[MPlayer-users] when playing mkv with 5.1 AAC stream mplayer outputs it always as 5.1 even when -channels 2 is given

LLoyd Bates LLoydBates at gmx.de
Fri Jul 30 10:40:42 CEST 2004


I have a mkv file with an AAC 5.1 stream. 
When playing just my right loudspeaker works.

mplayer tells me that it is a AAC 5.1 stream and that it's played as 2ch
--
Checking audio filter chain for 44100Hz/6ch/16bit -> 44100Hz/2ch/16bit...
AF_pre: af format: 2 bps, 6 ch, 44100 hz, little endian signed int 
AF_pre: 44100Hz 6ch Signed 16-bit (Little-Endian)
AO: [oss] 44100Hz 2ch Signed 16-bit (Little-Endian) (2 bps)
Building audio filter chain for 44100Hz/6ch/16bit -> 44100Hz/2ch/16bit...
Starting playback...
--
(same behaviour with alsa)
problem is that if i use mplayer with -channels 2 it sound exactly the same as with -channels 6

the output tells me that it's playing with 2ch (-channels 2) and the other one with 6ch (-channels 6) but it sounds exactly the same!
One could say the soundstream is at fault.

well i extracted the stream with mkvextract.

faad2 tells me it's 5.1, no problem. 
running 'faad -dw temp.aac | lame -q 9 -b 160 --cbr - temp.mp3' (extracted it before as temp.aac) gives me a stereo mp3
that plays AND sounds right. not like the mplayer output with -channels 2

the aac 5.1 stream is working. mplayer 'thinks' it's downmixing the 5.1 stream to 2ch but it isn't!
downsampling via faad2 -d temp.aac worked fine and produced the stereo output.

i also tried this with the latest CVS snapshot 'MPlayer-2004-0730' compiled with './configure && make install'
no difference!




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