Media Capture
From W3C Wiki
The Media Capture API (a.k.a. navigator.getUserMedia) is developed by a joint task force between the WebRTC and Device APIs Working Groups (see the task force charter).
This page serves as a coordination point for the work in this task force.
Documents
The scenario/req draft, and the API draft. Both are currently Editor's drafts.
Meetings
First telco took place on Feb 9th, 5.00 - 6.30pm CET. Minutes: http://lists.w3.org/Archives/Public/public-media-capture/2012Feb/att-0021/minutes-2012-02-09.html
Second Telco took place on Feb 28th, 5.00 - 6.30pm CET. Minutes: http://lists.w3.org/Archives/Public/public-media-capture/2012Feb/att-0049/minutes-2012-02-28.html
Third Telco took place on April 24th, 10.00 - 11.30pm CET. Minutes: http://lists.w3.org/Archives/Public/public-media-capture/2012Apr/att-0031/minutes-2012-04-24.html
Fourth Telco took place on May 9th, 10.00 - 11.30pm CET. Minutes: http://lists.w3.org/Archives/Public/public-media-capture/2012May/0070.html
Fifth Telco took place June 7th, 5.00 - 6.30pm CET. Minutes: http://lists.w3.org/Archives/Public/public-media-capture/2012Jun/0055.html
Sixth Telco: Aug 23rd. Minutes: http://lists.w3.org/Archives/Public/public-media-capture/2012Aug/0149.html
Next telco scheduled for Oct 9th, 10.00 - 11.30pm CET.
F2f meeting scheduled for Oct 30 2012
Useful resources
Mailing lists
- Archives of the public-media-capture@w3.org mailing-list are publicly available. This mailing-list should be used for all technical discussions within the group.
Tracker
- Tracker is used to track actions within the group. We're only using the ACTION section.
- Buganizer, the "Media Capture and Streams" component, is available for tracking issues and bugs.
IRC
The group uses IRC to take minutes and exchange info during calls and face-to-face meetings:
- IRC info: #mediacap on irc.w3.org, port 6665
- You may use the W3C Web client, specifying a username and channel #mediacap
- You may find more info on IRC usage at W3C
Open Items
Note: just a first brain dump; has not been discussed or agreed in any way.//Stefan 2012-04-24
Simple image capture API
- Proposed http://lists.w3.org/Archives/Public/public-media-capture/2012Mar/0008.html
- Discussion not concluded
- Move into a later version???
- New proposal from Travis that includes support for image capture: http://dvcs.w3.org/hg/dap/raw-file/tip/media-stream-capture/proposals/SettingsAPI_proposal_v4.html
iFrame behavior
- Proposed http://lists.w3.org/Archives/Public/public-media-capture/2012Mar/0024.html
- Both positive and negative feedback
- No conclusion
Direct assignment of MediaStream to Video
- Discussed. Pro's and con's
- Current assumption: new direct assignment using srcStream; change to a specific mediastream scheme for minting an URL (http://lists.w3.org/Archives/Public/public-media-capture/2012Oct/0023.html)
Possibility to from JS create a dummy track and add to a MediaStream
- dummy track can be used to insert DTMF in (to enable using IVR without access to mic or cam)
Possibility to select sources other than cam or mic
- we need the possibility to use other sources than the actual device to getUserMedia so that users can fake the access to a camera
- there is also another need: the webrtc reqs mandate that the screen should be a valid source (to enable screen sharing)
Enable display of level in Audio tracks
- need documented in Travis' scenarios document https://dvcs.w3.org/hg/dap/raw-file/tip/media-stream-capture/scenarios.html
- documented as req A14 in http://datatracker.ietf.org/doc/draft-ietf-rtcweb-use-cases-and-requirements/?include_text=1
- the API(s - there are currently two proposals) developed by the Audio WG may be used, but when they will be compatible with MediaStreams is uncertain
- currently possible with web audio api
Enable adjustment of audio level
- documented as req A15 in http://datatracker.ietf.org/doc/draft-ietf-rtcweb-use-cases-and-requirements/?include_text=1
- web audio api possible to use
Possibility to change streams without doing getUserMedia
- proposed by Anant in telco April 24th 2012 (documented towards the end of http://lists.w3.org/Archives/Public/public-media-capture/2012Apr/att-0031/minutes-2012-04-24.html)
- Travis submitted a proposal on that can be used for this purpose in http://lists.w3.org/Archives/Public/public-media-capture/2012Jul/0069.html
- Update of Travis' proposal: http://dvcs.w3.org/hg/dap/raw-file/tip/media-stream-capture/proposals/SettingsAPI_proposal_v4.html
Closed Items
Change getUserMedia to force error handling
- Proposed http://lists.w3.org/Archives/Public/public-media-capture/2012Mar/0085.html
- Not that much support, more discussion needed
- Concluded that we should not do this in http://lists.w3.org/Archives/Public/public-media-capture/2012May/0060.html
Direct assignment of MediaStream to Canvas
- Proposed http://lists.w3.org/Archives/Public/public-media-capture/2012Apr/0045.html
- Discussion started
- Concluded that we should not do this right now in http://lists.w3.org/Archives/Public/public-media-capture/2012May/0060.html
Integration of MediaStream with media elements
- Description on how MediaStreams integrate with media elements must be added to the doc
- Jim Barnett has produced a draft: http://lists.w3.org/Archives/Public/public-media-capture/2012May/0064.html
- Is now incorporated in the getUserMedia document
How to deal with several active devices
- getUserMedia could return a MediaStream with a video track per camera
- or, getUserMedia could return a MediaStream with one video track (and the user selects which cam to use)
- have seen arguments for both (discussion started at http://lists.w3.org/Archives/Public/public-media-capture/2012Apr/0009.html)
- Discussed and resolved at the June 7 2012 telco. GetUserMedia could ask for max one track per kind, but if several getUserMedia calls are made before entering stable state the UI could be optimized to only bother the user once. See http://lists.w3.org/Archives/Public/public-media-capture/2012Jun/att-0055/minutes-2012-06-07.html, resource reservation
Resource reservation
- When are devices (camera/mike) reserved? GetUserMedia, attachment, other?
- When are devices released? Stop stream, stream GC'd, other?
- Was discussed at telco May 9th; agreed to go for option "getUserMedia" reserved/occupies devices
- Anant got actions to write up a proposal accordingly (recorded as Actions 2 and 3 at http://www.w3.org/2011/04/webrtc/mediacap/track/actions)
- In version Aug 13 2012 of http://dev.w3.org/2011/webrtc/editor/getusermedia.html this is included
