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swscale: fix byte overreads in SSE-optimized hscale().

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SSE-optimized hScale() scales up to 4 pixels at once, so we need to
allocate up to 3 padding pixels to prevent overreads. This fixes
valgrind errors in various swscale-tests on fate.
This commit is contained in:
Ronald S. Bultje 2011-09-15 07:30:34 -07:00
parent d7d2f0e63c
commit ea540401d6
1 changed files with 10 additions and 6 deletions
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16
libswscale/utils.c
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@ -184,8 +184,8 @@ static int initFilter(int16_t **outFilter, int16_t **filterPos, int *outFilterSi
emms_c(); //FIXME this should not be required but it IS (even for non-MMX versions) emms_c(); //FIXME this should not be required but it IS (even for non-MMX versions)
// NOTE: the +1 is for the MMX scaler which reads over the end // NOTE: the +3 is for the MMX(+1)/SSE(+3) scaler which reads over the end
FF_ALLOC_OR_GOTO(NULL, *filterPos, (dstW+1)*sizeof(int16_t), fail); FF_ALLOC_OR_GOTO(NULL, *filterPos, (dstW+3)*sizeof(int16_t), fail);
if (FFABS(xInc - 0x10000) <10) { // unscaled if (FFABS(xInc - 0x10000) <10) { // unscaled
int i; int i;
@ -471,7 +471,7 @@ static int initFilter(int16_t **outFilter, int16_t **filterPos, int *outFilterSi
// Note the +1 is for the MMX scaler which reads over the end // Note the +1 is for the MMX scaler which reads over the end
/* align at 16 for AltiVec (needed by hScale_altivec_real) */ /* align at 16 for AltiVec (needed by hScale_altivec_real) */
FF_ALLOCZ_OR_GOTO(NULL, *outFilter, *outFilterSize*(dstW+1)*sizeof(int16_t), fail); FF_ALLOCZ_OR_GOTO(NULL, *outFilter, *outFilterSize*(dstW+3)*sizeof(int16_t), fail);
/* normalize & store in outFilter */ /* normalize & store in outFilter */
for (i=0; i<dstW; i++) { for (i=0; i<dstW; i++) {
@ -491,10 +491,14 @@ static int initFilter(int16_t **outFilter, int16_t **filterPos, int *outFilterSi
} }
} }
(*filterPos)[dstW]= (*filterPos)[dstW-1]; // the MMX scaler will read over the end (*filterPos)[dstW+0] =
(*filterPos)[dstW+1] =
(*filterPos)[dstW+2] = (*filterPos)[dstW-1]; // the MMX/SSE scaler will read over the end
for (i=0; i<*outFilterSize; i++) { for (i=0; i<*outFilterSize; i++) {
int j= dstW*(*outFilterSize); int k= (dstW - 1) * (*outFilterSize) + i;
(*outFilter)[j + i]= (*outFilter)[j + i - (*outFilterSize)]; (*outFilter)[k + 1 * (*outFilterSize)] =
(*outFilter)[k + 2 * (*outFilterSize)] =
(*outFilter)[k + 3 * (*outFilterSize)] = (*outFilter)[k];
} }
ret=0; ret=0;