File much too large

[revnice]

I've got a home made avi (about 4 mins and 57 meg)

I've replaced the audio with an 5 meg mp3

However, when I Save as AVI, the resulting file is 300 + meg.

I've got Audio Compression set to MP3 and Video Compression set to Full Processing Mode and Microsoft Video 1

The file intended for posting on UTube.

What should the settings be to get the smallest quality file?

Thanks - rev

[admin]

You need to select "Direct Stream Copy" for the video option if you don't intend to re-encode the video (which you probably shouldn't need to).

[revnice]

* Audio Compression > MP3 (actually it's disabled because I'm using Audio from Another Source)
* Video > Direct Stream Copy
* Video Compression > Microsoft Video 1

That still resulted in a 313 meg file. 6x larger than when it had wav audio.

When mixing down, the audio portion remains about the same so it must be another video setting?

[admin]

If you select Video -> Direct Stream Copy, you shouldn't then be able to select Video Compression, because it should be greyed out (see screenshot).

[revnice]

Oh yes, you're right. Thanks.

That brought the file size to 53 meg.

Presumably, that's a small as it can go?

[admin]

How big was the video originally? If you used "Direct Stream Copy", the video part should be untouched, and the only thing changed would be the audio part.

Actually, for the audio, you can still select between "Direct Stream Copy" and "Full Processing" (under the "Audio" menu). Selecting DSC will ensure that the selected audio is added as it is without any changes (so if it's a MP3, it will remain a MP3). In that case, the entire movie file should be around the same size as before, at most an extra 5 MB if your video didn't have audio before. If you selected Audio -> Full Processing, then you'll have to select a compression method again, and the associated settings (probably unnecessary if you're just going to re-compress the MP3 into another MP3).

[revnice]

Thanks admin, you're a goldmine. DSC for the audio is what I really want.

Here's what's puzzling me. The original movie was about 57 meg and I replaced a 46 meg wav audio with a 5 meg mp3. That should make the final file about 20 meg.

But it didn't, the movie is around the same size as before.

Why do you think that is?

[admin]

I suspect the original movie didn't have WAV audio at all, as WAV audio at about 4 minutes would already be about 40MB. If you want, you can check what kind of audio your original video had by loading it in VirtualDub, then from the "File" menu, select "File Information" - the compression algorithm and data rate of the original audio should be listed there.