From d8863d37e2a266820b1faffcb19f9bd385a0ecee Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Tue, 29 Jan 2002 01:43:15 +0000
Subject: [PATCH] area averageing scaling support (-sws 5) (is identical to
bilinear for upscale)
Originally committed as revision 4403 to svn://svn.mplayerhq.hu/mplayer/trunk/postproc
---
postproc/swscale.c | 25 +++++++++++++++++--------
postproc/swscale.h | 1 +
2 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/postproc/swscale.c b/postproc/swscale.c
index dc52b2677e5..7acdfbd0741 100644
--- a/postproc/swscale.c
+++ b/postproc/swscale.c
@@ -604,6 +604,7 @@ void SwScale_YV12slice(unsigned char* src[], int srcStride[], int srcSliceY ,
case 2: flags|= SWS_BICUBIC; break;
case 3: flags|= SWS_X; break;
case 4: flags|= SWS_POINT; break;
+ case 5: flags|= SWS_AREA; break;
default:flags|= SWS_BILINEAR; break;
}
@@ -666,7 +667,7 @@ static inline void initFilter(int16_t **outFilter, int16_t **filterPos, int *out
int xDstInSrc;
if (flags&SWS_BICUBIC) filterSize= 4;
else if(flags&SWS_X ) filterSize= 4;
- else filterSize= 2;
+ else filterSize= 2; // SWS_BILINEAR / SWS_AREA
// printf("%d %d %d\n", filterSize, srcW, dstW);
filter= (double*)memalign(8, dstW*sizeof(double)*filterSize);
@@ -705,6 +706,7 @@ static inline void initFilter(int16_t **outFilter, int16_t **filterPos, int *out
}
else
{
+ //Bilinear upscale / linear interpolate / Area averaging
for(j=0; j<filterSize; j++)
{
double d= ABS((xx<<16) - xDstInSrc)/(double)(1<<16);
@@ -721,9 +723,10 @@ static inline void initFilter(int16_t **outFilter, int16_t **filterPos, int *out
else // downscale
{
int xDstInSrc;
- if(flags&SWS_BICUBIC) filterSize= (int)ceil(1 + 4.0*srcW / (double)dstW);
- else if(flags&SWS_X) filterSize= (int)ceil(1 + 4.0*srcW / (double)dstW);
- else filterSize= (int)ceil(1 + 2.0*srcW / (double)dstW);
+ if(flags&SWS_BICUBIC) filterSize= (int)ceil(1 + 4.0*srcW / (double)dstW);
+ else if(flags&SWS_X) filterSize= (int)ceil(1 + 4.0*srcW / (double)dstW);
+ else if(flags&SWS_AREA) filterSize= (int)ceil(1 + 1.0*srcW / (double)dstW);
+ else /* BILINEAR */ filterSize= (int)ceil(1 + 2.0*srcW / (double)dstW);
// printf("%d %d %d\n", *filterSize, srcW, dstW);
filter= (double*)memalign(8, dstW*sizeof(double)*filterSize);
@@ -749,15 +752,19 @@ static inline void initFilter(int16_t **outFilter, int16_t **filterPos, int *out
else
coeff=0.0;
}
-/* else if(flags & SWS_X)
+ else if(flags & SWS_AREA)
{
- }*/
+ double srcPixelSize= (1<<16)/(double)xInc;
+ if(d + srcPixelSize/2 < 0.5) coeff= 1.0;
+ else if(d - srcPixelSize/2 < 0.5) coeff= (0.5-d)/srcPixelSize + 0.5;
+ else coeff=0.0;
+ }
else
{
coeff= 1.0 - d;
if(coeff<0) coeff=0;
}
-// printf("%1.3f %d %d \n", coeff, (int)d, xDstInSrc);
+// printf("%1.3f %2.3f %d \n", coeff, d, xDstInSrc);
filter[i*filterSize + j]= coeff;
xx++;
}
@@ -1225,7 +1232,9 @@ SwsContext *getSwsContext(int srcW, int srcH, int srcFormat, int dstW, int dstH,
else if(flags&SWS_BICUBIC)
fprintf(stderr, "\nSwScaler: BICUBIC scaler ");
else if(flags&SWS_POINT)
- fprintf(stderr, "\nSwScaler: POINT scaler ");
+ fprintf(stderr, "\nSwScaler: Nearest Neighbor / POINT scaler ");
+ else if(flags&SWS_AREA)
+ fprintf(stderr, "\nSwScaler: Area Averageing scaler ");
else
fprintf(stderr, "\nSwScaler: ehh flags invalid?! ");
diff --git a/postproc/swscale.h b/postproc/swscale.h
index c00260fe670..6ddd5ae44a2 100644
--- a/postproc/swscale.h
+++ b/postproc/swscale.h
@@ -22,6 +22,7 @@
#define SWS_BICUBIC 4
#define SWS_X 8
#define SWS_POINT 0x10
+#define SWS_AREA 0x20
#define SWS_FULL_UV_IPOL 0x100
#define SWS_PRINT_INFO 0x1000
--
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