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[Bug 20733] New: Format need to define how to negotiate: width, height, frame-rate

From: <bugzilla@jessica.w3.org>
Date: Tue, 22 Jan 2013 12:53:29 +0000
To: public-media-capture@w3.org
Message-ID: <bug-20733-5753@http.www.w3.org/Bugs/Public/>
https://www.w3.org/Bugs/Public/show_bug.cgi?id=20733

            Bug ID: 20733
           Summary: Format need to define how to negotiate: width, height,
                    frame-rate
    Classification: Unclassified
           Product: WebRTC Working Group
           Version: unspecified
          Hardware: All
                OS: All
            Status: NEW
          Severity: major
          Priority: P2
         Component: Media Capture and Streams
          Assignee: public-media-capture@w3.org
          Reporter: jay@peepo.com
                CC: public-media-capture@w3.org

Suggestion: browser should honour user defined format and frame rate.
possibly subject to camera providing given format and frame rate, 

afaict 

There is currently no defined way to negotiate the video format

  A camera may offer a variety of formats and frame rates

  The user may have chosen a desired format and frame rate

  The browser may auto-select a format and frame rate

Evidence:

  Method:
    set format and frame rate:**
      $ v4l2-ctl --set-fmt-video=width=320,height=240  //320x240
      $ v4l2-ctl --set-parm=60  //60fps
      $ v4l2-ctl --all  // check current settings

    load http://www.gnote.org in browser

    check format and frame rate again:
      $ v4l2-ctl --all  // ie did they change?

  Results:

    Chrome v24.0.1312.52 
      format is changed to 640x480
      user defined fps is retained

    Opera v12.12.1707
      user defined format is retained
      fps is changed to 25fps

    Firefox 21.0a1 (2013-01-21)
      format is changed to 640x480
      fps is changed to 30fps

Tests were not exhaustive, it may be helpful to have other tests, particularly
using a UVC compliant camera

my apologies if I missed something obvious.

~:"

**  v4l2 is a Linux API to control camera output
    v4l2-ctl provides an interface to this API

    Camera: Sony Eye Camera available formats:
      640x480@15
      640x480@30
      640x480@40
      640x480@50
      640x480@60
      320x240@30
      320x240@40
      320x240@50
      320x240@60
      320x240@75
      320x240@100
      320x240@125

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Received on Tuesday, 22 January 2013 12:53:30 GMT

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