Audio output

Collaboration diagram for Audio output:

Modules
	Audio output modules
	Audio formats
	Audio meter API
	Audio output volume

Files
file	vlc_aout.h
	Audio output modules interface.

Macros
#define	AOUT_MAX_ADVANCE_TIME   (AOUT_MAX_PREPARE_TIME + VLC_TICK_FROM_SEC(1))
#define	AOUT_MAX_PREPARE_TIME   VLC_TICK_FROM_SEC(2)
#define	AOUT_MIN_PREPARE_TIME   AOUT_MAX_PTS_ADVANCE
#define	AOUT_MAX_PTS_ADVANCE   VLC_TICK_FROM_MS(40)
	Maximum advance of actual audio playback time to coded PTS, above which downsampling will be performed.
#define	AOUT_MAX_PTS_DELAY   VLC_TICK_FROM_MS(60)
	Maximum delay of actual audio playback time from coded PTS, above which upsampling will be performed.
#define	AOUT_MAX_RESAMPLING   10
#define	AOUT_FMTS_IDENTICAL(p_first, p_second)
#define	AOUT_FMTS_SIMILAR(p_first, p_second)
#define	AOUT_FMT_LINEAR(p_format)    (aout_BitsPerSample((p_format)->i_format) != 0)
#define	VLC_CODEC_SPDIFL   VLC_FOURCC('s','p','d','i')
#define	VLC_CODEC_SPDIFB   VLC_FOURCC('s','p','d','b')
#define	AOUT_FMT_SPDIF(p_format)
#define	AOUT_FMT_HDMI(p_format)
#define	AOUT_VAR_CHAN_UNSET   0 /* must be zero */
#define	AOUT_VAR_CHAN_STEREO   1
#define	AOUT_VAR_CHAN_RSTEREO   2
#define	AOUT_VAR_CHAN_LEFT   3
#define	AOUT_VAR_CHAN_RIGHT   4
#define	AOUT_VAR_CHAN_DOLBYS   5
#define	AOUT_VAR_CHAN_MONO   7
#define	AOUT_MIX_MODE_UNSET   0
#define	AOUT_MIX_MODE_STEREO   1
#define	AOUT_MIX_MODE_BINAURAL   2
#define	AOUT_MIX_MODE_4_0   3
#define	AOUT_MIX_MODE_5_1   4
#define	AOUT_MIX_MODE_7_1   5
#define	AOUT_SPDIF_SIZE   6144
#define	A52_FRAME_NB   1536
#define	AOUT_VOLUME_DEFAULT   256
#define	AOUT_VOLUME_MAX   512

Functions
float	aout_VolumeGet (audio_output_t *)
	Gets the volume of the audio output stream (independent of mute).
int	aout_VolumeSet (audio_output_t *, float)
	Sets the volume of the audio output stream.
int	aout_VolumeUpdate (audio_output_t *aout, int value, float *volp)
	Adjusts the volume.
int	aout_MuteGet (audio_output_t *)
	Gets the audio output stream mute flag.
int	aout_MuteSet (audio_output_t *, bool)
	Sets the audio output stream mute flag.
char *	aout_DeviceGet (audio_output_t *)
	Gets the currently selected device.
int	aout_DeviceSet (audio_output_t *aout, const char *id)
	Selects an audio output device.
int	aout_DevicesList (audio_output_t *aout, char ***ids, char ***names)
	Enumerates possible audio output devices.

Detailed Description

Macro Definition Documentation

A52_FRAME_NB

#define A52_FRAME_NB   1536

AOUT_FMT_HDMI

#define AOUT_FMT_HDMI

(

p_format

)

Value:

    ( (p_format)->i_format == VLC_CODEC_EAC3        \
    ||(p_format)->i_format == VLC_CODEC_DTSHD       \
    ||(p_format)->i_format == VLC_CODEC_TRUEHD      \
    ||(p_format)->i_format == VLC_CODEC_MLP         \
    )

AOUT_FMT_LINEAR

#define AOUT_FMT_LINEAR

(

p_format

)

(aout_BitsPerSample((p_format)->i_format) != 0)

AOUT_FMT_SPDIF

#define AOUT_FMT_SPDIF

(

p_format

)

Value:

    ( ((p_format)->i_format == VLC_CODEC_SPDIFL)       \
       || ((p_format)->i_format == VLC_CODEC_SPDIFB)   \
       || ((p_format)->i_format == VLC_CODEC_A52)      \
       || ((p_format)->i_format == VLC_CODEC_DTS) )

AOUT_FMTS_IDENTICAL

#define AOUT_FMTS_IDENTICAL	(		p_first,
			p_second
	)

Value:

    (                          \
    ((p_first)->i_format == (p_second)->i_format)                           \
      && AOUT_FMTS_SIMILAR(p_first, p_second) )

AOUT_FMTS_SIMILAR

#define AOUT_FMTS_SIMILAR	(		p_first,
			p_second
	)

Value:

    (                            \
    ((p_first)->i_rate == (p_second)->i_rate)                               \
      && ((p_first)->channel_type == (p_second)->channel_type)            \
      && ((p_first)->i_physical_channels == (p_second)->i_physical_channels)\
      && ((p_first)->i_chan_mode == (p_second)->i_chan_mode) )

AOUT_MAX_ADVANCE_TIME

#define AOUT_MAX_ADVANCE_TIME   (AOUT_MAX_PREPARE_TIME + VLC_TICK_FROM_SEC(1))

AOUT_MAX_PREPARE_TIME

#define AOUT_MAX_PREPARE_TIME   VLC_TICK_FROM_SEC(2)

AOUT_MAX_PTS_ADVANCE

#define AOUT_MAX_PTS_ADVANCE   VLC_TICK_FROM_MS(40)

Maximum advance of actual audio playback time to coded PTS, above which downsampling will be performed.

AOUT_MAX_PTS_DELAY

#define AOUT_MAX_PTS_DELAY   VLC_TICK_FROM_MS(60)

Maximum delay of actual audio playback time from coded PTS, above which upsampling will be performed.

AOUT_MAX_RESAMPLING

#define AOUT_MAX_RESAMPLING   10

AOUT_MIN_PREPARE_TIME

#define AOUT_MIN_PREPARE_TIME   AOUT_MAX_PTS_ADVANCE

AOUT_MIX_MODE_4_0

#define AOUT_MIX_MODE_4_0   3

AOUT_MIX_MODE_5_1

#define AOUT_MIX_MODE_5_1   4

AOUT_MIX_MODE_7_1

#define AOUT_MIX_MODE_7_1   5

AOUT_MIX_MODE_BINAURAL

#define AOUT_MIX_MODE_BINAURAL   2

AOUT_MIX_MODE_STEREO

#define AOUT_MIX_MODE_STEREO   1

AOUT_MIX_MODE_UNSET

#define AOUT_MIX_MODE_UNSET   0

AOUT_SPDIF_SIZE

#define AOUT_SPDIF_SIZE   6144

AOUT_VAR_CHAN_DOLBYS

#define AOUT_VAR_CHAN_DOLBYS   5

AOUT_VAR_CHAN_LEFT

#define AOUT_VAR_CHAN_LEFT   3

AOUT_VAR_CHAN_MONO

#define AOUT_VAR_CHAN_MONO   7

AOUT_VAR_CHAN_RIGHT

#define AOUT_VAR_CHAN_RIGHT   4

AOUT_VAR_CHAN_RSTEREO

#define AOUT_VAR_CHAN_RSTEREO   2

AOUT_VAR_CHAN_STEREO

#define AOUT_VAR_CHAN_STEREO   1

AOUT_VAR_CHAN_UNSET

#define AOUT_VAR_CHAN_UNSET   0 /* must be zero */

AOUT_VOLUME_DEFAULT

#define AOUT_VOLUME_DEFAULT   256

AOUT_VOLUME_MAX

#define AOUT_VOLUME_MAX   512

VLC_CODEC_SPDIFB

#define VLC_CODEC_SPDIFB   VLC_FOURCC('s','p','d','b')

VLC_CODEC_SPDIFL

#define VLC_CODEC_SPDIFL   VLC_FOURCC('s','p','d','i')

Function Documentation

aout_DeviceGet()

char * aout_DeviceGet

(

audio_output_t *

aout

)

Gets the currently selected device.

Returns

the selected device ID (caller must free() it) NULL if no device is selected or in case of error.

References var_GetNonEmptyString().

aout_DeviceSet()

int aout_DeviceSet	(	audio_output_t *	aout,
		const char *	id
	)

Selects an audio output device.

Parameters

aout	the audio output to set the device for
id	device ID to select, or NULL for the default device

Returns

zero on success, non-zero on error.

References aout_owner(), device_select, aout_owner_t::lock, vlc_mutex_lock(), and vlc_mutex_unlock().

aout_DevicesList()

int aout_DevicesList	(	audio_output_t *	aout,
		char ***	ids,
		char ***	names
	)

Enumerates possible audio output devices.

The function will heap-allocate two tables of heap-allocated strings; the caller is responsible for freeing all strings and both tables.

Parameters

aout	the audio output to get the device list from
ids	pointer to a table of device identifiers [OUT]
names	pointer to a table of device human-readable descriptions [OUT]

Returns

the number of devices, or negative on error.

Note

In case of error, *ids and *names are undefined.

References aout_owner(), aout_owner_t::count, aout_owner_t::dev, aout_dev::id, aout_owner_t::list, aout_owner_t::lock, aout_dev::name, strdup(), unlikely, vlc_alloc(), vlc_list_foreach, vlc_mutex_lock(), and vlc_mutex_unlock().

aout_MuteGet()

int aout_MuteGet

(

audio_output_t *

aout

)

Gets the audio output stream mute flag.

Returns

0 if not muted, 1 if muted, -1 if undefined.

References var_InheritBool().

Referenced by vlc_player_aout_IsMuted().

aout_MuteSet()

int aout_MuteSet	(	audio_output_t *	aout,
		bool	mute
	)

Sets the audio output stream mute flag.

Returns

0 on success, -1 on failure.

References aout_owner(), aout_owner_t::lock, mute_set, vlc_mutex_lock(), and vlc_mutex_unlock().

Referenced by vlc_player_aout_Mute().

aout_VolumeGet()

float aout_VolumeGet

(

audio_output_t *

aout

)

Gets the volume of the audio output stream (independent of mute).

Returns

Current audio volume (0. = silent, 1. = nominal), or a strictly negative value if undefined.

References var_GetFloat().

Referenced by aout_VolumeUpdate(), vlc_player_aout_GetVolume(), and vlc_strfplayer().

aout_VolumeSet()

int aout_VolumeSet	(	audio_output_t *	aout,
		float	vol
	)

Sets the volume of the audio output stream.

Note

The mute status is not changed.

Returns

0 on success, -1 on failure.

References aout_owner(), aout_owner_t::lock, vlc_mutex_lock(), vlc_mutex_unlock(), and volume_set.

Referenced by aout_VolumeUpdate(), and vlc_player_aout_SetVolume().

aout_VolumeUpdate()

int aout_VolumeUpdate	(	audio_output_t *	aout,
		int	value,
		float *	volp
	)

Adjusts the volume.

Parameters

aout	the audio output to update the volume for
value	how much to increase (> 0) or decrease (< 0) the volume
volp	if non-NULL, will contain contain the resulting volume

References AOUT_VOLUME_DEFAULT, AOUT_VOLUME_MAX, aout_VolumeGet(), aout_VolumeSet(), clampf(), and var_InheritFloat().

Referenced by vlc_player_aout_IncrementVolume().