M4A Demuxer that extracts audio from M4A/MP4 containers. The audio is decoded into pcm with the help of the provided decoder. format. More...

#include <ContainerM4A.h>

Inheritance diagram for ContainerM4A:

Public Member Functions
	ContainerM4A ()
	Default constructor: If no decoder is provided, the raw audio data is provided to the defined output.
	ContainerM4A (MultiDecoder &decoder)
	Constructor with decoder. Sets up the demuxer and decoder notification.
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
AudioInfo	audioInfo () override
	provides the actual input AudioInfo
AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
virtual AudioInfo	audioInfoOut ()
virtual bool	begin (AudioInfo info) override
bool	begin () override
	Initialize the demuxer and decoder.
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
void	end () override
	End the demuxer and decoder, releasing resources.
M4AAudioDemuxer &	getDemuxer ()
Print *	getOutput ()
Print *	getOutput ()
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
bool	isResultPCM () override
	Returns true if the result is PCM (decoder is present).
const char *	mime () override
	Provides "audio/mp4".
	operator bool () override
	Returns true if the demuxer is active.
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
void	setAudioInfo (AudioInfo from) override
	for most decoders this is not needed
void	setAudioInfo (AudioInfo from) override
	for most decoders this is not needed
virtual void	setChunkOffsetsBuffer (BaseBuffer< uint32_t > &buffer)
	Sets the buffer to use for sample sizes. This is currently not used!
virtual bool	setCodecConfig (const uint8_t *data, size_t len)
	Some decoders need e.g. a magic cookie to provide the relevant info for decoding.
virtual bool	setCodecConfig (const uint8_t *data, size_t len)
	Some decoders need e.g. a magic cookie to provide the relevant info for decoding.
bool	setDecoder (MultiDecoder &decoder)
	Sets the decoder to use for audio frames.
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active).
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active).
virtual void	setOutput (AudioOutput &out_stream)
	Defines where the decoded result is written to.
virtual void	setOutput (AudioStream &out_stream)
	Defines where the decoded result is written to.
void	setOutput (Print &out_stream) override
	Set the output stream for decoded or raw audio.
virtual void	setSampleSizesBuffer (BaseBuffer< stsz_sample_size_t > &buffer)
	Sets the buffer to use for sample sizes. You can use this to provide a custom buffer that does not rely on RAM (e.g a file based buffer or one using Redis).
size_t	write (const uint8_t *data, size_t len) override
	Feed data to the demuxer for parsing.

Public Attributes
int	id
	custom id to be used by application

Protected Member Functions
void	notifyAudioChange (AudioInfo info)
void	notifyAudioChange (AudioInfo info)
void	writeBlocking (Print out, uint8_t data, size_t len)
void	writeBlocking (Print out, uint8_t data, size_t len)

Static Protected Member Functions
static void	decodeAudio (const M4AAudioDemuxer::Frame &frame, void *ref)
	Static callback for demuxed audio frames. Handles decoder selection and magic cookie for ALAC.

Protected Attributes
M4AAudioDemuxer	demux
	Internal demuxer instance.
AudioInfo	info
bool	is_active = false
	True if demuxer is active.
bool	is_magic_cookie_processed
	True if ALAC magic cookie has been processed.
bool	is_notify_active = true
Vector< AudioInfoSupport * >	notify_vector
MultiDecoder *	p_decoder = nullptr
	Pointer to the MultiDecoder.
Print *	p_print = nullptr

Detailed Description

M4A Demuxer that extracts audio from M4A/MP4 containers. The audio is decoded into pcm with the help of the provided decoder. format.

Audio-only, single-track: a thin ContainerDecoder wrapper around M4AAudioDemuxer (which itself inherits its MP4-box parsing from M4ACommonDemuxer), so it plugs directly into AudioPlayer/MultiDecoder the same way any other AudioDecoder does. If you also need the video track out of an interleaved .mp4 - or a second, independent audio track - use DemuxerMP4 (AudioCodecs/ContainerMP4.h) instead; it's a separate, multi-track implementation (own MP4-box handlers, per-track state, chunk-offset-based interleave resolution) rather than a superset of this class, since M4ACommonDemuxer's single-track audio_config model doesn't extend to per-track state without a rework. The two share the same box-parsing shape (stsd/mp4a/esds for AAC, stsd/alac for ALAC's magic cookie) but not code - keep that in mind if a bug is found in one, it may well apply to the other too.

Note: The underlying MP4Parser expects the moov box (sample/format info) to come before the mdat box (audio payload) - i.e. the file must be "faststart", e.g. via 'ffmpeg -movflags +faststart'. If mdat comes first, decoding fails since the needed format info isn't available yet; by default this is logged as an error. Call getDemuxer().getParser().setRequireMoovBeforeMdat(false) to downgrade that to a warning and attempt to continue anyway.

Author: Phil Schatzmann

Copyright: GPLv3

Constructor & Destructor Documentation

◆ ContainerM4A() [1/2]

ContainerM4A ( )

inline

Default constructor: If no decoder is provided, the raw audio data is provided to the defined output.

◆ ContainerM4A() [2/2]

ContainerM4A ( MultiDecoder & decoder )

inline

Constructor with decoder. Sets up the demuxer and decoder notification.

Parameters

decoder Reference to a MultiDecoder for PCM output.

Member Function Documentation

◆ addNotifyAudioChange() [1/2]

virtual void addNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, CodecNOP, EncodedAudioOutput, and EncodedAudioStream.

◆ addNotifyAudioChange() [2/2]

virtual void addNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, CodecNOP, EncodedAudioOutput, and EncodedAudioStream.

◆ audioInfo() [1/2]

AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in CodecNOP, CodecNOP, CodecNOP, DecoderBasic, DSFDecoder, MP3DecoderHelix, MP3DecoderMAD, OggContainerDecoder, OpusAudioDecoder, OpusMultiStreamAudioDecoder, VorbisDecoder, VorbisDecoder, WAVDecoder, and WavIMADecoder.

◆ audioInfo() [2/2]

AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in CodecNOP, CodecNOP, CodecNOP, DecoderBasic, DSFDecoder, MP3DecoderHelix, MP3DecoderMAD, OggContainerDecoder, OpusAudioDecoder, OpusMultiStreamAudioDecoder, VorbisDecoder, VorbisDecoder, WAVDecoder, and WavIMADecoder.

◆ audioInfoOut() [1/2]

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

provides the actual output AudioInfo: this is usually the same as audioInfo() unless we use a transforming stream

Reimplemented in ChannelFormatConverterStream, ChannelFormatConverterStreamT< T >, FormatConverterStream, MP3EncoderShine, NumberFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, Pipeline, PureDataStream, PWMAudioOutput< PWMDriverT >, ResampleStream, ResampleStreamT< TInterpolator >, and SupportedRatesStream.

◆ audioInfoOut() [2/2]

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

provides the actual output AudioInfo: this is usually the same as audioInfo() unless we use a transforming stream

Reimplemented in ChannelFormatConverterStream, ChannelFormatConverterStreamT< T >, FormatConverterStream, MP3EncoderShine, NumberFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, Pipeline, PureDataStream, PWMAudioOutput< PWMDriverT >, ResampleStream, ResampleStreamT< TInterpolator >, and SupportedRatesStream.

◆ begin() [1/2]

virtual bool begin ( AudioInfo info )

inlineoverridevirtualinherited

Reimplemented from AudioWriter.

◆ begin() [2/2]

bool begin ( )

inlineoverridevirtual

Initialize the demuxer and decoder.

Returns: true on success.

Reimplemented from AudioDecoder.

◆ clearNotifyAudioChange() [1/2]

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >, RTSPClient< EthernetClient, EthernetUDP >, and RTSPClient< WiFiClient, WiFiUDP >.

◆ clearNotifyAudioChange() [2/2]

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >, RTSPClient< EthernetClient, EthernetUDP >, and RTSPClient< WiFiClient, WiFiUDP >.

◆ decodeAudio()

void decodeAudio	(	const M4AAudioDemuxer::Frame &	frame,
		void *	ref )

inlinestaticprotected

Static callback for demuxed audio frames. Handles decoder selection and magic cookie for ALAC.

Parameters

frame	The demuxed audio frame.
ref	Reference to the ContainerM4A instance.

◆ end()

void end ( )

inlineoverridevirtual

End the demuxer and decoder, releasing resources.

Reimplemented from AudioDecoder.

◆ getDemuxer()

M4AAudioDemuxer & getDemuxer ( )

inline

◆ getOutput() [1/2]

Print * getOutput ( )

inlineinherited

◆ getOutput() [2/2]

Print * getOutput ( )

inlineinherited

◆ isNotifyActive() [1/2]

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

◆ isNotifyActive() [2/2]

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

◆ isResultPCM()

bool isResultPCM ( )

inlineoverridevirtual

Returns true if the result is PCM (decoder is present).

Returns: true if PCM output, false otherwise.

Reimplemented from ContainerDecoder.

◆ mime()

const char * mime ( )

inlineoverridevirtual

Provides "audio/mp4".

Implements AudioDecoder.

◆ notifyAudioChange() [1/2]

void notifyAudioChange ( AudioInfo info )

inlineprotectedinherited

◆ notifyAudioChange() [2/2]

void notifyAudioChange ( AudioInfo info )

inlineprotectedinherited

◆ operator bool()

operator bool ( )

inlineoverridevirtual

Returns true if the demuxer is active.

Returns: true if active, false otherwise.

Implements AudioWriter.

◆ removeNotifyAudioChange() [1/2]

virtual bool removeNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Removes a target in order not to be notified about audio changes.

◆ removeNotifyAudioChange() [2/2]

virtual bool removeNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Removes a target in order not to be notified about audio changes.

◆ setAudioInfo() [1/2]

void setAudioInfo ( AudioInfo from )

inlineoverridevirtualinherited

for most decoders this is not needed

Implements AudioWriter.

Reimplemented in CodecNOP, and CodecNOP.

◆ setAudioInfo() [2/2]

void setAudioInfo ( AudioInfo from )

inlineoverridevirtualinherited

for most decoders this is not needed

Implements AudioWriter.

Reimplemented in CodecNOP, and CodecNOP.

◆ setChunkOffsetsBuffer()

virtual void setChunkOffsetsBuffer ( BaseBuffer< uint32_t > & buffer )

inlinevirtual

Sets the buffer to use for sample sizes. This is currently not used!

Parameters

buffer Reference to the buffer to use.

◆ setCodecConfig() [1/2]

virtual bool setCodecConfig	(	const uint8_t *	data,
		size_t	len )

inlinevirtualinherited

Some decoders need e.g. a magic cookie to provide the relevant info for decoding.

Reimplemented in DecoderALAC, and MultiDecoder.

◆ setCodecConfig() [2/2]

virtual bool setCodecConfig	(	const uint8_t *	data,
		size_t	len )

inlinevirtualinherited

Some decoders need e.g. a magic cookie to provide the relevant info for decoding.

Reimplemented in DecoderALAC, and MultiDecoder.

◆ setDecoder()

bool setDecoder ( MultiDecoder & decoder )

inline

Sets the decoder to use for audio frames.

Parameters

decoder Reference to a MultiDecoder for PCM output.

Returns: true if set successfully, false otherwise.

◆ setNotifyActive() [1/2]

void setNotifyActive ( bool flag )

inlineinherited

Deactivate/Reactivate automatic AudioInfo updates: (default is active).

◆ setNotifyActive() [2/2]

void setNotifyActive ( bool flag )

inlineinherited

Deactivate/Reactivate automatic AudioInfo updates: (default is active).

◆ setOutput() [1/3]

virtual void setOutput ( AudioOutput & out_stream )

inlinevirtualinherited

Defines where the decoded result is written to.

◆ setOutput() [2/3]

virtual void setOutput ( AudioStream & out_stream )

inlinevirtualinherited

Defines where the decoded result is written to.

◆ setOutput() [3/3]

void setOutput ( Print & out_stream )

inlineoverridevirtual

Set the output stream for decoded or raw audio.

Parameters

out_stream Output AudioStream.

Reimplemented from AudioDecoder.

◆ setSampleSizesBuffer()

virtual void setSampleSizesBuffer ( BaseBuffer< stsz_sample_size_t > & buffer )

inlinevirtual

Sets the buffer to use for sample sizes. You can use this to provide a custom buffer that does not rely on RAM (e.g a file based buffer or one using Redis).

Parameters

buffer Reference to the buffer to use.

◆ write()

size_t write	(	const uint8_t *	data,
		size_t	len )

inlineoverridevirtual

Feed data to the demuxer for parsing.

Parameters

data	Pointer to input data.
len	Length of input data.

Returns: Number of bytes processed (always len).

Implements AudioWriter.

◆ writeBlocking() [1/2]

void writeBlocking	(	Print *	out,
		uint8_t *	data,
		size_t	len )

inlineprotectedinherited

◆ writeBlocking() [2/2]

void writeBlocking	(	Print *	out,
		uint8_t *	data,
		size_t	len )

inlineprotectedinherited

Member Data Documentation

◆ demux

M4AAudioDemuxer demux

protected

Internal demuxer instance.

◆ id

int id

inherited

custom id to be used by application

◆ info

AudioInfo info

protectedinherited

◆ is_active

bool is_active = false

protected

True if demuxer is active.

◆ is_magic_cookie_processed

bool is_magic_cookie_processed

protected

Initial value:

=

false

True if ALAC magic cookie has been processed.

◆ is_notify_active

bool is_notify_active = true

protectedinherited

◆ notify_vector

Vector< AudioInfoSupport * > notify_vector

protectedinherited

◆ p_decoder

MultiDecoder* p_decoder = nullptr

protected

Pointer to the MultiDecoder.

◆ p_print

Print * p_print = nullptr

protectedinherited

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

src/AudioTools/AudioCodecs/ContainerM4A.h

Public Member Functions

Public Attributes

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ContainerM4A() [1/2]

◆ ContainerM4A() [2/2]

Member Function Documentation

◆ addNotifyAudioChange() [1/2]

◆ addNotifyAudioChange() [2/2]

◆ audioInfo() [1/2]

◆ audioInfo() [2/2]

◆ audioInfoOut() [1/2]

◆ audioInfoOut() [2/2]

◆ begin() [1/2]

◆ begin() [2/2]

◆ clearNotifyAudioChange() [1/2]

◆ clearNotifyAudioChange() [2/2]

◆ decodeAudio()

◆ end()

◆ getDemuxer()

◆ getOutput() [1/2]

◆ getOutput() [2/2]

◆ isNotifyActive() [1/2]

◆ isNotifyActive() [2/2]

◆ isResultPCM()

◆ mime()

◆ notifyAudioChange() [1/2]

◆ notifyAudioChange() [2/2]

◆ operator bool()

◆ removeNotifyAudioChange() [1/2]

◆ removeNotifyAudioChange() [2/2]

◆ setAudioInfo() [1/2]

◆ setAudioInfo() [2/2]

◆ setChunkOffsetsBuffer()

◆ setCodecConfig() [1/2]

◆ setCodecConfig() [2/2]

◆ setDecoder()

◆ setNotifyActive() [1/2]

◆ setNotifyActive() [2/2]

◆ setOutput() [1/3]

◆ setOutput() [2/3]

◆ setOutput() [3/3]

◆ setSampleSizesBuffer()

◆ write()

◆ writeBlocking() [1/2]

◆ writeBlocking() [2/2]

Member Data Documentation

◆ demux

◆ id

◆ info

◆ is_active

◆ is_magic_cookie_processed

◆ is_notify_active

◆ notify_vector

◆ p_decoder

◆ p_print