Dolby Digital = AC-3 = ATSC A/52



=== Output options ===
Output options from computer to amp:
    - discrete audio channels (eg. 6 separate audio cables)    [my current amp doesn't support this??]
    - digital PCM  [not sure whether many amps support this?]
    - encoded as AC-3   [it's not clear whether linux -- or maybe even Windows -- can output this, in real time...]



=== Linux software ===
    http://club.cdfreaks.com/showthread.php?s=&threadid=78614
            - explains lots of bits about encoding
    - AC-3 real-time encoder  http://essej.net/ac3jack/
    - AC-3 encoder  http://besweet.notrace.dk/      http://forum.doom9.org/showthread.php?t=56020





========= Research ===================

http://gentoo-wiki.com/HOWTO_Dolby_Digital_and_DTS

http://alsa.opensrc.org/SurroundSound
    Playing surround sound as PCM...  doing mixing, etc