[FFmpeg-devel] Fwd: [PATCH] lavfi: add xbr filter

[arwa arif]

On Sat, Nov 8, 2014 at 8:56 PM, Michael Niedermayer <michaelni at gmx.at>
wrote:

> Hi
>
> On Sat, Nov 08, 2014 at 08:27:18PM +0530, arwa arif wrote:
> > On Sat, Nov 8, 2014 at 6:21 PM, Michael Niedermayer <michaelni at gmx.at>
> > wrote:
> >
> > > On Sat, Nov 08, 2014 at 05:12:13PM +0530, arwa arif wrote:
> > > [...]
> > >
> > > > +static int df(uint32_t x, uint32_t y, const uint32_t *r2y)
> > > > +{
> > > > +
> > > > +#define YMASK 0xff0000
> > > > +#define UMASK 0x00ff00
> > > > +#define VMASK 0x0000ff
> > > > +
> > > > +    uint32_t yuv1 = r2y[x & 0xffffff];
> > > > +    uint32_t yuv2 = r2y[y & 0xffffff];
> > > > +
> > > > +    return abs((yuv1 & YMASK) - (yuv2 & YMASK)) > (48 << 16) ||
> > > > +           abs((yuv1 & UMASK) - (yuv2 & UMASK)) > ( 7 <<  8) ||
> > > > +           abs((yuv1 & VMASK) - (yuv2 & VMASK)) > ( 6 <<  0);
> > >
> > > the "> some constant" is wrong
> > > the new code expects this to be a scalar not a boolean
> > > adding the 3 absolute differences together should work better
> > >
> > > [...]
> > >
> > >
> > > Updated the patch.
>
> seems you lost ffmpeg-devel from the CC
> I just CC-ed you directly on the previous mails to make sure you
> dont miss the review/reply, normally all discussion is on ffmpeg-dev
> without CCes
> the patch and review should stay on ffmpeg-devel
>
> more comments below
>
>
> [...]
> > + * Hyllian's 2xBR v3.3b
> > + *
> > + * Copyright (C) 2011 Hyllian <sergiogdb at gmail.com>
>
>
> https://github.com/yoyofr/iFBA/blob/master/fba_src/src/intf/video/scalers/xbr.cpp
> contains
> "Copyright (C) 2011, 2012 Hyllian/Jararaca - sergiogdb at gmail.com"
>
> so unless i miss something that exact copyright line should be kept
> or already asked the author(s) and they agreed to LGPL
>
>
> > + *
> > + * Copyright (c) 2014 Arwa Arif <arwaarif1994 at gmail.com>
> > + *
> > + * FFmpeg is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2.1 of the License, or (at your option) any later version.
>
>
> https://github.com/yoyofr/iFBA/blob/master/fba_src/src/intf/video/scalers/xbr.cpp
> is GPL v2+
> ive read elsewhere that Hyllian wanted it to be LGPL, so LGPL should
> be fine but we should confirm that all authors of this file actually
> agree to LGPL and until then you can simply replace the LGPL header
> by the GPL v2+ one from xbr.cpp
> that is unless you found and used only code from LGPL licensed xbr
>
>
> > + *
> > + * FFmpeg is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with FFmpeg; if not, write to the Free Software
> > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> 02110-1301 USA
> > + */
> > +
> > +/**
> > + * @file
> > + * XBR Filter is used for depixelization of image.
> > + * This is based on Hyllian's 2xBR shader.
> > + *
> > + * @see : http://www.libretro.com/forums/viewtopic.php?f=6&t=134
> > + * @see :
> https://github.com/yoyofr/iFBA/blob/master/fba_src/src/intf/video/scalers/xbr.cpp
> > + * Future work : To implement x3 and x4 scale, and threading.
> > + */
> > +
> > +#include "libavutil/opt.h"
> > +#include "libavutil/avassert.h"
> > +#include "libavutil/pixdesc.h"
> > +#include "internal.h"
> > +
> > +#define RGB_MASK         0x00FFFFFF
> > +#define pg_lbmask        0x00FEFEFE
> > +#define pg_red_blue_mask 0x00FF00FF
> > +#define pg_green_mask    0x0000FF00
> > +
> > +typedef struct {
> > +    uint32_t rgbtoyuv[1<<24];
> > +} xBRContext;
> > +
> > +static uint32_t df(uint32_t x, uint32_t y, const uint32_t *r2y)
> > +{
> > +
> > +#define YMASK 0x00ff0000
> > +#define UMASK 0x0000ff00
> > +#define VMASK 0x000000ff
> > +
> > +    uint32_t yuv1 = r2y[x & 0x00ffffff];
> > +    uint32_t yuv2 = r2y[y & 0x00ffffff];
> > +
>
> > +    return abs((yuv1 & YMASK) - (yuv2 & YMASK)) > (48 << 16) +
> > +           abs((yuv1 & UMASK) - (yuv2 & UMASK)) > ( 7 <<  8) +
> > +           abs((yuv1 & VMASK) - (yuv2 & VMASK)) > ( 6 <<  0);
>
> the "> (some number)" is not correct df() is intended to be a
> scalar distance, aka distance between 2 points, like 7 meters would
> be. they are like points in  Y,U,V space instead of real world right/left,
> up/down, forward/backward.
> the sum of the abs() should work without any ">", the first 2 just
> need to be scaled down by 16 and 8 bit
>
> i think this is the only technical issue left, the patch should be
> fine after that to be applied
>
> [...]
>
> Updated the patch.


> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> I have often repented speaking, but never of holding my tongue.
> -- Xenocrates
>
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