[FFmpeg-devel] [PATCH 4/4] avfilter/vf_colormatrix: add 10 & 12 bit depth support

[Kieran Kunhya]

On Sun, 27 Mar 2016 at 13:22 Thomas Mundt <loudmax-at-yahoo.de at ffmpeg.org>
wrote:

> Ronald S. Bultje <rsbultje at gmail.com> schrieb am So, 27.3.2016:
> > On Sun, Mar 27, 2016 at 7:09 AM, Thomas Mundt <loudmax-at-yahoo.de at
> ffmpeg.org> wrote:
> >
> >> >>>Ronald S. Bultje <rsbultje at gmail.com> schrieb am Sa, 26.3.2016:
> >> > On Sat, Mar 26, 2016 at 10:04 AM, Thomas Mundt <loudmax-at-yahoo.de
> at
> >> ffmpeg.org> wrote:
> >> >
> >> >>>>>Kieran Kunhya <kierank at obe.tv> schrieb am Sa, 26.3.2016:
> >> >> >> On Fri, 25 Mar 2016 at 22:32 Thomas Mundt <loudmax-at-yahoo.de
> at>
> >> ffmpeg.org> wrote:
> >> >> >
> >> >> >> Signed-off-by: Thomas Mundt <loudmax at yahoo.de>
> >> >> >> ---
> >> >> >>  libavfilter/vf_colormatrix.c | 182
> >> >> >> ++++++++++++++++++++++++++++++++++++++++++-
> >> >> >>
> >> >>> >
> >> >> > These functions are basically the same, have you considered
> factoring
> >> the
> >> >> > code out?
> >> >> >
> >> >> > Kieran
> >> >>
> >> >> I thought keeping it seperate would be easier to review.
> >> >> But I can do that. Maybe as a subsequent patch?
> >> >
> >> >
> >> > I think he means templating out typelessly like h264/hevc/vp9 do. I
> agree
> >> > that would probably be nicer. Binary size is same but less duplicated
> >> code.
> >> >
> >> > Ronald
> >>
> >> Okay, I tried to solve this with the use of macros. The attached file is
> >> the result (interesting part starting at line 203).
> >> It works, but I´m not sure if this is what you expect.
> >> Also I didn´t find a way factoring out the two different av_clip.
> >> One could replace av_clip_uint8 by av_clip with limits 0 and 255. But
> this
> >> would have an impact on speed.
> >> If there is a more elegant way, could you please provide a short
> example?!
> >
> >
> > We don't like macros, but you're surprisingly close. Have a look at
> > libavcodec/bit_depth_template.c and grep for its usage in libavcodec.
> >
> > You'll end up with a vf_colormatrixdsp_template.c file, which includes
> > bit_depth_template.c for types/clips etc., and it will then define full
> > functions per bit depth. This is included in vf_colormatrixdsp.c, and
> that
> > defines the actual dsp functions which do the core of what this filter
> does.
> >
> > Since it's now in a dsp file, it'll be trivial to write x86 simd for it
> > (which I have also in the works).
> >
> > Ronald
>
> I looked into this and sadly have to say that this would take much more
> time than I have atm.
> I´m not a professional programmer so I would have to fiddle out the most
> things.
> Sorry, but then I think it´s maybe better to drop the high bit depht
> support patch for now.
>

This may help:
http://blog.pkh.me/p/20-templating-in-c.html

Kieran