(* * 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. * - Changes and updates by the UltraStar Deluxe Team * * Conversion of libavutil/rational.h * avutil version 51.9.1 * *) 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 ctypes, UConfig; type (* * rational number numerator/denominator *) PAVRational = ^TAVRational; TAVRational = record num: cint; ///< numerator den: cint; ///< denominator end; TAVRationalArray = array[0 .. (MaxInt div SizeOf(TAVRational))-1] of TAVRational; PAVRationalArray = ^TAVRationalArray; (** * 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): cint; {$IFDEF HasInline}inline;{$ENDIF} (** * Convert rational to double. * @param a rational to convert * @return (double) a *) function av_q2d(a: TAVRational): cdouble; {$IFDEF HasInline}inline;{$ENDIF} (** * Reduce a fraction. * This is useful for framerate calculations. * @param dst_num destination numerator * @param dst_den destination denominator * @param num source numerator * @param den source denominator * @param max the maximum allowed for dst_num & dst_den * @return 1 if exact, 0 otherwise *) function av_reduce(dst_num: PCint; dst_den: PCint; num: cint64; den: cint64; max: cint64): cint; cdecl; external av__util; (** * Multiply 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} (** * Divide 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} (** * Add 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} (** * Subtract 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} (** * Convert a double precision floating point number to a rational. * inf is expressed as {1,0} or {-1,0} depending on the sign. * * @param d double to convert * @param max the maximum allowed numerator and denominator * @return (AVRational) d *) function av_d2q(d: cdouble; max: cint): TAVRational; cdecl; external av__util; {av_const} (** * @return 1 if q1 is nearer to q than q2, -1 if q2 is nearer * than q1, 0 if they have the same distance. *) function av_nearer_q(q, q1, q2: TAVRational): cint; cdecl; external av__util; (** * Find the nearest value in q_list to q. * @param q_list an array of rationals terminated by {0, 0} * @return the index of the nearest value found in the array *) function av_find_nearest_q_idx(q: TAVRational; q_list: {const} PAVRationalArray): cint; cdecl; external av__util; implementation // This corresponds to the old c version and should be updated to // the new c version. function av_cmp_q (a: TAVRational; b: TAVRational): cint; {$IFDEF HasInline}inline;{$ENDIF} var tmp: cint64; begin tmp := a.num * cint64(b.den) - b.num * cint64(a.den); { old version if (tmp <> 0) then Result := (tmp shr 63) or 1 else Result := 0; } { C original: if(tmp) return ((tmp ^ a.den ^ b.den)>>63)|1; else if(b.den && a.den) return 0; else if(a.num && b.num) return (a.num>>31) - (b.num>>31); else return INT_MIN; } if tmp <> 0 then Result := ((tmp xor a.den xor b.den) >> 63) or 1 else if (b.den and a.den) <> 0 then Result := 0 else if (a.num and b.num) <> 0 then Result := (a.num >> 31) - (b.num >> 31) else Result := low(cint); end; function av_q2d(a: TAVRational): cdouble; {$IFDEF HasInline}inline;{$ENDIF} begin Result := a.num / a.den; end; end.