Implement SourceBuffer.writeHead attribute #4559
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This change implements a partial interface for SourceBuffer, adding the writeHead attribute. This attribute returns the highest buffer presentation timestamp written to the SbPlayer. The writeHead attribute is guarded by a Runtime Enabled Feature SourceBufferWriteHead. This feature is enabled by default for Cobalt builds and disabled for all other builds. Link to the original PR with most of the functional changes: youtube#121 b/326652276
osagie98
requested review from
sideb0ard,
jasonzhangxx,
xiaomings,
andrewsavage1 and
borongc
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Just realized that since the new interface is only included in Cobalt Starboard media builds, we may not need to guard it by a RuntimeEnabledFeature. I can remove that if needed |
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Ideally we'd add a web test for this in https://github.com/youtube/cobalt/tree/main/third_party/blink/web_tests/external/wpt/media-source/
| @@ -416,6 +423,12 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer { | |||
| base::TimeDelta currentMediaTime, | |||
| size_t newDataSize); | |||
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| #if BUILDFLAG(USE_STARBOARD_MEDIA) | |||
| // Returns the latest presentation timestamp of the buffers sent to the | |||
| // DemuxerStream. | |||
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Consider rephrasing, as the buffers are read from the DemuxerStream instead of sending to the DemuxerStream. Please also rephrase the comment above for GetWriteHead().
| @@ -140,6 +144,11 @@ class WebSourceBuffer { | |||
| // After this method is called, this WebSourceBuffer should never use the | |||
| // client pointer passed to SetClient(). | |||
| virtual void RemovedFromMediaSource() = 0; | |||
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| #if BUILDFLAG(USE_STARBOARD_MEDIA) | |||
| // Return the highest presentation timestamp written to the SbPlayer. | |||
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We don't have to mention SbPlayer here, as the implementation is no longer SbPlayer specific.
The same to the commit message of the PR.
| #if BUILDFLAG(USE_STARBOARD_MEDIA) | ||
| // Cobalt-specific method that returns the highest presentation | ||
| // timestamp written to the SbPlayer. | ||
| double writeHead(ExceptionState& exception_state) const; |
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getWriteHead()? Since it's no longer a method mapped from DOM. Please feel free to keep it as is if this is a convention in Chromium.
| // from the MediaSource object. | ||
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| [ | ||
| ImplementedAs=SourceBufferWriteHead |
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I am not sure the best convention for file names and class name here, i.e. shall we use SourceBufferWriteHead or CobaltSourceBuffer (and source_buffer_write_head.idl or cobalt_source_buffer.idl).
Just to bring this up, and please feel free to keep this as is for now or bring this to an internal sync for discussion.
This change implements a partial interface for SourceBuffer, adding the writeHead attribute. This attribute returns the highest buffer presentation timestamp written to the SbPlayer. The writeHead attribute is only included in Cobalt Starboard media builds.
Link to the original PR with most of the functional changes: #121
b/326652276