Functions that manipulate audio samples. More...

Functions
int	av_samples_fill_arrays (uint8_t *audio_data, int linesize, const uint8_t *buf, int nb_channels, int nb_samples, enum AVSampleFormat sample_fmt, int align)
	Fill plane data pointers and linesize for samples with sample format sample_fmt. More...

int	av_samples_alloc (uint8_t *audio_data, int linesize, int nb_channels, int nb_samples, enum AVSampleFormat sample_fmt, int align)
	Allocate a samples buffer for nb_samples samples, and fill data pointers and linesize accordingly. More...

int	av_samples_alloc_array_and_samples (uint8_t **audio_data, int linesize, int nb_channels, int nb_samples, enum AVSampleFormat sample_fmt, int align)
	Allocate a data pointers array, samples buffer for nb_samples samples, and fill data pointers and linesize accordingly. More...

int	av_samples_copy (uint8_t *dst, uint8_t const *src, int dst_offset, int src_offset, int nb_samples, int nb_channels, enum AVSampleFormat sample_fmt)
	Copy samples from src to dst. More...

int	av_samples_set_silence (uint8_t **audio_data, int offset, int nb_samples, int nb_channels, enum AVSampleFormat sample_fmt)
	Fill an audio buffer with silence. More...

Detailed Description

Functions that manipulate audio samples.

Function Documentation

◆ av_samples_fill_arrays()

int av_samples_fill_arrays	(	uint8_t **	audio_data,
		int *	linesize,
		const uint8_t *	buf,
		int	nb_channels,
		int	nb_samples,
		enum AVSampleFormat	sample_fmt,
		int	align
	)

Fill plane data pointers and linesize for samples with sample format sample_fmt.

The audio_data array is filled with the pointers to the samples data planes: for planar, set the start point of each channel's data within the buffer, for packed, set the start point of the entire buffer only.

The value pointed to by linesize is set to the aligned size of each channel's data buffer for planar layout, or to the aligned size of the buffer for all channels for packed layout.

The buffer in buf must be big enough to contain all the samples (use av_samples_get_buffer_size() to compute its minimum size), otherwise the audio_data pointers will point to invalid data.

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

Parameters

[out]	audio_data	array to be filled with the pointer for each channel
[out]	linesize	calculated linesize, may be NULL
	buf	the pointer to a buffer containing the samples
	nb_channels	the number of channels
	nb_samples	the number of samples in a single channel
	sample_fmt	the sample format
	align	buffer size alignment (0 = default, 1 = no alignment)

Returns: minimum size in bytes required for the buffer on success, or a negative error code on failure

◆ av_samples_alloc()

int av_samples_alloc	(	uint8_t **	audio_data,
		int *	linesize,
		int	nb_channels,
		int	nb_samples,
		enum AVSampleFormat	sample_fmt,
		int	align
	)

Allocate a samples buffer for nb_samples samples, and fill data pointers and linesize accordingly.

The allocated samples buffer can be freed by using av_freep(&audio_data[0]) Allocated data will be initialized to silence.

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

Parameters

[out]	audio_data	array to be filled with the pointer for each channel
[out]	linesize	aligned size for audio buffer(s), may be NULL
	nb_channels	number of audio channels
	nb_samples	number of samples per channel
	align	buffer size alignment (0 = default, 1 = no alignment)

Returns: >=0 on success or a negative error code on failure

Todo:: return the size of the allocated buffer in case of success at the next bump

See also: av_samples_fill_arrays(); av_samples_alloc_array_and_samples()

Examples: resampling_audio.c, and transcode_aac.c.

Referenced by init_converted_samples(), and main().

◆ av_samples_alloc_array_and_samples()

int av_samples_alloc_array_and_samples	(	uint8_t ***	audio_data,
		int *	linesize,
		int	nb_channels,
		int	nb_samples,
		enum AVSampleFormat	sample_fmt,
		int	align
	)

Allocate a data pointers array, samples buffer for nb_samples samples, and fill data pointers and linesize accordingly.

This is the same as av_samples_alloc(), but also allocates the data pointers array.

See also: av_samples_alloc()

Examples: resampling_audio.c.

Referenced by main().

◆ av_samples_copy()

int av_samples_copy	(	uint8_t **	dst,
		uint8_t const	src,
		int	dst_offset,
		int	src_offset,
		int	nb_samples,
		int	nb_channels,
		enum AVSampleFormat	sample_fmt
	)

Copy samples from src to dst.

Parameters

dst	destination array of pointers to data planes
src	source array of pointers to data planes
dst_offset	offset in samples at which the data will be written to dst
src_offset	offset in samples at which the data will be read from src
nb_samples	number of samples to be copied
nb_channels	number of audio channels
sample_fmt	audio sample format

◆ av_samples_set_silence()

int av_samples_set_silence	(	uint8_t **	audio_data,
		int	offset,
		int	nb_samples,
		int	nb_channels,
		enum AVSampleFormat	sample_fmt
	)

Fill an audio buffer with silence.

Parameters

audio_data	array of pointers to data planes
offset	offset in samples at which to start filling
nb_samples	number of samples to fill
nb_channels	number of audio channels
sample_fmt	audio sample format