[x264-devel] Resend: I tried to add 12 bit depth support into x264 (probably wrongly)

[Andrew Randrianasulu]

В сообщении от Saturday 21 March 2020 18:39:43 Henrik Gramner написал(а):
> On Sat, Mar 21, 2020 at 12:48 AM Andrew Randrianasulu
> <randrianasulu at gmail.com> wrote:
> > I think 12 bit part was simple, but I have no idea how to test it!
> 
> It's actually not that simple. There's a bunch of intermediate buffers
> that will have insufficient precision when going from 10-bit to 12-bit
> which will cause integer overflows.
> 
> The tricky part is to figure out exactly which ones those are and
> template them with suitable data types to handle it. That affects SIMD
> as well.

Thanks for explaining hard part ... I'll try to look more into x264 code, may some 
of those intra profiles actually can be added even by me.

threads I was referring to:
https://forum.doom9.org/showthread.php?t=174792
("XAVC Intra Class 300 4K UHD mezzanine for Broadcast Studio?')

http://www.ffastrans.com/frm/forum/viewtopic.php?t=771
("AVC-Intra Class 300")

I was mostly looking at unexposed (yet) functionality of ffmpeg/x264 as used 
by Cinelerra-GG, video editor I tend to hack on ...

https://cinelerra-gg.org/

I also was wrongly assuming 10 (12) bit output testing demand more-than-8 bit yuv input 
(I have no idea how to make those files, yet. I'll look!)

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