Re:Lepton image compression: saving 22% losslessly from imag...
by astrange on Thursday July 14, 2016 @06:26PM
(#12097669)
It wouldn't get much smaller. The reason DVDs are such a high bitrate compared to Handbrake rips isn't that MPEG2 is inefficient, it's because there's a keyframe twice a second. Most movie rips have a keyframe every 10 seconds.
It's mostly to let you fast forward, but there is a technical issue there. MPEG2 decoders aren't all mathematically identical, so what happens is the picture tends to drift away from the real thing after a while, and there's hacks like frequent keyframes and flipping the smallest DCT coefficient to get around it…
It's mostly to let you fast forward, but there is a technical issue there. MPEG2 decoders aren't all mathematically identical, so what happens is the picture tends to drift away from the real thing after a while, and there's hacks like frequent keyframes and flipping the smallest DCT coefficient to get around it…