DemuxerMTS Class Reference

ISO/IEC 13818-1 MPEG Transport Stream Demuxer: parses the fixed 188-byte TS packet framing, follows PAT -> PMT to discover the video and (optional) audio elementary stream PIDs and their codec (stream_type), reassembles each PES packet's payload from the TS packets between one payload_unit_start_indicator and the next, and forwards the raw elementary-stream bytes to setOutputVideo()/setOutputAudio() - same scope and design as DemuxerMPG (ContainerMPG.h): no decoding happens here, point the outputs at whatever decoder understands the codec. More...

#include <ContainerMTS.h>

Inheritance diagram for DemuxerMTS:

Public Member Functions
	DemuxerMTS (int bufferSize=8 *MTS_PACKET_SIZE)
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.
bool	isValid (const uint8_t *data, size_t len) override
const char *	mime () override
const char *	mimeVideo () override
	The container's MIME type (e.g. "video/avi", "video/mp4").
	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) override
	Defines where the decoded result is written to.
void	setOutputAudio (Print &out) override
void	setOutputVideo (Print &out) override
void	setOutputVideo (VideoOutput &out) override
void	setSendWavHeader (bool flag) override
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	appendToAudio (const uint8_t *data, size_t len)
void	appendToUnit (bool isVideo, const uint8_t *data, size_t len)
void	appendToVideo (const uint8_t *data, size_t len)
void	flushAudioUnit ()
void	flushUnit (bool isVideo)
void	flushVideoUnit ()
void	handlePesPayload (bool isVideo, const uint8_t *payload, size_t len, bool pusi)
void	notifyAudioChange (AudioInfo info)
bool	parse ()
void	parsePacket (const uint8_t *pkt)
void	parsePat (const uint8_t *data, size_t len, bool pusi)
void	parsePmt (const uint8_t *data, size_t len, bool pusi)
void	probeAudioHeader (const uint8_t *data, size_t len)
void	writeBlocking (Print *out, uint8_t *data, size_t len)

Protected Attributes
uint8_t	audio_channels = 0
bool	audio_frame_open = false
bool	audio_header_parsed = false
uint16_t	audio_pid = 0xFFFF
Vector< uint8_t >	audio_probe
uint32_t	audio_sample_rate = 0
uint8_t	audio_stream_type = 0
Vector< uint8_t >	audio_unit_buffer
size_t	audio_unit_len = 0
AudioInfo	info
bool	is_notify_active = true
bool	is_parsing_active = false
Vector< AudioInfoSupport * >	notify_vector
Print *	p_output_audio = nullptr
Print *	p_output_video = nullptr
VideoOutput *	p_output_video_video = nullptr
Print *	p_print = nullptr
MTSParseBuffer	parse_buffer
uint16_t	pmt_pid = 0xFFFF
uint32_t	total_bytes = 0
bool	video_frame_open = false
uint16_t	video_pid = 0xFFFF
uint8_t	video_stream_type = 0
Vector< uint8_t >	video_unit_buffer
size_t	video_unit_len = 0

Detailed Description

ISO/IEC 13818-1 MPEG Transport Stream Demuxer: parses the fixed 188-byte TS packet framing, follows PAT -> PMT to discover the video and (optional) audio elementary stream PIDs and their codec (stream_type), reassembles each PES packet's payload from the TS packets between one payload_unit_start_indicator and the next, and forwards the raw elementary-stream bytes to setOutputVideo()/setOutputAudio() - same scope and design as DemuxerMPG (ContainerMPG.h): no decoding happens here, point the outputs at whatever decoder understands the codec.

PES packet boundaries (marked by payload_unit_start_indicator) are used directly as access-unit boundaries - i.e. every new PES packet on the video/audio PID flushes the previous one as one complete write() call to the corresponding output, mirroring how a real TS muxer (including MuxerMTS itself) packetizes one access unit per PES packet. This is simpler than DemuxerMPG's own PES-length/start-code-driven framing, because TS's own PID demultiplexing already separates the elementary streams apart - no need to hunt for start codes in a mixed byte stream.

Note

v1 scope: a single video track and a single audio track (the first of each found in the PMT) - multi-program and multi-track transport streams are not supported. Recognized video stream_types are H.264 (0x1B), MPEG-1/2 (0x01/0x02), MPEG-4 (0x10) and MJPEG (0x06 - see MTS_STREAM_TYPE_MJPEG's own comment on why that mapping is a convention, not an ISO standard one); recognized audio stream_types are AAC/ADTS (0x0F) and MPEG-1/2 audio (0x03/0x04). The PES header is assumed to fit within the first TS packet of its PES packet (always true in practice - the PES optional header used here is at most 14 bytes, far under a TS packet's 184-byte payload capacity even with heavy adaptation-field stuffing); a PES header split across a TS packet boundary is logged and that access unit is dropped. Video width/height are not parsed (unlike DemuxerMPG, which can read them from MPEG-1's own sequence_header) - H.264 SPS parsing is out of scope for this library; getVideoInfo() reports only the codec (VideoFormat) and total bytes seen.

DemuxerMTS demuxer;
H264Decoder h264;  // or any AudioTools H264 decoder
demuxer.setOutputVideo(videoOutput);
AACDecoderHelix aac;
EncodedAudioStream audioOut(&i2s, &aac);
demuxer.setOutputAudio(audioOut);
demuxer.begin();
// feed raw .ts bytes:
demuxer.write(tsData, len);

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

DemuxerMTS()

DemuxerMTS ( int  bufferSize = 8 * MTS_PACKET_SIZE )

inline

Parameters

bufferSize

internal parse buffer size - must be able to hold at least one full 188-byte TS packet; a few packets' worth (the default) keeps write() from truncating a typical caller-sized chunk.

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.

appendToAudio()

void appendToAudio ( const uint8_t *  data, size_t  len  )

inlineprotected

appendToUnit()

void appendToUnit ( bool  isVideo, const uint8_t *  data, size_t  len  )

inlineprotected

appendToVideo()

void appendToVideo ( const uint8_t *  data, size_t  len  )

inlineprotected

Appends to video_unit_buffer with amortized (doubling) growth, same rationale as ContainerMPG.h's own appendToVideo/appendToAudio.

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 >.

end()

void end ( )

inlineoverridevirtual

Reimplemented from AudioDecoder.

flushAudioUnit()

void flushAudioUnit ( )

inlineprotected

flushUnit()

void flushUnit ( bool  isVideo )

inlineprotected

flushVideoUnit()

void flushVideoUnit ( )

inlineprotected

getAudioInfo()

AudioInfoFormat getAudioInfo ( )

inlineoverridevirtual

Common audio info, parsed from the audio ES's own ADTS/MPEG-audio frame header once seen - falls back to 44100/stereo if not yet available.

Implements Demuxer.

getOutput()

Print * getOutput ( )

inlineinherited

getVideoInfo()

VideoInfo getVideoInfo ( )

inlineoverridevirtual

Common video info - format is the PMT-reported codec once the PMT has been parsed (VideoFormat::UNKNOWN before then, or if the stream_type isn't one this container recognizes); width/height/fps are not parsed (see class comment) and stay 0.

Implements Demuxer.

handlePesPayload()

void handlePesPayload ( bool  isVideo, const uint8_t *  payload, size_t  len, bool  pusi  )

inlineprotected

Reassembles one PES packet's payload per PID from the TS packets between one payload_unit_start_indicator and the next - see class comment for why a PUSI boundary is used directly as the access-unit boundary instead of tracking PES_packet_length.

isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

isValid()

bool isValid ( const uint8_t *  data, size_t  len  )

inlineoverridevirtual

True if data starts with the TS sync byte (0x47), confirmed by a second sync byte 188 bytes later when enough data is available - see Demuxer::isValid().

Reimplemented from Demuxer.

mime()

const char * mime ( )

inlineoverridevirtual

Provides the audio mime, derived from the PMT's audio stream_type once parsed - "audio/aac" (the common case for .ts/HLS content) before that.

Implements Demuxer.

mimeVideo()

const char * mimeVideo ( )

inlineoverridevirtual

The container's MIME type (e.g. "video/avi", "video/mp4").

Implements Demuxer.

notifyAudioChange()

void notifyAudioChange ( AudioInfo  info )

inlineprotectedinherited

operator bool()

operator bool ( )

inlineoverridevirtual

Implements AudioWriter.

parse()

bool parse ( )

inlineprotected

Consumes one 188-byte packet (resyncing on the sync byte first, if needed) and parses it. Returns true if progress was made (call again

• more packets may already be buffered), false if it needs more data.

parsePacket()

void parsePacket ( const uint8_t *  pkt )

inlineprotected

parsePat()

void parsePat ( const uint8_t *  data, size_t  len, bool  pusi  )

inlineprotected

Parses the Program Association Section, picking the PID of the PMT for the first program listed (program_number != 0).

parsePmt()

void parsePmt ( const uint8_t *  data, size_t  len, bool  pusi  )

inlineprotected

Parses the (single-section) Program Map, picking out the PID/ stream_type of the first video and first audio elementary stream.

probeAudioHeader()

void probeAudioHeader ( const uint8_t *  data, size_t  len  )

inlineprotected

Inspects the first bytes of the audio ES for an ADTS (AAC) or MPEG audio frame header - whichever matches audio_stream_type - to determine sample_rate/channels. Same approach as ContainerMPG.h's probeAudioHeader(), adapted for ADTS's layout.

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 where the decoded result is written to.

Reimplemented from AudioDecoder.

setOutputAudio()

void setOutputAudio ( Print &  out )

inlineoverridevirtual

Defines the audio output stream - e.g. an EncodedAudioStream wrapping an AudioDecoder that matches the track's codec, or any other Print if you want the raw payload as-is.

Implements Demuxer.

setOutputVideo() [1/2]

void setOutputVideo ( Print &  out )

inlineoverridevirtual

Defines the video output - e.g. a VideoOutput implementation, or any other Print if you want the raw payload as-is.

Implements Demuxer.

setOutputVideo() [2/2]

void setOutputVideo ( VideoOutput &  out )

inlineoverridevirtual

Defines the video output - the VideoOutput-specific counterpart of setOutputVideo(Print&), for a target like PacedVideoOutput/ OutputTinyGPU/OutputOpenCV that implements VideoOutput but not Print (the two are unrelated types - see VideoFrameMeter's own comment). Part of the base interface (unlike other concrete-class-specific extras) so code holding only a Demuxer& (e.g. VideoPlayer) can wire it to an arbitrary VideoOutput& without knowing the concrete container format - every current demuxer already implemented this identically before it was pulled up into the interface.

Implements Demuxer.

setSendWavHeader()

void setSendWavHeader ( bool  flag )

inlineoverridevirtual

Not applicable: both AAC (ADTS) and MPEG audio are compressed and self-framed, never PCM - provided only to satisfy the Demuxer interface.

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

audio_channels

uint8_t audio_channels = 0

protected

audio_frame_open

bool audio_frame_open = false

protected

audio_header_parsed

bool audio_header_parsed = false

protected

audio_pid

uint16_t audio_pid = 0xFFFF

protected

audio_probe

Vector<uint8_t> audio_probe

protected

audio_sample_rate

uint32_t audio_sample_rate = 0

protected

audio_stream_type

uint8_t audio_stream_type = 0

protected

audio_unit_buffer

Vector<uint8_t> audio_unit_buffer

protected

audio_unit_len

size_t audio_unit_len = 0

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

is_parsing_active

bool is_parsing_active = false

protected

notify_vector

Vector<AudioInfoSupport*> notify_vector

protectedinherited

p_output_audio

Print* p_output_audio = nullptr

protected

p_output_video

Print* p_output_video = nullptr

protected

p_output_video_video

VideoOutput* p_output_video_video = nullptr

protected

p_print

Print* p_print = nullptr

protectedinherited

parse_buffer

MTSParseBuffer parse_buffer

protected

pmt_pid

uint16_t pmt_pid = 0xFFFF

protected

total_bytes

uint32_t total_bytes = 0

protected

video_frame_open

bool video_frame_open = false

protected

video_pid

uint16_t video_pid = 0xFFFF

protected

video_stream_type

uint8_t video_stream_type = 0

protected

video_unit_buffer

Vector<uint8_t> video_unit_buffer

protected

video_unit_len

size_t video_unit_len = 0

protected

---

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

• src/AudioTools/AudioCodecs/ContainerMTS.h