(* * Rational numbers * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> * * This library 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 of the License, or (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA *) unit rational; interface {$IFDEF win32} uses windows; {$endif} const {$IFDEF win32} av__util = 'avutil-49.dll'; {$ELSE} av__util = 'libavutil.so'; // .0d {$ENDIF} type (* * Rational number num/den. *) PAVRational = ^TAVRational; TAVRational = record num: integer; ///< numerator den: integer; ///< denominator end; (** * returns 0 if a==b, 1 if a>b and -1 if a<b. *) function av_cmp_q(a: TAVRational; b: TAVRational): integer; (** * converts the given AVRational to a double. *) function av_q2d(a: TAVRational): double; (** * reduce a fraction. * this is usefull for framerate calculations * @param max the maximum allowed for dst_nom & dst_den * @return 1 if exact, 0 otherwise *) function av_reduce(dst_nom: pinteger; dst_den: PInteger; nom: int64; den: int64; max: int64): integer; cdecl; external av__util; function av_mul_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; function av_div_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; function av_add_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; function av_sub_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; function av_d2q(d: double; max: integer): TAVRational; cdecl; external av__util; implementation function av_cmp_q (a: TAVRational; b: TAVRational): integer; var tmp: int64; begin tmp := a.num * b.den - b.num * a.den; if tmp = 0 then Result := (tmp shr 63) or 1 else Result := 0; end; function av_q2d(a: TAVRational): double; begin Result := a.num / a.den; end; end.