Audio class. More...

#include <mlt_audio.h>

Public Member Functions
void	mlt_audio_alloc_data (mlt_audio self)
	Allocate the data field based on the other properties of the Audio. More...

int	mlt_audio_calculate_frame_samples (float fps, int frequency, int64_t position)
	Determine the number of samples that belong in a frame at a time position. More...

int64_t	mlt_audio_calculate_samples_to_position (float fps, int frequency, int64_t position)
	Determine the number of samples that belong before a time position. More...

int	mlt_audio_calculate_size (mlt_audio self)
	Calculate the number of bytes needed for the Audio data. More...

int	mlt_audio_channel_layout_channels (mlt_channel_layout layout)
	Get the number of channels for a channel layout. More...

mlt_channel_layout	mlt_audio_channel_layout_default (int channels)
	Get a default channel layout for a given number of channels. More...

mlt_channel_layout	mlt_audio_channel_layout_id (const char *name)
	Get the id of channel layout from short name. More...

const char *	mlt_audio_channel_layout_name (mlt_channel_layout layout)
	Get the short name for a channel layout. More...

void	mlt_audio_close (mlt_audio self)
	Destroy an audio object created by mlt_audio_new(). More...

void	mlt_audio_copy (mlt_audio dst, mlt_audio src, int samples, int src_start, int dst_start)
	Copy audio samples from src to dst. More...

const char *	mlt_audio_format_name (mlt_audio_format format)
	Get the short name for an audio format. More...

int	mlt_audio_format_size (mlt_audio_format format, int samples, int channels)
	Get the amount of bytes needed for a block of audio. More...

void	mlt_audio_free_data (mlt_audio self)
	Free the data field using the destructor function. More...

void	mlt_audio_get_planes (mlt_audio self, uint8_t **planes)
	Populate an array of pointers each pointing to the beginning of an audio plane. More...

void	mlt_audio_get_values (mlt_audio self, void *data, int frequency, mlt_audio_format format, int samples, int *channels)
	Get the most common values for the audio. More...

int	mlt_audio_plane_count (mlt_audio self)
	Get the number of planes for the audio type. More...

int	mlt_audio_plane_size (mlt_audio self)
	Get the size of an audio plane. More...

void	mlt_audio_reverse (mlt_audio self)
	Reverse the audio samples. More...

void	mlt_audio_set_values (mlt_audio self, void *data, int frequency, mlt_audio_format format, int samples, int channels)
	Set the most common values for the audio. More...

void	mlt_audio_shrink (mlt_audio self, int samples)
	Shrink the audio to the new number of samples. More...

void	mlt_audio_silence (mlt_audio self, int samples, int start)
	Set a range of samples to silence. More...

Data Fields
int	channels

mlt_destructor	close

void *	data

mlt_audio_format	format

int	frequency

mlt_channel_layout	layout

mlt_destructor	release_data

int	samples

Detailed Description

Audio class.

Audio is the data object that represents audio for a period of time.

Member Function Documentation

◆ mlt_audio_alloc_data()

void mlt_audio_alloc_data ( mlt_audio self )

Allocate the data field based on the other properties of the Audio.

If the data field is already set, and a destructor function exists, the data will be released. Else, the data pointer will be overwritten without being released.

After this function call, the release_data field will be set and can be used to release the data when necessary.

Parameters

self	the Audio object

◆ mlt_audio_calculate_frame_samples()

int mlt_audio_calculate_frame_samples	(	float	fps,
		int	frequency,
		int64_t	position
	)

Determine the number of samples that belong in a frame at a time position.

Parameters

fps	the frame rate
frequency	the sample rate
position	the time position

Returns: the number of samples per channel

◆ mlt_audio_calculate_samples_to_position()

int64_t mlt_audio_calculate_samples_to_position	(	float	fps,
		int	frequency,
		int64_t	position
	)

Determine the number of samples that belong before a time position.

Parameters

fps	the frame rate
frequency	the sample rate
position	the time position

Returns: the number of samples per channel

◆ mlt_audio_calculate_size()

int mlt_audio_calculate_size ( mlt_audio self )

Calculate the number of bytes needed for the Audio data.

Parameters

self	the Audio object

Returns: the number of bytes

◆ mlt_audio_channel_layout_channels()

int mlt_audio_channel_layout_channels ( mlt_channel_layout layout )

Get the number of channels for a channel layout.

Parameters

layout the channel layout

Returns: the number of channels for the channel layout

◆ mlt_audio_channel_layout_default()

mlt_channel_layout mlt_audio_channel_layout_default ( int channels )

Get a default channel layout for a given number of channels.

Parameters

channels the number of channels

Returns: the default channel layout

◆ mlt_audio_channel_layout_id()

mlt_channel_layout mlt_audio_channel_layout_id ( const char * name )

Get the id of channel layout from short name.

Parameters

name	the channel layout short name

Returns: a channel layout

◆ mlt_audio_channel_layout_name()

const char * mlt_audio_channel_layout_name ( mlt_channel_layout layout )

Get the short name for a channel layout.

You do not need to deallocate the returned string.

Parameters

layout the channel layout

Returns: a string for the name of the channel layout

◆ mlt_audio_close()

void mlt_audio_close ( mlt_audio self )

Destroy an audio object created by mlt_audio_new().

Parameters

self	the Audio object

◆ mlt_audio_copy()

void mlt_audio_copy	(	mlt_audio	dst,
		mlt_audio	src,
		int	samples,
		int	src_start,
		int	dst_start
	)

Copy audio samples from src to dst.

Parameters

dst	the destination object
src	the source object
samples	the number of samples to copy
src_start	the number of samples to skip from the source
dst_start	the number of samples to skip from the destination

Returns: none

◆ mlt_audio_format_name()

const char * mlt_audio_format_name ( mlt_audio_format format )

Get the short name for an audio format.

You do not need to deallocate the returned string.

Parameters

format an audio format enum

Returns: a string for the name of the image format

◆ mlt_audio_format_size()

int mlt_audio_format_size	(	mlt_audio_format	format,
		int	samples,
		int	channels
	)

Get the amount of bytes needed for a block of audio.

Parameters

format	an audio format enum
samples	the number of samples per channel
channels	the number of channels

Returns: the number of bytes

◆ mlt_audio_free_data()

void mlt_audio_free_data ( mlt_audio self )

Free the data field using the destructor function.

If the constructor function does not exist, the value will be set to NULL without being released.

After this function call, the data and release_data fields will be NULL.

Parameters

self	the Audio object

◆ mlt_audio_get_planes()

void mlt_audio_get_planes	(	mlt_audio	self,
		uint8_t **	planes
	)

Populate an array of pointers each pointing to the beginning of an audio plane.

Parameters

	self	the Audio object
[out]	planes	the array of pointers to populate

◆ mlt_audio_get_values()

void mlt_audio_get_values	(	mlt_audio	self,
		void **	data,
		int *	frequency,
		mlt_audio_format *	format,
		int *	samples,
		int *	channels
	)

Get the most common values for the audio.

Parameters

	self	the Audio object
[out]	data	the buffer that contains the audio data
[out]	frequency	the sample rate
[out]	format	the audio format
[out]	samples	the number of samples in the data
[out]	channels	the number of audio channels

◆ mlt_audio_plane_count()

int mlt_audio_plane_count ( mlt_audio self )

Get the number of planes for the audio type.

Parameters

self	the Audio object

Returns: the number of planes.

◆ mlt_audio_plane_size()

int mlt_audio_plane_size ( mlt_audio self )

Get the size of an audio plane.

Parameters

self	the Audio object

Returns: the size of a plane.

◆ mlt_audio_reverse()

void mlt_audio_reverse ( mlt_audio self )

Reverse the audio samples.

Parameters

self	the Audio object

◆ mlt_audio_set_values()

void mlt_audio_set_values	(	mlt_audio	self,
		void *	data,
		int	frequency,
		mlt_audio_format	format,
		int	samples,
		int	channels
	)

Set the most common values for the audio.

Less common values will be set to reasonable defaults.

You should use the mlt_audio_calculate_frame_samples to determine the number of samples you want.

Parameters

self	the Audio object
data	the buffer that contains the audio data
frequency	the sample rate
format	the audio format
samples	the number of samples in the data
channels	the number of audio channels

◆ mlt_audio_shrink()

void mlt_audio_shrink	(	mlt_audio	self,
		int	samples
	)

Shrink the audio to the new number of samples.

Existing samples will be moved as necessary to ensure that the audio planes immediately follow each other. The samples field will be updated to match the new number.

Parameters

self	the Audio object
samples	the new number of samples to shrink to

◆ mlt_audio_silence()

void mlt_audio_silence	(	mlt_audio	self,
		int	samples,
		int	start
	)

Set a range of samples to silence.

Parameters

self	the Audio object
samples	the number of samples to silence
start	the sample at which to begin the silence

Returns: none

Field Documentation

◆ channels

int mlt_audio_s::channels

◆ close

mlt_destructor mlt_audio_s::close

◆ data

void* mlt_audio_s::data

◆ format

mlt_audio_format mlt_audio_s::format

◆ frequency

int mlt_audio_s::frequency

◆ layout

mlt_channel_layout mlt_audio_s::layout

◆ release_data

mlt_destructor mlt_audio_s::release_data

◆ samples

int mlt_audio_s::samples

The documentation for this struct was generated from the following files:

framework/mlt_audio.h
framework/mlt_audio.c

Public Member Functions

Data Fields

Detailed Description

Member Function Documentation

◆ mlt_audio_alloc_data()

◆ mlt_audio_calculate_frame_samples()

◆ mlt_audio_calculate_samples_to_position()

◆ mlt_audio_calculate_size()

◆ mlt_audio_channel_layout_channels()

◆ mlt_audio_channel_layout_default()

◆ mlt_audio_channel_layout_id()

◆ mlt_audio_channel_layout_name()

◆ mlt_audio_close()

◆ mlt_audio_copy()

◆ mlt_audio_format_name()

◆ mlt_audio_format_size()

◆ mlt_audio_free_data()

◆ mlt_audio_get_planes()

◆ mlt_audio_get_values()

◆ mlt_audio_plane_count()

◆ mlt_audio_plane_size()

◆ mlt_audio_reverse()

◆ mlt_audio_set_values()

◆ mlt_audio_shrink()

◆ mlt_audio_silence()

Field Documentation

◆ channels

◆ close

◆ data

◆ format

◆ frequency

◆ layout

◆ release_data

◆ samples