Jan Morgenstern wrote:out of interest, what's the channel order in your Vorbis stream? From the downmix settings above, it looks like it's L R Ls Rs C LFE, which would be different from the Xiph specification (L C R Ls Rs LFE).
The channels are in correct order, following Vorbis spec (L C R Ls Rs LFE), but mplayer rearranges the channels' order before passing the audio through the filters. Amazingly enough, this rearranged order is different for AC3 and Vorbis, so this filter only works with Vorbis.
Jan Morgenstern wrote:In any way, to replicate the stereo downmix settings of the original, C should be mixed at -3 dB and the surrounds at -6 dB, respectively. So, assuming that my guess about your channel order was correct, the line should be more like
The reason we chose AC3 for the online releases of ED and BBB is that it's still the only multichannel format that has a solid downmixing facility built in (AAC comes close, but some players still mess it up).
Thanks for the info. This downmixing facility of AC3 you speak of is in its specification? Has AC3 a facility for the audio creator to specify how the downmix should be done?
Given the right channel order, would it be good to hardcode this downmix setup (pan=2:1:0:0:1:0.5:0:0:0.5:0.7:0.7:0:0) inside ffmpeg Vorbis decoder to solve the problem of most players? (I am assuming that ffmpeg has interface to request the number of channels you want, I really don't remember if it works like that.)