From 5f63d108eb43be18c22d4fe45a5aaec10d8460d5 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 14 Jul 2004 18:23:49 +0000 Subject: simplify Originally committed as revision 3314 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/utils.c | 65 ++++++++++++++++++++++-------------------------------- 1 file changed, 26 insertions(+), 39 deletions(-) (limited to 'libavcodec') diff --git a/libavcodec/utils.c b/libavcodec/utils.c index be399e9b70..5b30125fcb 100644 --- a/libavcodec/utils.c +++ b/libavcodec/utils.c @@ -786,49 +786,36 @@ char av_get_pict_type_char(int pict_type){ } int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max){ - int exact=1, sign=0; - int64_t gcd; - - assert(den != 0); - - if(den < 0) - return av_reduce(dst_nom, dst_den, -nom, -den, max); - - sign= nom < 0; - nom= ABS(nom); - - gcd = ff_gcd(nom, den); - nom /= gcd; - den /= gcd; - - if(nom > max || den > max){ - AVRational a0={0,1}, a1={1,0}; - exact=0; - - for(;;){ - int64_t x= nom / den; - int64_t a2n= x*a1.num + a0.num; - int64_t a2d= x*a1.den + a0.den; - - if(a2n > max || a2d > max) break; - - nom %= den; - - a0= a1; - a1= (AVRational){a2n, a2d}; - if(nom==0) break; - x= nom; nom=den; den=x; - } - nom= a1.num; - den= a1.den; + AVRational a0={0,1}, a1={1,0}; + int sign= (nom<0) ^ (den<0); + int64_t gcd= ff_gcd(ABS(nom), ABS(den)); + + nom = ABS(nom)/gcd; + den = ABS(den)/gcd; + if(nom<=max && den<=max){ + a1= (AVRational){nom, den}; + den=0; } - assert(ff_gcd(nom, den) == 1); + while(den){ + int64_t x = nom / den; + int64_t next_den= nom - den*x; + int64_t a2n= x*a1.num + a0.num; + int64_t a2d= x*a1.den + a0.den; + + if(a2n > max || a2d > max) break; + + a0= a1; + a1= (AVRational){a2n, a2d}; + nom= den; + den= next_den; + } + assert(ff_gcd(a1.num, a1.den) == 1); - *dst_nom = sign ? -nom : nom; - *dst_den = den; + *dst_nom = sign ? -a1.num : a1.num; + *dst_den = a1.den; - return exact; + return den==0; } int64_t av_rescale(int64_t a, int64_t b, int64_t c){ -- cgit v1.2.3