gstreamer/gst/gstbufferpool.c
Edward Hervey 2e1db58e11 gstvalue: Add _append_and_take_value() public variants
API: gst_value_array_append_and_take_value
API: gst_value_list_append_and_take_value

We were already using this internally, this makes it public for code
which frequently appends values which are expensive to copy (like
structures, arrays, caps, ...).

Avoids copies of the values for users. The passed GValue will also
be 0-memset'ed for re-use.

New users can replace this kind of code:
gst_value_*_append_value(mycontainer, &myvalue);
g_value_unset(&myvalue);

by:

gst_value_*_append_and_take_value(mycontainer, &myvalue);

https://bugzilla.gnome.org/show_bug.cgi?id=701632
2013-06-05 12:58:05 +02:00

1160 lines
32 KiB
C

/* GStreamer
* Copyright (C) 2010 Wim Taymans <wim.taymans@gmail.com>
*
* gstbufferpool.c: GstBufferPool baseclass
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstbufferpool
* @short_description: Pool for buffers
* @see_also: #GstBuffer
*
* a #GstBufferPool is an object that can be used to pre-allocate and recycle
* buffers of the same size and with the same properties.
*
* A #GstBufferPool is created with gst_buffer_pool_new().
*
* After the buffer is created, it needs to be configured.
* gst_buffer_pool_get_config() get the current configuration structure from the
* pool. With gst_buffer_pool_config_set_params() and
* gst_buffer_pool_config_set_allocator() the bufferpool parameters and allocator
* can be configured. Other properties can be configured in the pool depending
* on the pool implementation.
*
* A bufferpool can have extra options that can be enabled with
* gst_buffer_pool_config_add_option(). The available options can be retrieved
* with gst_buffer_pool_get_options(). Some options allow for additional
* configuration properties to be set.
*
* After the configuration structure has been configured,
* gst_buffer_pool_set_config() updates the configuration in the pool. This can
* fail when the configuration structure is not accepted.
*
* After the a pool has been configured, it can be activated with
* gst_buffer_pool_set_active(). This will preallocate the configured resources
* in the pool.
*
* When the pool is active, gst_buffer_pool_acquire_buffer() can be used to
* retrieve a buffer from the pool.
*
* Buffer allocated from a bufferpool will automatically be returned to the pool
* with gst_buffer_pool_release_buffer() when their refcount drops to 0.
*
* The bufferpool can be deactivated again with gst_buffer_pool_set_active().
* All further gst_buffer_pool_acquire_buffer() calls will return an error. When
* all buffers are returned to the pool they will be freed.
*
* Use gst_object_unref() to release the reference to a bufferpool. If the
* refcount of the pool reaches 0, the pool will be freed.
*
* Last reviewed on 2012-03-28 (0.11.3)
*/
#include "gst_private.h"
#include "glib-compat-private.h"
#include <errno.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <sys/types.h>
#include "gstatomicqueue.h"
#include "gstpoll.h"
#include "gstinfo.h"
#include "gstquark.h"
#include "gstvalue.h"
#include "gstbufferpool.h"
GST_DEBUG_CATEGORY_STATIC (gst_buffer_pool_debug);
#define GST_CAT_DEFAULT gst_buffer_pool_debug
#define GST_BUFFER_POOL_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BUFFER_POOL, GstBufferPoolPrivate))
#define GST_BUFFER_POOL_LOCK(pool) (g_rec_mutex_lock(&pool->priv->rec_lock))
#define GST_BUFFER_POOL_UNLOCK(pool) (g_rec_mutex_unlock(&pool->priv->rec_lock))
struct _GstBufferPoolPrivate
{
GstAtomicQueue *queue;
GstPoll *poll;
GRecMutex rec_lock;
gboolean started;
gboolean active;
gint outstanding;
gboolean configured;
GstStructure *config;
guint size;
guint min_buffers;
guint max_buffers;
guint cur_buffers;
GstAllocator *allocator;
GstAllocationParams params;
};
enum
{
/* add more above */
LAST_SIGNAL
};
static void gst_buffer_pool_finalize (GObject * object);
G_DEFINE_TYPE (GstBufferPool, gst_buffer_pool, GST_TYPE_OBJECT);
static gboolean default_start (GstBufferPool * pool);
static gboolean default_stop (GstBufferPool * pool);
static gboolean default_set_config (GstBufferPool * pool,
GstStructure * config);
static GstFlowReturn default_alloc_buffer (GstBufferPool * pool,
GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
static GstFlowReturn default_acquire_buffer (GstBufferPool * pool,
GstBuffer ** buffer, GstBufferPoolAcquireParams * params);
static void default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer);
static void default_free_buffer (GstBufferPool * pool, GstBuffer * buffer);
static void default_release_buffer (GstBufferPool * pool, GstBuffer * buffer);
static void
gst_buffer_pool_class_init (GstBufferPoolClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
g_type_class_add_private (klass, sizeof (GstBufferPoolPrivate));
gobject_class->finalize = gst_buffer_pool_finalize;
klass->start = default_start;
klass->stop = default_stop;
klass->set_config = default_set_config;
klass->acquire_buffer = default_acquire_buffer;
klass->reset_buffer = default_reset_buffer;
klass->alloc_buffer = default_alloc_buffer;
klass->release_buffer = default_release_buffer;
klass->free_buffer = default_free_buffer;
GST_DEBUG_CATEGORY_INIT (gst_buffer_pool_debug, "bufferpool", 0,
"bufferpool debug");
}
static void
gst_buffer_pool_init (GstBufferPool * pool)
{
GstBufferPoolPrivate *priv;
priv = pool->priv = GST_BUFFER_POOL_GET_PRIVATE (pool);
g_rec_mutex_init (&priv->rec_lock);
priv->poll = gst_poll_new_timer ();
priv->queue = gst_atomic_queue_new (10);
pool->flushing = 1;
priv->active = FALSE;
priv->configured = FALSE;
priv->started = FALSE;
priv->config = gst_structure_new_id_empty (GST_QUARK (BUFFER_POOL_CONFIG));
gst_buffer_pool_config_set_params (priv->config, NULL, 0, 0, 0);
priv->allocator = NULL;
gst_allocation_params_init (&priv->params);
gst_buffer_pool_config_set_allocator (priv->config, priv->allocator,
&priv->params);
gst_poll_write_control (priv->poll);
GST_DEBUG_OBJECT (pool, "created");
}
static void
gst_buffer_pool_finalize (GObject * object)
{
GstBufferPool *pool;
GstBufferPoolPrivate *priv;
pool = GST_BUFFER_POOL_CAST (object);
priv = pool->priv;
GST_DEBUG_OBJECT (pool, "finalize");
gst_buffer_pool_set_active (pool, FALSE);
gst_atomic_queue_unref (priv->queue);
gst_poll_free (priv->poll);
gst_structure_free (priv->config);
g_rec_mutex_clear (&priv->rec_lock);
if (priv->allocator)
gst_object_unref (priv->allocator);
G_OBJECT_CLASS (gst_buffer_pool_parent_class)->finalize (object);
}
/**
* gst_buffer_pool_new:
*
* Creates a new #GstBufferPool instance.
*
* Returns: (transfer full): a new #GstBufferPool instance
*/
GstBufferPool *
gst_buffer_pool_new (void)
{
GstBufferPool *result;
result = g_object_newv (GST_TYPE_BUFFER_POOL, 0, NULL);
GST_DEBUG_OBJECT (result, "created new buffer pool");
return result;
}
static GstFlowReturn
default_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstBufferPoolPrivate *priv = pool->priv;
*buffer =
gst_buffer_new_allocate (priv->allocator, priv->size, &priv->params);
return GST_FLOW_OK;
}
static gboolean
mark_meta_pooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
{
GstBufferPool *pool = user_data;
GST_DEBUG_OBJECT (pool, "marking meta %p as POOLED in buffer %p", *meta,
buffer);
GST_META_FLAG_SET (*meta, GST_META_FLAG_POOLED);
GST_META_FLAG_SET (*meta, GST_META_FLAG_LOCKED);
return TRUE;
}
static GstFlowReturn
do_alloc_buffer (GstBufferPool * pool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstBufferPoolPrivate *priv = pool->priv;
GstFlowReturn result;
gint cur_buffers, max_buffers;
GstBufferPoolClass *pclass;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
if (G_UNLIKELY (!pclass->alloc_buffer))
goto no_function;
max_buffers = priv->max_buffers;
/* increment the allocation counter */
cur_buffers = g_atomic_int_add (&priv->cur_buffers, 1);
if (max_buffers && cur_buffers >= max_buffers)
goto max_reached;
result = pclass->alloc_buffer (pool, buffer, params);
if (G_UNLIKELY (result != GST_FLOW_OK))
goto alloc_failed;
gst_buffer_foreach_meta (*buffer, mark_meta_pooled, pool);
GST_LOG_OBJECT (pool, "allocated buffer %d/%d, %p", cur_buffers,
max_buffers, buffer);
return result;
/* ERRORS */
no_function:
{
GST_ERROR_OBJECT (pool, "no alloc function");
return GST_FLOW_NOT_SUPPORTED;
}
max_reached:
{
GST_DEBUG_OBJECT (pool, "max buffers reached");
g_atomic_int_add (&priv->cur_buffers, -1);
return GST_FLOW_EOS;
}
alloc_failed:
{
GST_WARNING_OBJECT (pool, "alloc function failed");
g_atomic_int_add (&priv->cur_buffers, -1);
return result;
}
}
/* the default implementation for preallocating the buffers
* in the pool */
static gboolean
default_start (GstBufferPool * pool)
{
guint i;
GstBufferPoolPrivate *priv = pool->priv;
GstBufferPoolClass *pclass;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
/* we need to prealloc buffers */
for (i = 0; i < priv->min_buffers; i++) {
GstBuffer *buffer;
if (do_alloc_buffer (pool, &buffer, NULL) != GST_FLOW_OK)
goto alloc_failed;
/* release to the queue, we call the vmethod directly, we don't need to do
* the other refcount handling right now. */
if (G_LIKELY (pclass->release_buffer))
pclass->release_buffer (pool, buffer);
}
return TRUE;
/* ERRORS */
alloc_failed:
{
GST_WARNING_OBJECT (pool, "failed to allocate buffer");
return FALSE;
}
}
/* must be called with the lock */
static gboolean
do_start (GstBufferPool * pool)
{
GstBufferPoolPrivate *priv = pool->priv;
if (!priv->started) {
GstBufferPoolClass *pclass;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
GST_LOG_OBJECT (pool, "starting");
/* start the pool, subclasses should allocate buffers and put them
* in the queue */
if (G_LIKELY (pclass->start)) {
if (!pclass->start (pool))
return FALSE;
}
priv->started = TRUE;
}
return TRUE;
}
static void
default_free_buffer (GstBufferPool * pool, GstBuffer * buffer)
{
gst_buffer_unref (buffer);
}
/* must be called with the lock */
static gboolean
default_stop (GstBufferPool * pool)
{
GstBufferPoolPrivate *priv = pool->priv;
GstBuffer *buffer;
GstBufferPoolClass *pclass;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
/* clear the pool */
while ((buffer = gst_atomic_queue_pop (priv->queue))) {
GST_LOG_OBJECT (pool, "freeing %p", buffer);
gst_poll_read_control (priv->poll);
if (G_LIKELY (pclass->free_buffer))
pclass->free_buffer (pool, buffer);
}
priv->cur_buffers = 0;
return TRUE;
}
/* must be called with the lock */
static gboolean
do_stop (GstBufferPool * pool)
{
GstBufferPoolPrivate *priv = pool->priv;
if (priv->started) {
GstBufferPoolClass *pclass;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
GST_LOG_OBJECT (pool, "stopping");
if (G_LIKELY (pclass->stop)) {
if (!pclass->stop (pool))
return FALSE;
}
priv->started = FALSE;
}
return TRUE;
}
/**
* gst_buffer_pool_set_active:
* @pool: a #GstBufferPool
* @active: the new active state
*
* Control the active state of @pool. When the pool is inactive, new calls to
* gst_buffer_pool_acquire_buffer() will return with #GST_FLOW_FLUSHING.
*
* Activating the bufferpool will preallocate all resources in the pool based on
* the configuration of the pool.
*
* Deactivating will free the resources again when there are no outstanding
* buffers. When there are outstanding buffers, they will be freed as soon as
* they are all returned to the pool.
*
* Returns: %FALSE when the pool was not configured or when preallocation of the
* buffers failed.
*/
gboolean
gst_buffer_pool_set_active (GstBufferPool * pool, gboolean active)
{
gboolean res = TRUE;
GstBufferPoolPrivate *priv;
g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
GST_LOG_OBJECT (pool, "active %d", active);
priv = pool->priv;
GST_BUFFER_POOL_LOCK (pool);
/* just return if we are already in the right state */
if (priv->active == active)
goto was_ok;
/* we need to be configured */
if (!priv->configured)
goto not_configured;
if (active) {
if (!do_start (pool))
goto start_failed;
/* unset the flushing state now */
gst_poll_read_control (priv->poll);
g_atomic_int_set (&pool->flushing, 0);
} else {
gint outstanding;
/* set to flushing first */
g_atomic_int_set (&pool->flushing, 1);
gst_poll_write_control (priv->poll);
/* when all buffers are in the pool, free them. Else they will be
* freed when they are released */
outstanding = g_atomic_int_get (&priv->outstanding);
GST_LOG_OBJECT (pool, "outstanding buffers %d", outstanding);
if (outstanding == 0) {
if (!do_stop (pool))
goto stop_failed;
}
}
priv->active = active;
GST_BUFFER_POOL_UNLOCK (pool);
return res;
was_ok:
{
GST_DEBUG_OBJECT (pool, "pool was in the right state");
GST_BUFFER_POOL_UNLOCK (pool);
return TRUE;
}
not_configured:
{
GST_ERROR_OBJECT (pool, "pool was not configured");
GST_BUFFER_POOL_UNLOCK (pool);
return FALSE;
}
start_failed:
{
GST_ERROR_OBJECT (pool, "start failed");
GST_BUFFER_POOL_UNLOCK (pool);
return FALSE;
}
stop_failed:
{
GST_WARNING_OBJECT (pool, "stop failed");
GST_BUFFER_POOL_UNLOCK (pool);
return FALSE;
}
}
/**
* gst_buffer_pool_is_active:
* @pool: a #GstBufferPool
*
* Check if @pool is active. A pool can be activated with the
* gst_buffer_pool_set_active() call.
*
* Returns: %TRUE when the pool is active.
*/
gboolean
gst_buffer_pool_is_active (GstBufferPool * pool)
{
gboolean res;
GST_BUFFER_POOL_LOCK (pool);
res = pool->priv->active;
GST_BUFFER_POOL_UNLOCK (pool);
return res;
}
static gboolean
default_set_config (GstBufferPool * pool, GstStructure * config)
{
GstBufferPoolPrivate *priv = pool->priv;
GstCaps *caps;
guint size, min_buffers, max_buffers;
GstAllocator *allocator;
GstAllocationParams params;
/* parse the config and keep around */
if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers,
&max_buffers))
goto wrong_config;
if (!gst_buffer_pool_config_get_allocator (config, &allocator, &params))
goto wrong_config;
GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config);
priv->size = size;
priv->min_buffers = min_buffers;
priv->max_buffers = max_buffers;
priv->cur_buffers = 0;
if (priv->allocator)
gst_object_unref (priv->allocator);
if ((priv->allocator = allocator))
gst_object_ref (allocator);
priv->params = params;
return TRUE;
wrong_config:
{
GST_WARNING_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config);
return FALSE;
}
}
/**
* gst_buffer_pool_set_config:
* @pool: a #GstBufferPool
* @config: (transfer full): a #GstStructure
*
* Set the configuration of the pool. The pool must be inactive and all buffers
* allocated form this pool must be returned or else this function will do
* nothing and return FALSE.
*
* @config is a #GstStructure that contains the configuration parameters for
* the pool. A default and mandatory set of parameters can be configured with
* gst_buffer_pool_config_set_params(), gst_buffer_pool_config_set_allocator()
* and gst_buffer_pool_config_add_option().
*
* If the parameters in @config can not be set exactly, this function returns
* FALSE and will try to update as much state as possible. The new state can
* then be retrieved and refined with gst_buffer_pool_get_config().
*
* This function takes ownership of @config.
*
* Returns: TRUE when the configuration could be set.
*/
gboolean
gst_buffer_pool_set_config (GstBufferPool * pool, GstStructure * config)
{
gboolean result;
GstBufferPoolClass *pclass;
GstBufferPoolPrivate *priv;
g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
g_return_val_if_fail (config != NULL, FALSE);
priv = pool->priv;
GST_BUFFER_POOL_LOCK (pool);
/* can't change the settings when active */
if (priv->active)
goto was_active;
/* we can't change when outstanding buffers */
if (g_atomic_int_get (&priv->outstanding) != 0)
goto have_outstanding;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
/* set the new config */
if (G_LIKELY (pclass->set_config))
result = pclass->set_config (pool, config);
else
result = FALSE;
if (result) {
if (priv->config)
gst_structure_free (priv->config);
priv->config = config;
/* now we are configured */
priv->configured = TRUE;
} else {
gst_structure_free (config);
}
GST_BUFFER_POOL_UNLOCK (pool);
return result;
/* ERRORS */
was_active:
{
gst_structure_free (config);
GST_WARNING_OBJECT (pool, "can't change config, we are active");
GST_BUFFER_POOL_UNLOCK (pool);
return FALSE;
}
have_outstanding:
{
gst_structure_free (config);
GST_WARNING_OBJECT (pool, "can't change config, have outstanding buffers");
GST_BUFFER_POOL_UNLOCK (pool);
return FALSE;
}
}
/**
* gst_buffer_pool_get_config:
* @pool: a #GstBufferPool
*
* Get a copy of the current configuration of the pool. This configuration
* can either be modified and used for the gst_buffer_pool_set_config() call
* or it must be freed after usage.
*
* Returns: (transfer full): a copy of the current configuration of @pool. use
* gst_structure_free() after usage or gst_buffer_pool_set_config().
*/
GstStructure *
gst_buffer_pool_get_config (GstBufferPool * pool)
{
GstStructure *result;
g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
GST_BUFFER_POOL_LOCK (pool);
result = gst_structure_copy (pool->priv->config);
GST_BUFFER_POOL_UNLOCK (pool);
return result;
}
static const gchar *empty_option[] = { NULL };
/**
* gst_buffer_pool_get_options:
* @pool: a #GstBufferPool
*
* Get a NULL terminated array of string with supported bufferpool options for
* @pool. An option would typically be enabled with
* gst_buffer_pool_config_add_option().
*
* Returns: (array zero-terminated=1) (transfer none): a NULL terminated array of strings.
*/
const gchar **
gst_buffer_pool_get_options (GstBufferPool * pool)
{
GstBufferPoolClass *pclass;
const gchar **result;
g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), NULL);
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
if (G_LIKELY (pclass->get_options)) {
if ((result = pclass->get_options (pool)) == NULL)
goto invalid_result;
} else
result = empty_option;
return result;
/* ERROR */
invalid_result:
{
g_warning ("bufferpool subclass returned NULL options");
return empty_option;
}
}
/**
* gst_buffer_pool_has_option:
* @pool: a #GstBufferPool
* @option: an option
*
* Check if the bufferpool supports @option.
*
* Returns: a NULL terminated array of strings.
*/
gboolean
gst_buffer_pool_has_option (GstBufferPool * pool, const gchar * option)
{
guint i;
const gchar **options;
g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), FALSE);
g_return_val_if_fail (option != NULL, FALSE);
options = gst_buffer_pool_get_options (pool);
for (i = 0; options[i]; i++) {
if (g_str_equal (options[i], option))
return TRUE;
}
return FALSE;
}
/**
* gst_buffer_pool_config_set_params:
* @config: a #GstBufferPool configuration
* @caps: caps for the buffers
* @size: the size of each buffer, not including prefix and padding
* @min_buffers: the minimum amount of buffers to allocate.
* @max_buffers: the maximum amount of buffers to allocate or 0 for unlimited.
*
* Configure @config with the given parameters.
*/
void
gst_buffer_pool_config_set_params (GstStructure * config, GstCaps * caps,
guint size, guint min_buffers, guint max_buffers)
{
g_return_if_fail (config != NULL);
g_return_if_fail (max_buffers == 0 || min_buffers <= max_buffers);
g_return_if_fail (caps == NULL || gst_caps_is_fixed (caps));
gst_structure_id_set (config,
GST_QUARK (CAPS), GST_TYPE_CAPS, caps,
GST_QUARK (SIZE), G_TYPE_UINT, size,
GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
}
/**
* gst_buffer_pool_config_set_allocator:
* @config: a #GstBufferPool configuration
* @allocator: a #GstAllocator
* @params: #GstAllocationParams
*
* Set the @allocator and @params on @config.
*
* One of @allocator and @params can be NULL, but not both. When @allocator
* is NULL, the default allocator of the pool will use the values in @param
* to perform its allocation. When @param is NULL, the pool will use the
* provided allocator with its default #GstAllocationParams.
*
* A call to gst_buffer_pool_set_config() can update the allocator and params
* with the values that it is able to do. Some pools are, for example, not able
* to operate with different allocators or cannot allocate with the values
* specified in @params. Use gst_buffer_pool_get_config() to get the currently
* used values.
*/
void
gst_buffer_pool_config_set_allocator (GstStructure * config,
GstAllocator * allocator, const GstAllocationParams * params)
{
g_return_if_fail (config != NULL);
g_return_if_fail (allocator != NULL || params != NULL);
gst_structure_id_set (config,
GST_QUARK (ALLOCATOR), GST_TYPE_ALLOCATOR, allocator,
GST_QUARK (PARAMS), GST_TYPE_ALLOCATION_PARAMS, params, NULL);
}
/**
* gst_buffer_pool_config_add_option:
* @config: a #GstBufferPool configuration
* @option: an option to add
*
* Enabled the option in @config. This will instruct the @bufferpool to enable
* the specified option on the buffers that it allocates.
*
* The supported options by @pool can be retrieved with gst_buffer_pool_get_options().
*/
void
gst_buffer_pool_config_add_option (GstStructure * config, const gchar * option)
{
const GValue *value;
GValue option_value = { 0, };
guint i, len;
g_return_if_fail (config != NULL);
value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
if (value) {
len = gst_value_array_get_size (value);
for (i = 0; i < len; ++i) {
const GValue *nth_val = gst_value_array_get_value (value, i);
if (g_str_equal (option, g_value_get_string (nth_val)))
return;
}
} else {
GValue new_array_val = { 0, };
g_value_init (&new_array_val, GST_TYPE_ARRAY);
gst_structure_id_take_value (config, GST_QUARK (OPTIONS), &new_array_val);
value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
}
g_value_init (&option_value, G_TYPE_STRING);
g_value_set_string (&option_value, option);
gst_value_array_append_and_take_value ((GValue *) value, &option_value);
}
/**
* gst_buffer_pool_config_n_options:
* @config: a #GstBufferPool configuration
*
* Retrieve the number of values currently stored in the
* options array of the @config structure.
*
* Returns: the options array size as a #guint.
*/
guint
gst_buffer_pool_config_n_options (GstStructure * config)
{
const GValue *value;
guint size = 0;
g_return_val_if_fail (config != NULL, 0);
value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
if (value) {
size = gst_value_array_get_size (value);
}
return size;
}
/**
* gst_buffer_pool_config_get_option:
* @config: a #GstBufferPool configuration
* @index: position in the option array to read
*
* Parse an available @config and get the option
* at @index of the options API array.
*
* Returns: a #gchar of the option at @index.
*/
const gchar *
gst_buffer_pool_config_get_option (GstStructure * config, guint index)
{
const GValue *value;
const gchar *ret = NULL;
g_return_val_if_fail (config != NULL, 0);
value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
if (value) {
const GValue *option_value;
option_value = gst_value_array_get_value (value, index);
if (option_value)
ret = g_value_get_string (option_value);
}
return ret;
}
/**
* gst_buffer_pool_config_has_option:
* @config: a #GstBufferPool configuration
* @option: an option
*
* Check if @config contains @option
*
* Returns: TRUE if the options array contains @option.
*/
gboolean
gst_buffer_pool_config_has_option (GstStructure * config, const gchar * option)
{
const GValue *value;
guint i, len;
g_return_val_if_fail (config != NULL, 0);
value = gst_structure_id_get_value (config, GST_QUARK (OPTIONS));
if (value) {
len = gst_value_array_get_size (value);
for (i = 0; i < len; ++i) {
const GValue *nth_val = gst_value_array_get_value (value, i);
if (g_str_equal (option, g_value_get_string (nth_val)))
return TRUE;
}
}
return FALSE;
}
/**
* gst_buffer_pool_config_get_params:
* @config: (transfer none): a #GstBufferPool configuration
* @caps: (out) (transfer none) (allow-none): the caps of buffers
* @size: (out) (allow-none): the size of each buffer, not including prefix and padding
* @min_buffers: (out) (allow-none): the minimum amount of buffers to allocate.
* @max_buffers: (out) (allow-none): the maximum amount of buffers to allocate or 0 for unlimited.
*
* Get the configuration values from @config.
*
* Returns: %TRUE if all parameters could be fetched.
*/
gboolean
gst_buffer_pool_config_get_params (GstStructure * config, GstCaps ** caps,
guint * size, guint * min_buffers, guint * max_buffers)
{
g_return_val_if_fail (config != NULL, FALSE);
if (caps) {
*caps = g_value_get_boxed (gst_structure_id_get_value (config,
GST_QUARK (CAPS)));
}
return gst_structure_id_get (config,
GST_QUARK (SIZE), G_TYPE_UINT, size,
GST_QUARK (MIN_BUFFERS), G_TYPE_UINT, min_buffers,
GST_QUARK (MAX_BUFFERS), G_TYPE_UINT, max_buffers, NULL);
}
/**
* gst_buffer_pool_config_get_allocator:
* @config: (transfer none): a #GstBufferPool configuration
* @allocator: (transfer none): a #GstAllocator
* @params: #GstAllocationParams
*
* Get the allocator and params from @config.
*/
gboolean
gst_buffer_pool_config_get_allocator (GstStructure * config,
GstAllocator ** allocator, GstAllocationParams * params)
{
g_return_val_if_fail (config != NULL, FALSE);
if (allocator)
*allocator = g_value_get_object (gst_structure_id_get_value (config,
GST_QUARK (ALLOCATOR)));
if (params) {
GstAllocationParams *p;
p = g_value_get_boxed (gst_structure_id_get_value (config,
GST_QUARK (PARAMS)));
if (p) {
*params = *p;
} else {
gst_allocation_params_init (params);
}
}
return TRUE;
}
static GstFlowReturn
default_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstFlowReturn result;
GstBufferPoolPrivate *priv = pool->priv;
while (TRUE) {
if (G_UNLIKELY (GST_BUFFER_POOL_IS_FLUSHING (pool)))
goto flushing;
/* try to get a buffer from the queue */
*buffer = gst_atomic_queue_pop (priv->queue);
if (G_LIKELY (*buffer)) {
gst_poll_read_control (priv->poll);
result = GST_FLOW_OK;
GST_LOG_OBJECT (pool, "acquired buffer %p", *buffer);
break;
}
/* no buffer, try to allocate some more */
GST_LOG_OBJECT (pool, "no buffer, trying to allocate");
result = do_alloc_buffer (pool, buffer, NULL);
if (G_LIKELY (result == GST_FLOW_OK))
/* we have a buffer, return it */
break;
if (G_UNLIKELY (result != GST_FLOW_EOS))
/* something went wrong, return error */
break;
/* check if we need to wait */
if (params && (params->flags & GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT)) {
GST_LOG_OBJECT (pool, "no more buffers");
break;
}
/* now wait */
GST_LOG_OBJECT (pool, "waiting for free buffers");
gst_poll_wait (priv->poll, GST_CLOCK_TIME_NONE);
}
return result;
/* ERRORS */
flushing:
{
GST_DEBUG_OBJECT (pool, "we are flushing");
return GST_FLOW_FLUSHING;
}
}
static inline void
dec_outstanding (GstBufferPool * pool)
{
if (g_atomic_int_dec_and_test (&pool->priv->outstanding)) {
/* all buffers are returned to the pool, see if we need to free them */
if (GST_BUFFER_POOL_IS_FLUSHING (pool)) {
/* take the lock so that set_active is not run concurrently */
GST_BUFFER_POOL_LOCK (pool);
/* recheck the flushing state in the lock, the pool could have been
* set to active again */
if (GST_BUFFER_POOL_IS_FLUSHING (pool))
do_stop (pool);
GST_BUFFER_POOL_UNLOCK (pool);
}
}
}
static gboolean
remove_meta_unpooled (GstBuffer * buffer, GstMeta ** meta, gpointer user_data)
{
if (!GST_META_FLAG_IS_SET (*meta, GST_META_FLAG_POOLED)) {
GST_META_FLAG_UNSET (*meta, GST_META_FLAG_LOCKED);
*meta = NULL;
}
return TRUE;
}
static void
default_reset_buffer (GstBufferPool * pool, GstBuffer * buffer)
{
GST_BUFFER_FLAGS (buffer) = 0;
GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
/* remove all metadata without the POOLED flag */
gst_buffer_foreach_meta (buffer, remove_meta_unpooled, pool);
}
/**
* gst_buffer_pool_acquire_buffer:
* @pool: a #GstBufferPool
* @buffer: (out): a location for a #GstBuffer
* @params: (transfer none) (allow-none) parameters.
*
* Acquire a buffer from @pool. @buffer should point to a memory location that
* can hold a pointer to the new buffer.
*
* @params can be NULL or contain optional parameters to influence the allocation.
*
* Returns: a #GstFlowReturn such as GST_FLOW_FLUSHING when the pool is
* inactive.
*/
GstFlowReturn
gst_buffer_pool_acquire_buffer (GstBufferPool * pool, GstBuffer ** buffer,
GstBufferPoolAcquireParams * params)
{
GstBufferPoolClass *pclass;
GstFlowReturn result;
g_return_val_if_fail (GST_IS_BUFFER_POOL (pool), GST_FLOW_ERROR);
g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
/* assume we'll have one more outstanding buffer we need to do that so
* that concurrent set_active doesn't clear the buffers */
g_atomic_int_inc (&pool->priv->outstanding);
if (G_LIKELY (pclass->acquire_buffer))
result = pclass->acquire_buffer (pool, buffer, params);
else
result = GST_FLOW_NOT_SUPPORTED;
if (G_LIKELY (result == GST_FLOW_OK)) {
/* all buffers from the pool point to the pool and have the refcount of the
* pool incremented */
(*buffer)->pool = gst_object_ref (pool);
} else {
dec_outstanding (pool);
}
return result;
}
static void
default_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
{
/* keep it around in our queue */
GST_LOG_OBJECT (pool, "released buffer %p", buffer);
gst_atomic_queue_push (pool->priv->queue, buffer);
gst_poll_write_control (pool->priv->poll);
}
/**
* gst_buffer_pool_release_buffer:
* @pool: a #GstBufferPool
* @buffer: (transfer full): a #GstBuffer
*
* Release @buffer to @pool. @buffer should have previously been allocated from
* @pool with gst_buffer_pool_acquire_buffer().
*
* This function is usually called automatically when the last ref on @buffer
* disappears.
*/
void
gst_buffer_pool_release_buffer (GstBufferPool * pool, GstBuffer * buffer)
{
GstBufferPoolClass *pclass;
g_return_if_fail (GST_IS_BUFFER_POOL (pool));
g_return_if_fail (buffer != NULL);
/* check that the buffer is ours, all buffers returned to the pool have the
* pool member set to NULL and the pool refcount decreased */
if (!g_atomic_pointer_compare_and_exchange (&buffer->pool, pool, NULL))
return;
pclass = GST_BUFFER_POOL_GET_CLASS (pool);
/* reset the buffer when needed */
if (G_LIKELY (pclass->reset_buffer))
pclass->reset_buffer (pool, buffer);
if (G_LIKELY (pclass->release_buffer))
pclass->release_buffer (pool, buffer);
dec_outstanding (pool);
/* decrease the refcount that the buffer had to us */
gst_object_unref (pool);
}