general question on media formats: avi,mpeg etc..

[CalcProgrammer1]

It depends on the codec. AVI is just a container format for many different file types. An uncompressed AVI (which is just bitmap frames and WAV audio) takes up huge amounts of space (gigabytes or more for just a few minutes at 640x480). There's also other codecs like M-JPEG (uses JPEG compression on frames), MP4 (Microsoft's early MPEG-4 encoding in AVI files), and DivX/XviD (proprietary MPEG-4 based compression). DivX encoders usually cost money, but XviD is supposed to be free, so you might try those out. You could also use MPEG-1 (low quality, low filesize) or MPEG-2 (what DVD's use, good quality but fairly large filesize) or MOV (QuickTime format) or WMV (Windows Media Video).