Audio and video slightly out of sync

w-d wrote on 5/22/2022, 4:44 PM

Hi, I'm using Vegas Pro 18.0. I have made a DVD and Blu-ray of my project using DVD Architect Build 100. (There is no version number, but the copyright year is 2018 and it's by MAGIX.)

The project settings in Vegas Pro 18.0 are 29.97 fps.

For the Blu-ray, I render to "Blu-ray 1920x1080-60i, 25 Mbps video stream."

For the DVD, I render to "DVD Architect NTSC Widescreen video stream."

For the audio, I render using Vegas Pro 14.0 to AC-3 Studio 5.1 and Stereo (there's no option to render AC-3 Studio or AC-3 5.1 in Vegas Pro 18.0). The project settings are also 29.97 fps.

When I preview the DVD or Blu-ray in DVD Architect (either 5.1 or stereo), the audio and video sync is perfect.

After I burn (it doesn't recompress) and play the DVD or Blu-ray in a real Blu-ray player, the audio and video seem to be synchronized at the beginning but become out of sync ever so slightly (seems to be a fraction of a second) for both the 5.1 and stereo tracks as the movie progresses. The movie is around 1.5 hrs long. This happens regardless of whether I play from beginning to end or if I go to a chapter mark near the end of the movie.

Any ideas what I can do to make it totally in sync?



DMT3 wrote on 5/22/2022, 4:50 PM

Have you seen the issue in other DVD/Bluray players?

w-d wrote on 5/22/2022, 5:10 PM

Thanks for your reply, @DMT3. I hooked up a Sony Blu-ray player and tried it. I got the same sort of sync issue when I tried going to a chapter at the end of the DVD and Blu-ray. (I didn't bother playing each of them through from start to finish.)

I see that the DVD and Blu-ray rendered video is indeed 29.97 fps, but when I ran MediaInfo on the 5.1 AC-3 that is rendered by Vegas Pro 14.0, MediaInfo shows the 5.1 AC-3 is 31.250 fps. I am not sure if this is a concern or not, because others are also reporting the AC-3 is 31.250 fps: and weirdly it works perfectly fine for me in the DVD Architect preview.

I had initially thought there is no fps for AC-3 audio and the AC-3 should be measured in sample rate using kHz, but maybe I am wrong about that.