(*
* 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 15120, Sun Aug 31 07:39:47 2008 UTC
*)
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)
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
);
(**
* rescale a 64bit 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}
(**
* rescale a 64bit 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}
(**
* rescale a 64bit integer by 2 rational numbers.
*)
function av_rescale_q (a: cint64; bq, cq: TAVRational): cint64;
cdecl; external av__util; {av_const}
implementation
end.
