VirtualDub Confusions! Help!

[moviebuff2]

Hello everyone:

I have an AVI file (approxiately 700MB) of which I want to edit out about 5 seconds. I did that using VirtualDub and ended with 2 AVI files one file is 400MB, the other 300MB, approximately.

The I merged those 2 AVI files, using VirtualDub. The problem is that the size of the final AVI drastically increased, from approximately 700MB to almost 2GB!!!

The settings I used with VirtualDub are: video - Direct Stream Copy, audio - Full Processing Mode. I save the file using Save as AVI.

How come merging 2 AVI files which total 700 MB results in a 2-GB file?

Would somebody help me please?

Thanks

[Laddydaddy]

Hello moviebuff2,
When you set the audio to full process mode it converts the audio to an uncompressed wav file. This will cause the file size to balloon up.

[uxbridge]

VirtualDub if left in audio full processing mode will default to uncompressed PCM audio. That could have caused your file growing while you saved it.
To check open the file again in VDub and click "File Information".

To make it properly you should use Direct Stream Copy in audio as well.

[moviebuff2]

Thanks.

But I did the same thing just a week ago and the size did not balloon like that.

I used VirtualDub to change the volume of an AVI file. Video setting - direct stream, audio - full processing. The final file's size was approximately the same size of the original file.

For this current project, I set "full processing" for audio because I want to increase the volume.

[redwudz]

If you are converting the file to MPEG or DVD, then use the WAV and encode with it, along with the video. Or run the WAV through ffmpeggui and convert to AC3, 2 channel and put it in when you author.

If you are going to leave it in AVI, like a Xvid, convert the sound to MP3. VD can do that, especially if you have the Lame MP3 codec. Or you can use AC3.

I can guarantee that if you convert a MP3 or most other compressed audio formats to WAV, they will grow in size quite a bit. Unless it was WAV in the first place.

[uxbridge]

go to FILE INFORMATION and have a look at what your audio originally is.
You should get info about codec (e.g. Mp3) and speed (e.g. 128 kbps).

Go to AUDIO_VOLUME and set it as you like.
Go to AUDIO_COMPRESSION and select something like Mp3 at the same speed you discovered in INFO.

Then save as AVI as usual.

[moviebuff2]

Thank you for all of those quick replies.

I finally remembered exactly what I did the last time when I used VirtualDub to increase the volume of my AIV file, without drastically increasing the file's size.

Here are the steps (somebody please correct me if I am wrong since I am only a novice at this "hobby").

1) Open VirtualDub
2) Open an AVI file
3) Click on video, select "Direct Stream"
4) Click on audio, select "Full Processing Mode".
5) Click on audio again and select "Volume" which is now highlighted.
6) A little window named "Audio Volume" appears. Check the little box next to "Adjust volume of audio channels". Use the slide to increase or to decrease the volume to the desired level.
7) Click "OK"
8 ) Click on audio, select "Direct Stream". The "Volume" will not be highlighted. But that's OK. The adjusted volume still remains in effect. (Why? How? I don't know. But it is there! )
9) Click on File, choose "Save as AVI"
10) Select a folder where you want to save the file (and remember it).

That's all, folks!

I tried these steps and my final file's size remained approximately the same as the original. The volume was adjusted to the level I desired.

Thanks again.

[redwudz]

I'm just guessing here, but it sounds like it reencoded the audio to the same format as the one in the original video. I'll have to try that when I get home. But if it works for you, good deal.

[moviebuff2]

Hi everyone:

I just found another way to adjust the audio volume, using VirtualDub, without increasing the final file's size.

http://www.divx-digest.com/articles/normalize_avi.html

Method no. 2

Enjoy!