FileFrameFilter Class Reference

Pipe stream into a matroska (mkv) file. More...

#include <fileframefilter.h>

Inheritance diagram for FileFrameFilter:

Collaboration diagram for FileFrameFilter:

Public Member Functions
	FileFrameFilter (const char *name, FrameFilter *next=NULL)
	Default constructor. More...
	~FileFrameFilter ()
	Default destructor.
void	activate (const char *fname, long int zerotime=0)
	Request streaming to disk asap (when config frames have arrived) // <pyapi>
void	deActivate ()
	Stop streaming to disk // <pyapi>
Public Member Functions inherited from FrameFilter
	FrameFilter (const char *name, FrameFilter *next=NULL)
	Default constructor. More...
virtual	~FrameFilter ()
	Virtual destructor // <pyapi>
virtual void	run (Frame *frame)
	Calls this->go(Frame* frame) and then calls the this->next->run(Frame* frame) (if this->next != NULL)
void	setVoid ()
	nullifies the next framefilter in the chain -> cuts the framefilter chain

Protected Member Functions
void	go (Frame *frame)
	Does the actual filtering/modification to the Frame. Define in subclass.
void	initFile ()
	Open file, reserve codec_contexes, streams, write preamble, set initialized=true if success.
void	closeFile ()
	Close file, dealloc codec_contexes, streams.
void	deActivate_ ()
void	writeHeader ()

Protected Attributes
bool	active
	Writing to file has been requested (but not necessarily achieved..)
bool	ready
	Got enough setup frames.
bool	initialized
	File was opened ok : codec_contexes, streams and av_format_context reserved (should be freed at some point)
long int	mstimestamp0
	Time of activation (i.e. when the recording started)
long int	zerotime
	Start time set explicitly by the user.
bool	zerotimeset
std::string	filename
AVRational	timebase
std::vector< AVCodecContext * >	codec_contexes
std::vector< AVStream * >	streams
AVFormatContext *	av_format_context
AVPacket *	avpkt
std::mutex	mutex
	Mutex protecting the "active" boolean.
std::condition_variable	condition
	Condition variable for the mutex.
std::vector< SetupFrame >	setupframes
	deep copies of the arrived setup frames
BasicFrame	internal_frame
	copy of the arrived frame and payload

Additional Inherited Members
Public Attributes inherited from FrameFilter
std::string	name
FrameFilter *	next
	The next frame filter in the chain to be applied.

Detailed Description

Pipe stream into a matroska (mkv) file.

This FrameFilter should be connected to the live stream at all times: it observes the setup frames (FrameTypes::setup) and saves them internally.

When the FileFrameFilter::activate method is called, it configures the files accordingly, and starts streaming into disk.

Notes about FFmpeg muxing & file output:

AVCodecContext : defines the codec AVFormatContext : defines the (de)muxing & has pointers to AVIOContext (in the ->pb member) AVIOContext : defines the input / output file AVStream : raw payload (video track, audio track)

avformat_alloc_output_context2(AVFormatContext* av_format_context, NULL, "matroska", NULL);

avio_open(AVIOContext* av_format_context->pb, filename.c_str(), AVIO_FLAG_WRITE);

AVStream* av_stream = avformat_new_stream(AVFormatContext* av_format_context, AVCodec* av_codec_context->codec);

Actual writing like this:

av_interleaved_write_frame(AVFormatContext* av_format_context, avpkt);

For an actual muxer implementation, see for example libavformat/movenc.c : ff_mov_write_packet => avio_write(pb, reformatted_data, size); (i.e. it uses the AVIOContext) ==> https://ffmpeg.org/doxygen/2.8/aviobuf_8c_source.html#l00178

AVIOContext is C-style "class" that can be re-defined: https://ffmpeg.org/doxygen/2.8/structAVIOContext.html

A custom AVIOContext can be created with "avio_alloc_context"

Constructor & Destructor Documentation

FileFrameFilter()

FileFrameFilter::FileFrameFilter	(	const char *	name,
		FrameFilter *	next = NULL
	)

Default constructor.

Parameters

name	name
next	next framefilter to be applied in the filterchain

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

• /home/sampsa/C/valkka/include/fileframefilter.h
• /home/sampsa/C/valkka/src/fileframefilter.cpp