Video_TS to MPEG-2 Sound Sync

[compufix2]

Okay, first off, we are testing a Video on Demand system. All VOD material needs to be MPEG1, 2 or 4 with MP2 audio. I have used FFmpegX to convert a DV stream exported from FinalCutPro with no issues. So I have some inhouse work on the system for my users to play with and test.

Next, we will most likely be getting some material on DVD that I want to convert and put on the system. My requirements are Half DVD resolution at 2000 kps or greater.

To test out this theory I used a ripper program to rip the main attraction VOB files from some DVD's I use for testing equipment and general entertainment. When I dump the resulting Video_TS file on VLC, the movie plays fine, all audio/vido is in sync, and I have access to the various video and audio tracks. Now...

I use FFmpegX and point the Video_TS folder as the source, I make sure my video encoding is set to Half DVD at 2000 kps, and that the FPS matches the original video. I then set my Audio to MP2 and choose the audio track I want (usually just the stero or maybe the AC3 5.1) and use the MPLAYER decode option. The process takes a bit of time, but I get a resulting MPG movie. The problem is no matter WHAT settings I try, the audio is always out of sync with the video, it is as if the video timeline is being sped up, or the audio slowed down. The sound track does not match even from the beginning titles.

Can someone tell me exactly what might be happening, and if there are settings I can look at. MP2 is the required audio format for what we need to do. I have not tried making an MPEG 4 movie yet with MP2 as the audio source.....wanted to stick with what I know worked for the DV conversion I did.

Help me please.....other than that...so far, so good.

-Mike

[major]

The sound sync problem is in fact a video sync problem. It is almost always the result of a mismatch in framerates. If your source is from a NTSC DVD then the framerate is probably NTSC FILM. You should as well "set 3:2" in the Options tab. However some NTSC movies are difficult to handle with the "Decode with mplayer" option in respect to sound sync, you should try "Decode with Quicktime" with them.

[compufix2]

But then I can't encode a Video_TS correct? using a Ripper like MTR to do main feature only.....should i get another utility to combine into one VOB file then run it through the decode with quicktime option? And does that require the MPEG2 component to be installed?

Thank you.

-Mike

[compufix2]

okay, thank you major for that, it is much better, but still not totally in sync. When I use a Video_TS as a source it automatically usesMPLayer for decoding. Is there anything else I can do to sync it better, or do I have to do the VOB directly with Quicktime decoding? Or use a different utility all together?

-Mike

[major]

You should extract as a single VOB file, then use the VOB file as source instead of the VIDEO_TS folder.

[compufix2]

What is the best tool for combining VOB files in a single Video_TS folder?

I will search, but if you have any recommendations, please let me know.

-Mike

[DaleMox]

If you mean combine multiple VOB files into 1 VOB file, then
In the terminal, move to the VIDEO_TS folder
(e.g. cd ~/Desktop/TEAM_AMERICA/VIDEO_TS)
The use cat to combine the vob files
(e.g. cat *.vob > ../TeamAmerica.vob)

Dale

[Johnson_Steve]

I use M.T.R. to get a single .vob just use Title-Chapter extration and select all the chapters then you get the whole movie in one .vob

[compufix2]

Success....I have had success...I will try that last tip about MTR, since I know the application is newer and has ongoing support and development.

I combined the VOB files using CAT as suggested and it worked fine, I also tried OSEx and took that single VOB file.

I am using ffmpeg to encode, using high quality, 2000 kbps, Mpeg2 at 3:2 and NTSC FILM for FPS.

I am using MP2 as the audio encode. The resulting file I have now has been right on.

So at least I know that when it gets to the point where material is given to me on DVD I can convert it for use with the system we are thinking of deploying...just a couple of things I noticed...

FFmpeg is much faster...

On a VOB that FFmpeg worked on, mg2enc MPEG2 give me an error about the YUV information not being found in the header....

mpg2enc has the letterbox option, and I only found that in ffmpeg if I use the decode with quicktime option...

So I am just using naitive 16:9 resolution for those files (at half DVD resolution)

Movies I ripped as a test worked well (3 of them), however I have had mixed results with the audio tracks...some get errors in VLC when I try to play, but overall it works...also Remember the Titans gave me a strobing effect...although I will not be having actual content available that we do not have the rights for, I am curious if that is an anomaly or could it be possible that I may see that in the future again?

Of course if I was really in a pinch I could just take the output of a DVD player and feed SVID and audio into an encoder and do it real time...but, what is the fun in that?

Once again, I am the only person with access to this system for testing and just want to make sure I have an answer for various situations.

So far so good....thank you all for your help and tips.