VirtualDub -- XviD file size problem

[higgins327]

Hi all!

I'm capturing raw data from old VHS tapes with a Pinnacle card and then attempt to re-encode that, so, it takes less space. My aim is to get size efficient avi files.

However, my regular settings with VirtualDub that I use with PVR recordings won't work for this raw data -- the file size remains large despite re-encoding. I use 1800 kbps XviD (768x576) and 128 kbps LAME mp3, and I can't make 1 hour 20 minute video weigh less than 3,6GB. I'm not the most skilled encoder, but that's bad even for me. I also noticed that all the frames in the created avi are key frames. Maybe that's causing the size bloat?

What information do you need to resolve my issue?

[Baldrick]

What xvid settings are you using? Profile level, Encoding type, etc?

You can try click load defaults and then change to 1800kbps and encode.

[higgins327]

You can try click load defaults and then change to 1800kbps and encode.

That, and Twopass - 2nd pass, is how I encode.

[jagabo]

You can try click load defaults and then change to 1800kbps and encode.

That, and Twopass - 2nd pass, is how I encode.

Did you perform the first pass (with the same video and same settings) first?

[higgins327]

Err... no.

Now that you ask it... it seems indeed weird that it makes one pass only.

[jagabo]

VirtualDub does not automatically perform both passes. You have to set everything up, set xvid to Twopass-1st pass, and Save the video. During the first pass Xvid is only examining the video and saving the information in the video.pass file. The video itself will be all black. Then you set Xvid to Twopass-2nd pass and save again. During the second pass it uses the information it saved in the first pass and compresses the video to the requested average bitrate.

If you didn't perform the first pass it was probably using an old video.pass file which has nothing to do with your current video. Hence the problem.

[higgins327]

Ah, now it all makes a lot more sense! Thanks!

So, essentially, I need to re-make the pass every time? That's cumbersome...

[jagabo]

So, essentially, I need to re-make the pass every time? That's cumbersome...

Switch to single pass target quantizer encoding. You always get the quality you want and it only takes a single pass. The down side is you don't know what the file size will be.

[higgins327]

Thanks a bunch! I really learned a lot here.