[MPlayer-users] Dolby Surround decoding

[Alexander Roalter]

Michael Holland wrote:
> Richard Bromley wrote:
>> Hi. I'm trying to get full Dolby Surround decoding working with
>> MPlayer, but there seems to be no way to decode the center channel.
> 
> Which "Dolby Surround"?
> The original home (not cinema) "Dolby Surround®" only had 3 channels, 
> according to
> http://electronics.howstuffworks.com/surround-sound4.htm
> 
> Perhaps you want "Dolby Pro Logic®"??
> 
> Still, if I understand correctly, the "center" channel is just the
> common parts of L & R, which you can do with any stereo signal.
> Simple in concept :-) Just like filtering out the low frequencies
> to send to the subwoofer.
> Is 'mplayer' the best place to do that? Or does it belong as a filter
> in ALSA etc?  Is that possible currently?
> (Better yet in the amplifier, of course.)
> 
> I'm new here, and posting under the assumption that somebody will
> correct me if I'm wrong.
I was always under the impression, dolby surround delivers 4 channels 
(albeit not discrete, of course), which would be left, right, center, 
surround.

But giving -af surround mplayer tells me he doesn't know how to downmix 
to 4 channels (with a six channel output on my nforce4 on-board sound 
system - i mailed something concerning this issue a few weeks ago.

And yes, I'd think it would be best if mplayer could do this, so 
although the signal coming to mplayer would not be discrete, the output 
would be a discrete 4.0 signal, which would be the thing I want.

As for a sample: I put a file called maverick.vob onto MPlayer's 
incoming ftp dir. It contains three dolby surround tracks, one in 
english, one in german and one in spanish. Uploading is not done yet, 
and I don't know if all the file will be uploaded or the connection will 
be lost before, but there should be enough for a try.

hth,
ALex