How to Voice over a video section that is sped up and/or split?

[DataDude]

I'm having two problems right now trying to do a voice over for a video.

The video I'm trying to do a voiceover has 3 different layers, the first layer is just the first part of a video, the 2nd part is a portion I split off and sped up, and the 3rd portion is the end of the video which is back to normal speed.

Problem a.) Whenever I do a voiceover on this project, it seems to be cutting out some portion of the beginning of the video. I have to go into the cut and split tool and restore the beginning region each time to get the whole audio for the voiceover and then reposition it.

Problem b.) During the "sped up" portion of the video, the audio just goes to crap, it seems as if the audio is also trying to speed up during this portion and just cuts in and out no matter what. I am failing to see where this setting is stemming from, is this audio somehow attached to that sped up portion somehow and how can I remove this relation? I literally just want to "voiceover" the video portions with audio, I don't want the audio to be affected by anything unless I tell it to.

EDIT: I should also mention, the actual sound file that gets saved to my hard drive, does not encounter the issue at all, so something about the audio lining up with the portion that it sped up is causing the issue in the editor. On that subject I also notice the "sped up" portion is so choppy, is there anyway to smooth that out? It just sits on a few frames at a time instead of giving me the actual sped up effect I'm going for.

[smrpix]

What editor are you using?

How are you inserting the voice over?

Try mixing down your layers to a single video file first, and then add the vo.

[johnmeyer]

I do speed ups and slow downs all the time. I use Vegas as my NLE. In most NLEs, you de-couple the audio from the video during the speed ups and slow downs, but make sure they are still synced during the normal play. In Vegas, this is pretty easy to do, and I suspect most other decent NLEs let you do the same thing.

[DataDude]

Ah my apologies for some reason I thought this was a VSDC specific help forum, just realizing now I must have jumped to conclusions based on where google took me hehe - but yeah the editor I'm using is VSDC. I did end up figuring it out, it looks like basically my computer just couldnt' handle the preview functionality in the editor when going over those heavily sped up portions (which is crazy considering how much beef my pc has), but when I actually export the video the sound is fine along w/ the speed up looking plenty smooth. Odd issue but glad to have it figured out now!

[smrpix]

Glad you got it sorted.

Assuming you are using h.264 video, yes, that will require a lot of computing power to decode and play at high speed. The computer may have to look as far as 10 seconds before or after a frame to create the full image and you are throwing frames at it at a higher than normal rate.

You may want to look into proxy workflows or mezzanine codecs to make the work go smoother going forward. (You can search those terms for deeper explanations.)