Help! audio badly out of sync w/video!

[Neil Sandow]

I’m having the same exact problem with Sony Vegas Pro 8.0b. I’m shooting in 24P 16:9 and my timeline is right on. When I check the project properties all the settings appear correct. I can render to wmv without incident. But when I render to mpg (Main Concept Mpeg-2, using the template for DVD Architect 24p NTSC widescreen video stream) I get sync problems in the VOB after running it through DVD Architect. Even the timeline in video architect is right on, but not the resulting vob. If I customize the mpeg by including the audio I end up with an mpg that has audio which lags a few seconds behind the video. I can also render fine to video for windows (avi) but the file is too large to be useful. What’s up with the render to mpg???

[Edward Troxel]

Make sure your timeline is set to match your render settings (i.e. 24p)

Edward Troxel

[Neil Sandow]

On a lark I decided to try a render to mpg using the default template setting (29.97 fps) even though the clip was shot at 24P (advanced) and the timeline showed: 23.976 fps progressive, 720x480x24, DV (removing 2-3-3-2 pulldown)

I included audio in the render and this time the resulting mpg was in sync. Is my camera lying to me when I set it to 24p? (Panasonic DVX100b)

[Thomas Wildgen]

I too have carefully checked that the timeline prefs are set the same as the media on the timeline. I still get out of sync renders. Some of my media I get from connection to a PolyCom system, Those files are all fine, it’s the ones that were captured from our streaming media server (asf format) One of our providers has changed their output format to us to 24P. After I saw that; I tried to adjust the settings in the timeline prefs to match the media clip, I am still not able to get a render come out in sync!

Tom Wildgen
WebCast Coordinator
WestLegalEdcenter

[Thomas Wildgen]

another file that I have tried 4 times to get to render out in sync has in the clip preferences the video listed as:

Streams
Audio: 01:58:14.827, 32,000 Hz, 16 Bit, Stereo, Windows Media Audio 9.1
Video: 01:58:14.854, 29.970 fps progressive, 320x240x24, Windows Media Video 9

29.97fps progressive? is that my problem? what setting can i use in the timeline preferences to match it? anybody have this issue?
this Clip is 1hr 10 min long, it starts out in sync but after 8-10 minutes it is noticably out of sync.

Tom Wildgen
WebCast Coordinator
WestLegalEdcenter

[Rick Mac]

Tom,

You can have Vegas automatically set your project settings to match your media. Here is how to do it.

1) Click on your project settings button, make sure that you
are on the video tab. Direltly across from your templates
box you will see three buttons, a floppy disk, a X, and a
folder. The folder is the button for “Match Media Settings”
Click on the match media button, and browse to a clip that
is of the type you want vegas to set it’s project settings
to. Select the clip and click the open button. Now your
project settings will match your media.

2) Pull your media onto the timeline and edit.

3) Render project to the format that you need.

Now that being said, I don’t expect this to fix your out of sync problems. I suspect that we have some file types and codecs that don’t want to play nice with each other. I suspect that all is fine until you try to render your media to a different type of file. As an experoiment have you tried rendering your project out to the same file type as your captured media? If that renders out in sync then your project settings are not the problem and we must look closer at our render settings. Test that out and get back to me.

Regards, Rick.

Rick Mac
Director of Audio Production
TCT Network – Directv 377

[Thomas Wildgen]

Rick,
thanks for the info on how to have vegas match the project settings to the media.
I tried it on a 1 hour clip and I still have audio about 3 or more seconds ahead of the video. It still looks in sync on the timeline.
One thing, the waveform on the audio line does not correspond to the audio I am hearing (using the computer speakers) but it still is in sync with the video. Is this a symptom?

Tom Wildgen
WebCast Coordinator
WestLegalEdcenter

[Rick Mac]

[Thomas Wildgen] “One thing, the waveform on the audio line does not correspond to the audio I am hearing (using the computer speakers) but it still is in sync with the video. Is this a symptom?”

Very well could be a symptom. Sounds like your computer’s soundcard is either running at a different audio sample rate than Vegas, or your soundcards internal clock is wacky.
I have seen where on some systems that the audio as you perseve it coming out of the computer speakers are in sync at the beginning of playing the project but quickly lag behind the picture after as little as 20-30 seconds.
Is this what is happening to you?

What kind of soundcard do you have and when you go into Vegas’ prefrences audio tab, what device is chosen for output (playback)?

Regards, Rick.

Rick Mac
Director of Audio Production
TCT Network – Directv 377

[Thomas Wildgen]

Not really, I have acceptable sync (these are streamed archived business conferences, sometimes it is very hard to see lip sync if they never have a close-up of a speaker)I looked into what my preferences are set at however. the output device is listed as Microsoft sound Mapper .I assume that is the on-board sound card. if it plays back OK but renders out of sync is that the culprit?Is there a way to see what the sound sampling rate is?
I tried some different render settings again, I am going to let them “cook” tonight and i will see in the morning.

Tom Wildgen
WebCast Coordinator
WestLegalEdcenter

[Rick Mac]

Thomas here is somthing to try.
This is from the Vegas help file.

Interpolate position
When check box is selected, the application will attempt to compensate for inaccurate devices by interpolating the playback or recording position. If you notice that your playback cursor is offset from what you are hearing, enable this option for the playback device.

Here’s how to get to it.

Option/Prefrences/Audio Device Tab
Select Advanced button
Put a check in the “Interpolate Position” Box
OK.

I this helps all done.
If not you might also experiment with another setting
in your advanced audio box.

Position bias
If the position of playback or record does not match what you hear after you enable Interpolate position, you can attempt to compensate using the Position bias slider.

Moving this slider will offset the position forward or backward to compensate for the inaccuracies of the device.

Hope this helps. Let me know.

Regards, Rick.

Rick Mac
Director of Audio Production
TCT Network – Directv 377