[x265] A new screenshots comparator and loads of new x264 x265 vp8 vp9 tests

[Steve Borho]

On Tue, Mar 4, 2014 at 8:04 PM, Niccolò Belli <darkbasic at linuxsystems.it> wrote:
> http://www.linuxsystems.it/2014/03/new-screenshots-comparator-loads-new-x264-x265-vp8-vp9-tests/
>
> Congratulations to the x265 team: at low bitrates x265 completely CRUSH x264
> if you use a very high quality source like the Blu-ray of "The Hobbit: An
> Unexpected Journey".
> Hopefully in the future it will improve at high bitrates too. hi10p is just
> too bugged to be useful right now.

Hi Niccolò,

I'd like to understand the steps you took to encode 10bit video. I
think it should show much better, particularly with the 0.8 tag or
later.  The two basic preconditions x265 needs is to build with
HIGH_BIT_DEPTH enabled and then provide it input pixels that are at
least 10bits of resolution and in YUV 4:2:0 or 4:4:4 format (4:4:4 is
less well tested, so I suggest 4:2:0 for eval).

A 10bit build of x265 will happily encode an 8bit input video, it just
shifts up all the pixels by two bits.  Not necessarily a good
demonstration of 10bit encode, but it is useful for comparison
purposes.  Similarly, an 8bit build of x265 will happily encode a
10bit video if you ask it to (by downshifting).  Not necessarily
useful except for comparison.

-- 
Steve Borho