Best way to compress avi files for web viewing and best format for view

"Yeah. The content is important here. But yet I'd recommend QuickTime format.
I have personally tried Flash videos, they are no good at all when it comes to quality. But Quicktime videos gives superb qualities in the cost of less size."

"I use FFmpeg on Ubuntu Linux to convert AVIs to MP4s. It reduces the file size by about 90% and the quality is OK. I use it for all my Youtube uploads.

Here's the command I use. Replace MVI_0963 (referenced twice) with the name of your video file.

ffmpeg -i MVI_0963.AVI -vcodec mpeg4 -acodec libfaac -ab 128kb -s 640x480 -b 1200kb -mbd rd -flags +4mv+aic -trellis 2 -cmp 2 -subcmp 2 -g 300 -pass 1/2 -r 25 mvi_0963.mp4"