Playback Channel

Playback Channel — audio stream for playback

Stability Level

Stable, unless otherwise indicated

Synopsis

#include <channel-playback.h>

struct              SpicePlaybackChannel;
struct              SpicePlaybackChannelClass;
void                spice_playback_channel_set_delay    (SpicePlaybackChannel *channel,
                                                         guint32 delay_ms);

Object Hierarchy

  GObject
   +----SpiceChannel
         +----SpicePlaybackChannel

Properties

  "min-latency"              guint                 : Read / Write
  "mute"                     gboolean              : Read / Write
  "nchannels"                guint                 : Read / Write
  "volume"                   gpointer              : Read / Write

Signals

  "playback-data"                                  : Run First
  "playback-get-delay"                             : Run First
  "playback-start"                                 : Run First
  "playback-stop"                                  : Run First

Description

SpicePlaybackChannel class handles an audio playback stream. The audio data is received via "playback-data" signal, and is controlled by the guest with "playback-stop" and "playback-start" signal events.

Note: You may be interested to let the SpiceAudio class play and record audio channels for your application.

Details

struct SpicePlaybackChannel

struct SpicePlaybackChannel;

The SpicePlaybackChannel struct is opaque and should not be accessed directly.

struct SpicePlaybackChannelClass

struct SpicePlaybackChannelClass {
    SpiceChannelClass parent_class;

    /* signals */
    void (*playback_start)(SpicePlaybackChannel *channel,
                           gint format, gint channels, gint freq);
    void (*playback_data)(SpicePlaybackChannel *channel, gpointer *data, gint size);
    void (*playback_stop)(SpicePlaybackChannel *channel);
};

Class structure for SpicePlaybackChannel.

SpiceChannelClass `parent_class`;	Parent class.
`playback_start` ()	Signal class handler for the "playback-start" signal.
`playback_data` ()	Signal class handler for the "playback-data" signal.
`playback_stop` ()	Signal class handler for the "playback-stop" signal.

spice_playback_channel_set_delay ()

void                spice_playback_channel_set_delay    (SpicePlaybackChannel *channel,
                                                         guint32 delay_ms);

Property Details

The `"min-latency"` property

  "min-latency"              guint                 : Read / Write

Playback min buffer size (ms).

Default value: 200

The `"mute"` property

  "mute"                     gboolean              : Read / Write

Mute.

Default value: FALSE

The `"nchannels"` property

  "nchannels"                guint                 : Read / Write

Number of Channels.

Allowed values: <= 255

Default value: 2

The `"volume"` property

  "volume"                   gpointer              : Read / Write

Playback volume.

Signal Details

The `"playback-data"` signal

void                user_function                      (SpicePlaybackChannel *channel,
                                                        gpointer              data,
                                                        gint                  data_size,
                                                        gpointer              user_data)      : Run First

Provide audio data to be played.

`channel` :	the SpicePlaybackChannel that emitted the signal
`data` :	pointer to audio data
`data_size` :	size in byte of `data`
`user_data` :	user data set when the signal handler was connected.

The `"playback-get-delay"` signal

void                user_function                      (SpicePlaybackChannel *channel,
                                                        gpointer              user_data)      : Run First

Notify when the current playback delay is requested

`channel` :	the SpicePlaybackChannel that emitted the signal
`user_data` :	user data set when the signal handler was connected.

The `"playback-start"` signal

void                user_function                      (SpicePlaybackChannel *channel,
                                                        gint                  format,
                                                        gint                  channels,
                                                        gint                  rate,
                                                        gpointer              user_data)      : Run First

Notify when the playback should start, and provide audio format characteristics.

`channel` :	the SpicePlaybackChannel that emitted the signal
`format` :	a SPICE_AUDIO_FMT
`channels` :	number of channels
`rate` :	audio rate
`latency` :	minimum playback latency in ms
`user_data` :	user data set when the signal handler was connected.

The `"playback-stop"` signal

void                user_function                      (SpicePlaybackChannel *channel,
                                                        gpointer              user_data)      : Run First

Notify when the playback should stop.

`channel` :	the SpicePlaybackChannel that emitted the signal
`user_data` :	user data set when the signal handler was connected.

			Spice-GTK Reference Manual
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