BufferPool

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.BufferPool.new_.

Once a pool is created, it needs to be configured. A call to gst.buffer_pool.BufferPool.getConfig returns the current configuration structure from the pool. With gst.buffer_pool.BufferPool.configSetParams and gst.buffer_pool.BufferPool.configSetAllocator 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.BufferPool.configAddOption. The available options can be retrieved with gst.buffer_pool.BufferPool.getOptions. Some options allow for additional configuration properties to be set.

After the configuration structure has been configured, gst.buffer_pool.BufferPool.setConfig updates the configuration in the pool. This can fail when the configuration structure is not accepted.

After the pool has been configured, it can be activated with gst.buffer_pool.BufferPool.setActive. This will preallocate the configured resources in the pool.

When the pool is active, gst.buffer_pool.BufferPool.acquireBuffer can be used to retrieve a buffer from the pool.

Buffers allocated from a bufferpool will automatically be returned to the pool with gst.buffer_pool.BufferPool.releaseBuffer when their refcount drops to 0.

The bufferpool can be deactivated again with gst.buffer_pool.BufferPool.setActive. All further gst.buffer_pool.BufferPool.acquireBuffer calls will return an error. When all buffers are returned to the pool they will be freed.

class BufferPool : ObjectGst {

this();

static void configAddOption(gst.structure.Structure config, string option);

static bool configGetAllocator(gst.structure.Structure config, gst.allocator.Allocator allocator, gst.allocation_params.AllocationParams params);

static string configGetOption(gst.structure.Structure config, uint index);

static bool configGetParams(gst.structure.Structure config, gst.caps.Caps caps, uint size, uint minBuffers, uint maxBuffers);

static bool configHasOption(gst.structure.Structure config, string option);

static uint configNOptions(gst.structure.Structure config);

static void configSetAllocator(gst.structure.Structure config, gst.allocator.Allocator allocator, gst.allocation_params.AllocationParams params);

static void configSetParams(gst.structure.Structure config, gst.caps.Caps caps, uint size, uint minBuffers, uint maxBuffers);

static bool configValidateParams(gst.structure.Structure config, gst.caps.Caps caps, uint size, uint minBuffers, uint maxBuffers);

gst.types.FlowReturn acquireBuffer(gst.buffer.Buffer buffer, gst.types.BufferPoolAcquireParams params);

gst.structure.Structure getConfig();

string[] getOptions();

bool hasOption(string option);

bool isActive();

void releaseBuffer(gst.buffer.Buffer buffer);

bool setActive(bool active);

bool setConfig(gst.structure.Structure config);

void setFlushing(bool flushing);

}

Constructors

this this(): Creates a new #GstBufferPool instance.

Members

Functions

acquireBuffer gst.types.FlowReturn acquireBuffer(gst.buffer.Buffer buffer, gst.types.BufferPoolAcquireParams params): Acquires a buffer from pool. buffer should point to a memory location that can hold a pointer to the new buffer. When the pool is empty, this function will by default block until a buffer is released into the pool again or when the pool is set to flushing or deactivated.
getConfig gst.structure.Structure getConfig(): Gets a copy of the current configuration of the pool. This configuration can be modified and used for the gst.buffer_pool.BufferPool.setConfig call.
getOptions string[] getOptions(): Gets a null terminated array of string with supported bufferpool options for pool. An option would typically be enabled with gst.buffer_pool.BufferPool.configAddOption.
hasOption bool hasOption(string option): Checks if the bufferpool supports option.
isActive bool isActive(): Checks if pool is active. A pool can be activated with the gst.buffer_pool.BufferPool.setActive call.
releaseBuffer void releaseBuffer(gst.buffer.Buffer buffer): Releases buffer to pool. buffer should have previously been allocated from pool with gst.buffer_pool.BufferPool.acquireBuffer.
setActive bool setActive(bool active): Controls the active state of pool. When the pool is inactive, new calls to gst.buffer_pool.BufferPool.acquireBuffer will return with gst.types.FlowReturn.Flushing.
setConfig bool setConfig(gst.structure.Structure config): Sets the configuration of the pool. If the pool is already configured, and the configuration hasn't changed, this function will return true. If the pool is active, this method will return false and active configuration will remain. Buffers allocated from this pool must be returned or else this function will do nothing and return false.
setFlushing void setFlushing(bool flushing): Enables or disables the flushing state of a pool without freeing or allocating buffers.

Static functions

configAddOption void configAddOption(gst.structure.Structure config, string option): Enables the option in config. This will instruct the bufferpool to enable the specified option on the buffers that it allocates.
configGetAllocator bool configGetAllocator(gst.structure.Structure config, gst.allocator.Allocator allocator, gst.allocation_params.AllocationParams params): Gets the allocator and params from config.
configGetOption string configGetOption(gst.structure.Structure config, uint index): Parses an available config and gets the option at index of the options API array.
configGetParams bool configGetParams(gst.structure.Structure config, gst.caps.Caps caps, uint size, uint minBuffers, uint maxBuffers): Gets the configuration values from config.
configHasOption bool configHasOption(gst.structure.Structure config, string option): Checks if config contains option.
configNOptions uint configNOptions(gst.structure.Structure config): Retrieves the number of values currently stored in the options array of the config structure.
configSetAllocator void configSetAllocator(gst.structure.Structure config, gst.allocator.Allocator allocator, gst.allocation_params.AllocationParams params): Sets the allocator and params on config.
configSetParams void configSetParams(gst.structure.Structure config, gst.caps.Caps caps, uint size, uint minBuffers, uint maxBuffers): Configures config with the given parameters.
configValidateParams bool configValidateParams(gst.structure.Structure config, gst.caps.Caps caps, uint size, uint minBuffers, uint maxBuffers): Validates that changes made to config are still valid in the context of the expected parameters. This function is a helper that can be used to validate changes made by a pool to a config when gst.buffer_pool.BufferPool.setConfig returns false. This expects that caps haven't changed and that min_buffers aren't lower then what we initially expected. This does not check if options or allocator parameters are still valid, won't check if size have changed, since changing the size is valid to adapt padding.

Inherited Members

From ObjectGst

checkUniqueness bool checkUniqueness(gst.object.ObjectGst[] list, string name): Checks to see if there is any object named name in list. This function does not do any locking of any kind. You might want to protect the provided list with the lock of the owner of the list. This function will lock each #GstObject in the list to compare the name, so be careful when passing a list with a locked object.
defaultDeepNotify void defaultDeepNotify(gobject.object.ObjectG object, gst.object.ObjectGst orig, gobject.param_spec.ParamSpec pspec, string[] excludedProps): A default deep_notify signal callback for an object. The user data should contain a pointer to an array of strings that should be excluded from the notify. The default handler will print the new value of the property using g_print.
replace bool replace(gst.object.ObjectGst oldobj, gst.object.ObjectGst newobj): Atomically modifies a pointer to point to a new object. The reference count of oldobj is decreased and the reference count of newobj is increased.
addControlBinding bool addControlBinding(gst.control_binding.ControlBinding binding): Attach the #GstControlBinding to the object. If there already was a #GstControlBinding for this property it will be replaced.
defaultError void defaultError(glib.error.ErrorG error, string debug_): A default error function that uses glib.global.printerr to display the error message and the optional debug string..
getControlBinding gst.control_binding.ControlBinding getControlBinding(string propertyName): Gets the corresponding #GstControlBinding for the property. This should be unreferenced again after use.
getControlRate gst.types.ClockTime getControlRate(): Obtain the control-rate for this object. Audio processing #GstElement objects will use this rate to sub-divide their processing loop and call gst.object.ObjectGst.syncValues in between. The length of the processing segment should be up to control-rate nanoseconds.
getGValueArray bool getGValueArray(string propertyName, gst.types.ClockTime timestamp, gst.types.ClockTime interval, gobject.value.Value[] values): Gets a number of #GValues for the given controlled property starting at the requested time. The array values need to hold enough space for n_values of #GValue.
getName string getName(): Returns a copy of the name of object. Caller should glib.global.gfree the return value after usage. For a nameless object, this returns null, which you can safely glib.global.gfree as well.
getParent gst.object.ObjectGst getParent(): Returns the parent of object. This function increases the refcount of the parent object so you should gst.object.ObjectGst.unref it after usage.
getPathString string getPathString(): Generates a string describing the path of object in the object hierarchy. Only useful (or used) for debugging.
getValue gobject.value.Value getValue(string propertyName, gst.types.ClockTime timestamp): Gets the value for the given controlled property at the requested time.
hasActiveControlBindings bool hasActiveControlBindings(): Check if the object has active controlled properties.
hasAncestor bool hasAncestor(gst.object.ObjectGst ancestor): Check if object has an ancestor ancestor somewhere up in the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
hasAsAncestor bool hasAsAncestor(gst.object.ObjectGst ancestor): Check if object has an ancestor ancestor somewhere up in the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
hasAsParent bool hasAsParent(gst.object.ObjectGst parent): Check if parent is the parent of object. E.g. a #GstElement can check if it owns a given #GstPad.
removeControlBinding bool removeControlBinding(gst.control_binding.ControlBinding binding): Removes the corresponding #GstControlBinding. If it was the last ref of the binding, it will be disposed.
setControlBindingDisabled void setControlBindingDisabled(string propertyName, bool disabled): This function is used to disable the control bindings on a property for some time, i.e. gst.object.ObjectGst.syncValues will do nothing for the property.
setControlBindingsDisabled void setControlBindingsDisabled(bool disabled): This function is used to disable all controlled properties of the object for some time, i.e. gst.object.ObjectGst.syncValues will do nothing.
setControlRate void setControlRate(gst.types.ClockTime controlRate): Change the control-rate for this object. Audio processing #GstElement objects will use this rate to sub-divide their processing loop and call gst.object.ObjectGst.syncValues in between. The length of the processing segment should be up to control-rate nanoseconds.
setName bool setName(string name): Sets the name of object, or gives object a guaranteed unique name (if name is null). This function makes a copy of the provided name, so the caller retains ownership of the name it sent.
setParent bool setParent(gst.object.ObjectGst parent): Sets the parent of object to parent. The object's reference count will be incremented, and any floating reference will be removed (see gst.object.ObjectGst.refSink).
suggestNextSync gst.types.ClockTime suggestNextSync(): Returns a suggestion for timestamps where buffers should be split to get best controller results.
syncValues bool syncValues(gst.types.ClockTime timestamp): Sets the properties of the object, according to the #GstControlSources that (maybe) handle them and for the given timestamp.
unparent void unparent(): Clear the parent of object, removing the associated reference. This function decreases the refcount of object.
connectDeepNotify ulong connectDeepNotify(string detail, T callback, Flag!"After" after): Connect to DeepNotify signal.

gst buffer_pool classes

BufferPool