streo mp3 player see: http://mbed.org/users/okini3939/notebook/I2S_AUDIO
Dependencies: FatFileSystemCpp I2SSlave TLV320 mbed
Fork of madplayer by
Diff: fixed.cpp
- Revision:
- 0:7627c79db971
diff -r 000000000000 -r 7627c79db971 fixed.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/fixed.cpp Fri Nov 26 12:18:30 2010 +0000 @@ -0,0 +1,79 @@ +/* + * libmad - MPEG audio decoder library + * Copyright (C) 2000-2004 Underbit Technologies, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * $Id: fixed.c,v 1.1 2010/11/23 20:12:57 andy Exp $ + */ + +# include "config.h" + +# include "global.h" + +# include "fixed.h" + +/* + * NAME: fixed->abs() + * DESCRIPTION: return absolute value of a fixed-point number + */ +mad_fixed_t mad_f_abs(mad_fixed_t x) +{ + return x < 0 ? -x : x; +} + +/* + * NAME: fixed->div() + * DESCRIPTION: perform division using fixed-point math + */ +mad_fixed_t mad_f_div(mad_fixed_t x, mad_fixed_t y) +{ + mad_fixed_t q, r; + unsigned int bits; + + q = mad_f_abs(x / y); + + if (x < 0) { + x = -x; + y = -y; + } + + r = x % y; + + if (y < 0) { + x = -x; + y = -y; + } + + if (q > mad_f_intpart(MAD_F_MAX) && + !(q == -mad_f_intpart(MAD_F_MIN) && r == 0 && (x < 0) != (y < 0))) + return 0; + + for (bits = MAD_F_FRACBITS; bits && r; --bits) { + q <<= 1, r <<= 1; + if (r >= y) + r -= y, ++q; + } + + /* round */ + if (2 * r >= y) + ++q; + + /* fix sign */ + if ((x < 0) != (y < 0)) + q = -q; + + return q << bits; +}