Rendered MPEG-1 video/audio sync problem

mdsh wrote on 12/11/2002, 6:41 PM

Hi,

I have VV3.0c. I am using it to cut down a SIF sized (352x288 25Hz PAL) MPEG-1 file to produce a short version.

My edit works OK on the timeline, it all plays in sync. If I render to the final MGEG1 1,500,000bps video (15 frame/GOP) with 224Kbps 44,100Hz stereo layer 2 sound when I play that back in, for instance, Quicktime or MS media player the sound runs at the correct rate but the video appears to run fast.

Even more strange, if I use the Explorer pane in VV3.0c to select the rendered MPEG-1 file VV tells me that the video is shorter than the audio.

As a test I rendered a 10sec section, and reading from the information given by the Explorer pane in VV3.0c I see:
Video: 352x288, 32 bit, 25.000fps, 00:00:08.13, MPEG-1
Audio: 44,100 Hz, Stereo, 00:00:10:00, MPEG Layer 2

This shows that the video is 213 frames and the audio is 250 frames, the video is 37 frames shorter than the audio, ie the video is 14.8% shorter than the audio.

Obviously this a total show stopper for this project. It appears that the MPEG 1 renderer in VV3.0c is broken, and broken quite badly.

Has anyone else experienced this problem with the latest version of Vegas Video? As I have said, I am using the latest version, 3.0c.

I guess I am going to have to render to an AVI and use Flask to re-render to an MPEG. This is a great pain and time consuming, and it means that VV is not capable of performing the task for which I purchased it.

Thanks.

Comments

SonyEPM wrote on 12/12/2002, 8:35 AM

If you open the file in media player>properties, what MPEG decoder is being used?

You might try using one of the fixed templates- PAL or NTSC VCD. I just tried both of those and they work ok in 3.0c (1 minute quick test).

Is there a reason you are using MPEG-1? Is Windows Media an option?

Lawrence wrote on 12/12/2002, 11:15 AM

Hi,

I have experienced this problem with mpeg2 and mpeg1 that is VBR type in VV3.
We tried with MSPro 6.5 and Premiere and also experienced the same problem.

We reformat the system that has this Dazzle DVC 2 encoder and recatpure the clip
in CBR. It's OK. We narrow down that this is an encoding problem.

I think probably due to some hardware encoder error or the Windows Registry Corrupt.

mdsh wrote on 12/12/2002, 6:47 PM

Hi

>If you open the file in media player>properties, what MPEG decoder is being used?

If I open the file in Media player, not something I usually do, the properties says it uses "Microsoft MPEG 1 Video Decover version 2". But, as I said the video/sound even plays out of sync in VV3.0c.

>You might try using one of the fixed templates- PAL or NTSC VCD. I just tried both >of those and they work ok in 3.0c (1 minute quick test).

I am making something for a client and the client *requires* 1.5Mbps MPEG-1. I tried PAL-VCD and I agree that that works fine.

>Is there a reason you are using MPEG-1?

Yes ther is a reasion, it is what the client requires. Sorry, I can't talk about the client here in an open forum, if you want more details please email me directly to my registered email address.

>Is Windows Media an option?

No, see above.

Later:
When I created my custom settings for the 1.5Mbps video bit rate I started with the "Default" settings and tweeked from there. I have found that if I start with the PAL-VCD and tweek from there the files do not have the audio/video sync problem. I asume that some of the settings on the "Default" set are not compatable with the 1.5Mbps video bitrate rate setting.

Thanks for taking the time to reply, your questions prompted me to aproach a solution from another direction.

Cheers.