diff options
| -rw-r--r-- | libavutil/common.h | 39 | ||||
| -rw-r--r-- | libavutil/version.h | 2 |
2 files changed, 40 insertions, 1 deletions
diff --git a/libavutil/common.h b/libavutil/common.h index 6f0f5827e0..813fb3775e 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -298,6 +298,42 @@ static av_always_inline av_const double av_clipd_c(double a, double amin, double else return a; } +/** + * Clip and convert a double value into the long long amin-amax range. + * This function is needed because conversion of floating point to integers when + * it does not fit in the integer's representation does not necessarily saturate + * correctly (usually converted to a cvttsd2si on x86) which saturates numbers + * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined + * behavior, allowing this sort of mathematically bogus conversions. This provides + * a safe alternative that is slower obviously but assures safety and better + * mathematical behavior. + * @param a value to clip + * @param amin minimum value of the clip range + * @param amax maximum value of the clip range + * @return clipped value + */ +static av_always_inline av_const int64_t av_rint64_clip_c(double a, int64_t amin, int64_t amax) +{ + int64_t res; +#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 + if (amin > amax) abort(); +#endif + // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles + // do range checks first + if (a >= 9223372036854775808.0) + return amax; + if (a <= -9223372036854775808.0) + return amin; + + // safe to call llrint and clip accordingly + res = llrint(a); + if (res > amax) + return amax; + if (res < amin) + return amin; + return res; +} + /** Compute ceil(log2(x)). * @param x value used to compute ceil(log2(x)) * @return computed ceiling of log2(x) @@ -511,6 +547,9 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x) #ifndef av_clipd # define av_clipd av_clipd_c #endif +#ifndef av_rint64_clip +# define av_rint64_clip av_rint64_clip_c +#endif #ifndef av_popcount # define av_popcount av_popcount_c #endif diff --git a/libavutil/version.h b/libavutil/version.h index 909f9a6256..bcad6587ae 100644 --- a/libavutil/version.h +++ b/libavutil/version.h @@ -56,7 +56,7 @@ */ #define LIBAVUTIL_VERSION_MAJOR 55 -#define LIBAVUTIL_VERSION_MINOR 5 +#define LIBAVUTIL_VERSION_MINOR 6 #define LIBAVUTIL_VERSION_MICRO 100 #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \ |