diff options
Diffstat (limited to 'libavutil/mathematics.c')
| -rw-r--r-- | libavutil/mathematics.c | 48 |
1 files changed, 42 insertions, 6 deletions
diff --git a/libavutil/mathematics.c b/libavutil/mathematics.c index 1a38f64823..2e0cf0cbd4 100644 --- a/libavutil/mathematics.c +++ b/libavutil/mathematics.c @@ -1,20 +1,20 @@ /* - * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> + * Copyright (c) 2005-2012 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 */ @@ -27,6 +27,8 @@ #include <limits.h> #include "mathematics.h" +#include "libavutil/common.h" +#include "avassert.h" #include "version.h" #if FF_API_AV_REVERSE @@ -57,10 +59,19 @@ int64_t av_gcd(int64_t a, int64_t b){ int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){ int64_t r=0; + av_assert2(c > 0); + av_assert2(b >=0); + av_assert2((unsigned)(rnd&~AV_ROUND_PASS_MINMAX)<=5 && (rnd&~AV_ROUND_PASS_MINMAX)!=4); - if (c <= 0 || b < 0 || rnd == 4 || rnd > 5) + if (c <= 0 || b < 0 || !((unsigned)(rnd&~AV_ROUND_PASS_MINMAX)<=5 && (rnd&~AV_ROUND_PASS_MINMAX)!=4)) return INT64_MIN; + if (rnd & AV_ROUND_PASS_MINMAX) { + if (a == INT64_MIN || a == INT64_MAX) + return a; + rnd -= AV_ROUND_PASS_MINMAX; + } + if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1)); if(rnd==AV_ROUND_NEAR_INF) r= c/2; @@ -127,6 +138,8 @@ int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b){ int64_t a= tb_a.num * (int64_t)tb_b.den; int64_t b= tb_b.num * (int64_t)tb_a.den; + if((FFABS(ts_a)|a|FFABS(ts_b)|b)<=INT_MAX) + return (ts_a*a > ts_b*b) - (ts_a*a < ts_b*b); if (av_rescale_rnd(ts_a, a, b, AV_ROUND_DOWN) < ts_b) return -1; if (av_rescale_rnd(ts_b, b, a, AV_ROUND_DOWN) < ts_a) return 1; return 0; @@ -138,3 +151,26 @@ int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod){ c-= mod; return c; } + +int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb){ + int64_t a, b, this; + + av_assert0(in_ts != AV_NOPTS_VALUE); + av_assert0(duration >= 0); + + if (*last == AV_NOPTS_VALUE || !duration || in_tb.num*(int64_t)out_tb.den <= out_tb.num*(int64_t)in_tb.den) { +simple_round: + *last = av_rescale_q(in_ts, in_tb, fs_tb) + duration; + return av_rescale_q(in_ts, in_tb, out_tb); + } + + a = av_rescale_q_rnd(2*in_ts-1, in_tb, fs_tb, AV_ROUND_DOWN) >>1; + b = (av_rescale_q_rnd(2*in_ts+1, in_tb, fs_tb, AV_ROUND_UP )+1)>>1; + if (*last < 2*a - b || *last > 2*b - a) + goto simple_round; + + this = av_clip64(*last, a, b); + *last = this + duration; + + return av_rescale_q(this, fs_tb, out_tb); +} |