[x264-devel] chrome 400 (grayscale only) output

[Emanuele Ruffaldi]

Dear Henrik,

I have just cleaned up the patch squashing it, removing unnecessary things
and, for filters/video/resize.c added quick paths for planar YUVs (9 CSPs)
without the memcpy.

The patch is made against the last master patch:
b00bcafe53a166b63a179a2f41470cd13b59f927 Cosmetics (2017-12-24 23:47:27
+0300)

Pull Request with single commit: *https://github.com/eruffaldi/x264/pull/5
<https://github.com/eruffaldi/x264/pull/5>*
Squashed Branch: https://github.com/eruffaldi/x264/tree/grayscale_squashed
Detailed Branch: https://github.com/eruffaldi/x264/tree/grayscale
<https://github.com/eruffaldi/x264/tree/grayscale_squashed>

Testing is reported here: https://github.com/eruffaldi/x264/issues/1

Best Regards,
Emanuele

2017-09-11 12:18 GMT+02:00 Emanuele Ruffaldi <emanuele.ruffaldi at gmail.com>:

>
> Hi,
>
> >> For a recording in a resource limited board with mono input I aimed at
> >> encoding directly the video without converting it to gray YUV (with UV
> as
> >> zero). This patch implements the changes in the library for supporting
> the
> >> mono input and the relative output CHROME_400.
>
> >Hi
>
> >Seems reasonable to avoid a bunch of unnecessary memory copying of
> >empty chroma planes in some use cases I guess. Is there any
> >compression efficiency gains over 4:2:0 with chroma set to
> >1<<(bit_depth-1)? I'd guess it's basically zero.
>
> I was not aware of this possibility, having time I could look into that
> but I don't know if the patch would be smaller.
>
> >The commits should be squashed into a single one.
> >False deltas (random unrelated changes) should be removed.
>
> Good point
>
> >The planar I420 to monochrome conversion should work for every other
> >YUV format with a standalone luma plane as well. Is the memcpy even
> >needed though?
>
> Fine. In the command line tool x264 the filter resize is in charge of the
> color space conversion and I have to verify if it allows a solution without
> the memcpy, this depends on the memory ownership policy in the filter.
>
> Best Regards,
>
> Emanuele
>
> > Henrik
>
> --
> --------
> Emanuele Ruffaldi, Ph.D. - Assistant Professor
> PERCRO, TeCIP Institute - Scuola Superiore Sant'Anna
> via Luigi Alamanni 13D, San Giuliano Terme 56010 (PI), Italy
> mob.: +39 340 46 72 468 - tel.: +39 050 882 508
> fax.: +39 050 882 564 - skype: pititaly
> http://www.percro.org - http://www.teslacore.it
> --------
>



-- 
--------
Emanuele Ruffaldi, Ph.D. - Assistant Professor
PERCRO, TeCIP Institute - Scuola Superiore Sant'Anna
via Luigi Alamanni 13D, San Giuliano Terme 56010 (PI), Italy
mob.: +39 340 46 72 468 - tel.: +39 050 882 508
fax.: +39 050 882 564 - skype: pititaly
http://www.percro.org - http://www.teslacore.it
--------
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