MultiVideoDemuxer Class Reference

Manages multiple Demuxers with automatic container-format detection - the container-side counterpart of MultiVideoDecoder (Video/MultiVideoDecoder.h), which does the same job one layer down for the video elementary stream's own codec. No demuxers are registered by default and this header has no container-parser dependency of its own (it only needs the Demuxer interface, ContainerCommon.h) - register whichever concrete demuxers (DemuxerAVI/DemuxerMP4/DemuxerMPG) your content actually needs via addDemuxer(). More...

#include <MultiVideoDemuxer.h>

Inheritance diagram for MultiVideoDemuxer:

Public Member Functions
void	addDemuxer (Demuxer &demuxer)
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
AudioInfoFormat	getAudioInfo () override
Print *	getOutput ()
VideoInfo	getVideoInfo () override
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
virtual bool	isValid (const uint8_t *data, size_t len)
const char *	mime () override
const char *	mimeVideo () override
	operator bool () override
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
Demuxer *	selectedDemuxer () const
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) override
void	setOutputAudio (Print &out) override
void	setOutputVideo (Print &out) override
void	setOutputVideo (VideoOutput &out) override
void	setSendWavHeader (bool flag) override
	Forwarded to every registered demuxer eagerly (see class comment).
VideoInfo	videoInfo () override
size_t	write (const uint8_t *data, size_t len) override

Public Attributes
int	id
	custom id to be used by application

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

Protected Attributes
Vector< Demuxer * >	demuxers {0}
AudioInfo	info
bool	is_first = true
bool	is_notify_active = true
Vector< AudioInfoSupport * >	notify_vector
Print *	p_print = nullptr
Demuxer *	p_selected = nullptr

Detailed Description

Manages multiple Demuxers with automatic container-format detection - the container-side counterpart of MultiVideoDecoder (Video/MultiVideoDecoder.h), which does the same job one layer down for the video elementary stream's own codec. No demuxers are registered by default and this header has no container-parser dependency of its own (it only needs the Demuxer interface, ContainerCommon.h) - register whichever concrete demuxers (DemuxerAVI/DemuxerMP4/DemuxerMPG) your content actually needs via addDemuxer().

Drop it in wherever a plain Demuxer& is expected - VideoPlayer in fact uses one internally as its own built-in demuxer, with addDemuxer() registering against it - or feed it via write() directly, and it self-selects the right registered demuxer from the stream's own container signature instead of the caller having to know the file format up front.

Detection runs once, on the very first write() call: each registered demuxer's own Demuxer::isValid() (content-sniffing - a virtual method with a default-false implementation, so a demuxer only takes part if it actually overrides it; DemuxerAVI/DemuxerMP4/DemuxerMPG all do - see their own class comments) is tried, in registration order, against that first call's bytes. Reliable in practice since every real container signature (AVI's "RIFF"/"AVI ", MP4's "ftyp" box, MPG's pack start_code) falls within the first dozen bytes of the file, comfortably inside any realistic first read/write() chunk. Every subsequent write() call, plus every other Demuxer method, is forwarded to that same demuxer for the rest of the stream - never re-detected.

setOutputAudio()/setOutputVideo()/setSendWavHeader() are applied to every registered demuxer eagerly (cheap - just stores pointers/a flag, no allocation) - call addDemuxer() for all of them before these, so whichever one gets selected on the first write() is already wired. Only the actually-selected demuxer's begin() is called (on selection, from inside write()) - matching MultiVideoDecoder's own memory-efficient lazy-init rationale.

Author

Phil Schatzmann

Copyright

GPLv3

Member Function Documentation

addDemuxer()

void addDemuxer ( Demuxer &  demuxer )

inline

Registers a demuxer under its own Demuxer::mimeVideo() - see the class comment for when/how it's later selected (content-sniffing via its own Demuxer::isValid()). Call before the first write() reaches this object.

Replaces, rather than adds to, any demuxer already registered under the same mimeVideo() - at most one entry per container format, for the same reason MultiVideoDecoder::addDecoder() does: a stale second entry for the same format would otherwise be permanently unreachable dead weight, never actually selected.

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

Defers actual demuxer init to the first write() (see class comment)

• always succeeds itself.

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 >.

end()

void end ( )

inlineoverridevirtual

Reimplemented from AudioDecoder.

getAudioInfo()

AudioInfoFormat getAudioInfo ( )

inlineoverridevirtual

Common audio info of the currently selected demuxer - an empty AudioInfoFormat before the first write()/if none matched.

Implements Demuxer.

getOutput()

Print * getOutput ( )

inlineinherited

getVideoInfo()

VideoInfo getVideoInfo ( )

inlineoverridevirtual

Common video info of the currently selected demuxer - an empty VideoInfo before the first write()/if none matched.

Implements Demuxer.

isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

isValid()

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

inlinevirtualinherited

True if data (the start of the stream, as handed to the first write()) looks like this demuxer's own container format - content-sniffing, not a guarantee (see the concrete class for exactly what's checked). Used by MultiVideoDemuxer to auto-select a registered demuxer (MultiVideoDemuxer.h); not otherwise part of the write()/parse path. Default false, matching VideoDecoder::isValid()'s own default - a demuxer not meant to be auto-detected this way simply never overrides it.

Reimplemented in DemuxerAVI, DemuxerMP4, and DemuxerMPG.

mime()

const char * mime ( )

inlineoverridevirtual

The audio MIME type of the currently selected demuxer's audio track

• see Demuxer::mime(). nullptr before the first write()/if none matched, or (depending on the concrete demuxer) until enough of the audio track's own metadata has been parsed.

Implements Demuxer.

mimeVideo()

const char * mimeVideo ( )

inlineoverridevirtual

The container MIME type of the currently selected demuxer (e.g. "video/avi") - nullptr before the first write()/if none matched.

Implements Demuxer.

notifyAudioChange()

void notifyAudioChange ( AudioInfo  info )

inlineprotectedinherited

operator bool()

operator bool ( )

inlineoverridevirtual

Implements AudioWriter.

removeNotifyAudioChange()

virtual bool removeNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

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

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

select()

void select ( Demuxer *  demuxer )

inlineprotected

selectedDemuxer()

Demuxer * selectedDemuxer ( ) const

inline

The demuxer detection picked for the current stream - nullptr before the first write(), or if none matched.

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 )

inlineoverridevirtual

Satisfies the AudioWriter/AudioDecoder interface - delegates to setOutputAudio(), matching every concrete Demuxer's own convention.

Reimplemented from AudioDecoder.

setOutputAudio()

void setOutputAudio ( Print &  out )

inlineoverridevirtual

Defines the audio output stream - forwarded to every registered demuxer eagerly (see class comment).

Implements Demuxer.

setOutputVideo() [1/2]

void setOutputVideo ( Print &  out )

inlineoverridevirtual

Defines the video output - forwarded to every registered demuxer eagerly (see class comment).

Implements Demuxer.

setOutputVideo() [2/2]

void setOutputVideo ( VideoOutput &  out )

inlineoverridevirtual

See Demuxer::setOutputVideo(VideoOutput&) - forwarded to every registered demuxer eagerly (same rationale as the Print& overload above).

Implements Demuxer.

setSendWavHeader()

void setSendWavHeader ( bool  flag )

inlineoverridevirtual

Forwarded to every registered demuxer eagerly (see class comment).

Implements Demuxer.

videoInfo()

VideoInfo videoInfo ( )

inlineoverridevirtualinherited

Fulfills VideoInfoSource::videoInfo(), so any Demuxer can be passed directly to e.g. OutputOpenCV::setVideoInfoSource() - note the reported 'format' is the container's codec (e.g. H264), not necessarily what ends up written to a raw-picture VideoOutput/Print (that depends on whatever decoder sits between the demuxer and the output); consumers that care about the decoded format should still set it explicitly and rely on this only for width/height.

Implements VideoInfoSource.

write()

size_t write ( const uint8_t *  data, size_t  len  )

inlineoverridevirtual

Implements AudioWriter.

writeBlocking()

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

inlineprotectedinherited

Member Data Documentation

demuxers

Vector<Demuxer *> demuxers {0}

protected

id

int id

inherited

custom id to be used by application

info

AudioInfo info

protectedinherited

is_first

bool is_first = true

protected

is_notify_active

bool is_notify_active = true

protectedinherited

notify_vector

Vector<AudioInfoSupport*> notify_vector

protectedinherited

p_print

Print* p_print = nullptr

protectedinherited

p_selected

Demuxer* p_selected = nullptr

protected

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

• src/AudioTools/Video/MultiVideoDemuxer.h