Audio related
[Common utility functions]


Modules
	Audio channel masks
	Audio channel convenience macros
Typedefs
typedef struct AVAudioFifo	AVAudioFifo
	Context for an Audio FIFO Buffer.
Functions
void	av_audio_fifo_free (AVAudioFifo *af)
	Free an AVAudioFifo.
AVAudioFifo *	av_audio_fifo_alloc (enum AVSampleFormat sample_fmt, int channels, int nb_samples)
	Allocate an AVAudioFifo.
int	av_audio_fifo_realloc (AVAudioFifo *af, int nb_samples)
	Reallocate an AVAudioFifo.
int	av_audio_fifo_write (AVAudioFifo af, void *data, int nb_samples)
	Write data to an AVAudioFifo.
int	av_audio_fifo_read (AVAudioFifo af, void *data, int nb_samples)
	Read data from an AVAudioFifo.
int	av_audio_fifo_drain (AVAudioFifo *af, int nb_samples)
	Drain data from an AVAudioFifo.
void	av_audio_fifo_reset (AVAudioFifo *af)
	Reset the AVAudioFifo buffer.
int	av_audio_fifo_size (AVAudioFifo *af)
	Get the current number of samples in the AVAudioFifo available for reading.
int	av_audio_fifo_space (AVAudioFifo *af)
	Get the current number of samples in the AVAudioFifo available for writing.
uint64_t	av_get_channel_layout (const char *name)
	Return a channel layout id that matches name, or 0 if no match is found.
void	av_get_channel_layout_string (char *buf, int buf_size, int nb_channels, uint64_t channel_layout)
	Return a description of a channel layout.
int	av_get_channel_layout_nb_channels (uint64_t channel_layout)
	Return the number of channels in the channel layout.
int64_t	av_get_default_channel_layout (int nb_channels)
	Return default channel layout for a given number of channels.

Typedef Documentation

typedef struct AVAudioFifo AVAudioFifo

Context for an Audio FIFO Buffer.

Operates at the sample level rather than the byte level.
Supports multiple channels with either planar or packed sample format.
Automatic reallocation when writing to a full buffer.

Definition at line 46 of file audio_fifo.h.

Function Documentation

AVAudioFifo* av_audio_fifo_alloc	(	enum AVSampleFormat	sample_fmt,
		int	channels,
		int	nb_samples
	)

Allocate an AVAudioFifo.

Parameters:

	sample_fmt	sample format
	channels	number of channels
	nb_samples	initial allocation size, in samples

Returns:: newly allocated AVAudioFifo, or NULL on error

Definition at line 59 of file audio_fifo.c.

Referenced by av_buffersink_read_samples(), avresample_open(), and config_output().

int av_audio_fifo_drain	(	AVAudioFifo *	af,
		int	nb_samples
	)

Drain data from an AVAudioFifo.

Removes the data without reading it.

Parameters:

	af	AVAudioFifo to drain
	nb_samples	number of samples to drain

Returns:: 0 if OK, or negative AVERROR code on failure

Definition at line 158 of file audio_fifo.c.

Referenced by avresample_read().

void av_audio_fifo_free ( AVAudioFifo * af )

Free an AVAudioFifo.

Parameters:

af

AVAudioFifo to free

Definition at line 44 of file audio_fifo.c.

Referenced by av_audio_fifo_alloc(), avresample_close(), and uninit().

int av_audio_fifo_read	(	AVAudioFifo *	af,
		void **	data,
		int	nb_samples
	)

Read data from an AVAudioFifo.

See also:: enum AVSampleFormat The documentation for AVSampleFormat describes the data layout.

Parameters:

	af	AVAudioFifo to read from
	data	audio data plane pointers
	nb_samples	number of samples to read

Returns:: number of samples actually read, or negative AVERROR code on failure.

Definition at line 138 of file audio_fifo.c.

Referenced by avresample_read(), ff_audio_data_read_from_fifo(), output_frame(), and read_from_fifo().

int av_audio_fifo_realloc	(	AVAudioFifo *	af,
		int	nb_samples
	)

Reallocate an AVAudioFifo.

Parameters:

	af	AVAudioFifo to reallocate
	nb_samples	new allocation size, in samples

Returns:: 0 if OK, or negative AVERROR code on failure

Definition at line 96 of file audio_fifo.c.

Referenced by av_audio_fifo_write().

void av_audio_fifo_reset ( AVAudioFifo * af )

Reset the AVAudioFifo buffer.

This empties all data in the buffer.

Parameters:

af

AVAudioFifo to reset

Definition at line 175 of file audio_fifo.c.

int av_audio_fifo_size ( AVAudioFifo * af )

Get the current number of samples in the AVAudioFifo available for reading.

Parameters:

af

the AVAudioFifo to query

Returns:: number of samples available for reading

Definition at line 185 of file audio_fifo.c.

Referenced by av_audio_fifo_write(), av_buffersink_read_samples(), avresample_available(), avresample_set_compensation(), get_available_samples(), handle_buffered_output(), and request_samples().

int av_audio_fifo_space ( AVAudioFifo * af )

Get the current number of samples in the AVAudioFifo available for writing.

Parameters:

af

the AVAudioFifo to query

Returns:: number of samples available for writing

Definition at line 190 of file audio_fifo.c.

Referenced by av_audio_fifo_write().

int av_audio_fifo_write	(	AVAudioFifo *	af,
		void **	data,
		int	nb_samples
	)

Write data to an AVAudioFifo.

The AVAudioFifo will be reallocated automatically if the available space is less than nb_samples.

See also:: enum AVSampleFormat The documentation for AVSampleFormat describes the data layout.

Parameters:

	af	AVAudioFifo to write to
	data	audio data plane pointers
	nb_samples	number of samples to write

Returns:: number of samples actually written, or negative AVERROR code on failure.

Definition at line 112 of file audio_fifo.c.

Referenced by av_buffersink_read_samples(), ff_audio_data_add_to_fifo(), and filter_samples().

uint64_t av_get_channel_layout ( const char * name )

Return a channel layout id that matches name, or 0 if no match is found.

name can be one or several of the following notations, separated by '+' or '|':

the name of an usual channel layout (mono, stereo, 4.0, quad, 5.0, 5.0(side), 5.1, 5.1(side), 7.1, 7.1(wide), downmix);
the name of a single channel (FL, FR, FC, LFE, BL, BR, FLC, FRC, BC, SL, SR, TC, TFL, TFC, TFR, TBL, TBC, TBR, DL, DR);
a number of channels, in decimal, optionally followed by 'c', yielding the default channel layout for that number of channels (
See also:
av_get_default_channel_layout);
a channel layout mask, in hexadecimal starting with "0x" (see the AV_CH_* macros).

Example: "stereo+FC" = "2+FC" = "2c+1c" = "0x7"

Definition at line 123 of file audioconvert.c.

Referenced by ff_parse_channel_layout(), init(), init_audio(), opt_channel_layout(), and parse_channel_name().

int av_get_channel_layout_nb_channels ( uint64_t channel_layout )

Return the number of channels in the channel layout.

Definition at line 173 of file audioconvert.c.

Referenced by audio_decode_frame(), auto_matrix(), av_asrc_buffer_add_buffer(), av_buffersink_read_samples(), av_get_channel_layout_string(), avcodec_open2(), avfilter_copy_buf_props(), avfilter_get_audio_buffer_ref_from_arrays(), avfilter_ref_buffer(), avresample_build_matrix(), avresample_get_matrix(), avresample_open(), avresample_set_matrix(), config_output(), config_props(), copy_buffer_ref(), ff_default_get_audio_buffer(), ff_filter_samples(), ff_mov_get_channel_layout_tag(), filter_samples(), init(), lavfi_read_header(), lavfi_read_packet(), main(), mov_read_dec3(), opt_channel_layout(), print_samplesref(), query_formats(), read_major_sync(), sane_layout(), stream_component_open(), swap_channel_layouts_on_filter(), swr_alloc_set_opts(), swr_init(), swr_set_matrix(), swri_rematrix(), swri_rematrix_init(), and transcode_init().