Audio format definitions
[Audio]

Definitions for several variations of audio data. More...

Data Structures
struct	gavl_audio_format_t
	Audio Format. More...
Defines
#define	GAVL_MAX_CHANNELS   128
	Maximum number of audio channels.
Enumerations
enum	gavl_sample_format_t {   GAVL_SAMPLE_NONE = 0,   GAVL_SAMPLE_U8 = 1,   GAVL_SAMPLE_S8 = 2,   GAVL_SAMPLE_U16 = 3,   GAVL_SAMPLE_S16 = 4,   GAVL_SAMPLE_S32 = 5,   GAVL_SAMPLE_FLOAT = 6,   GAVL_SAMPLE_DOUBLE = 7 }
	Format of one audio sample. More...
enum	gavl_interleave_mode_t {   GAVL_INTERLEAVE_NONE = 0,   GAVL_INTERLEAVE_2 = 1,   GAVL_INTERLEAVE_ALL = 2 }
enum	gavl_channel_id_t {   GAVL_CHID_NONE = 0,   GAVL_CHID_FRONT_CENTER,   GAVL_CHID_FRONT_LEFT,   GAVL_CHID_FRONT_RIGHT,   GAVL_CHID_FRONT_CENTER_LEFT,   GAVL_CHID_FRONT_CENTER_RIGHT,   GAVL_CHID_REAR_LEFT,   GAVL_CHID_REAR_RIGHT,   GAVL_CHID_REAR_CENTER,   GAVL_CHID_SIDE_LEFT,   GAVL_CHID_SIDE_RIGHT,   GAVL_CHID_LFE,   GAVL_CHID_AUX }
	Audio channel setup. More...
Functions
GAVL_PUBLIC const char *	gavl_sample_format_to_string (gavl_sample_format_t format)
	Convert a gavl_sample_format_t to a human readable string.
GAVL_PUBLIC gavl_sample_format_t	gavl_string_to_sample_format (const char *str)
	Convert a string to a sample format.
GAVL_PUBLIC int	gavl_num_sample_formats ()
	Get total number of supported sample formats.
GAVL_PUBLIC gavl_sample_format_t	gavl_get_sample_format (int index)
	Get the sample format from index.
GAVL_PUBLIC const char *	gavl_channel_id_to_string (gavl_channel_id_t id)
	Convert a gavl_channel_id_t to a human readable string.
GAVL_PUBLIC const char *	gavl_interleave_mode_to_string (gavl_interleave_mode_t mode)
	Convert a gavl_interleave_mode_t to a human readable string.
GAVL_PUBLIC void	gavl_audio_format_dump (const gavl_audio_format_t *format)
	Dump an audio format to stderr.
GAVL_PUBLIC int	gavl_channel_index (const gavl_audio_format_t *format, gavl_channel_id_t id)
	Get the index of a particular channel for a given format.
GAVL_PUBLIC int	gavl_front_channels (const gavl_audio_format_t *format)
	Get number of front channels for a given format.
GAVL_PUBLIC int	gavl_rear_channels (const gavl_audio_format_t *format)
	Get number of rear channels for a given format.
GAVL_PUBLIC int	gavl_side_channels (const gavl_audio_format_t *format)
	Get number of side channels for a given format.
GAVL_PUBLIC int	gavl_aux_channels (const gavl_audio_format_t *format)
	Get number of aux channels for a given format.
GAVL_PUBLIC int	gavl_lfe_channels (const gavl_audio_format_t *format)
	Get number of LFE channels for a given format.
GAVL_PUBLIC void	gavl_audio_format_copy (gavl_audio_format_t *dst, const gavl_audio_format_t *src)
	Copy one audio format to another.
GAVL_PUBLIC int	gavl_audio_formats_equal (const gavl_audio_format_t *format_1, const gavl_audio_format_t *format_2)
	Compare 2 audio formats.
GAVL_PUBLIC void	gavl_set_channel_setup (gavl_audio_format_t *format)
	Set the default channel setup and indices.
GAVL_PUBLIC int	gavl_bytes_per_sample (gavl_sample_format_t format)
	Get the number of bytes per sample for a given sample format.

---

Detailed Description

Definitions for several variations of audio data.

---

Define Documentation

#define GAVL_MAX_CHANNELS   128

Maximum number of audio channels.

---

Enumeration Type Documentation

enum gavl_sample_format_t

Format of one audio sample.

For multibyte numbers, the byte order is always machine native endian

Enumerator:

GAVL_SAMPLE_NONE	Undefined
GAVL_SAMPLE_U8	Unsigned 8 bit
GAVL_SAMPLE_S8	Signed 8 bit
GAVL_SAMPLE_U16	Unsigned 16 bit
GAVL_SAMPLE_S16	Signed 16 bit
GAVL_SAMPLE_S32	Signed 32 bit
GAVL_SAMPLE_FLOAT	Floating point (-1.0 .. 1.0)
GAVL_SAMPLE_DOUBLE	Double (-1.0 .. 1.0)

enum gavl_interleave_mode_t

Interleave mode of the channels

Enumerator:

GAVL_INTERLEAVE_NONE	No interleaving, all channels separate
GAVL_INTERLEAVE_2	Interleaved pairs of channels
GAVL_INTERLEAVE_ALL	Everything interleaved

enum gavl_channel_id_t

Audio channel setup.

These are the channel locations used to identify the channel order for an audio format

Enumerator:

GAVL_CHID_NONE	Undefined
GAVL_CHID_FRONT_CENTER	For mono
GAVL_CHID_FRONT_LEFT	Front left
GAVL_CHID_FRONT_RIGHT	Front right
GAVL_CHID_FRONT_CENTER_LEFT	Left of Center
GAVL_CHID_FRONT_CENTER_RIGHT	Right of Center
GAVL_CHID_REAR_LEFT	Rear left
GAVL_CHID_REAR_RIGHT	Rear right
GAVL_CHID_REAR_CENTER	Rear Center
GAVL_CHID_SIDE_LEFT	Side left
GAVL_CHID_SIDE_RIGHT	Side right
GAVL_CHID_LFE	Subwoofer
GAVL_CHID_AUX	Additional channel (can be more than one)

---

Function Documentation

GAVL_PUBLIC const char* gavl_sample_format_to_string

(

gavl_sample_format_t

format

)

Convert a gavl_sample_format_t to a human readable string.

Parameters:

format

A sample format

Returns:

A string describing the format

GAVL_PUBLIC gavl_sample_format_t gavl_string_to_sample_format

(

const char *

str

)

Convert a string to a sample format.

Parameters:

str

String

str must be one of the strings returned by gavl_sample_format_to_string

GAVL_PUBLIC int gavl_num_sample_formats

(

)

Get total number of supported sample formats.

Returns:

total number of supported sample formats

GAVL_PUBLIC gavl_sample_format_t gavl_get_sample_format

(

int

index

)

Get the sample format from index.

Parameters:

index

index (must be between 0 and the result of gavl_num_sample_formats)

Returns:

The sample format corresponding to index or GAVL_SAMPLE_NONE.

GAVL_PUBLIC const char* gavl_channel_id_to_string

(

gavl_channel_id_t

id

)

Convert a gavl_channel_id_t to a human readable string.

Parameters:

id

A channel id

GAVL_PUBLIC const char* gavl_interleave_mode_to_string

(

gavl_interleave_mode_t

mode

)

Convert a gavl_interleave_mode_t to a human readable string.

Parameters:

mode

An interleave mode

GAVL_PUBLIC void gavl_audio_format_dump

(

const gavl_audio_format_t *

format

)

Dump an audio format to stderr.

Parameters:

format

An audio format

GAVL_PUBLIC int gavl_channel_index	(	const gavl_audio_format_t *	format,
		gavl_channel_id_t	id
	)

Get the index of a particular channel for a given format.

Parameters:

	format	An audio format
	id	A channel id

Returns:

The index of the channel in the format or -1 if such a channel is not present

GAVL_PUBLIC int gavl_front_channels

(

const gavl_audio_format_t *

format

)

Get number of front channels for a given format.

Parameters:

format

An audio format

GAVL_PUBLIC int gavl_rear_channels

(

const gavl_audio_format_t *

format

)

Get number of rear channels for a given format.

Parameters:

format

An audio format

GAVL_PUBLIC int gavl_side_channels

(

const gavl_audio_format_t *

format

)

Get number of side channels for a given format.

Parameters:

format

An audio format

GAVL_PUBLIC int gavl_aux_channels

(

const gavl_audio_format_t *

format

)

Get number of aux channels for a given format.

Parameters:

format

An audio format

GAVL_PUBLIC int gavl_lfe_channels

(

const gavl_audio_format_t *

format

)

Get number of LFE channels for a given format.

Parameters:

format

An audio format

GAVL_PUBLIC void gavl_audio_format_copy	(	gavl_audio_format_t *	dst,
		const gavl_audio_format_t *	src
	)

Copy one audio format to another.

Parameters:

	dst	Destination format
	src	Source format

GAVL_PUBLIC int gavl_audio_formats_equal	(	const gavl_audio_format_t *	format_1,
		const gavl_audio_format_t *	format_2
	)

Compare 2 audio formats.

Parameters:

	format_1	First format
	format_2	Second format

Returns:

1 if the formats are equal, 0 else

GAVL_PUBLIC void gavl_set_channel_setup

(

gavl_audio_format_t *

format

)

Set the default channel setup and indices.

Parameters:

format

An audio format

Set a default channel setup and channel indices if only the number of channels is known. The result might be wrong if you have something else than mono or stereo from a stream, which has no informtions about the speaker configurations.

GAVL_PUBLIC int gavl_bytes_per_sample

(

gavl_sample_format_t

format

)

Get the number of bytes per sample for a given sample format.

Parameters:

format

A sample format