From 50ce2960263daf48227df758df9ade19db7154fa Mon Sep 17 00:00:00 2001
From: Mateusz <mateuszb@poczta.onet.pl>
Date: Tue, 24 Oct 2017 10:02:17 +0200
Subject: swscale: use dithering in DITHER_COPY only if not set -sws_dither
none
This patch uses dithering in DITHER_COPY macro only if
it was not used option '-sws_dither none'.
With option '-sws_dither none' it uses downshift.
For human eye dithering is OK, for video codecs not necessarily.
If user don't want to use dithering, we should respect that.
Signed-off-by: Mateusz Brzostek <mateuszb@poczta.onet.pl>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
libswscale/swscale_unscaled.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
(limited to 'libswscale')
diff --git a/libswscale/swscale_unscaled.c b/libswscale/swscale_unscaled.c
index 5d81cd5af9..5ec2116bcf 100644
--- a/libswscale/swscale_unscaled.c
+++ b/libswscale/swscale_unscaled.c
@@ -1485,7 +1485,25 @@ static int packedCopyWrapper(SwsContext *c, const uint8_t *src[],
#define DITHER_COPY(dst, dstStride, src, srcStride, bswap, dbswap)\
unsigned shift= src_depth-dst_depth, tmp;\
- if (shiftonly) {\
+ if (c->dither == SWS_DITHER_NONE) {\
+ for (i = 0; i < height; i++) {\
+ for (j = 0; j < length-7; j+=8) {\
+ dst[j+0] = dbswap(bswap(src[j+0])>>shift);\
+ dst[j+1] = dbswap(bswap(src[j+1])>>shift);\
+ dst[j+2] = dbswap(bswap(src[j+2])>>shift);\
+ dst[j+3] = dbswap(bswap(src[j+3])>>shift);\
+ dst[j+4] = dbswap(bswap(src[j+4])>>shift);\
+ dst[j+5] = dbswap(bswap(src[j+5])>>shift);\
+ dst[j+6] = dbswap(bswap(src[j+6])>>shift);\
+ dst[j+7] = dbswap(bswap(src[j+7])>>shift);\
+ }\
+ for (; j < length; j++) {\
+ dst[j] = dbswap(bswap(src[j])>>shift);\
+ }\
+ dst += dstStride;\
+ src += srcStride;\
+ }\
+ } else if (shiftonly) {\
for (i = 0; i < height; i++) {\
const uint8_t *dither= dithers[shift-1][i&7];\
for (j = 0; j < length-7; j+=8) {\
--
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