Decoder for MPEG-1 Layer II (MP2) audio using the TinyMP2 library. Compressed data provided via write() does not need to be aligned on frame boundaries: bytes are accumulated internally and decoded frame by frame; any invalid/garbage bytes are skipped automatically (resync). More...

#include <CodecMP2.h>

Inheritance diagram for MP2Decoder:

Public Member Functions
	MP2Decoder ()=default

	~MP2Decoder ()

virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.

AudioInfo	audioInfo () override
	provides the actual input AudioInfo

virtual AudioInfo	audioInfoOut ()

bool	begin () override

virtual bool	begin (AudioInfo info) override

virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.

void	end () override

Print *	getOutput ()

bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.

virtual bool	isResultPCM ()
	Returns true to indicate that the decoding result is PCM data.

const char *	mime () override
	Provides the mime type of the data that is expected by this decoder.

	operator bool () override

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

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.

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
	Defines the output Stream.

size_t	write (const uint8_t *data, size_t len) override
	Provide compressed MP2 data: no frame alignment required.

Public Attributes
int	id
	custom id to be used by application

Protected Member Functions
void	decode ()

void	notifyAudioChange (AudioInfo info)

void	provideResult (TinyMP2Decoder::FrameHeader &header)
	Notifies about audio info changes and writes the decoded PCM data.

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

Protected Attributes
bool	active = false

Vector< uint8_t >	buffer {0}

TinyMP2Decoder	decoder

AudioInfo	info

bool	is_notify_active = true

Vector< AudioInfoSupport * >	notify_vector

Print *	p_print = nullptr

Vector< int16_t >	pcm {0}

Detailed Description

Decoder for MPEG-1 Layer II (MP2) audio using the TinyMP2 library. Compressed data provided via write() does not need to be aligned on frame boundaries: bytes are accumulated internally and decoded frame by frame; any invalid/garbage bytes are skipped automatically (resync).

Depends on https://github.com/pschatzmann/TinyMP2

Author: Phil Schatzmann

Copyright: GPLv3

Constructor & Destructor Documentation

◆ MP2Decoder()

MP2Decoder ( )

default

◆ ~MP2Decoder()

~MP2Decoder ( )

inline

Member Function Documentation

◆ addNotifyAudioChange()

virtual void addNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, EncodedAudioOutput, EncodedAudioStream, AACDecoderFDK, DecoderBasic, CodecChain, MP3DecoderHelix, MP3DecoderMAD, OggContainerDecoder, RTSPClient< TcpClient, UdpSocket >, Pipeline, and Pipeline::ModifyingStreamAdapter.

◆ audioInfo()

AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

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

◆ audioInfoOut()

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

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

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

◆ begin() [1/2]

bool begin ( )

inlineoverridevirtual

Reimplemented from AudioDecoder.

◆ begin() [2/2]

virtual bool begin ( AudioInfo info )

inlineoverridevirtualinherited

Reimplemented from AudioWriter.

Reimplemented in DecoderBasic, and OggContainerDecoder.

◆ clearNotifyAudioChange()

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

◆ decode()

void decode ( )

inlineprotected

Decodes as many complete frames as are available in buffer; leading garbage is skipped one byte at a time, trailing incomplete data is kept for the next write()

◆ end()

void end ( )

inlineoverridevirtual

Reimplemented from AudioDecoder.

◆ getOutput()

Print * getOutput ( )

inlineinherited

◆ isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

◆ isResultPCM()

virtual bool isResultPCM ( )

inlinevirtualinherited

Returns true to indicate that the decoding result is PCM data.

Reimplemented in CopyDecoder, DecoderNetworkFormat, and ContainerM4A.

◆ mime()

const char * mime ( )

inlineoverridevirtual

Provides the mime type of the data that is expected by this decoder.

Implements AudioDecoder.

◆ notifyAudioChange()

void notifyAudioChange ( AudioInfo info )

inlineprotectedinherited

◆ operator bool()

operator bool ( )

inlineoverridevirtual

Implements AudioWriter.

◆ provideResult()

void provideResult ( TinyMP2Decoder::FrameHeader & header )

inlineprotected

Notifies about audio info changes and writes the decoded PCM data.

◆ removeNotifyAudioChange()

virtual bool removeNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

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

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

◆ setAudioInfo()

void setAudioInfo ( AudioInfo from )

inlineoverridevirtualinherited

for most decoders this is not needed

Implements AudioWriter.

Reimplemented in DecoderALAC, CodecChain, DSFDecoder, DecoderL8, OpusAudioDecoder, OpusMultiStreamAudioDecoder, CodecNOP, G729Decoder, and G7xxDecoder.

◆ setCodecConfig()

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.

◆ setNotifyActive()

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.

Reimplemented in ADTSDecoder, CodecChain, MTSDecoder, MTSDecoderTSDemux, and MetaDataFilterDecoder.

◆ setOutput() [2/3]

virtual void setOutput ( AudioStream & out_stream )

inlinevirtualinherited

Defines where the decoded result is written to.

Reimplemented in ADTSDecoder, CodecChain, MTSDecoder, MTSDecoderTSDemux, and MetaDataFilterDecoder.

◆ setOutput() [3/3]

void setOutput ( Print & out_stream )

inlineoverridevirtual

Defines the output Stream.

Reimplemented from AudioDecoder.

◆ write()

size_t write	(	const uint8_t *	data,
		size_t	len
	)

inlineoverridevirtual

Provide compressed MP2 data: no frame alignment required.

Implements AudioWriter.

◆ writeBlocking()

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

inlineprotectedinherited

Member Data Documentation

◆ active

bool active = false

protected

◆ buffer

Vector<uint8_t> buffer {0}

protected

◆ decoder

TinyMP2Decoder decoder

protected

◆ id

int id

inherited

custom id to be used by application

◆ info

AudioInfo info

protectedinherited

◆ is_notify_active

bool is_notify_active = true

protectedinherited

◆ notify_vector

Vector<AudioInfoSupport*> notify_vector

protectedinherited

◆ p_print

Print* p_print = nullptr

protected

◆ pcm

Vector<int16_t> pcm {0}

protected

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

src/AudioTools/AudioCodecs/CodecMP2.h

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ MP2Decoder()

◆ ~MP2Decoder()

Member Function Documentation

◆ addNotifyAudioChange()

◆ audioInfo()

◆ audioInfoOut()

◆ begin() [1/2]

◆ begin() [2/2]

◆ clearNotifyAudioChange()

◆ decode()

◆ end()

◆ getOutput()

◆ isNotifyActive()

◆ isResultPCM()

◆ mime()

◆ notifyAudioChange()

◆ operator bool()

◆ provideResult()

◆ removeNotifyAudioChange()

◆ setAudioInfo()

◆ setCodecConfig()

◆ setNotifyActive()

◆ setOutput() [1/3]

◆ setOutput() [2/3]

◆ setOutput() [3/3]

◆ write()

◆ writeBlocking()

Member Data Documentation

◆ active

◆ buffer

◆ decoder

◆ id

◆ info

◆ is_notify_active

◆ notify_vector

◆ p_print

◆ pcm