Audio our of sync after boosting volume. HELP!

[jungleexplorer]

I have some videos that have low volume. I want to increase the volume, but every time I increase the volume in VS10 and render the video, the audio tract starts out in sync, but slowly gets more and more out of sync. It happens every time I try on several different videos. What is causing this?

[Ken Berry]

How are you increasing the volume? Using the internal controls, or do you export the audio, increase the volume in a third party audio editing program, and then reinsert in VS?

[jungleexplorer]

How are you increasing the volume? Using the internal controls, or do you export the audio, increase the volume in a third party audio editing program, and then reinsert in VS?

I am just increasing the volume in VS10.

[Ken Berry]

Are you using SmartRender? If not, try using it. If you already are, try turning it off. In the past, with earlier versions of VS, SmartRender was associated with out of sync audio, though I confess I don't recall anyone else complaining about it recently. I personally alter audio levels quite a few times in my projects. However, I usually do so by going into audio mode where you see the audio lines, and adjust those up and down by "rubber banding".

[Davidk]

I've never had this problem, and been using VS Ultimate (8 versions) for years. And I do both (whole of clip) audio level change, usually down but occasionally up, using that level adjust item in the options window, and by rubber banding within a clip, eg when a voiceover is happening. Often both in the one project and occasionally (very) both within the same clip - eg, reduced background sounds such as wind noise but not altogether, and then the voiceover to go with it.

So, is it possible to describe just what you mean by "out of sync" audio with enuff detail, that we could try and replicate it?

[jungleexplorer]

I've never had this problem, and been using VS Ultimate (8 versions) for years. And I do both (whole of clip) audio level change, usually down but occasionally up, using that level adjust item in the options window, and by rubber banding within a clip, eg when a voiceover is happening. Often both in the one project and occasionally (very) both within the same clip - eg, reduced background sounds such as wind noise but not altogether, and then the voiceover to go with it.

So, is it possible to describe just what you mean by "out of sync" audio with enuff detail, that we could try and replicate it?

Let me describe what I mean by out of sync. I am boosting the audio of the whole 2 hour video by 300%. After rendering, the audio track is in sequence at the beginning of the video, but slowly gets ahead of the video as time goes by. By the end of the video audio track is about 30 seconds ahead of the video track. That is as detailed as I can get. I have rendered this video using Smart Render, not using smart render, with and without proxy. It is the same every time no matter what I do. Yes, the original video is in sync. It does the same thing on my Desktop and on my Laptop. I though it might be some kind of lag with my video drive so I put the original file on my Samsung EVO 850 SSD to make sure there was drive lag. Still the same.

[asik1]

While I hardly did any 2H videos but 90-110 very often, I used to do rubber banding but now I do it in attributes (quicker). never had a sync issue.
I do only HD stuff.

[jungleexplorer]

While I hardly did any 2H videos but 90-110 very often, I used to do rubber banding but now I do it in attributes (quicker). never had a sync issue.
I do only HD stuff.

I am having this trouble on not one, but multiple videos, on two separate computers. These are 720p quality videos.

[asik1]

Very strange, this video is SD (not 720P) and at reasonable data rate fo SD.
Your system should "grind" it without looking back.
Is this the source file or the rendered one? have you tried different codec, just to get it over?
Why insisting on full 2H ? split and done.

[Ken Berry]

Thanks for providing that Properties shot. I think it answers the question about why this is happening. I suspect -- but would welcome your confirmation -- that the video in the project was filmed using a mobile phone or something similar. I note from the Properties box that the specific clip mentioned there has a frame rate of 29.90 fps. That is not a standard frame rate which for NTSC should be 29.97 fps (often shown as 30 fps). A lot of smart phones these days use variable frame rates, and that is fine if you don't do much editing on them.

I am also wondering what your project properties are or how you went about rendering the project. Did you, for instance, go to Share > Same as Project Properties or Share > Same as First Clip? Or something else?

But what I think is happening is that since you have altered the volume of the audio, that would be being rendered at the standard frame rate of 29.97 fps while the video is probably being rendered at the very slightly slower frame rate of 29.90 fps. Some of your clips may, indeed, have an even slower frame rate. My own very new smart phone seems to produce video which varies from 29.45 fps when there is little action or movement in what I am filming, up to 29.92 fps when there is more action or movement. It may not sound like much but cumulatively, over a project the length of yours, it mounts up. In other words, the audio is being rendered slightly faster than the video speed, and so the audio gets away from what is happening in the video.

The only thing I can think to suggest is to use a third party video converter program like Handbrake or Format Factory (both free) and convert them to the standard frame rate of 29.97 fps or 30 fps. Then put them all back in VS, do your edits, raise the volume and render. This time, everything should be in sync. I guess you could also do much the same in VS though it may be slower. You would have to use the original video without the volume increased, and render it to a new file using 29.97 fps. Then when you have the new video, alter the volume then, and render it again. I realize mpeg-4 video is a lossy format, but if the output properties are almost, but not quite, identical with the original properties, I don't think you will notice any quality loss.

[jungleexplorer]

Very strange, this video is SD (not 720P) and at reasonable data rate fo SD.
Your system should "grind" it without looking back.
Is this the source file or the rendered one? have you tried different codec, just to get it over?
Why insisting on full 2H ? split and done.

Original source file that, Audio is in sync on this file.

Rendered file. Audio out of sync.

[jungleexplorer]

Thanks for providing that Properties shot. I think it answers the question about why this is happening. I suspect -- but would welcome your confirmation -- that the video in the project was filmed using a mobile phone or something similar. I note from the Properties box that the specific clip mentioned there has a frame rate of 29.90 fps. That is not a standard frame rate which for NTSC should be 29.97 fps (often shown as 30 fps). A lot of smart phones these days use variable frame rates, and that is fine if you don't do much editing on them.

I am also wondering what your project properties are or how you went about rendering the project. Did you, for instance, go to Share > Same as Project Properties or Share > Same as First Clip? Or something else?

But what I think is happening is that since you have altered the volume of the audio, that would be being rendered at the standard frame rate of 29.97 fps while the video is probably being rendered at the very slightly slower frame rate of 29.90 fps. Some of your clips may, indeed, have an even slower frame rate. My own very new smart phone seems to produce video which varies from 29.45 fps when there is little action or movement in what I am filming, up to 29.92 fps when there is more action or movement. It may not sound like much but cumulatively, over a project the length of yours, it mounts up. In other words, the audio is being rendered slightly faster than the video speed, and so the audio gets away from what is happening in the video.

The only thing I can think to suggest is to use a third party video converter program like Handbrake or Format Factory (both free) and convert them to the standard frame rate of 29.97 fps or 30 fps. Then put them all back in VS, do your edits, raise the volume and render. This time, everything should be in sync. I guess you could also do much the same in VS though it may be slower. You would have to use the original video without the volume increased, and render it to a new file using 29.97 fps. Then when you have the new video, alter the volume then, and render it again. I realize mpeg-4 video is a lossy format, but if the output properties are almost, but not quite, identical with the original properties, I don't think you will notice any quality loss.

Now that makes sense. These are old gospel movies that were original converted from 16MM film to DVD. I ripped them from the DVD and upscaled them in VS to their current state for a missionary that is old and cannot lug heavy equipment around to show his films anymore in the remote villages he works in Mexico. I fixed him up with a lightweight Pico Pocket Projector and a 40 watt portable bluetooth speaker, but the videos are not loud enough for the small crowds he shows his movies, so he asked me if I could boost the volume. Here is the kit. I set him up with.

[jungleexplorer]

Just a follow up. Handbrake is able to do it and increase the volume in one step. Thanks for the advice I appreciate it.