A problem about dynamic change media type RRS feed

  • Question

  • Hi

       I  have asked the question  about spdif media type set between MFT and SAR before. Right now I found  it will fail if  I set the media type first to PCM then change it to SPDIF, but when  I  set the media type to SPDIF at the begin , it works all right .

       I also found another issue.As there are two audio render in my PC, one is  high definition audio device speaker and the other is high definition audio device spdif. when set the default device as  high definition audio device speaker, it work well  as I change the media type from 2 channel  to  5.1 channel or 7.1 channel, but it failed if set high definition audio device spdif as the default . A strange thing is that it works well in  both situation when change media type from 5.1 to 2ch or 7.1 to 2 ch.

       I guess that it is the problem of the audio render , as SDK says , some media sink won't change media type  during streaming , but why it can work when change type from 7.1 to 2 ch,? I was confused about this.   

       Best wishes

    Monday, April 21, 2008 1:23 AM


  • You're correct that the SAR (audio renderer media sink) won't allow dynamic changes to the media type.  I'll speculate that that is what's behind this behavior that you're seeing.


    I wouldn't be surprised if the cases that appear to work have some MFT in the topology before the SAR that is able to "absorb" the media type change (i.e. they'll change the input type but not the output type, and then the SAR's input type remains unchanged).  And in the cases that appear not to work, there is no such node in the topology.  You could try always putting a resampler MFT in your topology (even if it's apparently unnecessary) and seeing if that fixes the case that don't work.

    Wednesday, May 14, 2008 3:02 PM