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., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
23 * SECTION:gstbufferpool
24 * @short_description: Pool for buffers
25 * @see_also: #GstBuffer
27 * A #GstBufferPool is an object that can be used to pre-allocate and recycle
28 * buffers of the same size and with the same properties.
30 * A #GstBufferPool is created with gst_buffer_pool_new().
32 * Once a pool is created, it needs to be configured. A call to
33 * gst_buffer_pool_get_config() returns the current configuration structure from
34 * the pool. With gst_buffer_pool_config_set_params() and
35 * gst_buffer_pool_config_set_allocator() the bufferpool parameters and
36 * allocator can be configured. Other properties can be configured in the pool
37 * depending on the pool implementation.
39 * A bufferpool can have extra options that can be enabled with
40 * gst_buffer_pool_config_add_option(). The available options can be retrieved
41 * with gst_buffer_pool_get_options(). Some options allow for additional
42 * configuration properties to be set.
44 * After the configuration structure has been configured,
45 * gst_buffer_pool_set_config() updates the configuration in the pool. This can
46 * fail when the configuration structure is not accepted.
48 * After the a pool has been configured, it can be activated with
49 * gst_buffer_pool_set_active(). This will preallocate the configured resources
52 * When the pool is active, gst_buffer_pool_acquire_buffer() can be used to
53 * retrieve a buffer from the pool.
55 * Buffers allocated from a bufferpool will automatically be returned to the
56 * pool with gst_buffer_pool_release_buffer() when their refcount drops to 0.
58 * The bufferpool can be deactivated again with gst_buffer_pool_set_active().
59 * All further gst_buffer_pool_acquire_buffer() calls will return an error. When
60 * all buffers are returned to the pool they will be freed.
62 * Use gst_object_unref() to release the reference to a bufferpool. If the
63 * refcount of the pool reaches 0, the pool will be freed.
66 #include "gst_private.h"
67 #include "glib-compat-private.h"
73 #include <sys/types.h>
75 #include "gstatomicqueue.h"
81 #include "gstbufferpool.h"
83 GST_DEBUG_CATEGORY_STATIC (gst_buffer_pool_debug);
84 #define GST_CAT_DEFAULT gst_buffer_pool_debug
86 #define GST_BUFFER_POOL_GET_PRIVATE(obj) \
87 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BUFFER_POOL, GstBufferPoolPrivate))
89 #define GST_BUFFER_POOL_LOCK(pool) (g_rec_mutex_lock(&pool->priv->rec_lock))
90 #define GST_BUFFER_POOL_UNLOCK(pool) (g_rec_mutex_unlock(&pool->priv->rec_lock))
92 struct _GstBufferPoolPrivate
94 GstAtomicQueue *queue;
101 gint outstanding; /* number of buffers that are in use */
104 GstStructure *config;
110 GstAllocator *allocator;
111 GstAllocationParams params;
114 static void gst_buffer_pool_finalize (GObject * object);
116 G_DEFINE_TYPE (GstBufferPool, gst_buffer_pool, GST_TYPE_OBJECT);
118 static gboolean default_start (GstBufferPool * pool);
119 static gboolean default_stop (GstBufferPool * pool);
120 static gboolean default_set_config (GstBufferPool * pool,
121 GstStructure * config);
122 static GstFlowReturn default_alloc_buffer (GstBufferPool * pool,
123 GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
124 static GstFlowReturn default_acquire_buffer (GstBufferPool * pool,
125 GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
126 static void default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer);
127 static void default_free_buffer (GstBufferPool * pool, GstBuffer * buffer);
128 static void default_release_buffer (GstBufferPool * pool, GstBuffer * buffer);
131 gst_buffer_pool_class_init (GstBufferPoolClass * klass)
133 GObjectClass *gobject_class = (GObjectClass *) klass;
135 g_type_class_add_private (klass, sizeof (GstBufferPoolPrivate));
137 gobject_class->finalize = gst_buffer_pool_finalize;
139 klass->start = default_start;
140 klass->stop = default_stop;
141 klass->set_config = default_set_config;
142 klass->acquire_buffer = default_acquire_buffer;
143 klass->reset_buffer = default_reset_buffer;
144 klass->alloc_buffer = default_alloc_buffer;
145 klass->release_buffer = default_release_buffer;
146 klass->free_buffer = default_free_buffer;
148 GST_DEBUG_CATEGORY_INIT (gst_buffer_pool_debug, "bufferpool", 0,
153 gst_buffer_pool_init (GstBufferPool * pool)
155 GstBufferPoolPrivate *priv;
157 priv = pool->priv = GST_BUFFER_POOL_GET_PRIVATE (pool);
159 g_rec_mutex_init (&priv->rec_lock);
161 priv->poll = gst_poll_new_timer ();
162 priv->queue = gst_atomic_queue_new (16);
164 priv->active = FALSE;
165 priv->configured = FALSE;
166 priv->started = FALSE;
167 priv->config = gst_structure_new_id_empty (GST_QUARK (BUFFER_POOL_CONFIG));
168 gst_buffer_pool_config_set_params (priv->config, NULL, 0, 0, 0);
169 priv->allocator = NULL;
170 gst_allocation_params_init (&priv->params);
171 gst_buffer_pool_config_set_allocator (priv->config, priv->allocator,
173 /* 1 control write for flushing */
174 gst_poll_write_control (priv->poll);
175 /* 1 control write for marking that we are not waiting for poll */
176 gst_poll_write_control (priv->poll);
178 GST_DEBUG_OBJECT (pool, "created");
182 gst_buffer_pool_finalize (GObject * object)
185 GstBufferPoolPrivate *priv;
187 pool = GST_BUFFER_POOL_CAST (object);
190 GST_DEBUG_OBJECT (pool, "finalize");
192 gst_buffer_pool_set_active (pool, FALSE);
193 gst_atomic_queue_unref (priv->queue);
194 gst_poll_free (priv->poll);
195 gst_structure_free (priv->config);
196 g_rec_mutex_clear (&priv->rec_lock);
198 gst_object_unref (priv->allocator);
200 G_OBJECT_CLASS (gst_buffer_pool_parent_class)->finalize (object);
204 * gst_buffer_pool_new:
206 * Creates a new #GstBufferPool instance.
208 * Returns: (transfer floating): a new #GstBufferPool instance
211 gst_buffer_pool_new (void)
213 GstBufferPool *result;
215 result = g_object_newv (GST_TYPE_BUFFER_POOL, 0, NULL);
216 GST_DEBUG_OBJECT (result, "created new buffer pool");
222 default_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
223 GstBufferPoolAcquireParams * params)
225 GstBufferPoolPrivate *priv = pool->priv;
228 gst_buffer_new_allocate (priv->allocator, priv->size, &priv->params);
234 mark_meta_pooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
236 GstBufferPool *pool = user_data;
238 GST_DEBUG_OBJECT (pool, "marking meta %p as POOLED in buffer %p", *meta,
240 GST_META_FLAG_SET (*meta, GST_META_FLAG_POOLED);
241 GST_META_FLAG_SET (*meta, GST_META_FLAG_LOCKED);
247 do_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
248 GstBufferPoolAcquireParams * params)
250 GstBufferPoolPrivate *priv = pool->priv;
251 GstFlowReturn result;
252 gint cur_buffers, max_buffers;
253 GstBufferPoolClass *pclass;
255 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
257 if (G_UNLIKELY (!pclass->alloc_buffer))
260 max_buffers = priv->max_buffers;
262 /* increment the allocation counter */
263 cur_buffers = g_atomic_int_add (&priv->cur_buffers, 1);
264 if (max_buffers && cur_buffers >= max_buffers)
267 result = pclass->alloc_buffer (pool, buffer, params);
268 if (G_UNLIKELY (result != GST_FLOW_OK))
271 /* lock all metadata and mark as pooled, we want this to remain on
272 * the buffer and we want to remove any other metadata that gets added
274 gst_buffer_foreach_meta (*buffer, mark_meta_pooled, pool);
276 /* un-tag memory, this is how we expect the buffer when it is
278 GST_BUFFER_FLAG_UNSET (*buffer, GST_BUFFER_FLAG_TAG_MEMORY);
280 GST_LOG_OBJECT (pool, "allocated buffer %d/%d, %p", cur_buffers,
281 max_buffers, buffer);
288 GST_ERROR_OBJECT (pool, "no alloc function");
289 return GST_FLOW_NOT_SUPPORTED;
293 GST_DEBUG_OBJECT (pool, "max buffers reached");
294 g_atomic_int_add (&priv->cur_buffers, -1);
299 GST_WARNING_OBJECT (pool, "alloc function failed");
300 g_atomic_int_add (&priv->cur_buffers, -1);
305 /* the default implementation for preallocating the buffers in the pool */
307 default_start (GstBufferPool * pool)
310 GstBufferPoolPrivate *priv = pool->priv;
311 GstBufferPoolClass *pclass;
313 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
315 /* we need to prealloc buffers */
316 for (i = 0; i < priv->min_buffers; i++) {
319 if (do_alloc_buffer (pool, &buffer, NULL) != GST_FLOW_OK)
322 /* release to the queue, we call the vmethod directly, we don't need to do
323 * the other refcount handling right now. */
324 if (G_LIKELY (pclass->release_buffer))
325 pclass->release_buffer (pool, buffer);
332 GST_WARNING_OBJECT (pool, "failed to allocate buffer");
337 /* must be called with the lock */
339 do_start (GstBufferPool * pool)
341 GstBufferPoolPrivate *priv = pool->priv;
343 if (!priv->started) {
344 GstBufferPoolClass *pclass;
346 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
348 GST_LOG_OBJECT (pool, "starting");
349 /* start the pool, subclasses should allocate buffers and put them
351 if (G_LIKELY (pclass->start)) {
352 if (!pclass->start (pool))
355 priv->started = TRUE;
362 default_free_buffer (GstBufferPool * pool, GstBuffer * buffer)
364 gst_buffer_unref (buffer);
368 do_free_buffer (GstBufferPool * pool, GstBuffer * buffer)
370 GstBufferPoolPrivate *priv;
371 GstBufferPoolClass *pclass;
374 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
376 g_atomic_int_add (&priv->cur_buffers, -1);
377 GST_LOG_OBJECT (pool, "freeing buffer %p (%u left)", buffer,
380 if (G_LIKELY (pclass->free_buffer))
381 pclass->free_buffer (pool, buffer);
384 /* must be called with the lock */
386 default_stop (GstBufferPool * pool)
388 GstBufferPoolPrivate *priv = pool->priv;
392 while ((buffer = gst_atomic_queue_pop (priv->queue))) {
393 gst_poll_read_control (priv->poll);
394 do_free_buffer (pool, buffer);
396 return priv->cur_buffers == 0;
399 /* must be called with the lock */
401 do_stop (GstBufferPool * pool)
403 GstBufferPoolPrivate *priv = pool->priv;
406 GstBufferPoolClass *pclass;
408 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
410 GST_LOG_OBJECT (pool, "stopping");
411 if (G_LIKELY (pclass->stop)) {
412 if (!pclass->stop (pool))
415 priv->started = FALSE;
421 * gst_buffer_pool_set_active:
422 * @pool: a #GstBufferPool
423 * @active: the new active state
425 * Control the active state of @pool. When the pool is inactive, new calls to
426 * gst_buffer_pool_acquire_buffer() will return with %GST_FLOW_FLUSHING.
428 * Activating the bufferpool will preallocate all resources in the pool based on
429 * the configuration of the pool.
431 * Deactivating will free the resources again when there are no outstanding
432 * buffers. When there are outstanding buffers, they will be freed as soon as
433 * they are all returned to the pool.
435 * Returns: %FALSE when the pool was not configured or when preallocation of the
439 gst_buffer_pool_set_active (GstBufferPool * pool, gboolean active)
442 GstBufferPoolPrivate *priv;
444 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
446 GST_LOG_OBJECT (pool, "active %d", active);
450 GST_BUFFER_POOL_LOCK (pool);
451 /* just return if we are already in the right state */
452 if (priv->active == active)
455 /* we need to be configured */
456 if (!priv->configured)
460 if (!do_start (pool))
463 /* unset the flushing state now */
464 gst_poll_read_control (priv->poll);
465 g_atomic_int_set (&pool->flushing, 0);
469 /* set to flushing first */
470 g_atomic_int_set (&pool->flushing, 1);
471 gst_poll_write_control (priv->poll);
473 /* when all buffers are in the pool, free them. Else they will be
474 * freed when they are released */
475 outstanding = g_atomic_int_get (&priv->outstanding);
476 GST_LOG_OBJECT (pool, "outstanding buffers %d", outstanding);
477 if (outstanding == 0) {
482 priv->active = active;
483 GST_BUFFER_POOL_UNLOCK (pool);
489 GST_DEBUG_OBJECT (pool, "pool was in the right state");
490 GST_BUFFER_POOL_UNLOCK (pool);
495 GST_ERROR_OBJECT (pool, "pool was not configured");
496 GST_BUFFER_POOL_UNLOCK (pool);
501 GST_ERROR_OBJECT (pool, "start failed");
502 GST_BUFFER_POOL_UNLOCK (pool);
507 GST_WARNING_OBJECT (pool, "stop failed");
508 GST_BUFFER_POOL_UNLOCK (pool);
514 * gst_buffer_pool_is_active:
515 * @pool: a #GstBufferPool
517 * Check if @pool is active. A pool can be activated with the
518 * gst_buffer_pool_set_active() call.
520 * Returns: %TRUE when the pool is active.
523 gst_buffer_pool_is_active (GstBufferPool * pool)
527 GST_BUFFER_POOL_LOCK (pool);
528 res = pool->priv->active;
529 GST_BUFFER_POOL_UNLOCK (pool);
535 default_set_config (GstBufferPool * pool, GstStructure * config)
537 GstBufferPoolPrivate *priv = pool->priv;
539 guint size, min_buffers, max_buffers;
540 GstAllocator *allocator;
541 GstAllocationParams params;
543 /* parse the config and keep around */
544 if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers,
548 if (!gst_buffer_pool_config_get_allocator (config, &allocator, ¶ms))
551 GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config);
554 priv->min_buffers = min_buffers;
555 priv->max_buffers = max_buffers;
556 priv->cur_buffers = 0;
559 gst_object_unref (priv->allocator);
560 if ((priv->allocator = allocator))
561 gst_object_ref (allocator);
562 priv->params = params;
568 GST_WARNING_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
574 * gst_buffer_pool_set_config:
575 * @pool: a #GstBufferPool
576 * @config: (transfer full): a #GstStructure
578 * Set the configuration of the pool. The pool must be inactive and all buffers
579 * allocated form this pool must be returned or else this function will do
580 * nothing and return FALSE.
582 * @config is a #GstStructure that contains the configuration parameters for
583 * the pool. A default and mandatory set of parameters can be configured with
584 * gst_buffer_pool_config_set_params(), gst_buffer_pool_config_set_allocator()
585 * and gst_buffer_pool_config_add_option().
587 * If the parameters in @config can not be set exactly, this function returns
588 * %FALSE and will try to update as much state as possible. The new state can
589 * then be retrieved and refined with gst_buffer_pool_get_config().
591 * This function takes ownership of @config.
593 * Returns: %TRUE when the configuration could be set.
596 gst_buffer_pool_set_config (GstBufferPool * pool, GstStructure * config)
599 GstBufferPoolClass *pclass;
600 GstBufferPoolPrivate *priv;
602 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
603 g_return_val_if_fail (config != NULL, FALSE);
607 GST_BUFFER_POOL_LOCK (pool);
608 /* can't change the settings when active */
612 /* we can't change when outstanding buffers */
613 if (g_atomic_int_get (&priv->outstanding) != 0)
614 goto have_outstanding;
616 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
618 /* set the new config */
619 if (G_LIKELY (pclass->set_config))
620 result = pclass->set_config (pool, config);
626 gst_structure_free (priv->config);
627 priv->config = config;
629 /* now we are configured */
630 priv->configured = TRUE;
632 gst_structure_free (config);
634 GST_BUFFER_POOL_UNLOCK (pool);
641 gst_structure_free (config);
642 GST_WARNING_OBJECT (pool, "can't change config, we are active");
643 GST_BUFFER_POOL_UNLOCK (pool);
648 gst_structure_free (config);
649 GST_WARNING_OBJECT (pool, "can't change config, have outstanding buffers");
650 GST_BUFFER_POOL_UNLOCK (pool);
656 * gst_buffer_pool_get_config:
657 * @pool: a #GstBufferPool
659 * Get a copy of the current configuration of the pool. This configuration
660 * can either be modified and used for the gst_buffer_pool_set_config() call
661 * or it must be freed after usage.
663 * Returns: (transfer full): a copy of the current configuration of @pool. use
664 * gst_structure_free() after usage or gst_buffer_pool_set_config().
667 gst_buffer_pool_get_config (GstBufferPool * pool)
669 GstStructure *result;
671 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
673 GST_BUFFER_POOL_LOCK (pool);
674 result = gst_structure_copy (pool->priv->config);
675 GST_BUFFER_POOL_UNLOCK (pool);
680 static const gchar *empty_option[] = { NULL };
683 * gst_buffer_pool_get_options:
684 * @pool: a #GstBufferPool
686 * Get a %NULL terminated array of string with supported bufferpool options for
687 * @pool. An option would typically be enabled with
688 * gst_buffer_pool_config_add_option().
690 * Returns: (array zero-terminated=1) (transfer none): a %NULL terminated array
694 gst_buffer_pool_get_options (GstBufferPool * pool)
696 GstBufferPoolClass *pclass;
697 const gchar **result;
699 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
701 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
703 if (G_LIKELY (pclass->get_options)) {
704 if ((result = pclass->get_options (pool)) == NULL)
707 result = empty_option;
714 g_warning ("bufferpool subclass returned NULL options");
720 * gst_buffer_pool_has_option:
721 * @pool: a #GstBufferPool
724 * Check if the bufferpool supports @option.
726 * Returns: a %NULL terminated array of strings.
729 gst_buffer_pool_has_option (GstBufferPool * pool, const gchar * option)
732 const gchar **options;
734 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
735 g_return_val_if_fail (option != NULL, FALSE);
737 options = gst_buffer_pool_get_options (pool);
739 for (i = 0; options[i]; i++) {
740 if (g_str_equal (options[i], option))
747 * gst_buffer_pool_config_set_params:
748 * @config: a #GstBufferPool configuration
749 * @caps: caps for the buffers
750 * @size: the size of each buffer, not including prefix and padding
751 * @min_buffers: the minimum amount of buffers to allocate.
752 * @max_buffers: the maximum amount of buffers to allocate or 0 for unlimited.
754 * Configure @config with the given parameters.
757 gst_buffer_pool_config_set_params (GstStructure * config, GstCaps * caps,
758 guint size, guint min_buffers, guint max_buffers)
760 g_return_if_fail (config != NULL);
761 g_return_if_fail (max_buffers == 0 || min_buffers <= max_buffers);
762 g_return_if_fail (caps == NULL || gst_caps_is_fixed (caps));
764 gst_structure_id_set (config,
765 GST_QUARK (CAPS), GST_TYPE_CAPS, caps,
766 GST_QUARK (SIZE), G_TYPE_UINT, size,
767 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
768 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
772 * gst_buffer_pool_config_set_allocator:
773 * @config: a #GstBufferPool configuration
774 * @allocator: a #GstAllocator
775 * @params: #GstAllocationParams
777 * Set the @allocator and @params on @config.
779 * One of @allocator and @params can be %NULL, but not both. When @allocator
780 * is %NULL, the default allocator of the pool will use the values in @param
781 * to perform its allocation. When @param is %NULL, the pool will use the
782 * provided @allocator with its default #GstAllocationParams.
784 * A call to gst_buffer_pool_set_config() can update the allocator and params
785 * with the values that it is able to do. Some pools are, for example, not able
786 * to operate with different allocators or cannot allocate with the values
787 * specified in @params. Use gst_buffer_pool_get_config() to get the currently
791 gst_buffer_pool_config_set_allocator (GstStructure * config,
792 GstAllocator * allocator, const GstAllocationParams * params)
794 g_return_if_fail (config != NULL);
795 g_return_if_fail (allocator != NULL || params != NULL);
797 gst_structure_id_set (config,
798 GST_QUARK (ALLOCATOR), GST_TYPE_ALLOCATOR, allocator,
799 GST_QUARK (PARAMS), GST_TYPE_ALLOCATION_PARAMS, params, NULL);
803 * gst_buffer_pool_config_add_option:
804 * @config: a #GstBufferPool configuration
805 * @option: an option to add
807 * Enabled the option in @config. This will instruct the @bufferpool to enable
808 * the specified option on the buffers that it allocates.
810 * The supported options by @pool can be retrieved with gst_buffer_pool_get_options().
813 gst_buffer_pool_config_add_option (GstStructure * config, const gchar * option)
816 GValue option_value = { 0, };
819 g_return_if_fail (config != NULL);
821 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
823 len = gst_value_array_get_size (value);
824 for (i = 0; i < len; ++i) {
825 const GValue *nth_val = gst_value_array_get_value (value, i);
827 if (g_str_equal (option, g_value_get_string (nth_val)))
831 GValue new_array_val = { 0, };
833 g_value_init (&new_array_val, GST_TYPE_ARRAY);
834 gst_structure_id_take_value (config, GST_QUARK (OPTIONS), &new_array_val);
835 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
837 g_value_init (&option_value, G_TYPE_STRING);
838 g_value_set_string (&option_value, option);
839 gst_value_array_append_and_take_value ((GValue *) value, &option_value);
843 * gst_buffer_pool_config_n_options:
844 * @config: a #GstBufferPool configuration
846 * Retrieve the number of values currently stored in the options array of the
849 * Returns: the options array size as a #guint.
852 gst_buffer_pool_config_n_options (GstStructure * config)
857 g_return_val_if_fail (config != NULL, 0);
859 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
861 size = gst_value_array_get_size (value);
867 * gst_buffer_pool_config_get_option:
868 * @config: a #GstBufferPool configuration
869 * @index: position in the option array to read
871 * Parse an available @config and get the option at @index of the options API
874 * Returns: a #gchar of the option at @index.
877 gst_buffer_pool_config_get_option (GstStructure * config, guint index)
880 const gchar *ret = NULL;
882 g_return_val_if_fail (config != NULL, 0);
884 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
886 const GValue *option_value;
888 option_value = gst_value_array_get_value (value, index);
890 ret = g_value_get_string (option_value);
896 * gst_buffer_pool_config_has_option:
897 * @config: a #GstBufferPool configuration
900 * Check if @config contains @option.
902 * Returns: %TRUE if the options array contains @option.
905 gst_buffer_pool_config_has_option (GstStructure * config, const gchar * option)
910 g_return_val_if_fail (config != NULL, 0);
912 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
914 len = gst_value_array_get_size (value);
915 for (i = 0; i < len; ++i) {
916 const GValue *nth_val = gst_value_array_get_value (value, i);
918 if (g_str_equal (option, g_value_get_string (nth_val)))
926 * gst_buffer_pool_config_get_params:
927 * @config: (transfer none): a #GstBufferPool configuration
928 * @caps: (out) (transfer none) (allow-none): the caps of buffers
929 * @size: (out) (allow-none): the size of each buffer, not including prefix and padding
930 * @min_buffers: (out) (allow-none): the minimum amount of buffers to allocate.
931 * @max_buffers: (out) (allow-none): the maximum amount of buffers to allocate or 0 for unlimited.
933 * Get the configuration values from @config.
935 * Returns: %TRUE if all parameters could be fetched.
938 gst_buffer_pool_config_get_params (GstStructure * config, GstCaps ** caps,
939 guint * size, guint * min_buffers, guint * max_buffers)
941 g_return_val_if_fail (config != NULL, FALSE);
944 *caps = g_value_get_boxed (gst_structure_id_get_value (config,
947 return gst_structure_id_get (config,
948 GST_QUARK (SIZE), G_TYPE_UINT, size,
949 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
950 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
954 * gst_buffer_pool_config_get_allocator:
955 * @config: (transfer none): a #GstBufferPool configuration
956 * @allocator: (transfer none): a #GstAllocator
957 * @params: #GstAllocationParams
959 * Get the @allocator and @params from @config.
961 * Returns: %TRUE, if the values are set.
964 gst_buffer_pool_config_get_allocator (GstStructure * config,
965 GstAllocator ** allocator, GstAllocationParams * params)
967 g_return_val_if_fail (config != NULL, FALSE);
970 *allocator = g_value_get_object (gst_structure_id_get_value (config,
971 GST_QUARK (ALLOCATOR)));
973 GstAllocationParams *p;
975 p = g_value_get_boxed (gst_structure_id_get_value (config,
976 GST_QUARK (PARAMS)));
980 gst_allocation_params_init (params);
987 default_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
988 GstBufferPoolAcquireParams * params)
990 GstFlowReturn result;
991 GstBufferPoolPrivate *priv = pool->priv;
994 if (G_UNLIKELY (GST_BUFFER_POOL_IS_FLUSHING (pool)))
997 /* try to get a buffer from the queue */
998 *buffer = gst_atomic_queue_pop (priv->queue);
999 if (G_LIKELY (*buffer)) {
1000 gst_poll_read_control (priv->poll);
1001 result = GST_FLOW_OK;
1002 GST_LOG_OBJECT (pool, "acquired buffer %p", *buffer);
1006 /* no buffer, try to allocate some more */
1007 GST_LOG_OBJECT (pool, "no buffer, trying to allocate");
1008 result = do_alloc_buffer (pool, buffer, NULL);
1009 if (G_LIKELY (result == GST_FLOW_OK))
1010 /* we have a buffer, return it */
1013 if (G_UNLIKELY (result != GST_FLOW_EOS))
1014 /* something went wrong, return error */
1017 /* check if we need to wait */
1018 if (params && (params->flags & GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT)) {
1019 GST_LOG_OBJECT (pool, "no more buffers");
1023 /* now we release the control socket, we wait for a buffer release or
1025 gst_poll_read_control (pool->priv->poll);
1026 GST_LOG_OBJECT (pool, "waiting for free buffers or flushing");
1027 gst_poll_wait (priv->poll, GST_CLOCK_TIME_NONE);
1028 gst_poll_write_control (pool->priv->poll);
1036 GST_DEBUG_OBJECT (pool, "we are flushing");
1037 return GST_FLOW_FLUSHING;
1042 dec_outstanding (GstBufferPool * pool)
1044 if (g_atomic_int_dec_and_test (&pool->priv->outstanding)) {
1045 /* all buffers are returned to the pool, see if we need to free them */
1046 if (GST_BUFFER_POOL_IS_FLUSHING (pool)) {
1047 /* take the lock so that set_active is not run concurrently */
1048 GST_BUFFER_POOL_LOCK (pool);
1049 /* recheck the flushing state in the lock, the pool could have been
1050 * set to active again */
1051 if (GST_BUFFER_POOL_IS_FLUSHING (pool))
1054 GST_BUFFER_POOL_UNLOCK (pool);
1060 remove_meta_unpooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
1062 if (!GST_META_FLAG_IS_SET (*meta, GST_META_FLAG_POOLED)) {
1063 GST_META_FLAG_UNSET (*meta, GST_META_FLAG_LOCKED);
1070 default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer)
1072 GST_BUFFER_FLAGS (buffer) &= GST_BUFFER_FLAG_TAG_MEMORY;
1074 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
1075 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
1076 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
1077 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
1078 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
1080 /* remove all metadata without the POOLED flag */
1081 gst_buffer_foreach_meta (buffer, remove_meta_unpooled, pool);
1085 * gst_buffer_pool_acquire_buffer:
1086 * @pool: a #GstBufferPool
1087 * @buffer: (out): a location for a #GstBuffer
1088 * @params: (transfer none) (allow-none): parameters.
1090 * Acquire a buffer from @pool. @buffer should point to a memory location that
1091 * can hold a pointer to the new buffer.
1093 * @params can be %NULL or contain optional parameters to influence the
1096 * Returns: a #GstFlowReturn such as %GST_FLOW_FLUSHING when the pool is
1100 gst_buffer_pool_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
1101 GstBufferPoolAcquireParams * params)
1103 GstBufferPoolClass *pclass;
1104 GstFlowReturn result;
1106 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), GST_FLOW_ERROR);
1107 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
1109 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
1111 /* assume we'll have one more outstanding buffer we need to do that so
1112 * that concurrent set_active doesn't clear the buffers */
1113 g_atomic_int_inc (&pool->priv->outstanding);
1115 if (G_LIKELY (pclass->acquire_buffer))
1116 result = pclass->acquire_buffer (pool, buffer, params);
1118 result = GST_FLOW_NOT_SUPPORTED;
1120 if (G_LIKELY (result == GST_FLOW_OK)) {
1121 /* all buffers from the pool point to the pool and have the refcount of the
1122 * pool incremented */
1123 (*buffer)->pool = gst_object_ref (pool);
1125 dec_outstanding (pool);
1132 default_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
1134 GST_LOG_OBJECT (pool, "released buffer %p %d", buffer,
1135 GST_MINI_OBJECT_FLAGS (buffer));
1137 /* memory should be untouched */
1138 if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY))
1141 /* size should have been reset. This is not a catch all, pool with
1142 * size requirement per memory should do their own check. */
1143 if (gst_buffer_get_size (buffer) != pool->priv->size)
1146 /* all memory should be exclusive to this buffer (and thus be writable) */
1147 if (!gst_buffer_is_all_memory_writable (buffer))
1150 /* keep it around in our queue */
1151 gst_atomic_queue_push (pool->priv->queue, buffer);
1152 gst_poll_write_control (pool->priv->poll);
1158 do_free_buffer (pool, buffer);
1164 * gst_buffer_pool_release_buffer:
1165 * @pool: a #GstBufferPool
1166 * @buffer: (transfer full): a #GstBuffer
1168 * Release @buffer to @pool. @buffer should have previously been allocated from
1169 * @pool with gst_buffer_pool_acquire_buffer().
1171 * This function is usually called automatically when the last ref on @buffer
1175 gst_buffer_pool_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
1177 GstBufferPoolClass *pclass;
1179 g_return_if_fail (GST_IS_BUFFER_POOL (pool));
1180 g_return_if_fail (buffer != NULL);
1182 /* check that the buffer is ours, all buffers returned to the pool have the
1183 * pool member set to NULL and the pool refcount decreased */
1184 if (!g_atomic_pointer_compare_and_exchange (&buffer->pool, pool, NULL))
1187 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
1189 /* reset the buffer when needed */
1190 if (G_LIKELY (pclass->reset_buffer))
1191 pclass->reset_buffer (pool, buffer);
1193 if (G_LIKELY (pclass->release_buffer))
1194 pclass->release_buffer (pool, buffer);
1196 dec_outstanding (pool);
1198 /* decrease the refcount that the buffer had to us */
1199 gst_object_unref (pool);