HDTV -> MPEG2 -> MF4 DVD & audio sync

eswrite · Post by **eswrite** » Thu Mar 31, 2005 9:33 pm

I have wanted to burn some of my favorite HDTV shows to DVD for some time. When I finally tried this using MF3.5, I ran into its lack of support for AC-3, so I upgraded ($$$) to MF4.

I had hoped that this would be a 3 step process:

1) Capture HDTV material using MyHD card.
2) Use HDTVtoMPEG2 to remove commercials and convert HDTV transport stream (.tp) file to MPEG2.
3) Use MF4 to import video, create chapters, convert to DVD video and burn.

Unfortunately, it didn't take me long to notice that MF4's output got progressively worse with respect to audio/video sync. I read here that VideoReDo would help with this, so I used it in step 2 to accomplish the same task HDTVtoMPEG2 was accomplishing. A little better, but still, progressively worsening audio sync.

I tried many of the fixes suggested here (VIODRIVER settings), and talked to support, who indicated I should select "MPEG2 audio as non-compliant". None of this worked. I am pretty much convinced that MF4 is unable to downsize video from HDTV resolution to DVD compliant resolutions without mangling audio sync during re-encode. Someone (phd) suggested using XtreamMPEG to do the down-sizing conversion, and that solved the problem.

So this is now my full capture-to-DVD process:

1) Capture HDTV material using MyHD card.
2) Use VideoReDo to load and clean-up (commercials, audio sync) .tp file.
3) Use XtreamMPEG to down-size from 1080i or 720p content down to DVD compliant dimensions.
4) Use MF4 to import video, create chapters, burn --- but no video editing whatsoever!!!

This is a shame: not only do I have to pay for additional software when I have already paid for MF4 to do the job, but it really turns the task into more of a hassle than I'd like. Oh, well. There will be a patch to fix this, right?

EDIT: I forgot to mention that XtreamMPEG's output does not contain AC-3, so I don't really need MF4. More interestingly, the fact that I now have audio sync could be due to the fact that MF4 doesn't have to deal with AC-3 as much as it may have to do with not having to re-size the video.

maddrummer3301 · Post by **maddrummer3301** » Fri Apr 01, 2005 4:18 am

As long as you don't perform any editing to the mpeg2 file MF4 should
create chapters/menu's/and burn without sync problems.
Seems to be a bug in uleads software lately when it comes to
editing mpeg2 files.

You can also import the mpeg's with pcm or mpeg audio and have
MF4 change the audio to AC-3 2/0 by checking the
"consider mpeg audio as non-compliant" (gear icon).
MF4 will only convert the audio to the settings you have set
for the "Project Properties" (target).
It will not re-encode the video if it's dvd compliant.

The audio/sync is usually caused in MF3/MF4 by cutting into a mpeg
stream and then merging the 2 files back together. Seems like the joining
isn't going well.

Hope this helps,

MD

G-Omaha · Post by **G-Omaha** » Sat Apr 02, 2005 3:29 am

HDTVtoMPEG2 sometimes does not work all that good ans is most likely the culprit.

eswrite · Post by **eswrite** » Thu Apr 07, 2005 8:40 pm

@madrunner

As long as you don't perform any editing to the mpeg2 file MF4 should
create chapters/menu's/and burn without sync problems.

I have an update on this. Even if you feed it compliant MPEG2, that's not the end of the story. In my latest tests, I demuxed the video and audio, down-sized the video to DVD-compliant dimensions and fed video + audio into MF4. I verified that the MPEG2 did not get re-encoded by noting that processing time was fairly quick (about 40 min for a 1:30 clip). Now, the sound is out of sync by the same amount from start to finish. (Before, when I fed a 1440x720 clip with AC3 sound, sync got progressively worse). This confirms that not only does MF4 have a problem when it resizes video, but it also doesn't do all that well with AC3--the whole reason I went ahead and upgraded to MF4. Oh, well. I'll keep trying...

Right now, I'm spending hours and hours with VirtualDubMod+Avisynth+QuEnc trying to generate DVD-compliant MPEG2 files I can spoon-feed to MF4. I'm doing this because I realized XtreamMPEG's output at 4:3 letterboxed is not the same (of lesser quality) than video that remains at a 16:9 ratio, but it's sure amounting to a lot of work. Best $70 I've ever spent.

maddrummer3301 · Post by **maddrummer3301** » Sat Apr 09, 2005 2:38 am

Your HD card should be all hardware based.
Is your machine fast enough to playback the HD video and
does it have a s-video or composite out?
Some HD recorders downconvert in realtime (hardware based)
out the s-video/composite outputs.

You can record that realtime conversion into another computer
or your own system if fast enough (dvd recorder etc).

MD