gstaudiosink

gstaudiosink — Simple base class for audio sinks

Synopsis

#include <gst/audio/gstaudiosink.h>

struct              GstAudioSink;
struct              GstAudioSinkClass;

Object Hierarchy

  GObject
   +----GstObject
         +----GstElement
               +----GstBaseSink
                     +----GstBaseAudioSink
                           +----GstAudioSink

Description

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)

Details

struct GstAudioSink

struct GstAudioSink;

Opaque GstAudioSink.

struct GstAudioSinkClass

struct GstAudioSinkClass {
  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 */
  /* FIXME 0.11: change return value to gint, as most implementation use that
   * already anyway */
  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);
};

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.

			GStreamer Base Plugins 0.10 Library Reference Manual
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