[MPlayer-users] CD-AC3 ?

Arpi arpi at thot.banki.hu
Sat May 17 13:20:57 CEST 2003


> Can mplayer play a CD-AC3 disk? Or a Wav file encoded in AC3?
> Please take a look at
> http://www.5dot1.com/articles/ac-3_5_1_audio_onto_a_cd-r.html
> The sample files are at
> http://www.modernrecording.com/articles/2000/apr/Sal_640kbps_1min.ZIP
> http://www.modernrecording.com/articles/2000/apr/Sal_256kbps_3min.ZIP

i've checked it, it's a big hack (and violates the cdrom standards)
for external cd players + ac3 decoders.

the headers are set up as normal cd audio (byteswapped LPCM), but instead of
pcm samples, they contain ac3 frames together with some extra data.
actually it's the same as the output of: 
mplayer somefile_with_ac3_audio -ac hwac3 -o pcm

if you have an ac3-capable amplifier connected to audio cd player via
sp/dif, the amp. will notice the ac3 frames and decode them.
but all software players or normal amps will play just noise.

it's possible to support in mplayer, but imho it doesn't worth that mess.

> When I play these it plays them as normal uncompressed PCM. It's the same
> even if I use a -ac a52 or -afm liba52

as headers lie that it's lpcm stream

do -dumpaudio, then byteswap the resulting file and then play with -rawaudio

A'rpi / Astral & ESP-team

Developer of MPlayer G2, the Movie Framework for all - http://www.MPlayerHQ.hu

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