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
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 * After the buffer is created, it needs to be configured.
33 * gst_buffer_pool_get_config() get the current configuration structure from the
34 * pool. With gst_buffer_pool_config_set_params() and
35 * gst_buffer_pool_config_set_allocator() the bufferpool parameters and allocator
36 * can be configured. Other properties can be configured in the pool depending
37 * 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 * Buffer allocated from a bufferpool will automatically be returned to the pool
56 * 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 2012-03-28 (0.11.3)
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;
106 GstStructure *config;
111 GstAllocator *allocator;
112 GstAllocationParams params;
121 static void gst_buffer_pool_finalize (GObject * object);
123 G_DEFINE_TYPE (GstBufferPool, gst_buffer_pool, GST_TYPE_OBJECT);
125 static gboolean default_start (GstBufferPool * pool);
126 static gboolean default_stop (GstBufferPool * pool);
127 static gboolean default_set_config (GstBufferPool * pool,
128 GstStructure * config);
129 static GstFlowReturn default_alloc_buffer (GstBufferPool * pool,
130 GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
131 static GstFlowReturn default_acquire_buffer (GstBufferPool * pool,
132 GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
133 static void default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer,
134 GstBufferPoolAcquireParams * params);
135 static void default_free_buffer (GstBufferPool * pool, GstBuffer * buffer);
136 static void default_release_buffer (GstBufferPool * pool, GstBuffer * buffer);
139 gst_buffer_pool_class_init (GstBufferPoolClass * klass)
141 GObjectClass *gobject_class = (GObjectClass *) klass;
143 g_type_class_add_private (klass, sizeof (GstBufferPoolPrivate));
145 gobject_class->finalize = gst_buffer_pool_finalize;
147 klass->start = default_start;
148 klass->stop = default_stop;
149 klass->set_config = default_set_config;
150 klass->acquire_buffer = default_acquire_buffer;
151 klass->reset_buffer = default_reset_buffer;
152 klass->alloc_buffer = default_alloc_buffer;
153 klass->release_buffer = default_release_buffer;
154 klass->free_buffer = default_free_buffer;
156 GST_DEBUG_CATEGORY_INIT (gst_buffer_pool_debug, "bufferpool", 0,
161 gst_buffer_pool_init (GstBufferPool * pool)
163 GstBufferPoolPrivate *priv;
165 priv = pool->priv = GST_BUFFER_POOL_GET_PRIVATE (pool);
167 g_rec_mutex_init (&priv->rec_lock);
169 priv->poll = gst_poll_new_timer ();
170 priv->queue = gst_atomic_queue_new (10);
172 priv->active = FALSE;
173 priv->configured = FALSE;
174 priv->started = FALSE;
175 priv->config = gst_structure_new_id_empty (GST_QUARK (BUFFER_POOL_CONFIG));
176 gst_buffer_pool_config_set_params (priv->config, NULL, 0, 0, 0);
177 priv->allocator = NULL;
178 gst_allocation_params_init (&priv->params);
179 gst_buffer_pool_config_set_allocator (priv->config, priv->allocator,
181 gst_poll_write_control (priv->poll);
183 GST_DEBUG_OBJECT (pool, "created");
187 gst_buffer_pool_finalize (GObject * object)
190 GstBufferPoolPrivate *priv;
192 pool = GST_BUFFER_POOL_CAST (object);
195 GST_DEBUG_OBJECT (pool, "finalize");
197 gst_buffer_pool_set_active (pool, FALSE);
198 gst_atomic_queue_unref (priv->queue);
199 gst_poll_free (priv->poll);
200 gst_structure_free (priv->config);
201 g_rec_mutex_clear (&priv->rec_lock);
203 gst_allocator_unref (priv->allocator);
205 G_OBJECT_CLASS (gst_buffer_pool_parent_class)->finalize (object);
209 * gst_buffer_pool_new:
211 * Creates a new #GstBufferPool instance.
213 * Returns: (transfer full): a new #GstBufferPool instance
216 gst_buffer_pool_new (void)
218 GstBufferPool *result;
220 result = g_object_newv (GST_TYPE_BUFFER_POOL, 0, NULL);
221 GST_DEBUG_OBJECT (result, "created new buffer pool");
227 default_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
228 GstBufferPoolAcquireParams * params)
230 GstBufferPoolPrivate *priv = pool->priv;
233 gst_buffer_new_allocate (priv->allocator, priv->size, &priv->params);
239 mark_meta_pooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
241 GstBufferPool *pool = user_data;
243 GST_DEBUG_OBJECT (pool, "marking meta %p as POOLED in buffer %p", *meta,
245 GST_META_FLAG_SET (*meta, GST_META_FLAG_POOLED);
246 GST_META_FLAG_SET (*meta, GST_META_FLAG_LOCKED);
251 /* the default implementation for preallocating the buffers
254 default_start (GstBufferPool * pool)
257 GstBufferPoolPrivate *priv = pool->priv;
258 GstBufferPoolClass *pclass;
260 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
262 /* no alloc function, error */
263 if (G_UNLIKELY (pclass->alloc_buffer == NULL))
266 /* we need to prealloc buffers */
267 for (i = 0; i < priv->min_buffers; i++) {
270 if (pclass->alloc_buffer (pool, &buffer, NULL) != GST_FLOW_OK)
273 gst_buffer_foreach_meta (buffer, mark_meta_pooled, pool);
274 GST_LOG_OBJECT (pool, "prealloced buffer %d: %p", i, buffer);
275 /* release to the queue, we call the vmethod directly, we don't need to do
276 * the other refcount handling right now. */
277 if (G_LIKELY (pclass->release_buffer))
278 pclass->release_buffer (pool, buffer);
285 GST_WARNING_OBJECT (pool, "no alloc function");
290 GST_WARNING_OBJECT (pool, "alloc function failed");
295 /* must be called with the lock */
297 do_start (GstBufferPool * pool)
299 if (!pool->priv->started) {
300 GstBufferPoolClass *pclass;
302 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
304 GST_LOG_OBJECT (pool, "starting");
305 /* start the pool, subclasses should allocate buffers and put them
307 if (G_LIKELY (pclass->start)) {
308 if (!pclass->start (pool))
311 pool->priv->started = TRUE;
318 default_free_buffer (GstBufferPool * pool, GstBuffer * buffer)
320 gst_buffer_unref (buffer);
323 /* must be called with the lock */
325 default_stop (GstBufferPool * pool)
328 GstBufferPoolClass *pclass;
330 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
333 while ((buffer = gst_atomic_queue_pop (pool->priv->queue))) {
334 GST_LOG_OBJECT (pool, "freeing %p", buffer);
335 gst_poll_read_control (pool->priv->poll);
337 if (G_LIKELY (pclass->free_buffer))
338 pclass->free_buffer (pool, buffer);
343 /* must be called with the lock */
345 do_stop (GstBufferPool * pool)
347 if (pool->priv->started) {
348 GstBufferPoolClass *pclass;
350 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
352 GST_LOG_OBJECT (pool, "stopping");
353 if (G_LIKELY (pclass->stop)) {
354 if (!pclass->stop (pool))
357 pool->priv->started = FALSE;
363 * gst_buffer_pool_set_active:
364 * @pool: a #GstBufferPool
365 * @active: the new active state
367 * Control the active state of @pool. When the pool is active, new calls to
368 * gst_buffer_pool_acquire_buffer() will return with GST_FLOW_FLUSHING.
370 * Activating the bufferpool will preallocate all resources in the pool based on
371 * the configuration of the pool.
373 * Deactivating will free the resources again when there are no outstanding
374 * buffers. When there are outstanding buffers, they will be freed as soon as
375 * they are all returned to the pool.
377 * Returns: %FALSE when the pool was not configured or when preallocation of the
381 gst_buffer_pool_set_active (GstBufferPool * pool, gboolean active)
385 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
387 GST_LOG_OBJECT (pool, "active %d", active);
389 GST_BUFFER_POOL_LOCK (pool);
390 /* just return if we are already in the right state */
391 if (pool->priv->active == active)
394 /* we need to be configured */
395 if (!pool->priv->configured)
399 if (!do_start (pool))
402 /* unset the flushing state now */
403 gst_poll_read_control (pool->priv->poll);
404 g_atomic_int_set (&pool->flushing, 0);
408 /* set to flushing first */
409 g_atomic_int_set (&pool->flushing, 1);
410 gst_poll_write_control (pool->priv->poll);
412 /* when all buffers are in the pool, free them. Else they will be
413 * freed when they are released */
414 outstanding = g_atomic_int_get (&pool->priv->outstanding);
415 GST_LOG_OBJECT (pool, "outstanding buffers %d", outstanding);
416 if (outstanding == 0) {
421 pool->priv->active = active;
422 GST_BUFFER_POOL_UNLOCK (pool);
428 GST_DEBUG_OBJECT (pool, "pool was in the right state");
429 GST_BUFFER_POOL_UNLOCK (pool);
434 GST_ERROR_OBJECT (pool, "pool was not configured");
435 GST_BUFFER_POOL_UNLOCK (pool);
440 GST_ERROR_OBJECT (pool, "start failed");
441 GST_BUFFER_POOL_UNLOCK (pool);
446 GST_WARNING_OBJECT (pool, "stop failed");
447 GST_BUFFER_POOL_UNLOCK (pool);
453 * gst_buffer_pool_is_active:
454 * @pool: a #GstBufferPool
456 * Check if @pool is active. A pool can be activated with the
457 * gst_buffer_pool_set_active() call.
459 * Returns: %TRUE when the pool is active.
462 gst_buffer_pool_is_active (GstBufferPool * pool)
466 GST_BUFFER_POOL_LOCK (pool);
467 res = pool->priv->active;
468 GST_BUFFER_POOL_UNLOCK (pool);
474 default_set_config (GstBufferPool * pool, GstStructure * config)
476 GstBufferPoolPrivate *priv = pool->priv;
478 guint size, min_buffers, max_buffers;
479 GstAllocator *allocator;
480 GstAllocationParams params;
482 /* parse the config and keep around */
483 if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers,
487 if (!gst_buffer_pool_config_get_allocator (config, &allocator, ¶ms))
490 GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config);
493 priv->min_buffers = min_buffers;
494 priv->max_buffers = max_buffers;
497 gst_allocator_unref (priv->allocator);
498 if ((priv->allocator = allocator))
499 gst_allocator_ref (allocator);
500 priv->params = params;
506 GST_WARNING_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
512 * gst_buffer_pool_set_config:
513 * @pool: a #GstBufferPool
514 * @config: (transfer full): a #GstStructure
516 * Set the configuration of the pool. The pool must be inactive and all buffers
517 * allocated form this pool must be returned or else this function will do
518 * nothing and return FALSE.
520 * @config is a #GstStructure that contains the configuration parameters for
521 * the pool. A default and mandatory set of parameters can be configured with
522 * gst_buffer_pool_config_set(). This function takes ownership of @config.
524 * Returns: TRUE when the configuration could be set.
527 gst_buffer_pool_set_config (GstBufferPool * pool, GstStructure * config)
530 GstBufferPoolClass *pclass;
532 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
533 g_return_val_if_fail (config != NULL, FALSE);
535 GST_BUFFER_POOL_LOCK (pool);
536 /* can't change the settings when active */
537 if (pool->priv->active)
540 /* we can't change when outstanding buffers */
541 if (g_atomic_int_get (&pool->priv->outstanding) != 0)
542 goto have_outstanding;
544 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
546 /* set the new config */
547 if (G_LIKELY (pclass->set_config))
548 result = pclass->set_config (pool, config);
553 if (pool->priv->config)
554 gst_structure_free (pool->priv->config);
555 pool->priv->config = config;
557 /* now we are configured */
558 pool->priv->configured = TRUE;
560 gst_structure_free (config);
562 GST_BUFFER_POOL_UNLOCK (pool);
569 gst_structure_free (config);
570 GST_WARNING_OBJECT (pool, "can't change config, we are active");
571 GST_BUFFER_POOL_UNLOCK (pool);
576 gst_structure_free (config);
577 GST_WARNING_OBJECT (pool, "can't change config, have outstanding buffers");
578 GST_BUFFER_POOL_UNLOCK (pool);
584 * gst_buffer_pool_get_config:
585 * @pool: a #GstBufferPool
587 * Get a copy of the current configuration of the pool. This configuration
588 * can either be modified and used for the gst_buffer_pool_set_config() call
589 * or it must be freed after usage.
591 * Returns: (transfer full): a copy of the current configuration of @pool. use
592 * gst_structure_free() after usage or gst_buffer_pool_set_config().
595 gst_buffer_pool_get_config (GstBufferPool * pool)
597 GstStructure *result;
599 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
601 GST_BUFFER_POOL_UNLOCK (pool);
602 result = gst_structure_copy (pool->priv->config);
603 GST_BUFFER_POOL_UNLOCK (pool);
608 static const gchar *empty_option[] = { NULL };
611 * gst_buffer_pool_get_options:
612 * @pool: a #GstBufferPool
614 * Get a NULL terminated array of string with supported bufferpool options for
615 * @pool. An option would typically be enabled with
616 * gst_buffer_pool_config_add_option().
618 * Returns: (array zero-terminated=1) (transfer none): a NULL terminated array of strings.
621 gst_buffer_pool_get_options (GstBufferPool * pool)
623 GstBufferPoolClass *pclass;
624 const gchar **result;
626 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
628 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
630 if (G_LIKELY (pclass->get_options)) {
631 if ((result = pclass->get_options (pool)) == NULL)
634 result = empty_option;
641 g_warning ("bufferpool subclass returned NULL options");
647 * gst_buffer_pool_has_option:
648 * @pool: a #GstBufferPool
651 * Check if the bufferpool supports @option.
653 * Returns: a NULL terminated array of strings.
656 gst_buffer_pool_has_option (GstBufferPool * pool, const gchar * option)
659 const gchar **options;
661 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
662 g_return_val_if_fail (option != NULL, FALSE);
664 options = gst_buffer_pool_get_options (pool);
666 for (i = 0; options[i]; i++) {
667 if (g_str_equal (options[i], option))
674 * gst_buffer_pool_config_set_params:
675 * @config: a #GstBufferPool configuration
676 * @caps: caps for the buffers
677 * @size: the size of each buffer, not including prefix and padding
678 * @min_buffers: the minimum amount of buffers to allocate.
679 * @max_buffers: the maximum amount of buffers to allocate or 0 for unlimited.
681 * Configure @config with the given parameters.
684 gst_buffer_pool_config_set_params (GstStructure * config, GstCaps * caps,
685 guint size, guint min_buffers, guint max_buffers)
687 g_return_if_fail (config != NULL);
688 g_return_if_fail (max_buffers == 0 || min_buffers <= max_buffers);
690 gst_structure_id_set (config,
691 GST_QUARK (CAPS), GST_TYPE_CAPS, caps,
692 GST_QUARK (SIZE), G_TYPE_UINT, size,
693 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
694 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
698 * gst_buffer_pool_config_set_allocator:
699 * @config: a #GstBufferPool configuration
700 * @allocator: a #GstAllocator
701 * @params: #GstAllocationParams
703 * Set the @allocator and @params on @config.
705 * One of @allocator and @params can be NULL, but not both. When @allocator
706 * is NULL, the default allocator of the pool will use the values in @param
707 * to perform its allocation. When @param is NULL, the pool will use the
708 * provided allocator with its default #GstAllocationParams.
710 * A call to gst_buffer_pool_set_config() can update the allocator and params
711 * with the values that it is able to do. Some pools are, for example, not able
712 * to operate with different allocators or cannot allocate with the values
713 * specified in @params. Use gst_buffer_pool_get_config() to get the currently
717 gst_buffer_pool_config_set_allocator (GstStructure * config,
718 GstAllocator * allocator, const GstAllocationParams * params)
720 g_return_if_fail (config != NULL);
721 g_return_if_fail (allocator != NULL || params != NULL);
723 gst_structure_id_set (config,
724 GST_QUARK (ALLOCATOR), GST_TYPE_ALLOCATOR, allocator,
725 GST_QUARK (PARAMS), GST_TYPE_ALLOCATION_PARAMS, params, NULL);
729 * gst_buffer_pool_config_add_option:
730 * @config: a #GstBufferPool configuration
731 * @option: an option to add
733 * Enabled the option in @config. This will instruct the @bufferpool to enable
734 * the specified option on the buffers that it allocates.
736 * The supported options by @pool can be retrieved with gst_buffer_pool_get_options().
739 gst_buffer_pool_config_add_option (GstStructure * config, const gchar * option)
742 GValue option_value = { 0, };
745 g_return_if_fail (config != NULL);
747 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
749 len = gst_value_array_get_size (value);
750 for (i = 0; i < len; ++i) {
751 const GValue *nth_val = gst_value_array_get_value (value, i);
753 if (g_str_equal (option, g_value_get_string (nth_val)))
757 GValue new_array_val = { 0, };
759 g_value_init (&new_array_val, GST_TYPE_ARRAY);
760 gst_structure_id_take_value (config, GST_QUARK (OPTIONS), &new_array_val);
761 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
763 g_value_init (&option_value, G_TYPE_STRING);
764 g_value_set_string (&option_value, option);
765 gst_value_array_append_value ((GValue *) value, &option_value);
766 g_value_unset (&option_value);
770 * gst_buffer_pool_config_n_options:
771 * @config: a #GstBufferPool configuration
773 * Retrieve the number of values currently stored in the
774 * options array of the @config structure.
776 * Returns: the options array size as a #guint.
779 gst_buffer_pool_config_n_options (GstStructure * config)
784 g_return_val_if_fail (config != NULL, 0);
786 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
788 size = gst_value_array_get_size (value);
794 * gst_buffer_pool_config_get_option:
795 * @config: a #GstBufferPool configuration
796 * @index: position in the option array to read
798 * Parse an available @config and get the option
799 * at @index of the options API array.
801 * Returns: a #gchar of the option at @index.
804 gst_buffer_pool_config_get_option (GstStructure * config, guint index)
807 const gchar *ret = NULL;
809 g_return_val_if_fail (config != NULL, 0);
811 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
813 const GValue *option_value;
815 option_value = gst_value_array_get_value (value, index);
817 ret = g_value_get_string (option_value);
823 * gst_buffer_pool_config_has_option:
824 * @config: a #GstBufferPool configuration
827 * Check if @config contains @option
829 * Returns: TRUE if the options array contains @option.
832 gst_buffer_pool_config_has_option (GstStructure * config, const gchar * option)
837 g_return_val_if_fail (config != NULL, 0);
839 value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
841 len = gst_value_array_get_size (value);
842 for (i = 0; i < len; ++i) {
843 const GValue *nth_val = gst_value_array_get_value (value, i);
845 if (g_str_equal (option, g_value_get_string (nth_val)))
853 * gst_buffer_pool_config_get_params:
854 * @config: (transfer none): a #GstBufferPool configuration
855 * @caps: (out) (transfer none) (allow-none): the caps of buffers
856 * @size: (out) (allow-none): the size of each buffer, not including prefix and padding
857 * @min_buffers: (out) (allow-none): the minimum amount of buffers to allocate.
858 * @max_buffers: (out) (allow-none): the maximum amount of buffers to allocate or 0 for unlimited.
860 * Get the configuration values from @config.
862 * Returns: %TRUE if all parameters could be fetched.
865 gst_buffer_pool_config_get_params (GstStructure * config, GstCaps ** caps,
866 guint * size, guint * min_buffers, guint * max_buffers)
868 g_return_val_if_fail (config != NULL, FALSE);
871 *caps = g_value_get_boxed (gst_structure_id_get_value (config,
874 return gst_structure_id_get (config,
875 GST_QUARK (SIZE), G_TYPE_UINT, size,
876 GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
877 GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
881 * gst_buffer_pool_config_get_allocator:
882 * @config: (transfer none): a #GstBufferPool configuration
883 * @allocator: (transfer none): a #GstAllocator
884 * @params: #GstAllocationParams
886 * Get the allocator and params from @config.
889 gst_buffer_pool_config_get_allocator (GstStructure * config,
890 GstAllocator ** allocator, GstAllocationParams * params)
892 g_return_val_if_fail (config != NULL, FALSE);
895 *allocator = g_value_get_boxed (gst_structure_id_get_value (config,
896 GST_QUARK (ALLOCATOR)));
898 GstAllocationParams *p;
900 p = g_value_get_boxed (gst_structure_id_get_value (config,
901 GST_QUARK (PARAMS)));
905 gst_allocation_params_init (params);
912 default_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
913 GstBufferPoolAcquireParams * params)
915 GstFlowReturn result;
916 GstBufferPoolClass *pclass;
917 GstBufferPoolPrivate *priv = pool->priv;
919 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
922 if (G_UNLIKELY (GST_BUFFER_POOL_IS_FLUSHING (pool)))
925 /* try to get a buffer from the queue */
926 *buffer = gst_atomic_queue_pop (pool->priv->queue);
927 if (G_LIKELY (*buffer)) {
928 gst_poll_read_control (pool->priv->poll);
929 result = GST_FLOW_OK;
930 GST_LOG_OBJECT (pool, "acquired buffer %p", *buffer);
935 if (priv->max_buffers == 0) {
936 /* no max_buffers, we allocate some more */
937 if (G_LIKELY (pclass->alloc_buffer)) {
938 result = pclass->alloc_buffer (pool, buffer, params);
939 if (result == GST_FLOW_OK && *buffer)
940 gst_buffer_foreach_meta (*buffer, mark_meta_pooled, pool);
942 result = GST_FLOW_ERROR;
944 result = GST_FLOW_NOT_SUPPORTED;
945 GST_LOG_OBJECT (pool, "alloc buffer %p", *buffer);
949 /* check if we need to wait */
950 if (params && (params->flags & GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT)) {
951 GST_LOG_OBJECT (pool, "no more buffers");
952 result = GST_FLOW_EOS;
957 GST_LOG_OBJECT (pool, "waiting for free buffers");
958 gst_poll_wait (pool->priv->poll, GST_CLOCK_TIME_NONE);
966 GST_DEBUG_OBJECT (pool, "we are flushing");
967 return GST_FLOW_FLUSHING;
972 dec_outstanding (GstBufferPool * pool)
974 if (g_atomic_int_dec_and_test (&pool->priv->outstanding)) {
975 /* all buffers are returned to the pool, see if we need to free them */
976 if (GST_BUFFER_POOL_IS_FLUSHING (pool)) {
977 /* take the lock so that set_active is not run concurrently */
978 GST_BUFFER_POOL_LOCK (pool);
979 /* recheck the flushing state in the lock, the pool could have been
980 * set to active again */
981 if (GST_BUFFER_POOL_IS_FLUSHING (pool))
984 GST_BUFFER_POOL_UNLOCK (pool);
990 remove_meta_unpooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
992 if (!GST_META_FLAG_IS_SET (*meta, GST_META_FLAG_POOLED)) {
993 GST_META_FLAG_UNSET (*meta, GST_META_FLAG_LOCKED);
1000 default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer,
1001 GstBufferPoolAcquireParams * params)
1003 GST_BUFFER_FLAGS (buffer) = 0;
1005 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
1006 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
1007 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
1008 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
1009 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
1011 /* remove all metadata without the POOLED flag */
1012 gst_buffer_foreach_meta (buffer, remove_meta_unpooled, pool);
1016 * gst_buffer_pool_acquire_buffer:
1017 * @pool: a #GstBufferPool
1018 * @buffer: (out): a location for a #GstBuffer
1019 * @params: (transfer none) (allow-none) parameters.
1021 * Acquire a buffer from @pool. @buffer should point to a memory location that
1022 * can hold a pointer to the new buffer.
1024 * @params can be NULL or contain optional parameters to influence the allocation.
1026 * Returns: a #GstFlowReturn such as GST_FLOW_FLUSHING when the pool is
1030 gst_buffer_pool_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
1031 GstBufferPoolAcquireParams * params)
1033 GstBufferPoolClass *pclass;
1034 GstFlowReturn result;
1036 g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), GST_FLOW_ERROR);
1037 g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
1039 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
1041 /* assume we'll have one more outstanding buffer we need to do that so
1042 * that concurrent set_active doesn't clear the buffers */
1043 g_atomic_int_inc (&pool->priv->outstanding);
1045 if (G_LIKELY (pclass->acquire_buffer))
1046 result = pclass->acquire_buffer (pool, buffer, params);
1048 result = GST_FLOW_NOT_SUPPORTED;
1050 if (G_LIKELY (result == GST_FLOW_OK)) {
1051 /* all buffers from the pool point to the pool and have the refcount of the
1052 * pool incremented */
1053 (*buffer)->pool = gst_object_ref (pool);
1054 /* now reset the buffer when needed */
1055 if (G_LIKELY (pclass->reset_buffer))
1056 pclass->reset_buffer (pool, *buffer, params);
1058 dec_outstanding (pool);
1065 default_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
1067 /* keep it around in our queue */
1068 GST_LOG_OBJECT (pool, "released buffer %p", buffer);
1069 gst_atomic_queue_push (pool->priv->queue, buffer);
1070 gst_poll_write_control (pool->priv->poll);
1074 * gst_buffer_pool_release_buffer:
1075 * @pool: a #GstBufferPool
1076 * @buffer: (transfer full): a #GstBuffer
1078 * Release @buffer to @pool. @buffer should have previously been allocated from
1079 * @pool with gst_buffer_pool_acquire_buffer().
1081 * This function is usually called automatically when the last ref on @buffer
1085 gst_buffer_pool_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
1087 GstBufferPoolClass *pclass;
1089 g_return_if_fail (GST_IS_BUFFER_POOL (pool));
1090 g_return_if_fail (buffer != NULL);
1092 /* check that the buffer is ours, all buffers returned to the pool have the
1093 * pool member set to NULL and the pool refcount decreased */
1094 if (!g_atomic_pointer_compare_and_exchange (&buffer->pool, pool, NULL))
1097 pclass = GST_BUFFER_POOL_GET_CLASS (pool);
1099 if (G_LIKELY (pclass->release_buffer))
1100 pclass->release_buffer (pool, buffer);
1102 dec_outstanding (pool);
1104 /* decrease the refcount that the buffer had to us */
1105 gst_object_unref (pool);