diff options
Diffstat (limited to 'libavutil/common.h')
| -rw-r--r-- | libavutil/common.h | 139 |
1 files changed, 121 insertions, 18 deletions
diff --git a/libavutil/common.h b/libavutil/common.h index d2ddcba9ed..8142b31fdb 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -1,20 +1,20 @@ /* * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * Libav is distributed in the hope that it will be useful, + * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -26,6 +26,10 @@ #ifndef AVUTIL_COMMON_H #define AVUTIL_COMMON_H +#if defined(__cplusplus) && !defined(__STDC_CONSTANT_MACROS) && !defined(UINT64_C) +#error missing -D__STDC_CONSTANT_MACROS / #define __STDC_CONSTANT_MACROS +#endif + #include <errno.h> #include <inttypes.h> #include <limits.h> @@ -50,17 +54,43 @@ #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b)) /* assume b>0 */ #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b)) +/* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */ +#define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \ + : ((a) + (1<<(b)) - 1) >> (b)) +/* Backwards compat. */ +#define FF_CEIL_RSHIFT AV_CEIL_RSHIFT + +#define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b)) +#define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b)) /** - * Fast a / (1 << b) rounded toward +inf, assuming a >= 0 and b >= 0. + * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they + * are not representable as absolute values of their type. This is the same + * as with *abs() + * @see FFNABS() */ -#define AV_CEIL_RSHIFT(a, b) \ - (av_builtin_constant_p(b) ? ((a) + (1 << (b)) - 1) >> (b) \ - : -((-(a)) >> (b))) - #define FFABS(a) ((a) >= 0 ? (a) : (-(a))) #define FFSIGN(a) ((a) > 0 ? 1 : -1) +/** + * Negative Absolute value. + * this works for all integers of all types. + * As with many macros, this evaluates its argument twice, it thus must not have + * a sideeffect, that is FFNABS(x++) has undefined behavior. + */ +#define FFNABS(a) ((a) <= 0 ? (a) : (-(a))) + +/** + * Comparator. + * For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0 + * if x == y. This is useful for instance in a qsort comparator callback. + * Furthermore, compilers are able to optimize this to branchless code, and + * there is no risk of overflow with signed types. + * As with many macros, this evaluates its argument multiple times, it thus + * must not have a side-effect. + */ +#define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y))) + #define FFMAX(a,b) ((a) > (b) ? (a) : (b)) #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c) #define FFMIN(a,b) ((a) > (b) ? (b) : (a)) @@ -96,6 +126,26 @@ av_const int av_log2_16bit(unsigned v); */ static av_always_inline av_const int av_clip_c(int a, int amin, int amax) { +#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 + if (amin > amax) abort(); +#endif + if (a < amin) return amin; + else if (a > amax) return amax; + else return a; +} + +/** + * Clip a signed 64bit integer value into the amin-amax range. + * @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_clip64_c(int64_t a, int64_t amin, int64_t amax) +{ +#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 + if (amin > amax) abort(); +#endif if (a < amin) return amin; else if (a > amax) return amax; else return a; @@ -119,7 +169,7 @@ static av_always_inline av_const uint8_t av_clip_uint8_c(int a) */ static av_always_inline av_const int8_t av_clip_int8_c(int a) { - if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F; + if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F; else return a; } @@ -141,7 +191,7 @@ static av_always_inline av_const uint16_t av_clip_uint16_c(int a) */ static av_always_inline av_const int16_t av_clip_int16_c(int a) { - if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF; + if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF; else return a; } @@ -152,8 +202,8 @@ static av_always_inline av_const int16_t av_clip_int16_c(int a) */ static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a) { - if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF; - else return a; + if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF); + else return (int32_t)a; } /** @@ -164,7 +214,7 @@ static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a) */ static av_always_inline av_const int av_clip_intp2_c(int a, int p) { - if ((a + (1 << p)) & ~((1 << (p + 1)) - 1)) + if (((unsigned)a + (1 << p)) & ~((2 << p) - 1)) return (a >> 31) ^ ((1 << p) - 1); else return a; @@ -183,6 +233,17 @@ static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p) } /** + * Clear high bits from an unsigned integer starting with specific bit position + * @param a value to clip + * @param p bit position to clip at + * @return clipped value + */ +static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p) +{ + return a & ((1 << p) - 1); +} + +/** * Add two signed 32-bit values with saturation. * * @param a one value @@ -215,6 +276,26 @@ static av_always_inline int av_sat_dadd32_c(int a, int b) */ static av_always_inline av_const float av_clipf_c(float a, float amin, float amax) { +#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 + if (amin > amax) abort(); +#endif + if (a < amin) return amin; + else if (a > amax) return amax; + else return a; +} + +/** + * Clip a double value into the amin-amax range. + * @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 double av_clipd_c(double a, double amin, double amax) +{ +#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 + if (amin > amax) abort(); +#endif if (a < amin) return amin; else if (a > amax) return amax; else return a; @@ -250,7 +331,12 @@ static av_always_inline av_const int av_popcount_c(uint32_t x) */ static av_always_inline av_const int av_popcount64_c(uint64_t x) { - return av_popcount(x) + av_popcount(x >> 32); + return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32)); +} + +static av_always_inline av_const int av_parity_c(uint32_t v) +{ + return av_popcount(v) & 1; } #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24)) @@ -266,15 +352,20 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x) * input, this could be *ptr++. * @param ERROR Expression to be evaluated on invalid input, * typically a goto statement. + * + * @warning ERROR should not contain a loop control statement which + * could interact with the internal while loop, and should force an + * exit from the macro code (e.g. through a goto or a return) in order + * to prevent undefined results. */ #define GET_UTF8(val, GET_BYTE, ERROR)\ - val= GET_BYTE;\ + val= (GET_BYTE);\ {\ uint32_t top = (val & 128) >> 1;\ - if ((val & 0xc0) == 0x80)\ + if ((val & 0xc0) == 0x80 || val >= 0xFE)\ ERROR\ while (val & top) {\ - int tmp= GET_BYTE - 128;\ + int tmp= (GET_BYTE) - 128;\ if(tmp>>6)\ ERROR\ val= (val<<6) + tmp;\ @@ -389,6 +480,9 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x) #ifndef av_clip # define av_clip av_clip_c #endif +#ifndef av_clip64 +# define av_clip64 av_clip64_c +#endif #ifndef av_clip_uint8 # define av_clip_uint8 av_clip_uint8_c #endif @@ -410,6 +504,9 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x) #ifndef av_clip_uintp2 # define av_clip_uintp2 av_clip_uintp2_c #endif +#ifndef av_mod_uintp2 +# define av_mod_uintp2 av_mod_uintp2_c +#endif #ifndef av_sat_add32 # define av_sat_add32 av_sat_add32_c #endif @@ -419,9 +516,15 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x) #ifndef av_clipf # define av_clipf av_clipf_c #endif +#ifndef av_clipd +# define av_clipd av_clipd_c +#endif #ifndef av_popcount # define av_popcount av_popcount_c #endif #ifndef av_popcount64 # define av_popcount64 av_popcount64_c #endif +#ifndef av_parity +# define av_parity av_parity_c +#endif |