[mythtv-users] nuvexport problems

[David Watkins]

On 31/07/07, Ben Edwards <funkytwig at gmail.com> wrote:
> I used to use nuvexport very successfully however I am having real
> problems.  I have tried using the stock ffmpeg for Ubuntu feisty,
> compiling it myself and using the one from medibuntu archives.
> Whatever I do, svcd, vidx, divx ... the results always look like 5th
> generation VHS copies!  I generally accept the defaults.
>
> I also dont seem to be able to get mytharchive working without lipsync
> problems (c other posting) so I have no way of archiving stuff;(
>

I've never used mytharchive and I don't do much transcoding at all but
I can offer a couple of suggestions to attack your lip-sync issue.  I
record from DVB-T in the UK.

1)  If your source is DVB then I'd recommend always doing a lossless
transcode first from within mythtv.  It doesn't degrade the quality,
doesn't take very long (even on low-powered hardware) and seems to
make any subsequent processing much more reliable.

2)  Find out if your lip-sync error is consistent.  For example I
transcode some material for my PSP (using mencoder) and have a
completely consistent 300ms offset between sound and picture (can't
remember which way), which I can fix by supplying the correct offset
in the mencoder command line.  To find out what the offset is, either
mplayer or xine (maybe both) have the ability to delay or advance the
soundtrack, so you play your file, keep adjusting the delay until it
looks right and read off the offset value.  If it turns out that, for
your mytharchive settings, the offset was consistent then you could
get your hands dirty and try and find a way to add the offset to
mytharchive.


Even with the small amount of transcding I do I've had lots of
problems.  The main issue seems to be consistency, some recordings
transcode well, others don't, even though they play well in mythtv.
My suspicion is that it's all down to errors in the MPEG 2 files so I
assume transcoding is more critical of errors than watching.