If you have standard dial-up, it's going to go frame-by-frame. The data can't go out fast enough to do anything except frame by frame.
A 640 X 480 24-bit color frame contains 7372800 bits. At 56Kbaud, it will take 164.5 seconds (2 minutes 41.5 seconds) to transmit one frame (including the modem synchronizing bits).
2. Lower resolution.
Leaving out every other pixel both vertically and horizontally divides the size of each frame by 4, making transmission of the 1843200 bits take only 1/4 of the time.
Sending the picture in grayscale instead of color reduces the size to 2457600 bits, and the time to 1/3 of that taken with color.
4. Reduced color set.
Using 256 colors also reduces the size to 2457600 bits and the time to 1/3 of that taken with 24-bit color.
5. Intermittent capture.
Instead of capturing one frame every 164.5 seconds, capture a 20 second segment every so often, and transmit it over a longer period. The receiving person then can reconstitute it at the faster speed by downloading, then playing.
6. Data compression.
Using data compressing techniques (such as mpeg) allows the subsequent frames to send only the data needed for the changing parts of the picture.