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GStreamer Base Plugins 0.10 Library Reference Manual | |
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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 */
/* 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);
} 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. |