(*
* 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
* revision 16844, Wed Jan 28 08:50:10 2009 UTC
*
* update, MiSchi, no code change
* Fri Jun 12 2009 21:50:00 UTC
*)
{
* update to
* avutil max. version 50.7.0, Mon, Jan 4 2010 24:00:00 UTC
* MiSchi
}
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 *)
{$ENDIF}
interface
uses
ctypes,
rational,
UConfig;
const
M_E = 2.7182818284590452354; // e
M_LN2 = 0.69314718055994530942; // log_e 2
M_LN10 = 2.30258509299404568402; // log_e 10
M_PI = 3.14159265358979323846; // pi
M_SQRT1_2 = 0.70710678118654752440; // 1/sqrt(2)
{$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}
implementation
end.
