diff options
Diffstat (limited to 'libavutil/rational.c')
| -rw-r--r-- | libavutil/rational.c | 171 |
1 files changed, 163 insertions, 8 deletions
diff --git a/libavutil/rational.c b/libavutil/rational.c index 4053936194..cab443818a 100644 --- a/libavutil/rational.c +++ b/libavutil/rational.c @@ -2,20 +2,20 @@ * rational numbers * Copyright (c) 2003 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 */ @@ -69,6 +69,7 @@ int av_reduce(int *dst_num, int *dst_den, den = next_den; } av_assert2(av_gcd(a1.num, a1.den) <= 1U); + av_assert2(a1.num <= max && a1.den <= max); *dst_num = sign ? -a1.num : a1.num; *dst_den = a1.den; @@ -105,16 +106,20 @@ AVRational av_sub_q(AVRational b, AVRational c) AVRational av_d2q(double d, int max) { AVRational a; -#define LOG2 0.69314718055994530941723212145817656807550013436025 int exponent; int64_t den; if (isnan(d)) return (AVRational) { 0,0 }; - if (isinf(d)) + if (fabs(d) > INT_MAX + 3LL) return (AVRational) { d < 0 ? -1 : 1, 0 }; - exponent = FFMAX( (int)(log(fabs(d) + 1e-20)/LOG2), 0); + frexp(d, &exponent); + exponent = FFMAX(exponent-1, 0); den = 1LL << (61 - exponent); - av_reduce(&a.num, &a.den, (int64_t)(d * den + 0.5), den, max); + // (int64_t)rint() and llrint() do not work with gcc on ia64 and sparc64, + // see Ticket2713 for affected gcc/glibc versions + av_reduce(&a.num, &a.den, floor(d * den + 0.5), den, max); + if ((!a.num || !a.den) && d && max>0 && max<INT_MAX) + av_reduce(&a.num, &a.den, floor(d * den + 0.5), den, INT_MAX); return a; } @@ -143,3 +148,153 @@ int av_find_nearest_q_idx(AVRational q, const AVRational* q_list) return nearest_q_idx; } + +uint32_t av_q2intfloat(AVRational q) { + int64_t n; + int shift; + int sign = 0; + + if (q.den < 0) { + q.den *= -1; + q.num *= -1; + } + if (q.num < 0) { + q.num *= -1; + sign = 1; + } + + if (!q.num && !q.den) return 0xFFC00000; + if (!q.num) return 0; + if (!q.den) return 0x7F800000 | (q.num & 0x80000000); + + shift = 23 + av_log2(q.den) - av_log2(q.num); + if (shift >= 0) n = av_rescale(q.num, 1LL<<shift, q.den); + else n = av_rescale(q.num, 1, ((int64_t)q.den) << -shift); + + shift -= n >= (1<<24); + shift += n < (1<<23); + + if (shift >= 0) n = av_rescale(q.num, 1LL<<shift, q.den); + else n = av_rescale(q.num, 1, ((int64_t)q.den) << -shift); + + av_assert1(n < (1<<24)); + av_assert1(n >= (1<<23)); + + return sign<<31 | (150-shift)<<23 | (n - (1<<23)); +} + +#ifdef TEST + +#include "integer.h" + +int main(void) +{ + AVRational a,b,r; + int i,j,k; + static const int64_t numlist[] = { + INT64_MIN, INT64_MIN+1, INT64_MAX, INT32_MIN, INT32_MAX, 1,0,-1, + 123456789, INT32_MAX-1, INT32_MAX+1LL, UINT32_MAX-1, UINT32_MAX, UINT32_MAX+1LL + }; + + for (a.num = -2; a.num <= 2; a.num++) { + for (a.den = -2; a.den <= 2; a.den++) { + for (b.num = -2; b.num <= 2; b.num++) { + for (b.den = -2; b.den <= 2; b.den++) { + int c = av_cmp_q(a,b); + double d = av_q2d(a) == av_q2d(b) ? + 0 : (av_q2d(a) - av_q2d(b)); + if (d > 0) d = 1; + else if (d < 0) d = -1; + else if (d != d) d = INT_MIN; + if (c != d) + av_log(NULL, AV_LOG_ERROR, "%d/%d %d/%d, %d %f\n", a.num, + a.den, b.num, b.den, c,d); + r = av_sub_q(av_add_q(b,a), b); + if(b.den && (r.num*a.den != a.num*r.den || !r.num != !a.num || !r.den != !a.den)) + av_log(NULL, AV_LOG_ERROR, "%d/%d ", r.num, r.den); + } + } + } + } + + for (i = 0; i < FF_ARRAY_ELEMS(numlist); i++) { + int64_t a = numlist[i]; + + for (j = 0; j < FF_ARRAY_ELEMS(numlist); j++) { + int64_t b = numlist[j]; + if (b<=0) + continue; + for (k = 0; k < FF_ARRAY_ELEMS(numlist); k++) { + int64_t c = numlist[k]; + int64_t res; + AVInteger ai; + + if (c<=0) + continue; + res = av_rescale_rnd(a,b,c, AV_ROUND_ZERO); + + ai = av_mul_i(av_int2i(a), av_int2i(b)); + ai = av_div_i(ai, av_int2i(c)); + + if (av_cmp_i(ai, av_int2i(INT64_MAX)) > 0 && res == INT64_MIN) + continue; + if (av_cmp_i(ai, av_int2i(INT64_MIN)) < 0 && res == INT64_MIN) + continue; + if (av_cmp_i(ai, av_int2i(res)) == 0) + continue; + + // Special exception for INT64_MIN, remove this in case INT64_MIN is handled without off by 1 error + if (av_cmp_i(ai, av_int2i(res-1)) == 0 && a == INT64_MIN) + continue; + + av_log(NULL, AV_LOG_ERROR, "%"PRId64" * %"PRId64" / %"PRId64" = %"PRId64" or %"PRId64"\n", a,b,c, res, av_i2int(ai)); + } + } + } + + for (a.num = 1; a.num <= 10; a.num++) { + for (a.den = 1; a.den <= 10; a.den++) { + if (av_gcd(a.num, a.den) > 1) + continue; + for (b.num = 1; b.num <= 10; b.num++) { + for (b.den = 1; b.den <= 10; b.den++) { + int start; + if (av_gcd(b.num, b.den) > 1) + continue; + if (av_cmp_q(b, a) < 0) + continue; + for (start = 0; start < 10 ; start++) { + int acc= start; + int i; + + for (i = 0; i<100; i++) { + int exact = start + av_rescale_q(i+1, b, a); + acc = av_add_stable(a, acc, b, 1); + if (FFABS(acc - exact) > 2) { + av_log(NULL, AV_LOG_ERROR, "%d/%d %d/%d, %d %d\n", a.num, + a.den, b.num, b.den, acc, exact); + return 1; + } + } + } + } + } + } + } + + for (a.den = 1; a.den < 0x100000000U/3; a.den*=3) { + for (a.num = -1; a.num < (1<<27); a.num += 1 + a.num/100) { + float f = av_int2float(av_q2intfloat(a)); + float f2 = av_q2d(a); + if (fabs(f - f2) > fabs(f)/5000000) { + av_log(NULL, AV_LOG_ERROR, "%d/%d %f %f\n", a.num, + a.den, f, f2); + return 1; + } + + } + } + + return 0; +} +#endif |