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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-06-21 22:41:25 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-07-08 08:57:40 +0200 |
| commit | 8c022099351c04ae21e0b8696ea71a690ed03cd2 (patch) | |
| tree | 6d01f7a2e0b32b370e227c5c4603099e201a6e6e /libavcodec/ffwavesynth.c | |
| parent | cf2bd3ce79b12256d7d129b2ada5ee649b9a27eb (diff) | |
avcodec/ffwavesynth: Simplify lcg_seek(), avoid negative case
Fixes: negation of -9223372036854775808 cannot be represented in type 'int64_t' (aka 'long'); cast to an unsigned type to negate this value to itself
Fixes: 15289/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFWAVESYNTH_fuzzer-5709034499342336
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavcodec/ffwavesynth.c')
| -rw-r--r-- | libavcodec/ffwavesynth.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/libavcodec/ffwavesynth.c b/libavcodec/ffwavesynth.c index cf8c780f3e..b2cc7c8fc1 100644 --- a/libavcodec/ffwavesynth.c +++ b/libavcodec/ffwavesynth.c @@ -113,18 +113,12 @@ static uint32_t lcg_next(uint32_t *s) return *s; } -static void lcg_seek(uint32_t *s, int64_t dt) +static void lcg_seek(uint32_t *s, uint32_t dt) { uint32_t a, c, t = *s; - if (dt >= 0) { - a = LCG_A; - c = LCG_C; - } else { /* coefficients for a step backward */ - a = LCG_AI; - c = (uint32_t)(-LCG_AI * LCG_C); - dt = -dt; - } + a = LCG_A; + c = LCG_C; while (dt) { if (dt & 1) t = a * t + c; |