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Re: [mediacapture-main] Add a mechanism to inform a video track about its type of content

From: Peter Boström via GitHub <sysbot+gh@w3.org>
Date: Tue, 27 Sep 2016 21:42:27 +0000
To: public-media-capture-logs@w3.org
Message-ID: <issue_comment.created-250007845-1475012546-sysbot+gh@w3.org>
How about having an optional writable attribute on MediaStreamTrack? 
An enum like contentTypeHint: {"text", "realtime"}. This could be nil 
by default (or set to a default by gUM()). We would like to use this 
hint to set encoder settings such as max QP for video tracks and drop 
frames over blocky video.

Blink currently uses "screencast" settings for anything tab/desktop 
capture and "normal" settings for USB capture devices, but choosing 
these settings aren't exposed to the open web. If you screenshare 
video games the settings chosen by screencast are less apropriate 
(high QP is fairly OK), but for regular text (screensharing GitHub for
 instance) screenshare settings are better, since it won't degrade 
into something non-readable but rather drop frames instead. I would 
imagine that game livestreaming services would like to make use of 
this if using desktop/tab capture.

It could possibly also have {"speech", "music"} for audio as a hint to
 encoders, but I'm not sure how useful that hint is (my experience 
with audio encoders is limited). If this is video-only it could be 
named videoTypeHint, but my opinions on naming are fairly weak.

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Received on Tuesday, 27 September 2016 21:42:41 UTC

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