[MPlayer-advusers] [BUG] FAAD: compressed input bitrate missing, assuming 128kbit/s!

[Corey Hickey]

RC wrote:
>>I've found an Apple h.264/AAC trailer that doesn't have any sound. I
>>don't know if the problem lies with mplayer or with faad, but I figure
>>somebody here will be able to tell for sure.
> 
> Looks like MPlayer is to blame.  That audio stream is 7.1 channels,
> which mplayer apparently can't handle.

Ah, that's it. Thanks.

I remember seeing several places in mplayer audio code that assume a
maximum of 6 channels; up to now I'd never seen more in the wild. Maybe
I'll be able to fix mplayer to handle more, though, at this point, I
don't know what the proper fix is. It would be nice to handle an
arbitrary number.

> With -dumpaudio, I can output an AAC file that faad is happy to decode
> to a wav.  I haven't yet been able to play anything back, as none of the
> programs I use will even downmix 8 channel wav files.

When I use faad on the dumpstream it downmixes to 6 channels, which I
can then downmix to 2 with:
mplayer stream.wav -af pan=2:1:0:0:1:1:0:0:1:0.5:0.5:1:1

Or, 'faad -d' downmixes to 2 channels.

The audio by itself sounds fine to me.

Out of curiosity, how were you able to determine that the audio track
has 8 channels?

Thanks,
Corey