I had pretty much figured out that it was the demux/remux stage in almost all of the "MythTV to DVD" scripties and HOWTOs out there that was breaking the sync. After I looked into it, I discovered the that the PTS/DTS info is that the ProgramStream level... once it's demuxed into ES or PES's, you've screwed the pooch....After having used Project X for a long time now, and reading of these problems, I had a hunch it was the deumxing of the streams initially that may be causing the sync issues. After all, remuxing cannot add back what is not present in the demuxed streams, and so if the sync is not fixed at this stage, I can't see the remuxing magically sorting it out.
... UNLESS it's fixed before it's demuxed. After playing with ProjectX a bit more, I see that at the end of his little parsing, he spits this out:
--> MPEG Audio (0xC0) Audio PTS: first packet 00:00:00.333, last packet 02:08:19.185 Video PTS: start 1.GOP 00:00:00.400, end last GOP 02:08:21.192 -> adjusting audio at video-timeline -> src_audio: MPEG-1, Layer2, 48000Hz, stereo, 192kbps, noCRC @ 00:00:00.000 !> 81 frame(s) (1944ms) added @ 02:07:16.992p audio frames: wri/pre/skip/ins/add 318289/0/0/0/81 @ 02:07:18.936 done... ---> new File: /space/HOME_VIDEOS/Tape5.mpa
summary of created media files:
.Video (m2v): 228939 Frames 02:07:18.930 '/space/HOME_VIDEOS/Tape5.m2v'
Audio 0 (mp2): 318289 Frames 02:07:18.936 0/0/0/81 '/space/HOME_VIDEOS/Tape5.mpa'
=> 4372557132 bytes written...
That looks like he added 81 frames of audio (as padding?) to keep demuxed sync. Also, he threw out a bunch of bad B-frames, etc in the .m2v file.
I'll second that. It's not *too* slow... I'd say 5-10 minutes on a 2-3 gig, 1-hour capture. That's certainly acceptable if it's scripted.On my 2.4G system, demuxing takes only a few minutes - if its >30 minutes there could either be significant errors, non standard settings in ProjectX, or lots of other disk activity occuring at the same time.
Haven't played much with the CLI yet as my video processing is not done on my myth box, but this may now soon change if a suitable demux/edit/remux combo is found.
I haven't convinced myself that a simple byte offset ASCII file is sufficient for a cutlist. If it is, I'd like to try exporting a cutlist from mythtv to try GOPCHOPing.
-Cory
************************************************************************* * Cory Papenfuss * * Electrical Engineering candidate Ph.D. graduate student * * Virginia Polytechnic Institute and State University * *************************************************************************
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