[x265] Possible bug: Chrominance planes shifted when saturation is low

[Steve Borho]

On Thu, May 1, 2014 at 5:27 AM, Mario Rohkrämer <contact at ligh.de> wrote:
> Here is a report about encoded material with very low brightness and
> saturation, especially at the edges, and the chrominance is shifted away
> from the luminance, to the right.
>
> http://forum.doom9.org/showthread.php?p=1679520#post1679520
>
> I hope the reporter will be able to upload a sample to investigate if the
> issue is in the encoding or decoding part.
>
> But one line in the report makes it suspicious:
>
> +----
> And then i encoded with default settings (encoded a Yuy file and manually
> told it the resolution 1920x1080, other than it was as is).
> +----
>
> If he entered a different resolution for x265 than the YUV file really has,
> the shift is no surprise...
>
> No panic yet. Just be aware.

Reading the initial post, it does sound like the YUV resolution was
not quite what he thought it was.  The chroma would slide off faster
than the luma.

-- 
Steve Borho