Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Describe more precisely transfered track lifetime management. #30

Merged
merged 7 commits into from
Aug 26, 2021
Merged

Describe more precisely transfered track lifetime management. #30

Changes from 6 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
c83ae05
State lifetime management
youennf Jun 24, 2021
6714568
Update index.html
youennf Jun 24, 2021
45a1440
Update index.html
youennf Jun 24, 2021
e688441
Update index.html
youennf Jun 24, 2021
2878f19
Use the new Initialize the underlying source steps
youennf Aug 13, 2021
99059ea
Introducing originalContext and trackSource. Make lines shorter
youennf Aug 19, 2021
ffbb683
Update index.html
youennf Aug 26, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
28 changes: 24 additions & 4 deletions index.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -347,10 +347,29 @@ <h2>Examples</h2>
<h2>Transferable MediaStreamTrack</h2>
<div>
<p>A {{MediaStreamTrack}} is a <a data-cite="!HTML/#transferable-objects">transferable object</a>.
This allows manipulating real-time media outside the context it was requested or created in, for instance in workers or third-party iframes.</p>
<p>To preserve the existing privacy and security infrastructure, in particular for capture tracks, we need proper track and source lifetime management.
A future PR will properly specify this management.</p>
This allows manipulating real-time media outside the context it was requested or created in,
for instance in workers or third-party iframes.</p>
<p>To preserve the existing privacy and security infrastructure, in particular for capture tracks,
the track source lifetime management remains tied to the context that created it.
The transfer algorithm MUST ensure the following behaviors:</p>
<p>
<ol>
<li><p>The context named <var>originalContext</var> that created a track named <var>originalTrack</var> remains in control
of the <var>originalTrack</var> source, named <var>trackSource</var>, even when <var>originalTrack</var> is transferred into <var>transferredTrack</var>.</p>
</li>
<li>
<p>In particular, <var>originalContext</var> remains the proxy to privacy indicators of <var>trackSource</var>.
<var>transferredTrack</var> or any of its clones are considered as tracks using <var>trackSource</var>
as if they were tracks created in and controlled by <var>originalContext</var>.</p>
</li>
<li><p>When <var>originalContext</var> goes away, <var>trackSource</var> gets ended, thus <var>transferredTrack</var> gets ended.</p></li>
<li><p>When <var>originalContext</var> would have muted/unmuted <var>originalTrack</var>, <var>transferredTrack</var> gets muted/unmuted.</p></li>
<li><p>If <var>transferredTrack</var> is cloned in <var>transferredTrackClone</var>, <var>transferredTrackClone</var> is tied to <var>trackSource</var>.
It is not tied to <var>originalTrack</var> in any way.</p></li>
<li><p>If <var>transferredTrack</var> is transferred into <var>transferredAgainTrack</var>, <var>transferredAgainTrack</var> is tied to <var>trackSource</var>.
It is not to <var>transferredTrack</var> or <var>originalTrack</var> in any way.</p></li>
</ol>
</p>
</div>
<div>
<p>The WebIDL changes are the following:
Expand Down Expand Up @@ -389,7 +408,8 @@ <h2>Transferable MediaStreamTrack</h2>
<li><p>Initialize <var>track</var>.{{MediaStreamTrack/readyState}} to <var>dataHolder</var>.`[[readyState]]`.</p></li>
<li><p>Initialize <var>track</var>.{{MediaStreamTrack/enabled}} to <var>dataHolder</var>.`[[enabled]]`.</p></li>
<li><p>Initialize <var>track</var>.{{MediaStreamTrack/muted}} to <var>dataHolder</var>.`[[muted]]`.</p></li>
<li><p>Initialize <var>track</var> underlying source to <var>dataHolder</var>.`[[source]]`.</p></li>
<li><p>[=Initialize the underlying source=] of <var>track</var> to <var>dataHolder</var>.`[[source]]` with
{{MediaStreamTrack/tieSourceToContext}} equal to <code>false</code>.</p></li>
<li><p>Set <var>track</var>'s constraints to <var>dataHolder</var>.`[[constraints]]`.</p></li>
</ol>
</div>
Expand Down