[mythtv-users] no audio in dvdauthor step

[Martin Bene]

> Carl, demux (which as I understand, is done by ProjectX, right?) 
> produces two files - 1 video (*.m2v) and 1 audio (*.mpa). Are 
> you saying that it should produce second audio file (*.mp2 maybe)?

Ok. This answers one part of the question - there's only one audio
track, and it's in mpeg2 format.

Next question: what are you using to play the result produced by
dvdauthor, i.e where do you hear (or rather not hear) the missing audio?
What TV standard do you have?

If tv standard is NTSC and you're using a stand-alone DVD player, the
problem could be the format of the audio stream: It seems that NTSC DVDs
must have AC3 audio; other formats (like mpeg2) may be suppored by
players but are not compulsory.

If that's your problem, you'd have to convert the *.mpa file produced by
demultiplexing to AC3 Format before multiplexing.

Call to users here: what's the best way to do this given an the mpeg2
audio as input?

Just so you have something you can try right away (yes, the additional
mplex call is idiotic, but ffmpeg doesn't seem to like "naked" mpeg2
audio files, and I can't use the original file as input because I don't
want to lose the fixups projectx may have added to the audio stream.

mplex -f 3 -o xyz.mpg xyz.mpa
ffmpeg -i xyz.mpg -f ac3 -ab 192 -ar 48000 xyz.ac3

And then add that new .ac3 file as first audio file in the final mplex:

mplex -f 8 -o xyz.mpg xyz.m2v xyz.ac3 xyz.mpa

(giving you a DVD with both AC3 and MPEG2 autio tracks)

or just replace the mpa file with the ac3 file so your DVD has just the
ac3 audio.

Give that a try and let us know the results.

Bye, Martin