What bitrate can I expect with MPEG?

Question

What bit-rate (approximately) can I expect MPEG encoders to produce for 160x120 "ok-quality" webcam stream?

How much CPU-demanding will the encoding be? The decoding?

Are there any better encoding formats for that purpose? (In terms of bit-rate or CPU)

Answer 1

256 KBps is enough for QSIF (160x120, 25 fps) in MPEG2.

Any modern CPU (since Pentium IV) can encode and decode it in realtime.

There are hardware solutions (like Compro VideoMate H900 and E800 series), which cost about 100$ and up to 8 boards can be installed per PC.

Using them, you can get 8 full-size streams at once, to say nothing of QSIF.

MPEG4 can probably yield better results in terms of bandwidth, but it's more sensitive to the packet drops in the channel.

As for the sound, if you need telephony quality, you can use aLaw or uLaw codec, which require 64 kbps per channel and are not a problem even for a Casio calculator.