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

Clément Bœsch u at pkh.me
Mon Oct 27 20:54:11 CET 2014


On Tue, Oct 28, 2014 at 01:07:30AM +0530, arwa arif wrote:
[...]
> From 9c5fa6fa8f6091149570cded8ee65d232ae88e97 Mon Sep 17 00:00:00 2001
> From: Arwa Arif <arwaarif1994 at gmail.com>
> Date: Sat, 25 Oct 2014 22:04:51 +0530
> Subject: [PATCH] [PATCH]lavfi: add xbr filter
> 
> Makefile
> 
> allfilters.c
> 
> filters.texi
> 
> filters.texi
> 
> xbr-filter
> 
> xbr-filter
> 
> xbr-filter

Again, please drop these references

> ---
>  doc/filters.texi         |    7 +
>  libavfilter/Makefile     |    1 +
>  libavfilter/allfilters.c |    1 +
>  libavfilter/vf_xbr.c     |  317 ++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 326 insertions(+)
>  create mode 100644 libavfilter/vf_xbr.c
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index c70ddf3..5fa1d08 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -9159,6 +9159,13 @@ Only deinterlace frames marked as interlaced.
>  Default value is @samp{all}.
>  @end table
>  
> + at section xbr
> +
> +A high-quality magnification filter which is designed for pixel art. It follows a set
> +of edge-detection rules @url{http://www.libretro.com/forums/viewtopic.php?f=6&t=134}.
> +This filter was originally created by Hyllian. The current implementation scales the
> +image by scale factor 2.

image -> input

> +
>  @anchor{yadif}
>  @section yadif
>  
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 6d868e7..2c56e38 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -198,6 +198,7 @@ OBJS-$(CONFIG_VIDSTABDETECT_FILTER)          += vidstabutils.o vf_vidstabdetect.
>  OBJS-$(CONFIG_VIDSTABTRANSFORM_FILTER)       += vidstabutils.o vf_vidstabtransform.o
>  OBJS-$(CONFIG_VIGNETTE_FILTER)               += vf_vignette.o
>  OBJS-$(CONFIG_W3FDIF_FILTER)                 += vf_w3fdif.o
> +OBJS-$(CONFIG_XBR_FILTER)                    += vf_xbr.o
>  OBJS-$(CONFIG_YADIF_FILTER)                  += vf_yadif.o
>  OBJS-$(CONFIG_ZMQ_FILTER)                    += f_zmq.o
>  OBJS-$(CONFIG_ZOOMPAN_FILTER)                += vf_zoompan.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index d88a9ad..2352d44 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -213,6 +213,7 @@ void avfilter_register_all(void)
>      REGISTER_FILTER(VIDSTABTRANSFORM, vidstabtransform, vf);
>      REGISTER_FILTER(VIGNETTE,       vignette,       vf);
>      REGISTER_FILTER(W3FDIF,         w3fdif,         vf);
> +    REGISTER_FILTER(XBR,            xbr,            vf);
>      REGISTER_FILTER(YADIF,          yadif,          vf);
>      REGISTER_FILTER(ZMQ,            zmq,            vf);
>      REGISTER_FILTER(ZOOMPAN,        zoompan,        vf);
> diff --git a/libavfilter/vf_xbr.c b/libavfilter/vf_xbr.c
> new file mode 100644
> index 0000000..5c97173
> --- /dev/null
> +++ b/libavfilter/vf_xbr.c
> @@ -0,0 +1,317 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * 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.
> + *
> + * 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.

> + * 2xBR Filter v0.2.5 

trailing whitespace

> + * Reference : http://board.byuu.org/viewtopic.php?f=10&t=2248

dead link, and replace "Reference :" by "@see http://..."

Add a TODO with the following:
 - x3 and x4 scale
 - threading

> + */
> +
> +#include "libavutil/opt.h"
> +#include "libavutil/avassert.h"
> +#include "libavutil/pixdesc.h"
> +#include "internal.h"
> +
> +typedef struct {
> +    uint32_t rgbtoyuv[1<<24];
> +} xBRContext;
> +
> +/**
> +* Calculates the weight of difference of the pixels, by transforming these
> +* pixels into their Y'UV parts. It then uses the threshold used by HQx filters:
> +* 48*Y + 7*U + 6*V, to give it those smooth looking edges.
> +**/

> +static int d(AVFrame *in,int x1,int y1,int x2,int y2,const uint32_t *r2y){

Here and several times below, wrong coding style.

> +
> +#define YMASK 0xff0000
> +#define UMASK 0x00ff00
> +#define VMASK 0x0000ff
> +
> +    int r1 = *(in->data[0] + y1 * in->linesize[0] + x1*3);
> +    int g1 = *(in->data[0] + y1 * in->linesize[0] + x1*3 + 1);
> +    int b1 = *(in->data[0] + y1 * in->linesize[0] + x1*3 + 2);
> +
> +    int r2 = *(in->data[0] + y2 * in->linesize[0] + x2*3);
> +    int g2 = *(in->data[0] + y2 * in->linesize[0] + x2*3 + 1);
> +    int b2 = *(in->data[0] + y2 * in->linesize[0] + x2*3 + 2);
> +

> +    uint32_t c1 = (r1 | g1<<8 | b1<<16);
> +    uint32_t c2 = (r2 | g2<<8 | b2<<16);

pointless ( )

> +
> +    uint32_t yuv1 = r2y[c1 & 0xffffff];
> +    uint32_t yuv2 = r2y[c2 & 0xffffff];
> +
> +    return abs((yuv1 & YMASK) - (yuv2 & YMASK)) > (48 << 16) ||
> +           abs((yuv1 & UMASK) - (yuv2 & UMASK)) > ( 7 <<  8) ||
> +           abs((yuv1 & VMASK) - (yuv2 & VMASK)) > ( 6 <<  0);
> +}
> +
> +/**
> +* Mixes a pixel A, with pixel B, with B's transperancy set to 'a'
> +* In other words, A is a solid color (bottom) and B is a transparent color (top)
> +**/
> +static int mix(AVFrame *in,int x1,int y1,int x2,int y2,int a,int color){
> +
> +    int col1,col2;
> +    col1 = *(in->data[0] + y1 * in->linesize[0] + x1*3 + color);
> +    col2 = *(in->data[0] + y2 * in->linesize[0] + x2*3 + color);
> +
> +    return (a*col2 + (2-a)*col1)/2;
> +};
> +
> +/**
> +* Fills the output matrix
> +**/
> +static void fill(AVFrame *in,AVFrame *out,int u,int v,int x,int y,int mode,int new_x,int new_y){
> +
> +    int r,g,b;
> +    /*mix colors if they are not on boundary*/
> +    if(mode!=0 && u>=0 && v>=0 && u<in->width && v<in->height){
> +

> +	r = mix(in,u,v,x,y,1,0);
> +        g = mix(in,u,v,x,y,1,1);
> +        b = mix(in,u,v,x,y,1,2);

Here and several times below, you have tabs.

> +
> +    } else{
> +
> +	r = *(in->data[0] + y*in->linesize[0] + x*3);
> +        g = *(in->data[0] + y*in->linesize[0] + x*3 + 1);
> +        b = *(in->data[0] + y*in->linesize[0] + x*3 + 2);
> +    }
> +
> +    /*Insert blended color into scaledImageData*/
> +    *(out->data[0] + (new_y)*out->linesize[0] + (new_x)*3) = r;
> +    *(out->data[0] + (new_y)*out->linesize[0] + (new_x)*3 + 1) = g;
> +    *(out->data[0] + (new_y)*out->linesize[0] + (new_x)*3 + 2) = b;
> +
> +    return;
> +}

> +	

Trailing whitespaces here and several times below

> +/**
> +* Applies the xBR filter rules.
> +**/
> +static void apply_edge_detection_rules(AVFrame *in,AVFrame *out,int x,int y,const uint32_t *r2y){
> +
> +    /* Matrix: (10 is 0,0 i.e: current pixel)
> +    -2 | -1| 0| +1| +2 (x)
> +    ______________________________
> +    -2 |     [A1][B1][C1]
> +    -1 | [A0][ A][ B][ C][C4]
> +     0 | [D0][ D][ E][ F][F4]
> +    +1 | [G0][ G][ H][ I][I4]
> +    +2 |     [G5][H5][I5]
> +    |(y)|
> +    */
> +
> +    /*Cached Pixel Weight Difference*/
> +    int d_E_D    =  d(in,  x,    y,    x-1,  y,   r2y);
> +    int d_E_B    =  d(in,  x,    y,    x,    y-1, r2y);
> +    int d_E_F    =  d(in,  x,    y,    x+1,  y,   r2y);
> +    int d_E_H    =  d(in,  x,    y,    x,    y+1, r2y);
> +    int d_E_G    =  d(in,  x,    y,    x-1,  y+1, r2y);
> +    int d_E_C    =  d(in,  x,    y,    x+1,  y-1, r2y);
> +    int d_A_D0   =  d(in,  x-1,  y-1,  x-2,  y,   r2y);
> +    int d_A_B1   =  d(in,  x-1,  y-1,  x,    y-2, r2y);
> +    int d_D_B    =  d(in,  x-1,  y,    x,    y-1, r2y);
> +    int d_D_H    =  d(in,  x-1,  y,    x,    y+1, r2y);
> +    int d_D_A0   =  d(in,  x-1,  y,    x-2,  y-1, r2y);
> +    int d_B_F    =  d(in,  x,    y-1,  x+1,  y,   r2y);
> +    int d_B_A1   =  d(in,  x,    y-1,  x-1,  y-2, r2y);
> +    int d_E_A    =  d(in,  x,    y,    x-1,  y-1, r2y);
> +    int d_E_I    =  d(in,  x,    y,    x+1,  y+1, r2y);
> +    int d_C_F4   =  d(in,  x+1,  y-1,  x+2,  y,   r2y);
> +    int d_C_B1   =  d(in,  x+1,  y-1,  x,    y-2, r2y);
> +    int d_F_H    =  d(in,  x+1,  y,    x,    y+1, r2y);
> +    int d_F_C4   =  d(in,  x+1,  y,    x+2,  y-1, r2y);
> +    int d_B_C1   =  d(in,  x,    y-1,  x+1,  y-2, r2y);
> +    int d_G_D0   =  d(in,  x-1,  y+1,  x-2,  y,   r2y);
> +    int d_G_H5   =  d(in,  x-1,  y+1,  x,    y+2, r2y);
> +    int d_H_G5   =  d(in,  x,    y+1,  x-1,  y+2, r2y);
> +    int d_D_G0   =  d(in,  x-1,  y,    x-2,  y+1, r2y);
> +    int d_I_F4   =  d(in,  x+1,  y+1,  x+2,  y,   r2y);
> +    int d_I_H5   =  d(in,  x+1,  y+1,  x,    y+2, r2y);
> +    int d_H_I5   =  d(in,  x,    y+1,  x+1,  y+2, r2y);
> +    int d_H_I4   =  d(in,  x,    y+1,  x+2,  y+1, r2y);
> +
> +    /**
> +    * Note: On reading edge detection rules
> +    *
> +    * Each edge rule is an if..else statement, everytime on else, the
> +    * current pixel color pointed to by matrix[0] is used to color it's edge.
> +    *
> +    * Each if statement checks wether the sum of weight difference on the left is
> +    * lesser than that of the right weight differece.
> +    */
> +

> +    /**
> +    * Top Left Edge Detection Rule
> +    **/	
> +    if ((d_E_G+d_E_C+d_A_D0+d_A_B1+(4*d_D_B)) < (d_D_H+d_D_A0+d_B_F+d_B_A1+(4*d_E_A))){
> +	// Figure what color to blend with current pixel -->10
> +	if(d_E_D <= d_E_B)
> +	    fill(in,out,x-1,y,x,y,1,x*2,y*2);
> +	else
> +	    fill(in,out,x,y-1,x,y,1,x*2,y*2);
> +    } else{
> +	/*Insert current pixel color into scaledImageData*/
> +        fill(in,out,x,y,x,y,0,x*2,y*2);
> +    }

You can probably isolate this in a function or a macro somehow, but well...

[...]

Can you add a FATE test similar to this? See tests/fate/filter-video.mak.

What reference code did you use to check if your code generated the same bitmaps?

-- 
Clément B.
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