Sweden-Number/dlls/quartz/amundoc.c

74 lines
1.8 KiB
C

/*
* Copyright (C) Hidenori TAKESHIMA
*
* 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 2.1 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include <math.h>
#include "windef.h"
#include "wine/debug.h"
WINE_DEFAULT_DEBUG_CHANNEL(quartz);
/***********************************************************************
* AmpFactorToDB (QUARTZ.@)
*
* undocumented.
* converting from Amp to dB?
*
*/
LONG WINAPI QUARTZ_AmpFactorToDB( LONG amp )
{
LONG dB;
FIXME( "(%08ld): undocumented API.\n", amp );
if ( amp <= 0 || amp > 65536 )
return 0;
dB = (LONG)(2000.0 * log10((double)amp / 65536.0) + 0.5);
if ( dB >= 0 ) dB = 0;
if ( dB < -10000 ) dB = -10000;
return dB;
}
/***********************************************************************
* DBToAmpFactor (QUARTZ.@)
*
* undocumented.
* converting from dB to Amp?
*/
LONG WINAPI QUARTZ_DBToAmpFactor( LONG dB )
{
LONG amp;
FIXME( "(%08ld): undocumented API.\n", dB );
if ( dB >= 0 )
return 65535;
if ( dB < -10000 )
return 0;
amp = (LONG)(pow(10.0,dB / 2000.0) * 65536.0 + 0.5);
if ( amp <= 0 ) amp = 1;
if ( amp >= 65536 ) amp = 65535;
return amp;
}