> duplicate each image the number of frames you want it,
> leaving the encoder to discover that there is very little
> change when it use its preferred sequence.

When a number of successive frames are duplicates (FULLY similar), only the
first frame will contain the actual picture, and the rest won't take up
memory at all, until the next "I frame" appears (called "I frame" in mpeg1
and otherwise called "key frame". It always contains all data for the entire
picture).

Normally key-frames comes with a fixed interval, meaning between a fixed
amount of frames, but usually the amount can be adjusted by the user.. Good
encoders also search for significant changes in a movie, for example
switches between cameras in a talking sequence, and when found, it places a
key-frame there because the whole picture changes anyway.

It's possible with at least DivX to have 300 frames between key-frames. With
a rate of 25 pr sec, that means you could have 12 seconds holding the same
picture, without loosing memory.

Regards,
Hugo

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