NULL);
974 /* check that the buffer is ours, all buffers returned to the pool have the
975 * pool member set to NULL and the pool refcount decreased */
976 if (!g_atomic_pointer_compare_and_exchange (&buffer->pool, pool, NULL))
979 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
981 if (G_LIKELY (pclass->release_buffer))
982 pclass->release_buffer (pool, buffer);
984 dec_outstanding (pool);
986 /* decrease the refcount that the buffer had to us */
987 gst_object_unref (pool);