The MediaParser class provides cursor-based access to encoded media frames. More...

#include <MediaParser.h>

Inheritance diagram for gnash::media::MediaParser:

Public Types
typedef std::multimap < boost::uint64_t, boost::shared_ptr < SimpleBuffer > >	MetaTags
	A container for executable MetaTags contained in media streams.
typedef std::vector < MetaTags::mapped_type >	OrderedMetaTags
Public Member Functions
	MediaParser (std::auto_ptr< IOChannel > stream)
virtual	~MediaParser ()
virtual bool	seek (boost::uint32_t &time)=0
	Seeks to the closest possible position the given position, and returns the new position.
DSOEXPORT boost::uint64_t	getBufferLength () const
	Returns mininum length of available buffers in milliseconds.
DSOEXPORT bool	isBufferEmpty () const
	Return true if both audio and video buffers are empty.
DSOEXPORT boost::uint64_t	getBufferTime () const
	Return the time we want the parser thread to maintain in the buffer.
DSOEXPORT void	setBufferTime (boost::uint64_t t)
	Set the time we want the parser thread to maintain in the buffer.
DSOEXPORT bool	nextFrameTimestamp (boost::uint64_t &ts) const
	Get timestamp of the next frame available, if any.
DSOEXPORT bool	nextVideoFrameTimestamp (boost::uint64_t &ts) const
	Get timestamp of the video frame which would be returned on nextVideoFrame.
DSOEXPORT std::auto_ptr < EncodedVideoFrame >	nextVideoFrame ()
	Returns the next video frame in the parsed buffer, advancing video cursor.
DSOEXPORT bool	nextAudioFrameTimestamp (boost::uint64_t &ts) const
	Get timestamp of the audio frame which would be returned on nextAudioFrame.
DSOEXPORT std::auto_ptr < EncodedAudioFrame >	nextAudioFrame ()
	Returns the next audio frame in the parsed buffer, advancing audio cursor.
VideoInfo *	getVideoInfo ()
	Returns a VideoInfo class about the videostream.
AudioInfo *	getAudioInfo ()
	Returns a AudioInfo class about the audiostream.
bool	parsingCompleted () const
	Return true of parsing is completed.
virtual bool	indexingCompleted () const
	Return true of indexing is completed.
virtual boost::uint64_t	getBytesLoaded () const
	Return number of bytes parsed so far.
boost::uint64_t	getBytesTotal () const
	Return total number of bytes in input.
virtual bool	parseNextChunk ()=0
	Parse next chunk of input.
virtual void	fetchMetaTags (OrderedMetaTags &tags, boost::uint64_t ts)
	Retrieve any parsed metadata tags up to a specified timestamp.
virtual boost::optional< Id3Info >	getId3Info () const
	Get ID3 data from the parsed stream if it exists.
std::auto_ptr< VideoInfo >	_videoInfo
	Subclasses must set the following variables:
std::auto_ptr< AudioInfo >	_audioInfo
	Info about the audio stream (if any)
bool	_parsingComplete
	Whether the parsing is complete or not.
boost::uint64_t	_bytesLoaded
	Number of bytes loaded.
std::auto_ptr< IOChannel >	_stream
	The stream used to access the file.
boost::mutex	_streamMutex
boost::uint64_t	_bufferTime
boost::mutex	_bufferTimeMutex
std::auto_ptr< boost::thread >	_parserThread
boost::barrier	_parserThreadStartBarrier
boost::mutex	_parserThreadKillRequestMutex
bool	_parserThreadKillRequested
boost::condition	_parserThreadWakeup
boost::mutex	_qMutex
	mutex protecting access to the a/v encoded frames queues
boost::mutex	_bytesLoadedMutex
	Mutex protecting _bytesLoaded (read by main, set by parser)
bool	_seekRequest
void	startParserThread ()
	}@
void	stopParserThread ()
	Stop the parser thread.
void	clearBuffers ()
	Clear the a/v buffers.
void	pushEncodedAudioFrame (std::auto_ptr< EncodedAudioFrame > frame)
	Push an encoded audio frame to buffer.
void	pushEncodedVideoFrame (std::auto_ptr< EncodedVideoFrame > frame)
	Push an encoded video frame to buffer.
void	parserLoop ()
bool	parserThreadKillRequested () const
void	waitIfNeeded (boost::mutex::scoped_lock &qMutexLock)
void	wakeupParserThread ()
bool	bufferFull () const
	Method to check if buffer is full w/out locking the _qMutex.
static void	parserLoopStarter (MediaParser *mp)

Detailed Description

The MediaParser class provides cursor-based access to encoded media frames.

Cursor-based access allow seeking as close as possible to a specified time and fetching frames from there on, sequentially. See seek(), nextVideoFrame(), nextAudioFrame()

Input is received from a IOChannel object.

Member Typedef Documentation

typedef std::multimap<boost::uint64_t, boost::shared_ptr<SimpleBuffer> > gnash::media::MediaParser::MetaTags

A container for executable MetaTags contained in media streams.

Presently only known in FLV.

typedef std::vector<MetaTags::mapped_type> gnash::media::MediaParser::OrderedMetaTags

Constructor & Destructor Documentation

gnash::media::MediaParser::MediaParser ( std::auto_ptr< IOChannel > stream )

gnash::media::MediaParser::~MediaParser ( ) [virtual]

References stopParserThread(), gnash::key::i, and gnash::key::e.

Member Function Documentation

bool gnash::media::MediaParser::bufferFull ( ) const [protected]

Method to check if buffer is full w/out locking the _qMutex.

This is intended for being called by waitIfNeeded, which is passed a locked lock on _qMutex, and by parseNextChunk to determine whether to index-only or also push on queue.

References getBufferTime().

Referenced by gnash::media::FLVParser::parseNextChunk(), and waitIfNeeded().

void gnash::media::MediaParser::clearBuffers ( ) [protected]

Clear the a/v buffers.

References _qMutex, gnash::key::i, gnash::key::e, and _parserThreadWakeup.

Referenced by gnash::media::FLVParser::seek(), and gnash::media::ffmpeg::MediaParserFfmpeg::seek().

void gnash::media::MediaParser::fetchMetaTags	(	OrderedMetaTags &	tags,
		boost::uint64_t	ts
	)		`[virtual]`

Retrieve any parsed metadata tags up to a specified timestamp.

Parameters:

ts	The latest timestamp to retrieve metadata for.
tags	This is filled with shared pointers to metatags in timestamp order. Ownership of the data is shared. It is destroyed automatically along with the last owner. Metadata is currently only parsed from FLV streams. The default is a no-op.

Reimplemented in gnash::media::FLVParser.

AudioInfo* gnash::media::MediaParser::getAudioInfo ( ) [inline]

Returns a AudioInfo class about the audiostream.

Returns:: a AudioInfo class about the audiostream, or zero if unknown (no audio or not enough data parsed yet).

References _audioInfo.

boost::uint64_t gnash::media::MediaParser::getBufferLength ( ) const

Returns mininum length of available buffers in milliseconds.

TODO: FIXME: NOTE: this is currently used by NetStream.bufferLength but is bogus as it doesn't take the *current* playhead cursor time into account. A proper way would be having a getLastBufferTime () interface here, returning minimun timestamp of last available frames and let NetSTream::bufferLength() use that with playhead time to find out...

References _qMutex.

DSOEXPORT boost::uint64_t gnash::media::MediaParser::getBufferTime ( ) const [inline]

Return the time we want the parser thread to maintain in the buffer.

References _bufferTimeMutex, and _bufferTime.

Referenced by bufferFull().

virtual boost::uint64_t gnash::media::MediaParser::getBytesLoaded ( ) const [inline, virtual]

Return number of bytes parsed so far.

Reimplemented in gnash::media::FLVParser, gnash::media::gst::MediaParserGst, gnash::media::ffmpeg::MediaParserFfmpeg, and gnash::media::haiku::MediaParserHaiku.

boost::uint64_t gnash::media::MediaParser::getBytesTotal ( ) const [inline]

Return total number of bytes in input.

References _stream.

boost::optional< Id3Info > gnash::media::MediaParser::getId3Info ( ) const [virtual]

Get ID3 data from the parsed stream if it exists.

It's best to do this only when parsingComplete is true.

Reimplemented in gnash::media::gst::MediaParserGst, and gnash::media::ffmpeg::MediaParserFfmpeg.

References _.

VideoInfo* gnash::media::MediaParser::getVideoInfo ( ) [inline]

Returns a VideoInfo class about the videostream.

Returns:: a VideoInfo class about the videostream, or zero if unknown (no video or not enough data parsed yet).

References _videoInfo.

virtual bool gnash::media::MediaParser::indexingCompleted ( ) const [inline, virtual]

Return true of indexing is completed.

If this function returns false, parseNextChunk will be called even when buffers are full. Parsers supporting indexing separated from parsing should override this method and have parseNextChunk figure if they only need to index or to parse based on bufferFull.

Reimplemented in gnash::media::FLVParser.

Referenced by waitIfNeeded().

bool gnash::media::MediaParser::isBufferEmpty ( ) const

Return true if both audio and video buffers are empty.

NOTE: locks _qMutex

References _qMutex.

std::auto_ptr< EncodedAudioFrame > gnash::media::MediaParser::nextAudioFrame ( )

Returns the next audio frame in the parsed buffer, advancing audio cursor.

If no frame has been played before the first frame is returned. If there is no more frames in the parsed buffer NULL is returned. you can check with parsingCompleted() to know wheter this is due to EOF reached.

References _qMutex, parsingCompleted(), _audioInfo, parseNextChunk(), and _parserThreadWakeup.

bool gnash::media::MediaParser::nextAudioFrameTimestamp ( boost::uint64_t & ts ) const

Get timestamp of the audio frame which would be returned on nextAudioFrame.

Returns:: false if there no video frame left (either none or no more)

NOTE: locks _qMutex

References _qMutex, and gnash::media::EncodedAudioFrame::timestamp.

bool gnash::media::MediaParser::nextFrameTimestamp ( boost::uint64_t & ts ) const

Get timestamp of the next frame available, if any.

Parameters:

ts	will be set to timestamp of next available frame

Returns:: false if no frame is available yet

NOTE: locks _qMutex

References _qMutex, parsingCompleted(), _videoInfo, and parseNextChunk().

std::auto_ptr< EncodedVideoFrame > gnash::media::MediaParser::nextVideoFrame ( )

Returns the next video frame in the parsed buffer, advancing video cursor.

If no frame has been played before the first frame is returned. If there is no more frames in the parsed buffer NULL is returned. you can check with parsingCompleted() to know wheter this is due to EOF reached.

References _qMutex, parsingCompleted(), _videoInfo, parseNextChunk(), and _parserThreadWakeup.

bool gnash::media::MediaParser::nextVideoFrameTimestamp ( boost::uint64_t & ts ) const

Get timestamp of the video frame which would be returned on nextVideoFrame.

Returns:: false if there no video frame left (either none or no more)

NOTE: locks _qMutex

References _qMutex, and gnash::media::EncodedVideoFrame::timestamp().

virtual bool gnash::media::MediaParser::parseNextChunk ( ) [pure virtual]

Parse next chunk of input.

The implementations are required to parse a small chunk of input, so to avoid blocking too much if parsing conditions change (ie: seek or destruction requested)

When LOAD_MEDIA_IN_A_SEPARATE_THREAD is defined, this should never be called by users (consider protected).

Implemented in gnash::media::FLVParser, gnash::media::gst::MediaParserGst, gnash::media::ffmpeg::MediaParserFfmpeg, and gnash::media::haiku::MediaParserHaiku.

Referenced by nextFrameTimestamp(), nextVideoFrame(), nextAudioFrame(), and parserLoop().

void gnash::media::MediaParser::parserLoop ( ) [protected]

The parser loop runs in a separate thread and calls parseNextChunk until killed.

parseNextChunk is expected to push encoded frames on the queue, which may trigger the thread to be put to sleep when queues are full or parsing was completed.

References _parserThreadStartBarrier, parserThreadKillRequested(), parseNextChunk(), gnash::gnashSleep(), _qMutex, and waitIfNeeded().

Referenced by parserLoopStarter().

static void gnash::media::MediaParser::parserLoopStarter ( MediaParser * mp ) [inline, static, protected]

References parserLoop().

Referenced by startParserThread().

bool gnash::media::MediaParser::parserThreadKillRequested ( ) const [inline, protected]

References _parserThreadKillRequestMutex, and _parserThreadKillRequested.

Referenced by waitIfNeeded(), and parserLoop().

bool gnash::media::MediaParser::parsingCompleted ( ) const [inline]

Return true of parsing is completed.

If this function returns true, any call to nextVideoFrame() or nextAudioFrame() will always return NULL

TODO: make thread-safe

References _parsingComplete.

Referenced by nextFrameTimestamp(), nextVideoFrame(), nextAudioFrame(), and waitIfNeeded().

void gnash::media::MediaParser::pushEncodedAudioFrame ( std::auto_ptr< EncodedAudioFrame > frame ) [protected]

Push an encoded audio frame to buffer.

Will wait on a condition if buffer is full or parsing was completed

References _qMutex, gnash::key::i, gnash::key::e, and waitIfNeeded().

void gnash::media::MediaParser::pushEncodedVideoFrame ( std::auto_ptr< EncodedVideoFrame > frame ) [protected]

Push an encoded video frame to buffer.

Will wait on a condition if buffer is full or parsing was completed

References _qMutex, gnash::key::i, gnash::key::e, and waitIfNeeded().

virtual bool gnash::media::MediaParser::seek ( boost::uint32_t & time ) [pure virtual]

Seeks to the closest possible position the given position, and returns the new position.

Parameters:

time	input/output parameter, input requests a time, output return the actual time seeked to.

Returns:: true if the seek was valid, false otherwise.

Implemented in gnash::media::FLVParser, gnash::media::gst::MediaParserGst, gnash::media::ffmpeg::MediaParserFfmpeg, and gnash::media::haiku::MediaParserHaiku.

DSOEXPORT void gnash::media::MediaParser::setBufferTime ( boost::uint64_t t ) [inline]

Set the time we want the parser thread to maintain in the buffer.

Parameters:

t	Number of milliseconds to keep in the buffers.

References _bufferTimeMutex, _bufferTime, and gnash::key::t.

void gnash::media::MediaParser::startParserThread ( ) [protected]

}@

Start the parser thread

References _parserThread, parserLoopStarter(), and _parserThreadStartBarrier.

Referenced by gnash::media::FLVParser::FLVParser(), gnash::media::ffmpeg::MediaParserFfmpeg::MediaParserFfmpeg(), and gnash::media::gst::MediaParserGst::MediaParserGst().

void gnash::media::MediaParser::stopParserThread ( ) [protected]

Stop the parser thread.

This method should be always called by destructors of subclasses to ensure the parser thread won't attempt to access destroyed structures.

References _parserThread.

Referenced by gnash::media::FLVParser::~FLVParser(), ~MediaParser(), gnash::media::ffmpeg::MediaParserFfmpeg::~MediaParserFfmpeg(), and gnash::media::gst::MediaParserGst::~MediaParserGst().

void gnash::media::MediaParser::waitIfNeeded ( boost::mutex::scoped_lock & qMutexLock ) [protected]

Wait on the _parserThreadWakeup condition if buffer is full or parsing was completed.

Callers *must* pass a locked lock on _qMutex

References parsingCompleted(), indexingCompleted(), bufferFull(), parserThreadKillRequested(), and _parserThreadWakeup.

Referenced by pushEncodedAudioFrame(), pushEncodedVideoFrame(), and parserLoop().

void gnash::media::MediaParser::wakeupParserThread ( ) [protected]

Member Data Documentation

std::auto_ptr<AudioInfo> gnash::media::MediaParser::_audioInfo [protected]

Info about the audio stream (if any)

Referenced by nextAudioFrame(), getAudioInfo(), and gnash::media::gst::MediaParserGst::MediaParserGst().

boost::uint64_t gnash::media::MediaParser::_bufferTime [protected]

Referenced by getBufferTime(), and setBufferTime().

boost::mutex gnash::media::MediaParser::_bufferTimeMutex [mutable, protected]

Referenced by getBufferTime(), and setBufferTime().

boost::uint64_t gnash::media::MediaParser::_bytesLoaded [protected]

Number of bytes loaded.

Referenced by gnash::media::FLVParser::getBytesLoaded(), gnash::media::gst::MediaParserGst::parseNextChunk(), and gnash::media::gst::MediaParserGst::getBytesLoaded().

boost::mutex gnash::media::MediaParser::_bytesLoadedMutex [mutable, protected]

Mutex protecting _bytesLoaded (read by main, set by parser)

Referenced by gnash::media::FLVParser::getBytesLoaded(), gnash::media::gst::MediaParserGst::parseNextChunk(), and gnash::media::gst::MediaParserGst::getBytesLoaded().

std::auto_ptr<boost::thread> gnash::media::MediaParser::_parserThread [protected]

Referenced by startParserThread(), and stopParserThread().

bool gnash::media::MediaParser::_parserThreadKillRequested [protected]

Referenced by parserThreadKillRequested().

boost::mutex gnash::media::MediaParser::_parserThreadKillRequestMutex [mutable, protected]

Referenced by parserThreadKillRequested().

boost::barrier gnash::media::MediaParser::_parserThreadStartBarrier [protected]

Referenced by startParserThread(), and parserLoop().

boost::condition gnash::media::MediaParser::_parserThreadWakeup [protected]

Referenced by nextVideoFrame(), nextAudioFrame(), clearBuffers(), and waitIfNeeded().

bool gnash::media::MediaParser::_parsingComplete [protected]

Whether the parsing is complete or not.

Referenced by gnash::media::FLVParser::seek(), parsingCompleted(), gnash::media::ffmpeg::MediaParserFfmpeg::seek(), and gnash::media::gst::MediaParserGst::parseNextChunk().

boost::mutex gnash::media::MediaParser::_qMutex [mutable, protected]

mutex protecting access to the a/v encoded frames queues

Referenced by getBufferLength(), isBufferEmpty(), nextFrameTimestamp(), nextVideoFrameTimestamp(), nextVideoFrame(), nextAudioFrame(), nextAudioFrameTimestamp(), clearBuffers(), pushEncodedAudioFrame(), pushEncodedVideoFrame(), and parserLoop().

bool gnash::media::MediaParser::_seekRequest [protected]

On seek, this flag will be set, while holding a lock on _streamMutex. The parser, when obtained a lock on _streamMutex, will check this flag, if found to be true will clear the buffers and reset to false.

Referenced by gnash::media::FLVParser::seek().

std::auto_ptr<IOChannel> gnash::media::MediaParser::_stream [protected]

The stream used to access the file.

Referenced by getBytesTotal(), gnash::media::gst::MediaParserGst::MediaParserGst(), and gnash::media::gst::MediaParserGst::parseNextChunk().

boost::mutex gnash::media::MediaParser::_streamMutex [mutable, protected]

Referenced by gnash::media::FLVParser::seek(), gnash::media::ffmpeg::MediaParserFfmpeg::seek(), and gnash::media::gst::MediaParserGst::parseNextChunk().

std::auto_ptr<VideoInfo> gnash::media::MediaParser::_videoInfo [protected]

Subclasses *must* set the following variables:

Info about the video stream (if any)

Referenced by nextFrameTimestamp(), nextVideoFrame(), getVideoInfo(), and gnash::media::gst::MediaParserGst::MediaParserGst().

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

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation