Video-equivalent of "pitch-shifting."
On Aug 23, 10:02 am, isw wrote:
There is an interesting sort-of exception to frame rate conservation,
when film source is encoded at 24 FPS (actually about 23.98) and the
decoder performs 3-2 pulldown to deliver the NTSC-required 29.97 FPS,
but that's not germane to this discussion.
Actually, it is very germane, since 3-2 pulldown is similar
to how some primitive audio pitch/rate changing hardware worked,
by duplicating small time domain frames of audio at a fixed
proportion and rate. Some MPEG decoders do "special effects"
by varying the frame duplicate/drop fractions to slow down
or speed up playback using the same mechanism as for pulldown.
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