/**
* 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);
}
/**
* 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;
}
/**
* 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;
}
/**
* 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_set_flushing:
* @pool: a #GstBufferPool
* @flushing: whether to start or stop flushing
*
* Enable or disable the flushing state of a @pool without freeing or
* allocating buffers.
*
* Since: 1.4
*/
void
gst_buffer_pool_set_flushing (GstBufferPool * pool, gboolean flushing)
{
GstBufferPoolPrivate *priv;
g_return_if_fail (GST_IS_BUFFER_POOL (pool));
GST_LOG_OBJECT (pool, "flushing %d", flushing);
priv = pool->priv;
GST_BUFFER_POOL_LOCK (pool);
if (!priv->active) {
GST_WARNING_OBJECT (pool, "can't change flushing state of inactive pool");
goto done;
}
do_set_flushing (pool, flushing);
done:
GST_BUFFER_POOL_UNLOCK (pool);
}
/**
* gst_buffer_pool_set_active:
* @pool: a #GstBufferPool
* @active: the new active state
*
* Control the active state of @pool. When the pool is active, 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_set_config:
* @pool: a #GstBufferPool
* @config: (transfer full): a #GstStructure
*
* Set the configuration of the pool. If the pool is already configured, and
* the configuration haven't change, this function will return %TRUE. If the
* pool is active, this method will return %FALSE and active configuration
* will remain. 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);
/* nothing to do if config is unchanged */
if (priv->configured && gst_structure_is_equal (config, priv->config))
goto config_unchanged;
/* 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;
/* save the config regardless of the result so user can read back the
* modified config and evaluate if the changes are acceptable */
if (priv->config)
gst_structure_free (priv->config);
priv->config = config;
if (result) {
/* now we are configured */
priv->configured = TRUE;
}
GST_BUFFER_POOL_UNLOCK (pool);
return result;
config_unchanged:
{
gst_structure_free (config);
GST_BUFFER_POOL_UNLOCK (pool);
return TRUE;
}
/* ERRORS */
was_active:
{
gst_structure_free (config);
GST_INFO_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;
}
}
