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Wrong displaying region of html5 <video> after format change in mft video effect

    Question

  • Hi,

    I am doing mft format change to show the upscaled video frame onto a <video> in html5, according to this http://msdn.microsoft.com/en-us/library/windows/desktop/ee663587(v=vs.85).aspx

    When I initiate output format change in resolution, eg. 720x480 -> 1280x720, the output format of my mft effect changed, but the <video> only showed left-upper 720x480 part each frame. It looks like the mft produces an upscaled 1280x720 frame, but the <video> still has displaying region at  720x480.

    The problem is quite confusing, because the format change should have notified each backend mft components in the pipeline about its changed format. And the <video> at the end of the pipeline should have no problem at all showing the entire 1280x720 frame.

    So my questions are:

    1. Do current <video> support format change like the above description?

    2. If 1. is possible, what is the proper way of doing size format change to have correct displaying region? What do we need to implement other than the format change handling?

    Thanks




    • Edited by ErnestCC Tuesday, February 14, 2012 11:04 AM
    Tuesday, February 14, 2012 10:18 AM

All replies

  • Hello Ernest,

    After reviewing the W3C specification there does not appear to be any guidance on how to handle dynamic format changes. However, the specification is very clear about the size and shape of the rendered video. It is possible that you can force the video control to resize after the dynamic format change by setting the intrinsic height or width. However I don't think that this workaround is really acceptable.

    Do you have a file that contains a format change event that I can use to debug this issue?

    Thanks,

    James


    Windows Media SDK Technologies - Microsoft Developer Services - http://blogs.msdn.com/mediasdkstuff/

    Wednesday, February 15, 2012 11:45 PM
    Moderator
  • Thank you,James. So the problem is more likely on the brower, correct?

    I tried your suggested way to modify the videoHeight/Width during the format change, but the modification would lead to exceptions in WWAHOST. 

    And through what channel can I give you the file? Thanks 

    Friday, February 17, 2012 8:21 AM
  • You should be able to use https://skydrive.live.com/ and create a public folder. I would acually recommend that you talk with your Microsoft TAM. Her name is Michelle. Once she is engaged we can work closely to investigate this issue.

    -James


    Windows Media SDK Technologies - Microsoft Developer Services - http://blogs.msdn.com/mediasdkstuff/

    Friday, February 17, 2012 9:39 PM
    Moderator