playback audio/video synch

ninianne98 wrote on 12/17/2004, 12:35 PM
I'm using MPEGs my Hauppauge 250 saves off after editing out commercials. I've noticed that the audio seems to get a little out of synch the further into the program I play. The original MPEG is in synch, however playback of the rendered DVD VOB file shows the synch issues. I also have noticed a degrade in video quality - an increase in artifacting in motion scenes in the VOB playback. I suspect that it is because Architect Studio is having to redo the audio since it is not PCM. I have tried (using TMPGEnc) de-muxing the audio from the video and remuxing the m2v file into an mpg file with no audio (Studio won't recognize the m2v file as valid) and taking the WAV file as a separate audio track but this has not seemed to help.

What is the best approach to getting the sound & video into an architect project so that the most quality is preserved if you are starting out with the data already stored in an MPEG-2 file?

Comments

cbrillow wrote on 12/17/2004, 7:27 PM
This has all the earmarks of an analog-to-MPEG2 capture problem that is frequently seen and very difficult to sort out. The key clues are progressive loss-of-A/V sync and the ability to play the source file without problems in Media Player or a similar software player.

It's very likely that your captured file has dropped frames, invalid GOPs and timestamp problems, all of which add up to loss of A/V sync when prepared for DVD or re-rendered to MPEG. You can test for this with a freeware application called PVAStrumento. Womble also makes a product that can detect, and attempt to repair, files that exhibit these problems.

I used to struggle with the exact problem you describe. In my case, the captures were made by the Winfast PVR from a Winfast TV 2000 Expert tv tuner card. I found out that the MPEGs were bad, despite playing without problems in Media Player. I solved my problem by using other capture software, which wrote the files correctly. I would recommend that you look at Intervideo's software. I tried an evaluation copy of WINDVR 3, and it recorded MPEG files that did not have the GOP & timestamp problems, and allowed me to burn DVDs with good A/V sync.

You might have a look at their website and see if their applications support your Hauppage device. A quick download may reveal whether this is what's causing your trouble.

Good luck!
ninianne98 wrote on 12/23/2004, 8:43 AM
I was suspicious that the problem was something along these lines. I've gotten a demo of Womble and the GOP repair feature seems to take care of the issues, thanks for the recomendation - however the price is pretty steep for something that I plan to use just to repair headers, is there another tool out there that is specificly for repairing MPEG files?