int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max){ AVRational a0={0,1}, a1={1,0}; int sign= (num<0) ^ (den<0); int64_t gcd= av_gcd(FFABS(num), FFABS(den)); if(gcd){ num = FFABS(num)/gcd; den = FFABS(den)/gcd; } if(num<=max && den<=max){ a1= (AVRational){num, den}; den=0; } while(den){ uint64_t x = num / den; int64_t next_den= num - den*x; int64_t a2n= x*a1.num + a0.num; int64_t a2d= x*a1.den + a0.den; if(a2n > max || a2d > max){ if(a1.num) x= (max - a0.num) / a1.num; if(a1.den) x= FFMIN(x, (max - a0.den) / a1.den); if (den*(2*x*a1.den + a0.den) > num*a1.den) a1 = (AVRational){x*a1.num + a0.num, x*a1.den + a0.den}; break; } a0= a1; a1= (AVRational){a2n, a2d}; num= den; den= next_den; } assert(av_gcd(a1.num, a1.den) <= 1U); *dst_num = sign ? -a1.num : a1.num; *dst_den = a1.den; return den==0; }
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max){ AVRational a0={0,1}, a1={1,0}; int sign= (num<0) ^ (den<0); int64_t gcd= av_gcd(FFABS(num), FFABS(den)); if(gcd){ num = FFABS(num)/gcd; den = FFABS(den)/gcd; } if(num<=max && den<=max){ a1= (AVRational){num, den}; den=0; } while(den){ uint64_t x = num / den; int64_t next_den= num - den*x; int64_t a2n= x*a1.num + a0.num; int64_t a2d= x*a1.den + a0.den; if(a2n > max || a2d > max){ if(a1.num) x= (max - a0.num) / a1.num; if(a1.den) x= FFMIN(x, (max - a0.den) / a1.den); if (den*(2*x*a1.den + a0.den) > num*a1.den) a1 = (AVRational){x*a1.num + a0.num, x*a1.den + a0.den}; break; } a0= a1; a1= (AVRational){a2n, a2d}; num= den; den= next_den; } assert(av_gcd(a1.num, a1.den) <= 1U); *dst_num = sign ? -a1.num : a1.num; *dst_den = a1.den; return den==0; }