none
Video with alpha channel ... comes out opaque RRS feed

  • Question

  • Hi,

       Got an uncompressed avi with ARGB frames, each with an alpha channel.

    When I render this with media foundation, the frames are decoded, but the alpha seems to be ignored and the frames come out visible, but opaque.

    Please could Microsoft supply a sample application that demonstrates video streams that include alpha channels decoding correctly.

    Thank you.

    Best regards,
    Steve Williams
    Advance Software

    Monday, October 28, 2013 1:06 PM

All replies

  • bump
    Monday, January 20, 2014 8:44 PM
  • Hello.

    We need more information to help you.

    What sort of decoder do you use ?

    Tuesday, January 28, 2014 10:27 PM
  • Sorry for delayed response.

    A custom DX9 EVR presenter, controlled via source derived from MFPlayer

    Sunday, February 23, 2014 6:58 PM
  • Bump.

    Come on Microsoft. this can't be that hard to fix :)

    Can work around Media Foundation shortcomings by using alternative APIs, but don't you want it working properly ?

    In the event Media Foundation is no longer a priority and you have a new uber video API, link please.
    Saturday, March 29, 2014 10:21 AM
  • Your post didn't mention which version of the OS you are targeting, or what specific video format you are using...

    Monday, March 31, 2014 6:34 PM
  • Hey Chuck,

    Thanks for getting back to me.
    Got to target all your recent operating systems + future.

    So that's media foundation with dshow for legacy - that's falling off the bottom & not available on rt (afaik - please correct if I'm wrong on that - don't have a test system right now).

    codec - not selected yet - this is current/future work in progress.

    for video with alpha, I guess motion jpeg-2000 or HEVC if it supports RGBA, with no specific implementation selected yet. whatever hardware accelerates well would be good of course.

    I'd expect Microsoft to provide sample code demonstrating an uncompressed stream running through the pipeline as expected - if for nothing else, so you can test your own pipeline. Maybe it is functioning correctly and I'm just missing a flag somewhere. Sample code would enable us to drill down into codec issues once we have a base to work from.

    Understand we can colour key on legacy, but want full alpha available for hi-def where possible.

    Thanks for your time.

    directx12 solution would be helpful (not on beta yet - that would be appreciated too), but would be great to have legacy (vista +) working too.

    Cheers,
    Steve.
    Wednesday, April 2, 2014 1:06 AM