swscale: dont reshuffle bytes

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libswscale/swscale.c

@@ -1657,7 +1657,7 @@ static int rgbToRgbWrapper(SwsContext *c, const uint8_t* src[], int srcStride[],
         if ((dstFormat == PIX_FMT_RGB32_1 || dstFormat == PIX_FMT_BGR32_1) && !isRGBA32(srcFormat))
             dstPtr += ALT32_CORR;
 
-        if (dstStride[0]*srcBpp == srcStride[0]*dstBpp && srcStride[0] > 0)
+        if (dstStride[0]*srcBpp == srcStride[0]*dstBpp && srcStride[0] > 0 && !(srcStride[0]%srcBpp))
             conv(srcPtr, dstPtr + dstStride[0]*srcSliceY, srcSliceH*srcStride[0]);
         else {
             int i;