Suga koubou / Mbed 2 deprecated madplayer_lpc4088

MP3 Player. You can change fwd/rev speed and skip. see: http://mbed.org/users/okini3939/notebook/lpc4088_madplayer/

Dependencies:   I2SSlave SDFileSystem TLV320 mbed

madplayer/fixed.cpp@0:8ba6230eefbd, 2014-02-18 (annotated)

Committer:
okini3939
Date:
Tue Feb 18 00:22:50 2014 +0000
Revision:
0:8ba6230eefbd
1st build

Who changed what in which revision?

UserRevisionLine numberNew contents of line
okini3939 0:8ba6230eefbd 1 /*
okini3939 0:8ba6230eefbd 2 * libmad - MPEG audio decoder library
okini3939 0:8ba6230eefbd 3 * Copyright (C) 2000-2004 Underbit Technologies, Inc.
okini3939 0:8ba6230eefbd 4 *
okini3939 0:8ba6230eefbd 5 * This program is free software; you can redistribute it and/or modify
okini3939 0:8ba6230eefbd 6 * it under the terms of the GNU General Public License as published by
okini3939 0:8ba6230eefbd 7 * the Free Software Foundation; either version 2 of the License, or
okini3939 0:8ba6230eefbd 8 * (at your option) any later version.
okini3939 0:8ba6230eefbd 9 *
okini3939 0:8ba6230eefbd 10 * This program is distributed in the hope that it will be useful,
okini3939 0:8ba6230eefbd 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
okini3939 0:8ba6230eefbd 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
okini3939 0:8ba6230eefbd 13 * GNU General Public License for more details.
okini3939 0:8ba6230eefbd 14 *
okini3939 0:8ba6230eefbd 15 * You should have received a copy of the GNU General Public License
okini3939 0:8ba6230eefbd 16 * along with this program; if not, write to the Free Software
okini3939 0:8ba6230eefbd 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
okini3939 0:8ba6230eefbd 18 *
okini3939 0:8ba6230eefbd 19 * $Id: fixed.c,v 1.1 2010/11/23 20:12:57 andy Exp $
okini3939 0:8ba6230eefbd 20 */
okini3939 0:8ba6230eefbd 21
okini3939 0:8ba6230eefbd 22 # include "config.h"
okini3939 0:8ba6230eefbd 23
okini3939 0:8ba6230eefbd 24 # include "global.h"
okini3939 0:8ba6230eefbd 25
okini3939 0:8ba6230eefbd 26 # include "fixed.h"
okini3939 0:8ba6230eefbd 27
okini3939 0:8ba6230eefbd 28 /*
okini3939 0:8ba6230eefbd 29 * NAME: fixed->abs()
okini3939 0:8ba6230eefbd 30 * DESCRIPTION: return absolute value of a fixed-point number
okini3939 0:8ba6230eefbd 31 */
okini3939 0:8ba6230eefbd 32 mad_fixed_t mad_f_abs(mad_fixed_t x)
okini3939 0:8ba6230eefbd 33 {
okini3939 0:8ba6230eefbd 34 return x < 0 ? -x : x;
okini3939 0:8ba6230eefbd 35 }
okini3939 0:8ba6230eefbd 36
okini3939 0:8ba6230eefbd 37 /*
okini3939 0:8ba6230eefbd 38 * NAME: fixed->div()
okini3939 0:8ba6230eefbd 39 * DESCRIPTION: perform division using fixed-point math
okini3939 0:8ba6230eefbd 40 */
okini3939 0:8ba6230eefbd 41 mad_fixed_t mad_f_div(mad_fixed_t x, mad_fixed_t y)
okini3939 0:8ba6230eefbd 42 {
okini3939 0:8ba6230eefbd 43 mad_fixed_t q, r;
okini3939 0:8ba6230eefbd 44 unsigned int bits;
okini3939 0:8ba6230eefbd 45
okini3939 0:8ba6230eefbd 46 q = mad_f_abs(x / y);
okini3939 0:8ba6230eefbd 47
okini3939 0:8ba6230eefbd 48 if (x < 0) {
okini3939 0:8ba6230eefbd 49 x = -x;
okini3939 0:8ba6230eefbd 50 y = -y;
okini3939 0:8ba6230eefbd 51 }
okini3939 0:8ba6230eefbd 52
okini3939 0:8ba6230eefbd 53 r = x % y;
okini3939 0:8ba6230eefbd 54
okini3939 0:8ba6230eefbd 55 if (y < 0) {
okini3939 0:8ba6230eefbd 56 x = -x;
okini3939 0:8ba6230eefbd 57 y = -y;
okini3939 0:8ba6230eefbd 58 }
okini3939 0:8ba6230eefbd 59
okini3939 0:8ba6230eefbd 60 if (q > mad_f_intpart(MAD_F_MAX) &&
okini3939 0:8ba6230eefbd 61 !(q == -mad_f_intpart(MAD_F_MIN) && r == 0 && (x < 0) != (y < 0)))
okini3939 0:8ba6230eefbd 62 return 0;
okini3939 0:8ba6230eefbd 63
okini3939 0:8ba6230eefbd 64 for (bits = MAD_F_FRACBITS; bits && r; --bits) {
okini3939 0:8ba6230eefbd 65 q <<= 1, r <<= 1;
okini3939 0:8ba6230eefbd 66 if (r >= y)
okini3939 0:8ba6230eefbd 67 r -= y, ++q;
okini3939 0:8ba6230eefbd 68 }
okini3939 0:8ba6230eefbd 69
okini3939 0:8ba6230eefbd 70 /* round */
okini3939 0:8ba6230eefbd 71 if (2 * r >= y)
okini3939 0:8ba6230eefbd 72 ++q;
okini3939 0:8ba6230eefbd 73
okini3939 0:8ba6230eefbd 74 /* fix sign */
okini3939 0:8ba6230eefbd 75 if ((x < 0) != (y < 0))
okini3939 0:8ba6230eefbd 76 q = -q;
okini3939 0:8ba6230eefbd 77
okini3939 0:8ba6230eefbd 78 return q << bits;
okini3939 0:8ba6230eefbd 79 }