compression for streaming - dialup users

Trying to compress video for dialup users is almost impossible. Whatever you do, the quality will be poor. You might even want to avoid trying and just target people with broadband.

You have almost no bandwidth to use (50 kbps max, and usually less than 40)

In order to provide even barely acceptable video, you have to encode for the best connections, and assume that the connection will stay above 40 kbps.

At 40 kbps, you only have 32 kbps for video and 8 kbps for audio.

In regards to video, this will allow you only 200x150 resolution or lower, and quality will be poor even at that small postage-stamp-like size.

In regards to audio, you will have to use mono audio, and speech will sound acceptable, but music will suffer.

With streaming video or progressive download, expect users to suffer from pauses and other streaming problems.

For download video, you can encode to a higher rate, as the video will not be watched until the download finishes.

I would recommend 100 kbps for video and 22 kbps for audio. This allows 320x240 resolution video and higher quality mono audio - speech will sound good, and music acceptable.