(* * 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 *) (* This is a part of Pascal porting of ffmpeg. * Originally by Victor Zinetz for Delphi and Free Pascal on Windows. * For Mac OS X, some modifications were made by The Creative CAT, denoted as CAT * in the source codes *) (* * revision 12498, Wed Mar 19 06:17:43 2008 UTC *) unit rational; {$IFDEF FPC} {$MODE DELPHI} {$PACKENUM 4} (* use 4-byte enums *) {$PACKRECORDS C} (* C/C++-compatible record packing *) {$ELSE} {$MINENUMSIZE 4} (* use 4-byte enums *) {$ENDIF} {$I switches.inc} interface uses UConfig; type (* * Rational number num/den. *) PAVRational = ^TAVRational; TAVRational = record num: integer; ///< numerator den: integer; ///< denominator end; (** * Compare two rationals. * @param a first rational * @param b second rational * @return 0 if a==b, 1 if a>b and -1 if a<b. *) function av_cmp_q(a: TAVRational; b: TAVRational): integer; {$IFDEF HasInline}inline;{$ENDIF} (** * Rational to double conversion. * @param a rational to convert * @return (double) a *) function av_q2d(a: TAVRational): double; {$IFDEF HasInline}inline;{$ENDIF} (** * Reduce a fraction. * This is useful for framerate calculations. * @param dst_nom destination numerator * @param dst_den destination denominator * @param nom source numerator * @param den source denominator * @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; (** * Multiplies two rationals. * @param b first rational. * @param c second rational. * @return b*c. *) function av_mul_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; {av_const} (** * Divides one rational by another. * @param b first rational. * @param c second rational. * @return b/c. *) function av_div_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; {av_const} (** * Adds two rationals. * @param b first rational. * @param c second rational. * @return b+c. *) function av_add_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; {av_const} (** * Subtracts one rational from another. * @param b first rational. * @param c second rational. * @return b-c. *) function av_sub_q(b: TAVRational; c: TAVRational): TAVRational; cdecl; external av__util; {av_const} (** * Converts a double precision floating point number to a rational. * @param d double to convert * @param max the maximum allowed numerator and denominator * @return (AVRational) d. *) function av_d2q(d: double; max: integer): TAVRational; cdecl; external av__util; {av_const} implementation function av_cmp_q (a: TAVRational; b: TAVRational): integer; var tmp: int64; begin tmp := a.num * int64(b.den) - b.num * int64(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.