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Re: [mediacapture-screen-share] Define originAudio (#94)

From: henbos via GitHub <sysbot+gh@w3.org>
Date: Thu, 06 Dec 2018 09:41:52 +0000
To: public-webrtc-logs@w3.org
Message-ID: <issue_comment.created-444810595-1544089311-sysbot+gh@w3.org>
Note that in any case audio is optional (per previous decisions), so audio:true does not guarantee that you get audio, but the user should be allowed to choose audio depending on UA's capabilities (or choose to only share video without having to reject the request).

{audio:false} means you don't can't get audio, audio:{originAudio:false} means you're asking for audio, and any audio is acceptable as long as it does not include that particular audio source.

Examples that would satisfy originAudio:false:

- No audio (this is always OK because audio is always optional, even in audio:true case).
- Tab capture with audio from the tab - this works for all tabs except the origin's tab, so the UA can either not allow sharing that tab or if that tab is selected you get no audio.
- Browser window, with audio from all tabs except for the origin's tab.
- All desktop capture except the origin tab's audio. I don't expect anyone to implement this due to the technical complexity, so more likely: if this constraint is present, the user cannot choose desktop capture and still get audio (exclude choice or mute stream), but if the constraint isn't present it would be perfectly valid to do desktop capture with audio if the system is capable of it.

This constraint is not about forcing the UA to include any particular audio (just like audio:true does not say what choices a UA has to be able to capture), it's about forcing the UA to exclude a particular audio source. I.e. "please don't present the user with false choices" (a false choice being one that would include the origin audio and thus, for some applications, cause echo problems).

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Please view or discuss this issue at https://github.com/w3c/mediacapture-screen-share/pull/94#issuecomment-444810595 using your GitHub account
Received on Thursday, 6 December 2018 09:41:54 UTC

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