On Mon, Oct 27, 2014 at 12:40 AM, Clément Bœsch <u...@pkh.me> wrote:
> On Mon, Oct 27, 2014 at 12:28:35AM +0530, arwa arif wrote:
> > 1. I think I understood what is giving you segmentation fault. The mask
> > that I am creating is going out of bounds for the boundary pixels. I will
> > try to fix it. But, I am curious why is it working on my laptop?
>
> > 2. Thank you Clement for the mode part. It made the code look smaller.
> > Also, I chose numbers instead of alphabets because I was initially
> > accessing the required values by considering the numbers as indices of a
> > matrix. If you want, I can convert it to alphabets instead.
>
> It might be easier for maintaining and understanding the code since that's
> the convention of the specifications
>
> > 3. I think 4x can be done fast enough, but 3x will take time.
>
> Yeah, likely like hqx, right.
>
> > 4. I tried reading the hqx code, I am not very sure with what they have
> > done in init part. It will be grateful if you can maybe explain the
> > algorithm or maybe provide me with a link which explicitly explains it.
> >
>
> In the init() callback the rgb2yuv map (which you can find in the local
> context) is initialized. Then you have the function rgb2yuv() to do the
> convert, which takes in argument that map and the rgb24 color to lookup
> in.
>
> [...]
>
> --
> Clément B.
>
>
I have done all the changes except rgb to yuv conversion. I will most
probably do it by tonight.
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
>
From 10b627af85029fa9164337f66101e9acc33d03c0 Mon Sep 17 00:00:00 2001
From: Arwa Arif <arwaarif1...@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
---
doc/filters.texi | 7 ++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_xbr.c | 285 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 294 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
+@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.
+
@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..9ecf15e
--- /dev/null
+++ b/libavfilter/vf_xbr.c
@@ -0,0 +1,285 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * Copyright (c) 2014 Arwa Arif <arwaarif1...@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
+ * Reference : http://board.byuu.org/viewtopic.php?f=10&t=2248
+ */
+
+#include "libavutil/opt.h"
+#include "libavutil/avassert.h"
+#include "libavutil/pixdesc.h"
+#include "internal.h"
+
+/**
+* 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){
+
+ 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);
+
+ int r = (r1 - r2);
+ int g = (g1 - g2);
+ int b = (b1 - b2);
+
+ /*Convert RGB to Y'UV*/
+ int y = r * .299000 + g * .587000 + b * .114000;
+ int u = r * -.168736 + g * -.331264 + b * .500000;
+ int v = r * .500000 + g * -.418688 + b * -.081312;
+
+ /*Add HQx filters threshold & return*/
+ return (y*48) + (u*7) + (v*6);
+}
+
+/**
+* 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);
+
+ } 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;
+}
+
+/**
+* Applies the xBR filter rules.
+**/
+static void apply_edge_detection_rules(AVFrame *in,AVFrame *out,int x,int y){
+
+ /* 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);
+ int d_E_B = d(in, x, y, x, y-1);
+ int d_E_F = d(in, x, y, x+1, y);
+ int d_E_H = d(in, x, y, x, y+1);
+ int d_E_G = d(in, x, y, x-1, y+1);
+ int d_E_C = d(in, x, y, x+1, y-1);
+ int d_A_D0 = d(in, x-1, y-1, x-2, y);
+ int d_A_B1 = d(in, x-1, y-1, x, y-2);
+ int d_D_B = d(in, x-1, y, x, y-1);
+ int d_D_H = d(in, x-1, y, x, y+1);
+ int d_D_A0 = d(in, x-1, y, x-2, y-1);
+ int d_B_F = d(in, x, y-1, x+1, y);
+ int d_B_A1 = d(in, x, y-1, x-1, y-2);
+ int d_E_A = d(in, x, y, x-1, y-1);
+ int d_E_I = d(in, x, y, x+1, y+1);
+ int d_C_F4 = d(in, x+1, y-1, x+2, y);
+ int d_C_B1 = d(in, x+1, y-1, x, y-2);
+ int d_F_H = d(in, x+1, y, x, y+1);
+ int d_F_C4 = d(in, x+1, y, x+2, y-1);
+ int d_B_C1 = d(in, x, y-1, x+1, y-2);
+ int d_G_D0 = d(in, x-1, y+1, x-2, y);
+ int d_G_H5 = d(in, x-1, y+1, x, y+2);
+ int d_H_G5 = d(in, x, y+1, x-1, y+2);
+ int d_D_G0 = d(in, x-1, y, x-2, y+1);
+ int d_I_F4 = d(in, x+1, y+1, x+2, y);
+ int d_I_H5 = d(in, x+1, y+1, x, y+2);
+ int d_H_I5 = d(in, x, y+1, x+1, y+2);
+ int d_H_I4 = d(in, x, y+1, x+2, y+1);
+
+ /**
+ * 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);
+ }
+ /**
+ * Top Right Edge Detection Rule
+ **/
+ if ((d_E_I+d_E_A+d_C_F4+d_C_B1+(4*d_B_F)) < (d_F_H+d_F_C4+d_D_B+d_B_C1+(4*d_E_C))){
+ // Figure what color to blend with current pixel --> 10
+ if(d_E_B <= d_E_F)
+ fill(in,out,x,y-1,x,y,1,(x*2)+1,y*2);
+ else
+ fill(in,out,x+1,y,x,y,1,(x*2)+1,y*2);
+ } else{
+ /*Insert current pixel color into scaledImageData*/
+ fill(in,out,x,y,x,y,0,(x*2)+1,y*2);
+ }
+
+ /**
+ * Bottom Left Edge Detection Rule
+ **/
+ if ((d_E_A+d_E_I+d_G_D0+d_G_H5+(4*d_D_H)) < (d_D_B+d_D_G0+d_F_H+d_H_G5+(4*d_E_G))){
+ // Figure what color to blend with current pixel --> 10
+ if(d_E_D <= d_E_H)
+ fill(in,out,x-1,y,x,y,1,x*2,(y*2)+1);
+ else
+ fill(in,out,x,y+1,x,y,1,x*2,(y*2)+1);
+
+ } else{
+ /*Insert current pixel color into scaledImageData*/
+ fill(in,out,x,y,x,y,0,x*2,(y*2)+1);
+ }
+
+ /**
+ * Bottom Right Edge Detection Rule
+ **/
+ if ((d_E_C+d_E_G+d_I_F4+d_I_H5+(4*d_F_H)) < (d_D_H+d_H_I5+d_H_I4+d_B_F+(4*d_E_I))){
+ // Figure what color to blend with current pixel --> 10
+ if(d_E_F <= d_E_H)
+ fill(in,out,x+1,y,x,y,1,(x*2)+1,(y*2)+1);
+ else
+ fill(in,out,x,y+1,x,y,1,(x*2)+1,(y*2)+1);
+
+ } else{
+ /*Insert current pixel color into scaledImageData*/
+ fill(in,out,x,y,x,y,0,(x*2)+1,(y*2)+1);
+ }
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AVFilterLink *inlink = ctx->inputs[0];
+
+ outlink->w = inlink->w * 2 ;
+ outlink->h = inlink->h * 2 ;
+ return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,AV_PIX_FMT_NONE,
+ };
+
+ ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ int i,j;
+
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out) {
+ av_frame_free(&in);
+ return AVERROR(ENOMEM);
+ }
+
+ av_frame_copy_props(out, in);
+ for(i=0;i<inlink->w;i++)
+ for(j=0;j<inlink->h;j++)
+ apply_edge_detection_rules(in,out,i,j);
+
+ out->width = outlink->w;
+ out->height = outlink->h;
+
+ av_frame_free(&in);
+ return ff_filter_frame(outlink, out);
+}
+
+static const AVFilterPad xbr_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad xbr_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_output,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_xbr = {
+ .name = "xbr",
+ .description = NULL_IF_CONFIG_SMALL("Scale the input by 2 using xbr algorithm."),
+ .inputs = xbr_inputs,
+ .outputs = xbr_outputs,
+ .query_formats = query_formats,
+};
--
1.7.9.5
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