mpeg1 Sync Errors (program to fix mpeg1's?)

[thafenix]

I have a whole bunch of TV episodes that have been downloaded off of various fileshareing programs. All of the files are perfectly fine when I play them in their original form but once I demux them and re-encode the audio to 48k pcm or ac3 the audio is way out of sync (like almost 1.5 sec by the end of the 40 min episode) . I have done pretty much every method that I could find here and on doom9.org to fix the sync errors that I am running into with no luck. My thoughts are that I have to re-encode the files and then demux but I’ve had no luck with Tmpeg (newest version) or mainconcept 1.4 for video, and ac3 machine, sonar 2.0, winamp’s decode for audio and many other various authoring software(s). Any suggestions?


Fe-niX

[DPolwarth]

I have the same problem. I have trawled around on the message boards some time ago for a solution, but sadly there are no quick fixes.

First off, I should tell you that I have never succesfully solved this problem. However, I do know that it can be done, and I would like to give it a try. Its frustrating as many of my video clips cannot be transferred to VCD and played on my machine because of it.

The problem is caused, from what I have gleaned from others, because of a different encoding speed in the audio as opposed to the video. Its a little bit like recording the video at one frame rate, and the audio at another (I'm no expert on this, and I bow to the greater knowledge of anyone who can explain it better than me.) What it amounts to is a video clip that can be played perfectly in its original form, but confuses any program that tries to convert it to VCD. TMPGEnc simply cannot get its head around the different speeds, so does its best guess and screws it up.

That's the problem. Now for the solution. Put simply, you have to alter the pitch of the soundtrack. Altering the pitch also alters the speed, and if you can alter the speed so it matches the video component exactly, then the soundtrack will once again fit snugly with the video.

If that sounds a little tortured as a solution, you're right. Its not an elegant solution. as it relies upon 'best guess' problem solving rather than absolute correctness. However, I am assured it does work, and most importantly, it is the only way you can correct the problem. There is no software out there that will correct this automatically.

Like I said at the beginning, I have never tried the method myself, and do not know what software to use.

Please can someone help us both by giving us a practical method of correcting this problem, and tell us what software we need and how to use it?

It would be greatly appreciated,

Dan