[FFmpeg-cvslog] avcodec/ac3dec: Fix undefined shifts
Michael Niedermayer
git at videolan.org
Sun Mar 15 11:45:16 CET 2015
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Wed Mar 11 16:21:26 2015 +0100| [94ccbad488d1c315459b8dd22cebed114e72b226] | committer: Michael Niedermayer
avcodec/ac3dec: Fix undefined shifts
Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu <tfoucu at google.com>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=94ccbad488d1c315459b8dd22cebed114e72b226
---
libavcodec/ac3dec.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index ac53bdc..4e6e124 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -112,7 +112,7 @@ static const uint8_t ac3_default_coeffs[8][5][2] = {
static inline int
symmetric_dequant(int code, int levels)
{
- return ((code - (levels >> 1)) << 24) / levels;
+ return ((code - (levels >> 1)) * (1 << 24)) / levels;
}
/*
@@ -470,7 +470,7 @@ static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
int cpl_coord = s->cpl_coords[ch][band] << 5;
for (bin = band_start; bin < band_end; bin++) {
s->fixed_coeffs[ch][bin] =
- MULH(s->fixed_coeffs[CPL_CH][bin] << 4, cpl_coord);
+ MULH(s->fixed_coeffs[CPL_CH][bin] * (1 << 4), cpl_coord);
}
if (ch == 2 && s->phase_flags[band]) {
for (bin = band_start; bin < band_end; bin++)
@@ -567,8 +567,7 @@ static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, ma
av_log(s->avctx, AV_LOG_ERROR, "bap %d is invalid in plain AC-3\n", bap);
bap = 15;
}
- mantissa = get_sbits(gbc, quantization_tab[bap]);
- mantissa <<= 24 - quantization_tab[bap];
+ mantissa = (unsigned)get_sbits(gbc, quantization_tab[bap]) << (24 - quantization_tab[bap]);
break;
}
coeffs[freq] = mantissa >> exps[freq];
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