Muxer Class Reference

Common interface for muxers (MuxerAVI, MuxerMP4) that combine an already-encoded video track (and optionally an audio track) into a container written to a Print (a local File to record, or e.g. a network Client to publish a live stream to an HTTP/TCP client). Write code against this interface instead of a concrete class if it should work with either container format. More...

#include <ContainerCommon.h>

Inheritance diagram for Muxer:

Public Member Functions
virtual size_t	addAudioFrame (const uint8_t *data, size_t len)=0
virtual size_t	addI420Frame (const uint8_t *data, size_t len)=0
virtual size_t	addJpegFrame (const uint8_t *data, size_t len)=0
virtual size_t	addRGB565Frame (const uint8_t *data, size_t len)=0
virtual size_t	addVideoFrame (const uint8_t *data, size_t len, bool isKeyFrame=true)=0
virtual size_t	addYUV422Frame (const uint8_t *data, size_t len)=0
virtual AudioInfoFormat &	audioInfo ()=0
	Provides read/write access to the audio track's AudioInfoFormat.
virtual bool	begin ()=0
virtual void	end ()=0
	Closes the muxer.
virtual void	flush ()
float	getAudioSamplesPerVideoFrame ()
virtual MuxerVideoConfig	getVideoInfo ()=0
	Provides the video track configuration.
virtual const char *	mime ()=0
virtual	operator bool ()=0
virtual void	setAudioInfo (AudioInfoFormat info)=0
virtual void	setOutput (Print &out)=0
	Defines the output: e.g. a local File or a network Client.
virtual void	setStreamType (StreamContentType type)=0
	Selects whether write() feeds the video or the audio track.
virtual void	setVideoInfo (MuxerVideoConfig config)=0
	Defines the video track configuration - call before begin()
virtual StreamContentType	streamType ()=0
	The track write() currently targets (see setStreamType())
virtual size_t	write (const uint8_t *data, size_t len)=0

Protected Attributes
Print *	p_print = nullptr

Detailed Description

Common interface for muxers (MuxerAVI, MuxerMP4) that combine an already-encoded video track (and optionally an audio track) into a container written to a Print (a local File to record, or e.g. a network Client to publish a live stream to an HTTP/TCP client). Write code against this interface instead of a concrete class if it should work with either container format.

write() (VideoOutput) treats each call as one complete, already-encoded frame for both MuxerAVI and MuxerMP4 - callers must hand over the full frame in a single call, not build it up incrementally across several write() calls. flush() is a no-op for both.

Author

Phil Schatzmann

Copyright

GPLv3

Member Function Documentation

addAudioFrame()

virtual size_t addAudioFrame ( const uint8_t *  data, size_t  len  )

pure virtual

Writes one complete audio frame/block. Meaning is container- and codec-specific (e.g. one raw AAC frame vs. an arbitrary PCM block); see the concrete class.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

addI420Frame()

virtual size_t addI420Frame ( const uint8_t *  data, size_t  len  )

pure virtual

Writes one planar 4:2:0 YUV (I420/IYUV) frame. Expects exactly width*height*3/2 bytes.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

addJpegFrame()

virtual size_t addJpegFrame ( const uint8_t *  data, size_t  len  )

pure virtual

Writes one complete Motion-JPEG frame (a full, already-encoded JPEG image).

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

addRGB565Frame()

virtual size_t addRGB565Frame ( const uint8_t *  data, size_t  len  )

pure virtual

Writes one uncompressed RGB565 (16-bit, 5-6-5) frame. Expects exactly width*height*2 bytes.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

addVideoFrame()

virtual size_t addVideoFrame ( const uint8_t *  data, size_t  len, bool  isKeyFrame = true  )

pure virtual

Writes one complete, already-encoded video frame (e.g. one H.264 access unit).

Parameters

isKeyFrame

hints that the frame is independently decodable (a sync/seek point) - used where the container format can express it (e.g. MP4's 'trun' sample flags); ignored where it can't (AVI).

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

addYUV422Frame()

virtual size_t addYUV422Frame ( const uint8_t *  data, size_t  len  )

pure virtual

Writes one packed 4:2:2 YUV frame (YUY2/YUYV byte order). Expects exactly width*height*2 bytes.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

audioInfo()

virtual AudioInfoFormat & audioInfo ( )

pure virtual

Provides read/write access to the audio track's AudioInfoFormat.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

begin()

virtual bool begin ( )

pure virtual

Writes the container header. Call after configuring video (and audio, if any) and before writing any frames.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

end()

virtual void end ( )

pure virtual

Closes the muxer.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

flush()

virtual void flush ( )

inlinevirtual

Finalizes the frame most recently written via one or more write() calls - see class comment. Default no-op for implementations that display/decode synchronously in write() instead.

Reimplemented from VideoOutput.

getAudioSamplesPerVideoFrame()

float getAudioSamplesPerVideoFrame ( )

inline

Average number of audio samples per video frame, derived from audioInfo().sample_rate and getVideoInfo().fps - the natural audio chunk size to write once per video frame if you want to keep both tracks advancing at roughly the same pace as you write them (not a hard requirement - see addAudioFrame()/addVideoFrame()). 0 if fps hasn't been set.

getVideoInfo()

virtual MuxerVideoConfig getVideoInfo ( )

pure virtual

Provides the video track configuration.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

mime()

virtual const char * mime ( )

pure virtual

The container's MIME type (e.g. "video/avi", "video/mp4") - useful for e.g. an HTTP Content-Type header when streaming the muxed output to a client.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

operator bool()

virtual operator bool ( )

pure virtual

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

setAudioInfo()

virtual void setAudioInfo ( AudioInfoFormat  info )

pure virtual

Adds an (optional) interleaved audio track, including the codec selection (the 'format' field) - which AudioFormat values are actually supported (and what they mean, e.g. default codec if unset) is container-specific; see the concrete class. Call before begin().

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

setOutput()

virtual void setOutput ( Print &  out )

pure virtual

Defines the output: e.g. a local File or a network Client.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

setStreamType()

virtual void setStreamType ( StreamContentType  type )

pure virtual

Selects whether write() feeds the video or the audio track.

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

setVideoInfo()

virtual void setVideoInfo ( MuxerVideoConfig  config )

pure virtual

Defines the video track configuration - call before begin()

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

streamType()

virtual StreamContentType streamType ( )

pure virtual

The track write() currently targets (see setStreamType())

Implemented in MuxerAVI, MuxerMP4, and MuxerMPG.

write()

virtual size_t write ( const uint8_t *  data, size_t  len  )

pure virtualinherited

Implemented in MuxerAVI, MuxerMP4, MuxerMPG, H264Decoder, H264DecoderESP32S3< Alloc >, MJPEGDecoder, MPGDecoder, OutputOpenCV, OutputTFT_eSPI, and OutputTinyGPU.

Member Data Documentation

p_print

Print* p_print = nullptr

protected

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

• src/AudioTools/AudioCodecs/ContainerCommon.h