M4AFileSampleSizeBuffer Class Reference

A buffer that reads sample sizes from an M4A file using the M4AAudioFileDemuxer. No RAM is used to store the sample sizes as they are read directly from the file. More...

#include <M4AFileSampleSizeBuffer.h>

Inheritance diagram for M4AFileSampleSizeBuffer:

Public Member Functions
	M4AFileSampleSizeBuffer (AudioPlayer &player, ContainerM4A &container, const char *fileExt=".m4a")
	Constructor.
void	addFileExtension (const char *fileExt)
	Add a file extension to recognize as relevant for this buffer.
stsz_sample_size_t *	address () override
	Returns a pointer to the buffer's physical address.
int	available ()
	Returns the number of samples already read (i.e., the current sample index).
int	availableForWrite () override
	Returns the available space for writing.
void	clear ()
	same as reset
virtual int	clearArray (int len)
	Removes the next len entries.
bool	isEmpty ()
virtual bool	isFull ()
	checks if the buffer is full
virtual float	levelPercent ()
	Returns the level of the buffer in %.
bool	peek (stsz_sample_size_t &result)
	Peek is not supported for this buffer.
bool	read (stsz_sample_size_t &data) override
	Get the next sample size from the demuxer.
virtual int	readArray (stsz_sample_size_t data[], int len)
	reads multiple values
void	reset ()
	clears the buffer
virtual bool	resize (int bytes)
	Resizes the buffer if supported: returns false if not supported.
void	setReadBufferSize (size_t size)
	Defines how many samples are buffered with each file read.
size_t	size () override
	Returns the total number of samples in the file.
bool	write (stsz_sample_size_t data)
	Write is ignored; sample sizes are read directly from the file.
virtual int	writeArray (const stsz_sample_size_t data[], int len)
	Fills the buffer data.
virtual int	writeArrayOverwrite (const stsz_sample_size_t data[], int len)
	Fills the buffer data and overwrites the oldest data if the buffer is full.

Protected Member Functions
bool	isRelevantFile (const char *name)
	Checks if the given file name matches any of the registered extensions.

Static Protected Member Functions
static void	onFileChange (Stream *streamPtr, void *reference)
	Static callback for file change events. Updates the file pointer and re-parses the file if relevant.

Protected Attributes
M4AAudioFileDemuxer	demuxer
	Demuxer used to extract sample sizes.
Vector< const char * >	fileExtensions
	List of recognized file extensions.
ContainerM4A *	p_container = nullptr
File *	p_file = nullptr
	Pointer to the currently open file.
AudioPlayer *	p_player = nullptr
	Pointer to the AudioPlayer instance.

Detailed Description

A buffer that reads sample sizes from an M4A file using the M4AAudioFileDemuxer. No RAM is used to store the sample sizes as they are read directly from the file.

This buffer is designed to be used with an AudioPlayer instance for audio sources which are file based only. It provides a read interface that fetches the next sample size directly from the file via the demuxer, avoiding the need to store the entire sample size table in RAM.

Note

This buffer is can not be used for streaming sources; it is intended for the use with file-based playback.

This class registers a setOnStreamChangeCallback() with the player

Constructor & Destructor Documentation

M4AFileSampleSizeBuffer()

M4AFileSampleSizeBuffer ( AudioPlayer &  player, ContainerM4A &  container, const char *  fileExt = ".m4a"  )

inline

Constructor.

Parameters

player	Reference to the AudioPlayer instance.
fileExt	File extension to recognize as M4A (default ".m4a").

Member Function Documentation

addFileExtension()

void addFileExtension ( const char *  fileExt )

inline

Add a file extension to recognize as relevant for this buffer.

Parameters

fileExt

File extension string (e.g., ".m4a").

address()

stsz_sample_size_t * address ( )

inlineoverridevirtual

Returns a pointer to the buffer's physical address.

Returns

Always nullptr, as this buffer does not have a physical address.

Implements BaseBuffer< stsz_sample_size_t >.

available()

int available ( )

inlinevirtual

Returns the number of samples already read (i.e., the current sample index).

Returns

Number of samples read so far.

Implements BaseBuffer< stsz_sample_size_t >.

availableForWrite()

int availableForWrite ( )

inlineoverridevirtual

Returns the available space for writing.

Returns

Always 0, as this buffer does not support writing. No write buffer available

Implements BaseBuffer< stsz_sample_size_t >.

isRelevantFile()

bool isRelevantFile ( const char *  name )

inlineprotected

Checks if the given file name matches any of the registered extensions.

Parameters

name	File name to check.

Returns

true if the file is relevant, false otherwise.

onFileChange()

static void onFileChange ( Stream *  streamPtr, void *  reference  )

inlinestaticprotected

Static callback for file change events. Updates the file pointer and re-parses the file if relevant.

Parameters

streamPtr	Pointer to the new file stream.
reference	Pointer to the M4AFileSampleSizeBuffer instance.

peek()

bool peek ( stsz_sample_size_t &  result )

inlinevirtual

Peek is not supported for this buffer.

Parameters

result

Reference to store the peeked value (unused).

Returns

Always false. Peeking is not supported.

Implements BaseBuffer< stsz_sample_size_t >.

read()

bool read ( stsz_sample_size_t &  data )

inlineoverridevirtual

Get the next sample size from the demuxer.

Parameters

data	Reference to store the sample size.

Returns

true if successful, false otherwise.

Implements BaseBuffer< stsz_sample_size_t >.

reset()

void reset ( )

inlinevirtual

clears the buffer

Implements BaseBuffer< stsz_sample_size_t >.

setReadBufferSize()

void setReadBufferSize ( size_t  size )

inline

Defines how many samples are buffered with each file read.

Parameters

size	Number of bytes to buffer (will be divided by 4 for sample count).

size()

size_t size ( )

inlineoverridevirtual

Returns the total number of samples in the file.

Returns

Total sample count.

Implements BaseBuffer< stsz_sample_size_t >.

write()

bool write ( stsz_sample_size_t  data )

inlinevirtual

Write is ignored; sample sizes are read directly from the file.

Parameters

data	Sample size value (ignored).

Returns

Always true. This buffer is read-only.

Implements BaseBuffer< stsz_sample_size_t >.

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The documentation for this class was generated from the following file:

• src/AudioTools/AudioCodecs/M4AFileSampleSizeBuffer.h