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.
65 * Last reviewed on 2014-01-30 (1.3.0)
68 #include "gst_private.h"
69 #include "glib-compat-private.h"
75 #include <sys/types.h>
77 #include "gstatomicqueue.h"
83 #include "gstbufferpool.h"
85 GST_DEBUG_CATEGORY_STATIC (gst_buffer_pool_debug);
86 #define GST_CAT_DEFAULT gst_buffer_pool_debug
88 #define GST_BUFFER_POOL_GET_PRIVATE(obj) \
89 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BUFFER_POOL, GstBufferPoolPrivate))
91 #define GST_BUFFER_POOL_LOCK(pool) (g_rec_mutex_lock(&pool->priv->rec_lock))
92 #define GST_BUFFER_POOL_UNLOCK(pool) (g_rec_mutex_unlock(&pool->priv->rec_lock))
94 struct _GstBufferPoolPrivate
96 GstAtomicQueue *queue;
103 gint outstanding; /* number of buffers that are in use */
106 GstStructure *config;
112 GstAllocator *allocator;
113 GstAllocationParams params;
116 static void gst_buffer_pool_finalize (GObject * object);
118 G_DEFINE_TYPE (GstBufferPool, gst_buffer_pool, GST_TYPE_OBJECT);
120 static gboolean default_start (GstBufferPool * pool);
121 static gboolean default_stop (GstBufferPool * pool);
122 static gboolean default_set_config (GstBufferPool * pool,
123 GstStructure * config);
124 static GstFlowReturn default_alloc_buffer (GstBufferPool * pool,
125 GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
126 static GstFlowReturn default_acquire_buffer (GstBufferPool * pool,
127 GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
128 static void default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer);
129 static void default_free_buffer (GstBufferPool * pool, GstBuffer * buffer);
130 static void default_release_buffer (GstBufferPool * pool, GstBuffer * buffer);
133 gst_buffer_pool_class_init (GstBufferPoolClass * klass)
135 GObjectClass *gobject_class = (GObjectClass *) klass;
137 g_type_class_add_private (klass, sizeof (GstBufferPoolPrivate));
139 gobject_class->finalize = gst_buffer_pool_finalize;
141 klass->start = default_start;
142 klass->stop = default_stop;
143 klass->set_config = default_set_config;
144 klass->acquire_buffer = default_acquire_buffer;
145 klass->reset_buffer = default_reset_buffer;
146 klass->alloc_buffer = default_alloc_buffer;
147 klass->release_buffer = default_release_buffer;
148 klass->free_buffer = default_free_buffer;
150 GST_DEBUG_CATEGORY_INIT (gst_buffer_pool_debug, "bufferpool", 0,
155 gst_buffer_pool_init (GstBufferPool * pool)
157 GstBufferPoolPrivate *priv;
159 priv = pool->priv = GST_BUFFER_POOL_GET_PRIVATE (pool);
161 g_rec_mutex_init (&priv->rec_lock);
163 priv->poll = gst_poll_new_timer ();
164 priv->queue = gst_atomic_queue_new (16);
166 priv->active = FALSE;
167 priv->configured = FALSE;
168 priv->started = FALSE;
169 priv->config = gst_structure_new_id_empty (GST_QUARK (BUFFER_POOL_CONFIG));
170 gst_buffer_pool_config_set_params (priv->config, NULL, 0, 0, 0);
171 priv->allocator = NULL;
172 gst_allocation_params_init (&priv->params);
173 gst_buffer_pool_config_set_allocator (priv->config, priv->allocator,
175 /* 1 control write for flushing */
176 gst_poll_write_control (priv->poll);
177 /* 1 control write for marking that we are not waiting for poll */
178 gst_poll_write_control (priv->poll);
180 GST_DEBUG_OBJECT (pool, "created");
184 gst_buffer_pool_finalize (GObject * object)
187 GstBufferPoolPrivate *priv;
189 pool = GST_BUFFER_POOL_CAST (object);
192 GST_DEBUG_OBJECT (pool, "finalize");
194 gst_buffer_pool_set_active (pool, FALSE);
195 gst_atomic_queue_unref (priv->queue);
196 gst_poll_free (priv->poll);
197 gst_structure_free (priv->config);
198 g_rec_mutex_clear (&priv->rec_lock);
200 gst_object_unref (priv->allocator);
202 G_OBJECT_CLASS (gst_buffer_pool_parent_class)->finalize (object);
206 * gst_buffer_pool_new:
208 * Creates a new #GstBufferPool instance.
210 * Returns: (transfer floating): a new #GstBufferPool instance
213 gst_buffer_pool_new (void)
215 GstBufferPool *result;
217 result = g_object_newv (GST_TYPE_BUFFER_POOL, 0, NULL);
218 GST_DEBUG_OBJECT (result, "created new buffer pool");
224 default_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
225 GstBufferPoolAcquireParams * params)
227 GstBufferPoolPrivate *priv = pool->priv;
230 gst_buffer_new_allocate (priv->allocator, priv->size, &priv->params);
236 mark_meta_pooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
238 GstBufferPool *pool = user_data;
240 GST_DEBUG_OBJECT (pool, "marking meta %p as POOLED in buffer %p", *meta,
242 GST_META_FLAG_SET (*meta, GST_META_FLAG_POOLED);
243 GST_META_FLAG_SET (*meta, GST_META_FLAG_LOCKED);
249 do_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
250 GstBufferPoolAcquireParams * params)
252 GstBufferPoolPrivate *priv = pool->priv;
253 GstFlowReturn result;
254 gint cur_buffers, max_buffers;
255 GstBufferPoolClass *pclass;
257 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
259 if (G_UNLIKELY (!pclass->alloc_buffer))
262 max_buffers = priv->max_buffers;
264 /* increment the allocation counter */
265 cur_buffers = g_atomic_int_add (&priv->cur_buffers, 1);
266 if (max_buffers && cur_buffers >= max_buffers)
269 result = pclass->alloc_buffer (pool, buffer, params);
270 if (G_UNLIKELY (result != GST_FLOW_OK))
273 /* lock all metadata and mark as pooled, we want this to remain on
274 * the buffer and we want to remove any other metadata that gets added
276 gst_buffer_foreach_meta (*buffer, mark_meta_pooled, pool);
277 /* tag memory, this is how we expect the buffer when it is
279 GST_BUFFER_FLAG_SET (*buffer, GST_BUFFER_FLAG_TAG_MEMORY);
281 GST_LOG_OBJECT (pool, "allocated buffer %d/%d, %p", cur_buffers,
282 max_buffers, buffer);
289 GST_ERROR_OBJECT (pool, "no alloc function");
290 return GST_FLOW_NOT_SUPPORTED;
294 GST_DEBUG_OBJECT (pool, "max buffers reached");
295 g_atomic_int_add (&priv->cur_buffers, -1);
300 GST_WARNING_OBJECT (pool, "alloc function failed");
301 g_atomic_int_add (&priv->cur_buffers, -1);
306 /* the default implementation for preallocating the buffers in the pool */
308 default_start (GstBufferPool * pool)
311 GstBufferPoolPrivate *priv = pool->priv;
312 GstBufferPoolClass *pclass;
314 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
316 /* we need to prealloc buffers */
317 for (i = 0; i < priv->min_buffers; i++) {
320 if (do_alloc_buffer (pool, &buffer, NULL) != GST_FLOW_OK)
323 /* release to the queue, we call the vmethod directly, we don't need to do
324 * the other refcount handling right now. */
325 if (G_LIKELY (pclass->release_buffer))
326 pclass->release_buffer (pool, buffer);
333 GST_WARNING_OBJECT (pool, "failed to allocate buffer");
338 /* must be called with the lock */
340 do_start (GstBufferPool * pool)
342 GstBufferPoolPrivate *priv = pool->priv;
344 if (!priv->started) {
345 GstBufferPoolClass *pclass;
347 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
349 GST_LOG_OBJECT (pool, "starting");
350 /* start the pool, subclasses should allocate buffers and put them
352 if (G_LIKELY (pclass->start)) {
353 if (!pclass->start (pool))
356 priv->started = TRUE;
363 default_free_buffer (GstBufferPool * pool, GstBuffer * buffer)
365 gst_buffer_unref (buffer);
369 do_free_buffer (GstBufferPool * pool, GstBuffer * buffer)
371 GstBufferPoolPrivate *priv;
372 GstBufferPoolClass *pclass;
375 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
377 g_atomic_int_add (&priv->cur_buffers, -1);
378 GST_LOG_OBJECT (pool, "freeing buffer %p (%u left)", buffer,
381 if (G_LIKELY (pclass->free_buffer))
382 pclass->free_buffer (pool, buffer);
385 /* must be called with the lock */
387 default_stop (GstBufferPool * pool)
389 GstBufferPoolPrivate *priv = pool->priv;
393 while ((buffer = gst_atomic_queue_pop (priv->queue))) {
394 gst_poll_read_control (priv->poll);
395 do_free_buffer (pool, buffer);
397 return priv->cur_buffers == 0;
400 /* must be called with the lock */
402 do_stop (GstBufferPool * pool)
404 GstBufferPoolPrivate *priv = pool->priv;
407 GstBufferPoolClass *pclass;
409 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
411 GST_LOG_OBJECT (pool, "stopping");
412 if (G_LIKELY (pclass->stop)) {
413 if (!pclass->stop (pool))
416 priv->started = FALSE;
422 * gst_buffer_pool_set_active:
423 * @pool: a #GstBufferPool
424 * @active: the new active state
426 * Control the active state of @pool. When the pool is inactive, new calls to
427 * gst_buffer_pool_acquire_buffer() will return with %GST_FLOW_FLUSHING.
429 * Activating the bufferpool will preallocate all resources in the pool based on
430 * the configuration of the pool.
432 * Deactivating will free the resources again when there are no outstanding
433 * buffers. When there are outstanding buffers, they will be freed as soon as
434 * they are all returned to the pool.
436 * Returns: %FALSE when the pool was not configured or when preallocation of the
440 gst_buffer_pool_set_active (GstBufferPool * pool, gboolean active)
443 GstBufferPoolPrivate *priv;
445 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
447 GST_LOG_OBJECT (pool, "active %d", active);
451 GST_BUFFER_POOL_LOCK (pool);
452 /* just return if we are already in the right state */
453 if (priv->active == active)
456 /* we need to be configured */
457 if (!priv->configured)
461 if (!do_start (pool))
464 /* unset the flushing state now */
465 gst_poll_read_control (priv->poll);
466 g_atomic_int_set (&pool->flushing, 0);
470 /* set to flushing first */
471 g_atomic_int_set (&pool->flushing, 1);
472 gst_poll_write_control (priv->poll);
474 /* when all buffers are in the pool, free them. Else they will be
475 * freed when they are released */
476 outstanding = g_atomic_int_get (&priv->outstanding);
477 GST_LOG_OBJECT (pool, "outstanding buffers %d", outstanding);
478 if (outstanding == 0) {
483 priv->active = active;
484 GST_BUFFER_POOL_UNLOCK (pool);
490 GST_DEBUG_OBJECT (pool, "pool was in the right state");
491 GST_BUFFER_POOL_UNLOCK (pool);
496 GST_ERROR_OBJECT (pool, "pool was not configured");
497 GST_BUFFER_POOL_UNLOCK (pool);
502 GST_ERROR_OBJECT (pool, "start failed");
503 GST_BUFFER_POOL_UNLOCK (pool);
508 GST_WARNING_OBJECT (pool, "stop failed");
509 GST_BUFFER_POOL_UNLOCK (pool);
515 * gst_buffer_pool_is_active:
516 * @pool: a #GstBufferPool
518 * Check if @pool is active. A pool can be activated with the
519 * gst_buffer_pool_set_active() call.
521 * Returns: %TRUE when the pool is active.
524 gst_buffer_pool_is_active (GstBufferPool * pool)
528 GST_BUFFER_POOL_LOCK (pool);
529 res = pool->priv->active;
530 GST_BUFFER_POOL_UNLOCK (pool);
536 default_set_config (GstBufferPool * pool, GstStructure * config)
538 GstBufferPoolPrivate *priv = pool->priv;
540 guint size, min_buffers, max_buffers;
541 GstAllocator *allocator;
542 GstAllocationParams params;
544 /* parse the config and keep around */
545 if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers,
549 if (!gst_buffer_pool_config_get_allocator (config, &allocator, ¶ms))
552 GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config);
555 priv->min_buffers = min_buffers;
556 priv->max_buffers = max_buffers;
557 priv->cur_buffers = 0;
560 gst_object_unref (priv->allocator);
561 if ((priv->allocator = allocator))
562 gst_object_ref (allocator);
563 priv->params = params;
569 GST_WARNING_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
575 * gst_buffer_pool_set_config:
576 * @pool: a #GstBufferPool
577 * @config: (transfer full): a #GstStructure
579 * Set the configuration of the pool. The pool must be inactive and all buffers
580 * allocated form this pool must be returned or else this function will do
581 * nothing and return FALSE.
583 * @config is a #GstStructure that contains the configuration parameters for
584 * the pool. A default and mandatory set of parameters can be configured with
585 * gst_buffer_pool_config_set_params(), gst_buffer_pool_config_set_allocator()
586 * and gst_buffer_pool_config_add_option().
588 * If the parameters in @config can not be set exactly, this function returns
589 * %FALSE and will try to update as much state as possible. The new state can
590 * then be retrieved and refined with gst_buffer_pool_get_config().
592 * This function takes ownership of @config.
594 * Returns: %TRUE when the configuration could be set.
597 gst_buffer_pool_set_config (GstBufferPool * pool, GstStructure * config)
600 GstBufferPoolClass *pclass;
601 GstBufferPoolPrivate *priv;
603 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
604 g_return_val_if_fail (config != NULL, FALSE);
608 GST_BUFFER_POOL_LOCK (pool);
609 /* can't change the settings when active */
613 /* we can't change when outstanding buffers */
614 if (g_atomic_int_get (&priv->outstanding) != 0)
615 goto have_outstanding;
617 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
619 /* set the new config */
620 if (G_LIKELY (pclass->set_config))
621 result = pclass->set_config (pool, config);
627 gst_structure_free (priv->config);
628 priv->config = config;
630 /* now we are configured */
631 priv->configured = TRUE;
633 gst_structure_free (config);
635 GST_BUFFER_POOL_UNLOCK (pool);
642 gst_structure_free (config);
643 GST_WARNING_OBJECT (pool, "can't change config, we are active");
644 GST_BUFFER_POOL_UNLOCK (pool);
649 gst_structure_free (config);
650 GST_WARNING_OBJECT (pool, "can't change config, have outstanding buffers");
651 GST_BUFFER_POOL_UNLOCK (pool);
657 * gst_buffer_pool_get_config:
658 * @pool: a #GstBufferPool
660 * Get a copy of the current configuration of the pool. This configuration
661 * can either be modified and used for the gst_buffer_pool_set_config() call
662 * or it must be freed after usage.
664 * Returns: (transfer full): a copy of the current configuration of @pool. use
665 * gst_structure_free() after usage or gst_buffer_pool_set_config().
668 gst_buffer_pool_get_config (GstBufferPool * pool)
670 GstStructure *result;
672 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
674 GST_BUFFER_POOL_LOCK (pool);
675 result = gst_structure_copy (pool->priv->config);
676 GST_BUFFER_POOL_UNLOCK (pool);
681 static const gchar *empty_option[] = { NULL };
684 * gst_buffer_pool_get_options:
685 * @pool: a #GstBufferPool
687 * Get a %NULL terminated array of string with supported bufferpool options for
688 * @pool. An option would typically be enabled with
689 * gst_buffer_pool_config_add_option().
691 * Returns: (array zero-terminated=1) (transfer none): a %NULL terminated array
695 gst_buffer_pool_get_options (GstBufferPool * pool)
697 GstBufferPoolClass *pclass;
698 const gchar **result;
700 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
702 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
704 if (G_LIKELY (pclass->get_options)) {
705 if ((result = pclass->get_options (pool)) == NULL)
708 result = empty_option;
715 g_warning ("bufferpool subclass returned NULL options");
721 * gst_buffer_pool_has_option:
722 * @pool: a #GstBufferPool
725 * Check if the bufferpool supports @option.
727 * Returns: a %NULL terminated array of strings.
730 gst_buffer_pool_has_option (GstBufferPool * pool, const gchar * option)
733 const gchar **options;
735 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
736 g_return_val_if_fail (option != NULL, FALSE);
738 options = gst_buffer_pool_get_options (pool);
740 for (i = 0; options[i]; i++) {
741 if (g_str_equal (options[i], option))
748 * gst_buffer_pool_config_set_params:
749 * @config: a #GstBufferPool configuration
750 * @caps: caps for the buffers
751 * @size: the size of each buffer, not including prefix and padding
752 * @min_buffers: the minimum amount of buffers to allocate.
753 * @max_buffers: the maximum amount of buffers to allocate or 0 for unlimited.
755 * Configure @config with the given parameters.
758 gst_buffer_pool_config_set_params (GstStructure * config, GstCaps * caps,
759 guint size, guint min_buffers, guint max_buffers)
761 g_return_if_fail (config != NULL);
762 g_return_if_fail (max_buffers == 0 || min_buffers <= max_buffers);
763 g_return_if_fail (caps == NULL || gst_caps_is_fixed (caps));
765 gst_structure_id_set (config,
766 GST_QUARK (CAPS), GST_TYPE_CAPS, caps,
767 GST_QUARK (SIZE), G_TYPE_UINT, size,
768 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
769 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
773 * gst_buffer_pool_config_set_allocator:
774 * @config: a #GstBufferPool configuration
775 * @allocator: a #GstAllocator
776 * @params: #GstAllocationParams
778 * Set the @allocator and @params on @config.
780 * One of @allocator and @params can be %NULL, but not both. When @allocator
781 * is %NULL, the default allocator of the pool will use the values in @param
782 * to perform its allocation. When @param is %NULL, the pool will use the
783 * provided @allocator with its default #GstAllocationParams.
785 * A call to gst_buffer_pool_set_config() can update the allocator and params
786 * with the values that it is able to do. Some pools are, for example, not able
787 * to operate with different allocators or cannot allocate with the values
788 * specified in @params. Use gst_buffer_pool_get_config() to get the currently
792 gst_buffer_pool_config_set_allocator (GstStructure * config,
793 GstAllocator * allocator, const GstAllocationParams * params)
795 g_return_if_fail (config != NULL);
796 g_return_if_fail (allocator != NULL || params != NULL);
798 gst_structure_id_set (config,
799 GST_QUARK (ALLOCATOR), GST_TYPE_ALLOCATOR, allocator,
800 GST_QUARK (PARAMS), GST_TYPE_ALLOCATION_PARAMS, params, NULL);
804 * gst_buffer_pool_config_add_option:
805 * @config: a #GstBufferPool configuration
806 * @option: an option to add
808 * Enabled the option in @config. This will instruct the @bufferpool to enable
809 * the specified option on the buffers that it allocates.
811 * The supported options by @pool can be retrieved with gst_buffer_pool_get_options().
814 gst_buffer_pool_config_add_option (GstStructure * config, const gchar * option)
817 GValue option_value = { 0, };
820 g_return_if_fail (config != NULL);
822 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
824 len = gst_value_array_get_size (value);
825 for (i = 0; i < len; ++i) {
826 const GValue *nth_val = gst_value_array_get_value (value, i);
828 if (g_str_equal (option, g_value_get_string (nth_val)))
832 GValue new_array_val = { 0, };
834 g_value_init (&new_array_val, GST_TYPE_ARRAY);
835 gst_structure_id_take_value (config, GST_QUARK (OPTIONS), &new_array_val);
836 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
838 g_value_init (&option_value, G_TYPE_STRING);
839 g_value_set_string (&option_value, option);
840 gst_value_array_append_and_take_value ((GValue *) value, &option_value);
844 * gst_buffer_pool_config_n_options:
845 * @config: a #GstBufferPool configuration
847 * Retrieve the number of values currently stored in the options array of the
850 * Returns: the options array size as a #guint.
853 gst_buffer_pool_config_n_options (GstStructure * config)
858 g_return_val_if_fail (config != NULL, 0);
860 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
862 size = gst_value_array_get_size (value);
868 * gst_buffer_pool_config_get_option:
869 * @config: a #GstBufferPool configuration
870 * @index: position in the option array to read
872 * Parse an available @config and get the option at @index of the options API
875 * Returns: a #gchar of the option at @index.
878 gst_buffer_pool_config_get_option (GstStructure * config, guint index)
881 const gchar *ret = NULL;
883 g_return_val_if_fail (config != NULL, 0);
885 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
887 const GValue *option_value;
889 option_value = gst_value_array_get_value (value, index);
891 ret = g_value_get_string (option_value);
897 * gst_buffer_pool_config_has_option:
898 * @config: a #GstBufferPool configuration
901 * Check if @config contains @option.
903 * Returns: %TRUE if the options array contains @option.
906 gst_buffer_pool_config_has_option (GstStructure * config, const gchar * option)
911 g_return_val_if_fail (config != NULL, 0);
913 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
915 len = gst_value_array_get_size (value);
916 for (i = 0; i < len; ++i) {
917 const GValue *nth_val = gst_value_array_get_value (value, i);
919 if (g_str_equal (option, g_value_get_string (nth_val)))
927 * gst_buffer_pool_config_get_params:
928 * @config: (transfer none): a #GstBufferPool configuration
929 * @caps: (out) (transfer none) (allow-none): the caps of buffers
930 * @size: (out) (allow-none): the size of each buffer, not including prefix and padding
931 * @min_buffers: (out) (allow-none): the minimum amount of buffers to allocate.
932 * @max_buffers: (out) (allow-none): the maximum amount of buffers to allocate or 0 for unlimited.
934 * Get the configuration values from @config.
936 * Returns: %TRUE if all parameters could be fetched.
939 gst_buffer_pool_config_get_params (GstStructure * config, GstCaps ** caps,
940 guint * size, guint * min_buffers, guint * max_buffers)
942 g_return_val_if_fail (config != NULL, FALSE);
945 *caps = g_value_get_boxed (gst_structure_id_get_value (config,
948 return gst_structure_id_get (config,
949 GST_QUARK (SIZE), G_TYPE_UINT, size,
950 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
951 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
955 * gst_buffer_pool_config_get_allocator:
956 * @config: (transfer none): a #GstBufferPool configuration
957 * @allocator: (transfer none): a #GstAllocator
958 * @params: #GstAllocationParams
960 * Get the @allocator and @params from @config.
962 * Returns: %TRUE, if the values are set.
965 gst_buffer_pool_config_get_allocator (GstStructure * config,
966 GstAllocator ** allocator, GstAllocationParams * params)
968 g_return_val_if_fail (config != NULL, FALSE);
971 *allocator = g_value_get_object (gst_structure_id_get_value (config,
972 GST_QUARK (ALLOCATOR)));
974 GstAllocationParams *p;
976 p = g_value_get_boxed (gst_structure_id_get_value (config,
977 GST_QUARK (PARAMS)));
981 gst_allocation_params_init (params);
988 default_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
989 GstBufferPoolAcquireParams * params)
991 GstFlowReturn result;
992 GstBufferPoolPrivate *priv = pool->priv;
995 if (G_UNLIKELY (GST_BUFFER_POOL_IS_FLUSHING (pool)))
998 /* try to get a buffer from the queue */
999 *buffer = gst_atomic_queue_pop (priv->queue);
1000 if (G_LIKELY (*buffer)) {
1001 gst_poll_read_control (priv->poll);
1002 result = GST_FLOW_OK;
1003 GST_LOG_OBJECT (pool, "acquired buffer %p", *buffer);
1007 /* no buffer, try to allocate some more */
1008 GST_LOG_OBJECT (pool, "no buffer, trying to allocate");
1009 result = do_alloc_buffer (pool, buffer, NULL);
1010 if (G_LIKELY (result == GST_FLOW_OK))
1011 /* we have a buffer, return it */
1014 if (G_UNLIKELY (result != GST_FLOW_EOS))
1015 /* something went wrong, return error */
1018 /* check if we need to wait */
1019 if (params && (params->flags & GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT)) {
1020 GST_LOG_OBJECT (pool, "no more buffers");
1024 /* now we release the control socket, we wait for a buffer release or
1026 gst_poll_read_control (pool->priv->poll);
1027 GST_LOG_OBJECT (pool, "waiting for free buffers or flushing");
1028 gst_poll_wait (priv->poll, GST_CLOCK_TIME_NONE);
1029 gst_poll_write_control (pool->priv->poll);
1037 GST_DEBUG_OBJECT (pool, "we are flushing");
1038 return GST_FLOW_FLUSHING;
1043 dec_outstanding (GstBufferPool * pool)
1045 if (g_atomic_int_dec_and_test (&pool->priv->outstanding)) {
1046 /* all buffers are returned to the pool, see if we need to free them */
1047 if (GST_BUFFER_POOL_IS_FLUSHING (pool)) {
1048 /* take the lock so that set_active is not run concurrently */
1049 GST_BUFFER_POOL_LOCK (pool);
1050 /* recheck the flushing state in the lock, the pool could have been
1051 * set to active again */
1052 if (GST_BUFFER_POOL_IS_FLUSHING (pool))
1055 GST_BUFFER_POOL_UNLOCK (pool);
1061 remove_meta_unpooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
1063 if (!GST_META_FLAG_IS_SET (*meta, GST_META_FLAG_POOLED)) {
1064 GST_META_FLAG_UNSET (*meta, GST_META_FLAG_LOCKED);
1071 default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer)
1073 GST_BUFFER_FLAGS (buffer) &= GST_BUFFER_FLAG_TAG_MEMORY;
1075 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
1076 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
1077 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
1078 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
1079 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
1081 /* remove all metadata without the POOLED flag */
1082 gst_buffer_foreach_meta (buffer, remove_meta_unpooled, pool);
1086 * gst_buffer_pool_acquire_buffer:
1087 * @pool: a #GstBufferPool
1088 * @buffer: (out): a location for a #GstBuffer
1089 * @params: (transfer none) (allow-none) parameters.
1091 * Acquire a buffer from @pool. @buffer should point to a memory location that
1092 * can hold a pointer to the new buffer.
1094 * @params can be %NULL or contain optional parameters to influence the
1097 * Returns: a #GstFlowReturn such as %GST_FLOW_FLUSHING when the pool is
1101 gst_buffer_pool_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
1102 GstBufferPoolAcquireParams * params)
1104 GstBufferPoolClass *pclass;
1105 GstFlowReturn result;
1107 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), GST_FLOW_ERROR);
1108 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
1110 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
1112 /* assume we'll have one more outstanding buffer we need to do that so
1113 * that concurrent set_active doesn't clear the buffers */
1114 g_atomic_int_inc (&pool->priv->outstanding);
1116 if (G_LIKELY (pclass->acquire_buffer))
1117 result = pclass->acquire_buffer (pool, buffer, params);
1119 result = GST_FLOW_NOT_SUPPORTED;
1121 if (G_LIKELY (result == GST_FLOW_OK)) {
1122 /* all buffers from the pool point to the pool and have the refcount of the
1123 * pool incremented */
1124 (*buffer)->pool = gst_object_ref (pool);
1126 dec_outstanding (pool);
1133 default_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
1135 GST_LOG_OBJECT (pool, "released buffer %p %d", buffer,
1136 GST_MINI_OBJECT_FLAGS (buffer));
1138 if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY)) {
1139 /* keep it around in our queue */
1140 gst_atomic_queue_push (pool->priv->queue, buffer);
1141 gst_poll_write_control (pool->priv->poll);
1143 do_free_buffer (pool, buffer);
1148 * gst_buffer_pool_release_buffer:
1149 * @pool: a #GstBufferPool
1150 * @buffer: (transfer full): a #GstBuffer
1152 * Release @buffer to @pool. @buffer should have previously been allocated from
1153 * @pool with gst_buffer_pool_acquire_buffer().
1155 * This function is usually called automatically when the last ref on @buffer
1159 gst_buffer_pool_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
1161 GstBufferPoolClass *pclass;
1163 g_return_if_fail (GST_IS_BUFFER_POOL (pool));
1164 g_return_if_fail (buffer != NULL);
1166 /* check that the buffer is ours, all buffers returned to the pool have the
1167 * pool member set to NULL and the pool refcount decreased */
1168 if (!g_atomic_pointer_compare_and_exchange (&buffer->pool, pool, NULL))
1171 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
1173 /* reset the buffer when needed */
1174 if (G_LIKELY (pclass->reset_buffer))
1175 pclass->reset_buffer (pool, buffer);
1177 if (G_LIKELY (pclass->release_buffer))
1178 pclass->release_buffer (pool, buffer);
1180 dec_outstanding (pool);
1182 /* decrease the refcount that the buffer had to us */
1183 gst_object_unref (pool);