[FFmpeg-devel] [PATCH 2/2 v2] delogo: Take SAR into account

[Jean Delvare]

When interpolating, weights are based on relative distances, which
assume square pixels. If a non-1:1 sample aspect ratio is used, it
should be taken into account when comparing distances, because the
human eye and brain care about the picture as it is displayed, not
stored.

Signed-off-by: Jean Delvare <khali at linux-fr.org>
---
No functional change since v1, but rebasing was needed.

 libavfilter/version.h   |    2 +-
 libavfilter/vf_delogo.c |   14 ++++++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

--- ffmpeg.orig/libavfilter/vf_delogo.c	2013-06-25 21:56:27.049663266 +0200
+++ ffmpeg/libavfilter/vf_delogo.c	2013-06-25 22:00:58.615920845 +0200
@@ -56,7 +56,7 @@
  */
 static void apply_delogo(uint8_t *dst, int dst_linesize,
                          uint8_t *src, int src_linesize,
-                         int w, int h,
+                         int w, int h, AVRational sar,
                          int logo_x, int logo_y, int logo_w, int logo_h,
                          int band, int show, int direct)
 {
@@ -67,6 +67,7 @@ static void apply_delogo(uint8_t *dst, i
     uint8_t *topleft, *botleft, *topright;
     int xclipl, xclipr, yclipt, yclipb;
     int logo_x1, logo_x2, logo_y1, logo_y2;
+    int sar_num = sar.num ? : 1;
 
     xclipl = FFMAX(-logo_x, 0);
     xclipr = FFMAX(logo_x+logo_w-w, 0);
@@ -93,11 +94,11 @@ static void apply_delogo(uint8_t *dst, i
              xdst = dst+logo_x1+1,
              xsrc = src+logo_x1+1; x < logo_x2-1; x++, xdst++, xsrc++) {
 
-            /* Weighted interpolation based on relative distances */
-            weightl = (uint64_t)              (logo_x2-1-x) * (y-logo_y1) * (logo_y2-1-y);
-            weightr = (uint64_t)(x-logo_x1)                 * (y-logo_y1) * (logo_y2-1-y);
-            weightt = (uint64_t)(x-logo_x1) * (logo_x2-1-x)               * (logo_y2-1-y);
-            weightb = (uint64_t)(x-logo_x1) * (logo_x2-1-x) * (y-logo_y1);
+            /* Weighted interpolation based on relative distances, taking SAR into account */
+            weightl = (uint64_t)              (logo_x2-1-x) * (y-logo_y1) * (logo_y2-1-y) * sar.den;
+            weightr = (uint64_t)(x-logo_x1)                 * (y-logo_y1) * (logo_y2-1-y) * sar.den;
+            weightt = (uint64_t)(x-logo_x1) * (logo_x2-1-x)               * (logo_y2-1-y) * sar_num;
+            weightb = (uint64_t)(x-logo_x1) * (logo_x2-1-x) * (y-logo_y1)                 * sar_num;
 
             interp =
                 (topleft[src_linesize*(y-logo_y  -yclipt)]   +
@@ -239,6 +240,7 @@ static int filter_frame(AVFilterLink *in
                      in ->data[plane], in ->linesize[plane],
                      FF_CEIL_RSHIFT(inlink->w, hsub),
                      FF_CEIL_RSHIFT(inlink->h, vsub),
+                     in->sample_aspect_ratio,
                      s->x>>hsub, s->y>>vsub,
                      FF_CEIL_RSHIFT(s->w, hsub),
                      FF_CEIL_RSHIFT(s->h, vsub),
--- ffmpeg.orig/libavfilter/version.h	2013-06-25 18:13:56.702312485 +0200
+++ ffmpeg/libavfilter/version.h	2013-06-25 21:59:34.304666042 +0200
@@ -31,7 +31,7 @@
 
 #define LIBAVFILTER_VERSION_MAJOR  3
 #define LIBAVFILTER_VERSION_MINOR  77
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MICRO 102
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \

-- 
Jean Delvare