Strange issue with my Audio/Volume (1 Viewer)

Skywizard

MP Donator
  • Premium Supporter
  • June 14, 2015
    113
    25
    Canberra
    Home Country
    Australia Australia
    I don't think the issue I am having is to do with MP, but here goes

    I have MP 1 installed on a PC running Win 10. I am using on chip GPU (FWIIW) and am connect to my TV via HDMI.

    I have a SONOS PlayBar connected to the TV via optic link/toslink. The TV Audio is set to "TV Volume is Fixed" and the (TV) "speaker" is set to "Audio System". I can change the volume on MP by using my RC6 remote. I can also change the volume on the PlayBar using my logitech remote programmed for the SONOS.

    My issue is on some channels when I use the RC6 remote I see the on screen volume indicator and the volume is changed. Likewise I can also change the volume directly on the PlayBar.
    On other channels the volume is unaffected (the volume indicator is visible on the screen and moves accordingly) when using the RC6 and I have to use the SONOS for volume control.

    Is there any explanation why this is happening?

    My understanding is the the audio is coming from the PC through the HDMI cable to the TV and then from the TV to the PlayBar. So why would some channels be different for volume changing?
     

    mm1352000

    Retired Team Member
  • Premium Supporter
  • September 1, 2008
    21,577
    8,224
    Home Country
    New Zealand New Zealand
    So why would some channels be different for volume changing?
    Different audio encoding and/or bitstreaming configuration.

    My issue is on some channels when I use the RC6 remote I see the on screen volume indicator and the volume is changed. Likewise I can also change the volume directly on the PlayBar.
    In this case I expect the channel audio is 2 channel MPEG 1, MPEG 2 or HE-AAC. This would be decoded to PCM by whatever audio codec you're using. PCM audio output volume can be adjusted before being carried over HDMI and SPDIF to your PlayBar.

    On other channels the volume is unaffected (the volume indicator is visible on the screen and moves accordingly) when using the RC6 and I have to use the SONOS for volume control.
    In this case I expect the channel audio is 2, 2.1 or 5.1 channel Dolby Digital (AC3). I assume whatever audio codec you're using is configured to enable bitstreaming for DD/AC3. By definition, bitstreaming means the audio isn't decoded on the PC, which in turn means that the volume can't be adjusted. So the DD/AC3 audio is carried over HDMI and SPDIF to your PlayBar. The PlayBar decodes the audio and can adjust the volume.

    If you want to only adjust the volume in MediaPortal then you must disable bitstreaming.

    Note: all of the above is based on assumptions. Please always provide log files when you want help so that we don't have to make assumptions.
     

    Skywizard

    MP Donator
  • Premium Supporter
  • June 14, 2015
    113
    25
    Canberra
    Home Country
    Australia Australia
    Thats for the pointer - you are correct it is the different audio streams MPEG and Ac3 I checked the audio streams - it is the same when I use the HUMAX 4tune. I now just need to work out what is the best solution for me.

    If I connect the Sonos with the toslink directly to the MP PC (would that make a difference - I can try it and find out) then I have to manually use software to "turn it on". I can set it to turn on when it senses Audio from the PC but that also means when it switches on to record. But if I turn off the TV in MP then maybe I can use that setting.
    Connecting to the PC means that if I use the TV - rarely happens - then could either use the TV speakers or the input to the Sonos Amp from the TV RCA connectors - again manual switch on.... via an app or PC and the same for volume control - it is a pity that the logitech remote can only be programmed for volume and nothing more and then only for the playbar.

    I can see some fiddling coming on.

    If you want to only adjust the volume in MediaPortal then you must disable bitstreaming.

    I will have to do some reading on how to do that - more fiddling....
     

    Users who are viewing this thread

    Top Bottom