Encoding/Muxing .mpa and .mpv files

[WhiteRaven]

Hey guys,

I'm having trouble encoding some .mpv and .mpa files recorded by a program called WebSheduler (they're not demuxed files they were recorded that way). I'm trying to convert it to avi but my attempts so far have been futile. I've tried putting the files through ProjectX and then muxing the files together but only to find audio and video become progressively out of sync. I've tried frameserving both the original files and projectX'd files into VirtualDubMod and still have the same problem. Has anybody got any ideas on what I can do, or at least to mux the files together in sync?

[Pookie]

Really difficult to say. Does the original file have commercials? If so, cut them out using Mpeg2cut2. Also, Mpeg2Cut2 does quite a decent job demuxing files. Give it a shot. Are you certain the audio is .mpa and not an .ac3 renamed with the .mpa extension?

Go through some of the posts from the past year regarding bit rate changes of audio files during commercials. That's been the most frequent culprit when it comes to sync problems between audio and video. Take solace in knowing that you're not the only one who has to struggle with this :p

[WhiteRaven]

The audio is a ac3 audio source, I'm not sure if it's just a change of name or it's in a mpeg container or something.

I have tried cutting out the commercials but still no go, still sync problems:(

[Pookie]

Run the audio through AC3Cutter

http://ac3c.vidphiles.com/

Check out this related article

http://www.vidphiles.com/index.php/category/tipstricks/

[Imperial Llama]

Recording video and audio as separate files is not recommended because you lose all the timing information in the transport stream that is used to keep the video and audio in sync when errors occur. The separate files capture type in Web Scheduler is only recommended for radio stations (i.e. when there is only one stream you are interested in and therefore nothing else it needs to be keep it in sync with).

If your sync problem was caused by small sections missing from your streams due to reception errors then I can't think of anyway to fix the problem except to manually re-sync the audio each time it drifts out. Ideally you should use the "TS mux" capture type in Web Scheduler and demux it with ProjectX if you need separate files.

[DrP]

Project-x can take the separate PID files and sync them using the time stamps in the streams. You just have to add the two streams to the source dialogue as a single job, not two separate jobs. The video should go in as the first item.

Project-X screenie (http://img299.imageshack.us/img299/6825/projectx0wj.jpg)

*uh oh. Looks like WS' behaviour has changed some time in the past. Previously it used to just dump the PIDs direct to file without pulling the TS headers out which would let project-x do its thing, however the latest version records them as ES which means no sync info for the audio. If project-x reports the files as ES files, you are out of luck with this trick.