avcodec/pngdec: fix signed overflow

fixes fate ftrapv failure Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
11 years ago · cb079b1b2b
parent 03a5c44fae
commit cb079b1b2b
1 changed files with 1 additions and 1 deletions
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@ -226,7 +226,7 @@ static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
        if (bpp == 4) {
            p = *(int*)dst;
            for (; i < size; i += bpp) {
-                int s = *(int*)(src + i);
+                unsigned s = *(int*)(src + i);
                p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
                *(int*)(dst + i) = p;
            }