Looking for some help with AC3/DTS passthrough

January 25th, 2008 | Category: Coding | Author: elan

Specifically, I’m looking for someone with a surround receiver hooked up to run this binary and send me the console output (specifically, the stuff about “Asked to create device…”, “Considering…”, and “Picked…”). I’m trying to figure out why I’m apparently the only one able to do AC3/DTS passthrough.

Please note that there is nothing new about this new binary besides some extra debugging output. It does not work on the Mac Mini. It does not provide a workable solution for solving world hunger.

Thanks in advance for the help.

5 Comments so far

  1. yaneku January 25th, 2008 1:59 pm

    Ok, here we go!

    My XBMC settings:
    Audio Output: Digital
    AC3 capable: yes
    DTS capable: yes
    Built-in Output
    iec958

    I am using a white iMac 24″ connected to my reciever using a minijack-toslink cable. My DD/DTS capable reciever doesn’t understand that the signal is a digital one (works with VLC and DVD player though).

    In the following debug outputs I started XBMC, played file, pressed X to exit playing, and then I exited XBMC.

    Playing a mp3:
    http://pastebin.com/m69e53e70

    Playing a mkv with AC3:
    http://pastebin.com/d4db1302c

    Playing a mkv with DTS:
    http://pastebin.com/d10052134

    Playing another mkv with DTS:
    http://pastebin.com/d7a2af06f

    Hopes this helps!

  2. yaneku January 25th, 2008 2:02 pm

    btw. when playing the AC3 file I get alot of strange noise. When playng the DTS it is almost silent with some strange noise coming every ~5 seconds (randomly).

  3. yaneku January 25th, 2008 2:05 pm

    …and another clarification :-)
    When playing mp3s and videos without “digital sound” it works great using my digital minijack-toslink cable!

  4. yaneku January 25th, 2008 2:14 pm

    …and I got “PortaudioDirectSound.cpp:104]: Stream is stopped.” when I pressed the X key which seems correct.

    On one of the DTS files I got “PortaudioDirectSound.cpp:233]: Output underflowed.” during playing though, don’t know if this is related.

  5. elan January 25th, 2008 2:18 pm

    Alright, thanks very much for the feedback! I think this boils down to me needing to perform extra work to get the output device to be in “Encoded Digital Output” mode. Since I have a separate Digital Output on my machine it works out of the box for me. If you’re a Core Audio expert, feel free to chime in.

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