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00026 #include <stdint.h>
00027 #include <limits.h>
00028
00029 #include "mathematics.h"
00030 #include "libavutil/common.h"
00031 #include "avassert.h"
00032 #include "version.h"
00033
00034 #if FF_API_AV_REVERSE
00035 const uint8_t av_reverse[256]={
00036 0x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0,
00037 0x08,0x88,0x48,0xC8,0x28,0xA8,0x68,0xE8,0x18,0x98,0x58,0xD8,0x38,0xB8,0x78,0xF8,
00038 0x04,0x84,0x44,0xC4,0x24,0xA4,0x64,0xE4,0x14,0x94,0x54,0xD4,0x34,0xB4,0x74,0xF4,
00039 0x0C,0x8C,0x4C,0xCC,0x2C,0xAC,0x6C,0xEC,0x1C,0x9C,0x5C,0xDC,0x3C,0xBC,0x7C,0xFC,
00040 0x02,0x82,0x42,0xC2,0x22,0xA2,0x62,0xE2,0x12,0x92,0x52,0xD2,0x32,0xB2,0x72,0xF2,
00041 0x0A,0x8A,0x4A,0xCA,0x2A,0xAA,0x6A,0xEA,0x1A,0x9A,0x5A,0xDA,0x3A,0xBA,0x7A,0xFA,
00042 0x06,0x86,0x46,0xC6,0x26,0xA6,0x66,0xE6,0x16,0x96,0x56,0xD6,0x36,0xB6,0x76,0xF6,
00043 0x0E,0x8E,0x4E,0xCE,0x2E,0xAE,0x6E,0xEE,0x1E,0x9E,0x5E,0xDE,0x3E,0xBE,0x7E,0xFE,
00044 0x01,0x81,0x41,0xC1,0x21,0xA1,0x61,0xE1,0x11,0x91,0x51,0xD1,0x31,0xB1,0x71,0xF1,
00045 0x09,0x89,0x49,0xC9,0x29,0xA9,0x69,0xE9,0x19,0x99,0x59,0xD9,0x39,0xB9,0x79,0xF9,
00046 0x05,0x85,0x45,0xC5,0x25,0xA5,0x65,0xE5,0x15,0x95,0x55,0xD5,0x35,0xB5,0x75,0xF5,
00047 0x0D,0x8D,0x4D,0xCD,0x2D,0xAD,0x6D,0xED,0x1D,0x9D,0x5D,0xDD,0x3D,0xBD,0x7D,0xFD,
00048 0x03,0x83,0x43,0xC3,0x23,0xA3,0x63,0xE3,0x13,0x93,0x53,0xD3,0x33,0xB3,0x73,0xF3,
00049 0x0B,0x8B,0x4B,0xCB,0x2B,0xAB,0x6B,0xEB,0x1B,0x9B,0x5B,0xDB,0x3B,0xBB,0x7B,0xFB,
00050 0x07,0x87,0x47,0xC7,0x27,0xA7,0x67,0xE7,0x17,0x97,0x57,0xD7,0x37,0xB7,0x77,0xF7,
00051 0x0F,0x8F,0x4F,0xCF,0x2F,0xAF,0x6F,0xEF,0x1F,0x9F,0x5F,0xDF,0x3F,0xBF,0x7F,0xFF,
00052 };
00053 #endif
00054
00055 int64_t av_gcd(int64_t a, int64_t b){
00056 if(b) return av_gcd(b, a%b);
00057 else return a;
00058 }
00059
00060 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
00061 int64_t r=0;
00062 av_assert2(c > 0);
00063 av_assert2(b >=0);
00064 av_assert2((unsigned)rnd<=5 && rnd!=4);
00065
00066 if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1));
00067
00068 if(rnd==AV_ROUND_NEAR_INF) r= c/2;
00069 else if(rnd&1) r= c-1;
00070
00071 if(b<=INT_MAX && c<=INT_MAX){
00072 if(a<=INT_MAX)
00073 return (a * b + r)/c;
00074 else
00075 return a/c*b + (a%c*b + r)/c;
00076 }else{
00077 #if 1
00078 uint64_t a0= a&0xFFFFFFFF;
00079 uint64_t a1= a>>32;
00080 uint64_t b0= b&0xFFFFFFFF;
00081 uint64_t b1= b>>32;
00082 uint64_t t1= a0*b1 + a1*b0;
00083 uint64_t t1a= t1<<32;
00084 int i;
00085
00086 a0 = a0*b0 + t1a;
00087 a1 = a1*b1 + (t1>>32) + (a0<t1a);
00088 a0 += r;
00089 a1 += a0<r;
00090
00091 for(i=63; i>=0; i--){
00092
00093 a1+= a1 + ((a0>>i)&1);
00094 t1+=t1;
00095 if(c <= a1){
00096 a1 -= c;
00097 t1++;
00098 }
00099 }
00100 return t1;
00101 }
00102 #else
00103 AVInteger ai;
00104 ai= av_mul_i(av_int2i(a), av_int2i(b));
00105 ai= av_add_i(ai, av_int2i(r));
00106
00107 return av_i2int(av_div_i(ai, av_int2i(c)));
00108 }
00109 #endif
00110 }
00111
00112 int64_t av_rescale(int64_t a, int64_t b, int64_t c){
00113 return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
00114 }
00115
00116 int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,
00117 enum AVRounding rnd)
00118 {
00119 int64_t b= bq.num * (int64_t)cq.den;
00120 int64_t c= cq.num * (int64_t)bq.den;
00121 return av_rescale_rnd(a, b, c, rnd);
00122 }
00123
00124 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
00125 {
00126 return av_rescale_q_rnd(a, bq, cq, AV_ROUND_NEAR_INF);
00127 }
00128
00129 int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b){
00130 int64_t a= tb_a.num * (int64_t)tb_b.den;
00131 int64_t b= tb_b.num * (int64_t)tb_a.den;
00132 if((FFABS(ts_a)|a|FFABS(ts_b)|b)<=INT_MAX)
00133 return (ts_a*a > ts_b*b) - (ts_a*a < ts_b*b);
00134 if (av_rescale_rnd(ts_a, a, b, AV_ROUND_DOWN) < ts_b) return -1;
00135 if (av_rescale_rnd(ts_b, b, a, AV_ROUND_DOWN) < ts_a) return 1;
00136 return 0;
00137 }
00138
00139 int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod){
00140 int64_t c= (a-b) & (mod-1);
00141 if(c > (mod>>1))
00142 c-= mod;
00143 return c;
00144 }
00145
00146 int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb){
00147 int64_t a, b, this;
00148
00149 av_assert0(in_ts != AV_NOPTS_VALUE);
00150 av_assert0(duration >= 0);
00151
00152 if (*last == AV_NOPTS_VALUE || !duration || in_tb.num*(int64_t)out_tb.den <= out_tb.num*(int64_t)in_tb.den) {
00153 simple_round:
00154 *last = av_rescale_q(in_ts, in_tb, fs_tb) + duration;
00155 return av_rescale_q(in_ts, in_tb, out_tb);
00156 }
00157
00158 a = av_rescale_q_rnd(2*in_ts-1, in_tb, fs_tb, AV_ROUND_DOWN) >>1;
00159 b = (av_rescale_q_rnd(2*in_ts+1, in_tb, fs_tb, AV_ROUND_UP )+1)>>1;
00160 if (*last < 2*a - b || *last > 2*b - a)
00161 goto simple_round;
00162
00163 this = av_clip64(*last, a, b);
00164 *last = this + duration;
00165
00166 return av_rescale_q(this, fs_tb, out_tb);
00167 }