Create stub for cross-thread MediaSource attachments #4169
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Enables MediaSource, SourceBuffer, and SourceBufferList objects to be created on Dedicated Workers. Creation of these objects is not gated behind any H5VCC flags, but they will be non-transferable without usage of H5VCC flags. The initial implementation of CrossThreadMediaSourceAttachment is very bare bones, and does not allow for MediaElements to interact with the attached MediaSources yet. However, this lays the groundwork for supporting creating the relevant MediaSource objects on the worker thread, and the transfer process to get the reference back to the main thread. Usage of creating MediaSource URLs is gated through the `MediaSource.EnableInWorkers` H5VCC flag, in addition to existing flags `MediaElement.EnableUsingMediaSourceBufferedRange` and `MediaElement.EnableUsingMediaSourceAttachmentMethods`. If and only if all three flags are enabled, MediaSources created on Dedicated Workers and passed to `URL.createObjectURL` will return a non-empty string that can be sent to the main thread, and used to 'access' the MediaSourceAttachment. In addition, if and only if all three H5VCC flags are enabled, [`MediaSource.canConstructInDedicatedWorker`](https://developer.mozilla.org/en-US/docs/Web/API/MediaSource/canConstructInDedicatedWorker_static) will return true. This is based on the following Chromium commit: • https://chromium-review.googlesource.com/c/chromium/src/+/2407075 b/338425449
borongc
reviewed
Oct 8, 2024
borongc
reviewed
Oct 8, 2024
borongc
reviewed
Oct 8, 2024
borongc
reviewed
Oct 8, 2024
borongc
reviewed
Oct 15, 2024
borongc
reviewed
Oct 15, 2024
borongc
reviewed
Oct 15, 2024
borongc
reviewed
Oct 15, 2024
borongc
approved these changes
Oct 15, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Enables MediaSource, SourceBuffer, and SourceBufferList objects to be created on Dedicated Workers. Creation of these objects is not gated behind any H5VCC flags, but they will be non-transferable without usage of H5VCC flags.
The initial implementation of CrossThreadMediaSourceAttachment is very bare bones, and does not allow for MediaElements to interact with the attached MediaSources yet. However, this lays the groundwork for supporting creating the relevant MediaSource objects on the worker thread, and the transfer process to get the reference back to the main thread.
Usage of creating MediaSource URLs is gated through the
MediaSource.EnableInWorkersH5VCC flag, in addition to existing flagsMediaElement.EnableUsingMediaSourceBufferedRangeandMediaElement.EnableUsingMediaSourceAttachmentMethods. If and only if all three flags are enabled, MediaSources created on Dedicated Workers and passed toURL.createObjectURLwill return a non-empty string that can be sent to the main thread, and used to 'access' the MediaSourceAttachment. In addition, if and only if all three H5VCC flags are enabled,MediaSource.canConstructInDedicatedWorkerwill return true.This is based on the following Chromium commit:
• https://chromium-review.googlesource.com/c/chromium/src/+/2407075
b/338425449