[MEncoder-users] 2 Channel AC3 problem

[Another Sillyname]

Hi

I have been recording BBC HD Source material that I want to convert
into High Quality 720p Transcodes before I transfer them to my
library.

I've been able to successfully convert the video images the way I want
them however I'm having a problem with the audio side.....

specifically some of the streams contain 2 channel AC3.

If I try to convert these using -channels 6 -oac lavc -lavcopts
acodec=ac3:bitrate=384 then the output convert is only 2 channel Dolby
Digital rather then a 2 channel AC3 output.

If I try -oac copy I'm getting the AC3 retained correctly but am
getting noticeable 'clipping' during sound playback which isn't on the
source material (does -oac copy do anything funky to the material?)

Can someone posibly give me some ideas or pointers?

Also as mkv output is not working what do people recommend under linux
to produce x264/AC3 files?

Thanks in advance