how do i make a video file smaller?

[KAZERO]

ok...i created a video using adobe premiere 6 and i only used like 20 mb worth of video clips....but when i exported it, it turned out to be 322mb???? then i tried to compress it using the ligos indeo video 5.11 compressor on virtual dub...but it only brought the file down to 253 mb......how can i bring the file size down further?

[offline]

export at a lower bitrate or frame size.

[gll99]

In general there are a number of factors that can affect the file size of an AVI.

1- Uncompressed pcm audio can make up 75% of the size of a file. Check this and try an mp3 (or an other compressor) using the lowest audio bitrate as possible.

2- Try another compressor codec like DIVX, XVID or mpeg4 v3. You may have greater control on bitrate and achieve a better quality compress. I have found that lowering bitrates too much shows poorly in full screen mode.

3- Lowering the framerate for example from ntsc 29.97 per sec to 23.97 or lower will also have and effect on filesize. If you go below 23.97 you may notice a slight unnatural motion. Cartoons are usually passable as low as 15 frames per second. I accidently captured a Voyager episode at 15fps once. It was small, clear and great except for a slight lack of fluidity in the motion. If you do this as a conversion you may have to demux and remux to synch the audio and video again.

4- Choosing a smaller frame size such as 320x240 instead of 640x480
will have an effect. Although, don't do the math and expect a 75% reduction because the vertical and horizontal size are halved. The reduction will not be that great.

5- Applying an external smoothing filter or selecting a less sharp (smoother) image (eg.. available in the divx codec) will allow greater compression because of less change from frame to frame.

6- Choosing a greater distance bettwen keyframes will have some effect on file size.

7- RM (which of course is not avi) uses something quite differrent to reduce size its called a variable framerate in addition to variable bitrate. Framerate is usually constant but with RealMedia if you choose 30 fps it can actually vary from 15 to 30 fps depending on the action in the clip.
That is why it is so difficult to achieve a synch convertion from rm to avi.
I have used the new rm9 codec and if not for the conversion issue I would probably use it exclusively to capture video.

8- You may want to look at wmv8 (windows media) I have used it on some files with bitrates as low as 400 and some low motion stuff was pretty good considering I was encoding around 3mb per minute

Obviously some options will have a greater effect than others and the list is not exausted its only what I could recall in a few minutes.

[KAZERO]

what is the best video and audio compressor i can use?