#include <segment_coordinator.h>
Public Member Functions | |
| void | MarkAsTeletextStream (size_t input_stream_index) |
 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 available 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 |
| Protected Member Functions inherited from shaka::media::MediaHandler | |
| virtual Status | OnFlushRequest (size_t input_stream_index) |
| Event handler for flush request at the specific input stream index. | |
| 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) const |
| Status | DispatchStreamInfo (size_t stream_index, std::shared_ptr< const StreamInfo > stream_info) const |
| Dispatch the stream info to downstream handlers. | |
| Status | DispatchMediaSample (size_t stream_index, std::shared_ptr< const MediaSample > media_sample) const |
| Dispatch the media sample to downstream handlers. | |
| Status | DispatchTextSample (size_t stream_index, std::shared_ptr< const TextSample > text_sample) const |
| Dispatch the text sample to downstream handlers. | |
| Status | DispatchSegmentInfo (size_t stream_index, std::shared_ptr< const SegmentInfo > segment_info) const |
| Dispatch the segment info to downstream handlers. | |
| Status | DispatchScte35Event (size_t stream_index, std::shared_ptr< const Scte35Event > scte35_event) const |
| Dispatch the scte35 event to downstream handlers. | |
| Status | DispatchCueEvent (size_t stream_index, std::shared_ptr< const CueEvent > cue_event) const |
| Dispatch the cue event 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 downstream handlers. | |
| 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 () |
Additional Inherited Members | |
| Static Public Member Functions inherited from shaka::media::MediaHandler | |
| static Status | Chain (const std::vector< std::shared_ptr< MediaHandler > > &list) |
Detailed Description
SegmentCoordinator is a N-to-N media handler that coordinates segment boundaries across different stream types. All streams (video, audio, text) go through the same coordinator instance, similar to CueAlignmentHandler.
It receives SegmentInfo events from video/audio streams (emitted by ChunkingHandler) and replicates them to registered teletext streams, ensuring that teletext segments align with media segments.
This handler is designed to solve the alignment problem where teletext segments use mathematical calculation (segment_start + segment_duration) while video/audio use actual keyframe timestamps, causing misalignment especially with:
- Arbitrary input timestamps (not divisible by segment duration)
- MPEG-TS timestamp wrap-around scenarios
- Sources with offset keyframe timestamps
The coordinator only replicates SegmentInfo to teletext streams (cc_index >= 0). Other text formats (WebVTT files, TTML) and video/audio streams pass through unchanged.
Pipeline placement (all streams go through the same coordinator instance): Video/Audio → CueAligner → SegmentCoordinator → ChunkingHandler → ... Teletext → CueAligner → SegmentCoordinator → CcStreamFilter → TextChunker → ...
When ChunkingHandler emits SegmentInfo, it flows back through the coordinator, which then broadcasts it to all registered teletext stream indices.
Definition at line 46 of file segment_coordinator.h.
Member Function Documentation
◆ 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 24 of file segment_coordinator.cc.
◆ MarkAsTeletextStream()
| void shaka::media::SegmentCoordinator::MarkAsTeletextStream | ( | size_t | input_stream_index | ) |
Mark a stream as a teletext stream that should receive segment boundaries. This should be called during pipeline setup before processing begins.
- Parameters
-
input_stream_index The input stream index for the teletext stream.
Definition at line 18 of file segment_coordinator.cc.
◆ Process()
|
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 30 of file segment_coordinator.cc.
The documentation for this class was generated from the following files:
- packager/media/chunking/segment_coordinator.h
- packager/media/chunking/segment_coordinator.cc
