Encoding a DVD rendered to an MKV file through Avisynth - A/V not in sync..

[Lathe]

This is the weirdest thing...

Everything seemed to be going swimmingly. I had taken my original DVD of the film 'MOONTRAP' and using MakeMKV created an MKV file of the movie. Then playing around with Avisynth, I figured out how to denoise it a little using TemporalSoften or something like that. So, then using an x264 CMD line I rendered it using a few tweaks. The resulting file looked fine, BUT... when I went to mux it with the original audio from the same DVD MKV file, it ends up out of sync. It SEEMS to be in sync at the beginning, but gradually the audio begins to precede the video, so at the end of the 1:30 or so, there is about a 1 or 2 second lag in the video.

One think I DID notice was that strangely although the resulting MakeMKV rendered MKV file with MediInfo showed it to be at a 23.976 framerate, for some odd reason after encoding it with x264 the file read as 29.xxx I sure don't know where that came from. But if the audio is at the original frame rate and the video is now THAT far off, wouldn't the difference be FAR greater? Oddly, the running time shown on both files was 1:30. Very strange...

Then I remembered in the past (and also noticed the BDRB always includes this line in the encoding) that sometimes when the streams were out of sync I would include the AVS line 'AssumeFPS(24000,1001)' But, after reencoding it again with this command, it very oddly showed that it now had a running time of 1:53!?? WTF!? But, when playing it, the film actually ended at 1:30 and part of it for some weird reason started to repeat. So, I just ran it through MKVMerge and chopped off the extra. But, now that the video stream reads as 23.976, the audio is even farther off!

I can't for the life of me figure out WHY that is when both before and after files are the same length. And, I cannot figure out how the hell to get the A/V properly in sync. I TRIED playing around with the MKVMerge settings for 'stretch' and 'duration', but none of it made any sense.

I'm SURE that there must be some basic step I'm missing, but I sure cannot figure out what it is. Any help would be greatly appreciated!

Thank you!

[ProWo]

Post a mediainfo report (text mode) from the makemkv resulting mkv here.

[jagabo]

NTSC DVDs are always 29.97 fps, though the encoded frames may include a mix of hard and soft pulldown. Not all software accounts for that. What AviSynth source filter are you using with the mkv file? Try using LWlibavVideoSource() -- included in the LSMASH package.

[manono]

I had taken my original DVD of the film 'MOONTRAP' and using MakeMKV created an MKV file of the movie.

There's your mistake. Decrypt it to the original VOBs and then make a D2V file using DGIndex and use MPEG2Source on it. It's all explained in the excellent docs included in the DGMPGDec package.

[Lathe]

Ah, thank you all! Very good information and helpful.

I will remember this for future tries. Actually, I was able to 'cheat' and import it into BDRB and then drop the AVS code into it. It did render it correctly, but I needed to learn these things, thanks!