virtual dub increasing edited avi files

[colojim]

I record raw video with full 720x576 resolution at 25fps.
After recording I clean up the video by de interlacing, cropping off the noise at the bottom of the image and if necessary, do some filtering with Spot remover or something similar.

I then save the new avi as an avi without compression, but the new file is nearly 50% larger?
Anyone know why?
After that I convert to MPEG2, but I wonder if the process would go a lot faster if the cleaned up avi files were not so much larger than the originals.
Comments appreciated.

[bugster]

I can't explain why your new files are larger. Ar you sure they are raw avi to start with. Raw avi at that res is going to be more than 60Gb per hour!

Anyway, you could skip the saving from vdub step and simply frameserve directly to TmpGenc, or most mpeg-2 encoders.