A/V Synch Problem In Vegas 7/DVD Architect 4

tnw2933 wrote on 9/21/2006, 3:10 PM

I have run into an audio/video synchronization problem that after many hours of work I have not been able to solve.

I have created a project in Vegas 7.0a where the video is captured DV footage with audio captured as 48 KHz PCM. Some of the audio has been replaced at sevral positions on the timeline with 48 KHz .wav files captured from an audio CD and then upsampled in SoundForge 8.0b to 48 KHz. Thus the sample rate for all audio in the project is 48 KHz. On the Vegas 7 timeline the project's video and audio plays back in perfect synchronization. I then rendered the video to mpg2 using the MainConcept mpg2 encoder and the default template for a DVD Architect compatible NTSC file. The audio was rendered as stereo ac3 using the default template.

When I take the video and audio into DVD Architect 4, my audio is out of synch by about 3 seconds with the video. Specifically the audio is lagging behind the video by about 3 seconds. I observe this synchronizaiton problem when I preview the disk in DVDA4 and when I burn the disk, the A/V is indeed out of synch.

I returned to the orignal project before upsampling the CD audio files and used the CD audio at 44.1 KHz. This made no difference. The project rendered fine but once I took it into DVDA4 the A/V were out of synch by about 3 seconds.

Does anyone have any idea what is going on here and how to fix it?

Thanks in advance for responding.

Tom

Comments

tnw2933 wrote on 9/23/2006, 11:44 AM

I am replying to my own post on this problem. No one has responded so I must be the only person ever to encounter an A/V synch issue of this type.

I have managed to solve the problem although I am not sure what caused the problem. Each time I rendered the audio and video in this synch and then took them into DVDA4, the audio lagged the video by about 3-4 seconds. The soluton was to open two instances of Vegas 7. One instance contained the original project which, when rendered, produced the A/V synch problem in DVDA4. In the second instance of Vegas, I simply copied the clips on all audio and video tracks from the original project into the new instance of Vegas 7 taking care to place the clips properly and in the exact same timeline locations as the original project. I then rendered from the new instance of Vegas, took the audio and video into DVDA4, and the A/V was in perfect synch.

I have no idea what produced this problem, but I could consistently reporduce it until I opened the fresh instance of Vegas and copied all the clips over and then rendered both audio and video in the fresh instance. I spent more than 8 hours of work sorting all this out so I thought I would share the solution with any other poor soul who ever runs into the same problem.

Tom

vitalforce wrote on 9/23/2006, 11:55 AM

Thanks. Even for problems others haven't hit yet, one of the most valuable things about this forum is the problem-solving posts.