Voice Over file type .wav or .mp3?

Ponderer · Post by **Ponderer** » Tue Jan 11, 2005 4:55 am

Hi, I've been using VS8 for about 6 months. I'm working on a project where I'm inserting voice over clips in along with the video and titles and music. My system is a Athlon XP 2600+ with a gig of ram and a 7200rpm ATA 133 60gb HDD. The project is about 30 minutes worth of captured video (Digital 8 ). It seemed like everything was going great until at some point, when I was adding in the voice over clips, which are .wav files, I would play the video back and it would be choppy in some parts. Now, with a gig of ram, you would think that this would not happen. So I started wondering about my mixing different types of sound/music files together on the same project and wondered if that could have anything to do with it. Aside from the video, I have both MP3 and WMV format music. And as I mentioned I'm capturing the voice over bits with Gold Wave Studio in .wav format. Could this be part of the problem? If there are some Windows memory settings I could try I'd be happy to start there.

Thanks for your help,

THoff · Post by **THoff** » Tue Jan 11, 2005 5:14 am

At what point does the sound get choppy, during project playback in UVS, or when playing the rendered file outside UVS? If it's the former, then your system isn't quite able to keep up with a realtime preview -- the CPU could be 100% busy (according to Task Manager), or the I/O subsystem might be unable to keep with the disk access (possibly due to fragmentation).

Also, UVS V8.0 has a memory leak bug that was fixed in V8.01 that could exhaust all your RAM in short order. Again, have a look at Task Manager to see how your system is doing.

Ponderer · Post by **Ponderer** » Tue Jan 11, 2005 7:43 pm

Thanks THoff,
It get's choppy during playback, within UVS, about the same time the first Voice Over starts, so thats why I thought it had something to do with the Voice Over files. I guess since I did those later in the project it may be trying to "call" those files up from a different part of the drive. I did the 8.01 patch last night and it seemed to help a little. It's choppy for a few seconds, then it will clear up, then it's choppy again.

Yeah, I'm curious about my HDD space. I've got 27GB free, and I've tried to take off everything that I don't need onto my external HDD. I don't seem to be able to account for about 10GB of space on my drive though and I've Defragged about 10 times to try and get this issue fixed. But i bet that this has something to do with it. Any suggestions for finding excess files (besides a windows search) and or a better defrag?

kebrinton · Post by **kebrinton** » Tue Jan 11, 2005 8:21 pm

Ponderer,

You seem to be engaged in a project almost exactly like one I recently completed. My posts here were about mp3 vs. WAV files, and which to use.

One way to calm your mind about the "choppiness" would be to stop right now and just 'waste the time' creating a DVD-RW. (You won't waste a disk that way.) Play that in a DVD player and listen to your voice-overs. That's what I did.

My opinion is that you're hearing artifact and not damaged sound--like jerkiness on video playback.

My computer created a funny little hiccup when I used mp3 to do voice-over. It would repeat the last word of the audio file ("the ocean, the ocean"). WAV didn't do that so I changed everything to WAV.
Keith

Post by **Ken Berry** » Tue Jan 11, 2005 9:47 pm

Like Keith, I always do my voice-overs in WAV format (using Nero editor), while my music audio backgrounds are almost invariably MP3 (though very occasionally also WAV). I have never used WMV format in my videos. I can't for the moment lay my hands on the manual, so I cannot even say for sure that WMV is a usable format in VS8, though I assume it is. But my basic message is that there certainly should not be any problem mixing both WAV and MP3 formats...

kebrinton · Post by **kebrinton** » Wed Jan 12, 2005 2:06 am

I just remembered something else, and would like to throw it out to the forum for consideration.

I recently came upon this idea in some posting about video. Since mp3 format is already quite compressed, whereas .AVI format is not, to mix mp3 and .AVI on a video which is later going to be compressed into MPEG2 format might not be wise.

Not bad thinking, I thought when I first read that.

But later it occurred to me that perhaps mp3 might fall inside the definition of "compliant" and therefore escape further alteration. Or, not being video, it is not affected.

The whole question is pretty theoretical, and possibly irrelevant, since empirically people have fine success using mp3 sound in their videos. But I do wonder about the theory of it.

Keith

THoff · Post by **THoff** » Wed Jan 12, 2005 3:24 am

Whenever you transcode from one lossy compressed format to another, you lose fidelity -- there is just no way around that. Given this fact, you should avoid MP3, especially at lower bitrates.

Ponderer · Post by **Ponderer** » Wed Jan 12, 2005 8:00 pm

Okay, here is what happened. I went ahead and made clips out of all the sections of my project so I could move the main avi capture file to my external hard drive. After that I defragged the hard drive and with 34GB free space and the fresh defrag I get smooth playback within UVS.

I will go ahead and burn a copy to see if the mixed sound files will make any difference. I'll report back then.