|  |  |  | GStreamer Base Plugins 0.10 Library Reference Manual |  | 
|---|---|---|---|---|
GObject +----GstObject +----GstElement +----GstBaseSink +----GstBaseAudioSink +----GstAudioSink
This is the most simple base class for audio sinks that only requires subclasses to implement a set of simple functions:
| open() | Open the device. | 
| prepare() | Configure the device with the specified format. | 
| write() | Write samples to the device. | 
| reset() | Unblock writes and flush the device. | 
| delay() | Get the number of samples written but not yet played by the device. | 
| unprepare() | Undo operations done by prepare. | 
| close() | Close the device. | 
All scheduling of samples and timestamps is done in this base class together with GstBaseAudioSink using a default implementation of a GstRingBuffer that uses threads.
Last reviewed on 2006-09-27 (0.10.12)
typedef struct {
  GstBaseAudioSinkClass parent_class;
  /* vtable */
  /* open the device with given specs */
  gboolean (*open)      (GstAudioSink *sink);
  /* prepare resources and state to operate with the given specs */
  gboolean (*prepare)   (GstAudioSink *sink, GstRingBufferSpec *spec);
  /* undo anything that was done in prepare() */
  gboolean (*unprepare) (GstAudioSink *sink);
  /* close the device */
  gboolean (*close)     (GstAudioSink *sink);
  /* write samples to the device */
  guint    (*write)     (GstAudioSink *sink, gpointer data, guint length);
  /* get number of samples queued in the device */
  guint    (*delay)     (GstAudioSink *sink);
  /* reset the audio device, unblock from a write */
  void     (*reset)     (GstAudioSink *sink);
} GstAudioSinkClass;
GstAudioSink class. Override the vmethods to implement functionality.
| GstBaseAudioSinkClass parent_class; | the parent class structure. | 
| open() | Open the device. No configuration needs to be done at this point. This function is also used to check if the device is available. | 
| prepare() | Prepare the device to operate with the specified parameters. | 
| unprepare() | Undo operations done in prepare. | 
| close() | Close the device. | 
| write() | Write data to the device. | 
| delay() | Return how many samples are still in the device. This is used to drive the synchronisation. | 
| reset() | Returns as quickly as possible from a write and flush any pending samples from the device. |