Why is "fake" 50fps twice the size of 25fps?
I've been looking for some information on why the 50fps streams are twice the size of the 25fps streams.

Considering how MPEG, H.264 and almost all video compression works, only the _differences_ between subsequent frames are stored.

I'm thinking especially in the extreme case of "fake" 50fps, where frames from the 25fps are just duplicated, isn't the video encoder smart enough to say "Frame 2 -> see frame 1". "Frame 4 -> see frame 3", and so on, and there be very little increase in file size?

Is it because it messes up the motion estimation or something like this? Smooth movements (in 25fps) will look more juddery to the encoder when they "stop" every second frame in the fake 50fps version?

Messages In This Thread
Why is "fake" 50fps twice the size of 25fps? - by outhud - 22-07-2018, 04:23 PM

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