shaka::media::ChunkingHandler Class Reference

#include <chunking_handler.h>

Inheritance diagram for shaka::media::ChunkingHandler:

Public Member Functions
	ChunkingHandler (const ChunkingParams &chunking_params)
Public Member Functions inherited from shaka::media::MediaHandler
Status	SetHandler (size_t output_stream_index, std::shared_ptr< MediaHandler > handler)
	Connect downstream handler at the specified output stream index.
Status	AddHandler (std::shared_ptr< MediaHandler > handler)
	Connect downstream handler to the next availble output stream index.
Status	Initialize ()
bool	IsConnected ()
	Validate if the handler is connected to its upstream handler.

Protected Member Functions
MediaHandler implementation overrides.
Status	InitializeInternal () override
Status	Process (std::unique_ptr< StreamData > stream_data) override
Status	OnFlushRequest (size_t input_stream_index) override
	Event handler for flush request at the specific input stream index.
Protected Member Functions inherited from shaka::media::MediaHandler
virtual bool	ValidateOutputStreamIndex (size_t stream_index) const
	Validate if the stream at the specified index actually exists.
Status	Dispatch (std::unique_ptr< StreamData > stream_data)
Status	DispatchPeriodInfo (size_t stream_index, std::shared_ptr< const PeriodInfo > period_info)
	Dispatch the period info to downstream handlers.
Status	DispatchStreamInfo (size_t stream_index, std::shared_ptr< const StreamInfo > stream_info)
	Dispatch the stream info to downstream handlers.
Status	DispatchMediaSample (size_t stream_index, std::shared_ptr< const MediaSample > media_sample)
	Dispatch the media sample to downstream handlers.
Status	DispatchTextSample (size_t stream_index, std::shared_ptr< const TextSample > text_sample)
	Dispatch the text sample to downsream handlers.
Status	DispatchMediaEvent (size_t stream_index, std::shared_ptr< const MediaEvent > media_event)
	Dispatch the media event to downstream handlers.
Status	DispatchSegmentInfo (size_t stream_index, std::shared_ptr< const SegmentInfo > segment_info)
	Dispatch the segment info to downstream handlers.
Status	FlushDownstream (size_t output_stream_index)
	Flush the downstream connected at the specified output stream index.
Status	FlushAllDownstreams ()
	Flush all connected downstreams.
bool	initialized ()
size_t	num_input_streams () const
size_t	next_output_stream_index () const
const std::map< size_t, std::pair< std::shared_ptr < MediaHandler >, size_t > > &	output_handlers ()

Friends
class	ChunkingHandlerTest

Detailed Description

ChunkingHandler splits the samples into segments / subsegments based on the specified chunking params. This handler is a multi-in multi-out handler. If more than one input is provided, there should be one and only one video stream; also, all inputs should come from the same thread and are synchronized. There can be multiple chunking handler running in different threads or even different processes, we use the "consistent chunking algorithm" to make sure the chunks in different streams are aligned without explicit communcating with each other - which is not efficient and often difficult.

Consistent Chunking Algorithm:

1. Find the consistent chunkable boundary Let the timestamps for video frames be (t1, t2, t3, ...). Then a consistent chunkable boundary is simply the first chunkable boundary after (tk / N) != (tk-1 / N), where '/' denotes integer division, and N is the intended chunk duration.
2. Chunk only at the consistent chunkable boundary

This algorithm will make sure the chunks from different video streams are aligned if they have aligned GoPs. However, this algorithm will only work for video streams. To be able to chunk non video streams at similar positions as video streams, ChunkingHandler is designed to accept one video input and multiple non video inputs, the non video inputs are chunked when the video input is chunked. If the inputs are synchronized - which is true if the inputs come from the same demuxer, the video and non video chunks are aligned.

Definition at line 44 of file chunking_handler.h.

Member Function Documentation

Status shaka::media::ChunkingHandler::InitializeInternal ( )

overrideprotectedvirtual

Internal implementation of initialize. Note that it should only initialize the MediaHandler itself. Downstream handlers are handled in Initialize().

Implements shaka::media::MediaHandler.

Definition at line 28 of file chunking_handler.cc.

Status shaka::media::ChunkingHandler::Process ( std::unique_ptr< StreamData >  stream_data )

overrideprotectedvirtual

Process the incoming stream data. Note that (1) stream_data.stream_index should be the input stream index; (2) The implementation needs to call DispatchXxx to dispatch the processed stream data to the downstream handlers after finishing processing if needed.

Implements shaka::media::MediaHandler.

Definition at line 36 of file chunking_handler.cc.

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

• packager/media/chunking/chunking_handler.h
• packager/media/chunking/chunking_handler.cc