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Windows media player and AC-3 RRS feed

  • Question

  • I am able to play AVI files which contain AC-3 audio in Windows Media Player. I assume that it is using the external AC3Filter to do this.

    I am writing an ASF muxer which writes the audio as AC-3. The resulting WMV/ASF file plays OK in "Media Player Classic Home Cinema" which is using AC3Filter to decode the AC-3 audio. Also, GraphEdit can play these files (using AC3Filter) OK.

    But the strange thing is that when I try to play one of these WMV/ASF files in Windows Media Player it complains that "an audio codec is needed to play this file" - and the associated Web Help says "Dolby AC3 (2000) codec is not installed on your computer".

    Of course AC3Filter *is* installed, and Windows Media Player is able to use it when playing an AVI file with AC-3, and yet when asked to play a ASF file with AC-3 file it seems to think that the codec is NOT present. I have also tried using the Solveig ASf mux filter and that gives the same results.

    I would like to be sure that my MUX filter produces files that will play in Windows Media Player, but it looks as if this may be a problem with Windows Media Player.

    Does anyone know why Windows Media Player has this inconsistent behavour, and better still how to make it find and use the AC3Filter when ased to play ASf files?

     

    Tuesday, July 13, 2010 4:28 PM

Answers

  • I am not aware of any 3rd party MFTs that provide AC-3 support.  For DVD playback, IIRC, WMP still uses dshow for MPEG-2 and AC-3 support.

    As far as how WMP plays ASF files using MF, my understanding is you cannot change this (without resorting to hacking your Windows installation).  There is no dshow filter wrapper or a merit system in MF except for hardware devices and the merits are only approved by applying to MSFT.


    Please use Vote As Helpful (green up arrow at top-left of posts) and Mark As Answer where appropriate.
    My dshow site is http://tmhare.mvps.org.
    • Marked as answer by tiresias Tuesday, July 13, 2010 6:36 PM
    Tuesday, July 13, 2010 5:08 PM

All replies

  • This has come up several times before.  WMP uses Media Foundation to play ASF files in Vista forward.  Therefore it does not use dshow filters present on your system.  You cannot change this behavior short of hacking your Windows installation.  That is not supported here per the Terms of Use of these forums.
    Please use Vote As Helpful (green up arrow at top-left of posts) and Mark As Answer where appropriate.
    My dshow site is http://tmhare.mvps.org.
    Tuesday, July 13, 2010 4:31 PM
  • Thanks for that explanation. It seems that Windows Movie Maker has the same behaviour, so I guess that it too uses Media Foundation to import ASF files.

    I'm not familiar with Media Foundation, but is there some sort of plugin for Windows Media Player which WILL allow it to play AC-3 audio?

    Also, I suspect that the answer is no, but is it possible to configure Media Foundation, or write a wrapper which will allow a DirectShow decoder to be used in Media Foundadtion?

     

    Tuesday, July 13, 2010 4:57 PM
  • I am not aware of any 3rd party MFTs that provide AC-3 support.  For DVD playback, IIRC, WMP still uses dshow for MPEG-2 and AC-3 support.

    As far as how WMP plays ASF files using MF, my understanding is you cannot change this (without resorting to hacking your Windows installation).  There is no dshow filter wrapper or a merit system in MF except for hardware devices and the merits are only approved by applying to MSFT.


    Please use Vote As Helpful (green up arrow at top-left of posts) and Mark As Answer where appropriate.
    My dshow site is http://tmhare.mvps.org.
    • Marked as answer by tiresias Tuesday, July 13, 2010 6:36 PM
    Tuesday, July 13, 2010 5:08 PM