[mythtv-users] Transcoding advice (long)

[Andy]

Hi;

I'm delving into the dark depths of transcoding, and I can't seem to find
any clear answers. (probably because there are none.) Would like a little
advice if someone is willing to give it...

I have a MythTV setup with a PVR-250. I would like to record programs,
remove the commercials, and transcode to an MPEG-4 format to keep them small
but also to allow them to be played on a Windows PC. I also need the process
to be automated. I don't plan to watch the programs via Mythfrontend any
time soon.

Because of my Windows-compatability requirement, the internal encoder is not
a solution, I therefore have 2 options that I know of. Use nuvexport to
create a DivX file or use transcode or another program to directly transcode
the MPEG2 file to DivX. Seems to me that programs other than nuvexport won't
do anything with the cutlist, so I expect that nuvexport is the way to go.
The only thing is that some people have suggested that nuvexport is not the
best tool when the original files are already MPEG-2 as is the case with the
PVR-250 files. I expect that is due to the process that nuvexport uses of
decoding or "playing back" the encoded file and then re-encoding it.
Supposedly that will result in lower quality DivX files than if they are
transcoded directly from the MPEG-2 originals? If that's the case, I think
it's probably the lesser of 2 evils since as I said, I don't expect that
other programs can work with the MythTV cultists, and having an automated
way of removing the commercials (I assume if I'm going to automate I'll be
using mythcommflag) is important to me.

So, if I am correct (I'm not sure that I am) and I need to use nuvextract,
then I need some advice on how to get decent transcodes. I just tried a
transcode from a file that was recorded Video: 480x480, MPEG-2 PS, Bitrate
3000, Max. Bitrate 6000, Audio: 48000, Layer II, 224kbs. I set nuvextract to
DivX at 224kbs audio, 1000kbs video, 640x480. The resulting file had the
audio out of sync by at least 2 seconds! Any suggestions on how to fix that?

Since the original recording is only kept temporarily, should I set my MPEG2
recording parameters higher? Should it be at the same aspect ratio as the
final DivX, or does that matter?

Any suggestions are welcome. I have searched doom9.org quite a bit and still
don't have a clue! =(

-Andy.