CRF? What is it good for? Absolutely everything!
Unlike XviD that has no real constant rate factor unless you are doing full
first pass only the x264 codec offers us a great option called CRF. What it
means is constant quality throughout an encode based on CRF value. You are no
longer limited by some vague bitrate restriction you let the codec decide for
you what bitrate is needed without size restrictions. If your source is full on
action, grainy etc it will get a higher bitrate, if it's a dark action-free it
will get less. No more obscenely large files for sources that don't need it, no
more shit quality cause the source didn't compress but did meet the
bitrate/target size. Does anyone really still archives on cdrs/dvdrs? not many
I would bet so who cares about DVDR/x sizes? If anything with CRF you'd be able
to fit even more eps into your DVD5 cause shows like Grey's Anatomy, House,
In Treatment etc DO NOT need 1120mb sizes but far less.
Other benefits? sure, right now every live from air x264 group finds the most
cunning ways to pre faster, so the bare minimum within allowed settings is used,
with CRF that can finally change. Settings can be upped, release sizes will fit
the show and not some random bitrate setting. win win.
A bit about CRF:
https://trac.handbrake.fr/wiki/CRFGuideConstant Rate Factor will compress different frames by different amounts. It
does this by taking motion into account. The eye perceives more detail in still
objects than when they're in motion. Because of this, a video compressor can
apply more compression (drop more detail) when things are moving, and apply less
compression (retain more detail) when things are still. Subjectively, the video
will seem to have higher quality. If you were a computer, you would look at a
CRF encoding and say it was lower quality than the CQP copy. And it would be.
But if you're a human being, subjectively, the CRF copy will look better. It
least compresses the parts you see the most, and most compresses the parts you
see the least. When you use a constant rate factor, it varies the QP slightly.
When a scene has a lot of action and motion, it will raise the QP (compressing
more). This is because your eye will be distracted by everything going on, and
won't have the image on screen for enough time to see the heavier compression.
When a frame doesn't have a lot of motion, it will lower the QP, compressing it
less. This is because your eye will have more time to look at the image, so you
want it to be as much like the source as possible. When you use CRF you're
saying "use whatever bitrate is necessary to preserve this much detail."
Tema: Game of Thrones (Posjeta: 764380 )