(*
* copyright (c) 2005 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/mathematics.h
* avutil max. version 50.19.0, revision 23593, Mon Jul 21 01:00:00 2010 CET
*
*)
unit mathematics;
{$IFDEF FPC}
{$MODE DELPHI }
{$PACKENUM 4} (* use 4-byte enums *)
{$PACKRECORDS C} (* C/C++-compatible record packing *)
{$ELSE}
{$MINENUMSIZE 4} (* use 4-byte enums *)
{$ENDIF}
interface
uses
ctypes,
rational,
UConfig;
const
M_E = 2.7182818284590452354; // e
M_LN2 = 0.69314718055994530942; // log_e 2
M_LN10 = 2.30258509299404568402; // log_e 10
{$IF LIBAVUTIL_VERSION >= 50009000} // >= 50.9.0
M_LOG2_10 = 3.32192809488736234787; // log_2 10
{$IFEND}
M_PI = 3.14159265358979323846; // pi
M_SQRT1_2 = 0.70710678118654752440; // 1/sqrt(2)
{$IF LIBAVUTIL_VERSION >= 50014000} // >= 50.14.0
M_SQRT2 = 1.41421356237309504880; // sqrt(2)
{$IFEND}
{$IF LIBAVUTIL_VERSION >= 50005001} // >= 50.5.1
NAN = 0.0/0.0;
INFINITY = 1.0/0.0;
{$IFEND}
type
TAVRounding = (
AV_ROUND_ZERO = 0, ///< Round toward zero.
AV_ROUND_INF = 1, ///< Round away from zero.
AV_ROUND_DOWN = 2, ///< Round toward -infinity.
AV_ROUND_UP = 3, ///< Round toward +infinity.
AV_ROUND_NEAR_INF = 5 ///< Round to nearest and halfway cases away from zero.
);
{$IF LIBAVUTIL_VERSION >= 49013000} // 49.13.0
(**
* Returns the greatest common divisor of a and b.
* If both a or b are 0 or either or both are <0 then behavior is
* undefined.
*)
function av_gcd(a: cint64; b: cint64): cint64;
cdecl; external av__util; {av_const}
{$IFEND}
(**
* Rescales a 64-bit integer with rounding to nearest.
* A simple a*b/c isn't possible as it can overflow.
*)
function av_rescale (a, b, c: cint64): cint64;
cdecl; external av__util; {av_const}
(**
* Rescales a 64-bit integer with specified rounding.
* A simple a*b/c isn't possible as it can overflow.
*)
function av_rescale_rnd (a, b, c: cint64; enum: TAVRounding): cint64;
cdecl; external av__util; {av_const}
(**
* Rescales a 64-bit integer by 2 rational numbers.
*)
function av_rescale_q (a: cint64; bq, cq: TAVRational): cint64;
cdecl; external av__util; {av_const}
{$IF LIBAVUTIL_VERSION >= 50008000} // 50.8.0
(**
* Compares 2 timestamps each in its own timebases.
* The result of the function is undefined if one of the timestamps
* is outside the int64_t range when represented in the others timebase.
* @return -1 if ts_a is before ts_b, 1 if ts_a is after ts_b or 0 if they represent the same position
*)
function av_compare_ts(ts_a: cint64; tb_a: TAVRational; ts_b: cint64; tb_b: TAVRational): cint;
cdecl; external av__util;
{$IFEND}
{$IF LIBAVUTIL_VERSION >= 50018000} // 50.18.0
(**
* Compares 2 integers modulo mod.
* That is we compare integers a and b for which only the least
* significant log2(mod) bits are known.
*
* @param mod must be a power of 2
* @return a negative value if a is smaller than b
* a positiv value if a is greater than b
* 0 if a equals b
*)
function av_compare_mod(a: cuint64; b: cuint64; modVar: cuint64): cint64;
cdecl; external av__util;
{$IFEND}
implementation
end.
