356 lines
10 KiB
C
356 lines
10 KiB
C
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/*____________________________________________________________________________
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FreeAmp - The Free MP3 Player
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MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology
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Corp. http://www.xingtech.com
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Portions Copyright (C) 1998 EMusic.com
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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$Id: csbt.c,v 1.2 1999/10/19 07:13:08 elrod Exp $
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____________________________________________________________________________*/
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/**** csbt.c ***************************************************
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MPEG audio decoder, dct and window
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portable C
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1/7/96 mod for Layer III
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******************************************************************/
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#include <stdlib.h>
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#include <stdio.h>
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#include <float.h>
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#include <math.h>
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void fdct32(float *, float *);
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void fdct32_dual(float *, float *);
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void fdct32_dual_mono(float *, float *);
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void fdct16(float *, float *);
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void fdct16_dual(float *, float *);
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void fdct16_dual_mono(float *, float *);
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void fdct8(float *, float *);
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void fdct8_dual(float *, float *);
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void fdct8_dual_mono(float *, float *);
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void window(float *vbuf, int vb_ptr, short *pcm);
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void window_dual(float *vbuf, int vb_ptr, short *pcm);
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void window16(float *vbuf, int vb_ptr, short *pcm);
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void window16_dual(float *vbuf, int vb_ptr, short *pcm);
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void window8(float *vbuf, int vb_ptr, short *pcm);
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void window8_dual(float *vbuf, int vb_ptr, short *pcm);
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/*-------------------------------------------------------------------------*/
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/* circular window buffers */
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#include "mp3struct.h"
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////static signed int vb_ptr; // !!!!!!!!!!!!!
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////static signed int vb2_ptr; // !!!!!!!!!!!!!
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////static float pMP3Stream->vbuf[512]; // !!!!!!!!!!!!!
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////static float vbuf2[512]; // !!!!!!!!!!!!!
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float *dct_coef_addr();
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/*======================================================================*/
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static void gencoef() /* gen coef for N=32 (31 coefs) */
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{
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static int iOnceOnly = 0;
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int p, n, i, k;
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double t, pi;
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float *coef32;
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if (!iOnceOnly++)
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{
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coef32 = dct_coef_addr();
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pi = 4.0 * atan(1.0);
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n = 16;
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k = 0;
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for (i = 0; i < 5; i++, n = n / 2)
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{
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for (p = 0; p < n; p++, k++)
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{
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t = (pi / (4 * n)) * (2 * p + 1);
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coef32[k] = (float) (0.50 / cos(t));
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}
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}
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}
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}
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/*------------------------------------------------------------*/
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void sbt_init()
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{
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int i;
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static int first_pass = 1;
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if (first_pass)
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{
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gencoef();
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first_pass = 0;
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}
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/* clear window pMP3Stream->vbuf */
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for (i = 0; i < 512; i++)
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{
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pMP3Stream->vbuf[i] = 0.0F;
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pMP3Stream->vbuf2[i] = 0.0F;
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}
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pMP3Stream->vb2_ptr = pMP3Stream->vb_ptr = 0;
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}
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/*============================================================*/
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/*============================================================*/
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/*============================================================*/
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void sbt_mono(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct32(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
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pcm += 32;
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}
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}
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/*------------------------------------------------------------*/
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void sbt_dual(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct32_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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fdct32_dual(sample + 1, pMP3Stream->vbuf2 + pMP3Stream->vb_ptr);
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window_dual(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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window_dual(pMP3Stream->vbuf2, pMP3Stream->vb_ptr, pcm + 1);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
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pcm += 64;
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}
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}
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/*------------------------------------------------------------*/
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/* convert dual to mono */
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void sbt_dual_mono(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct32_dual_mono(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
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pcm += 32;
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}
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}
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/*------------------------------------------------------------*/
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/* convert dual to left */
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void sbt_dual_left(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct32_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
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pcm += 32;
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}
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}
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/*------------------------------------------------------------*/
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/* convert dual to right */
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void sbt_dual_right(float *sample, short *pcm, int n)
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{
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int i;
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sample++; /* point to right chan */
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for (i = 0; i < n; i++)
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{
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fdct32_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 32) & 511;
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pcm += 32;
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}
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}
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/*------------------------------------------------------------*/
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/*---------------- 16 pt sbt's -------------------------------*/
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/*------------------------------------------------------------*/
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void sbt16_mono(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct16(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
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pcm += 16;
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}
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}
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/*------------------------------------------------------------*/
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void sbt16_dual(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct16_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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fdct16_dual(sample + 1, pMP3Stream->vbuf2 + pMP3Stream->vb_ptr);
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window16_dual(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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window16_dual(pMP3Stream->vbuf2, pMP3Stream->vb_ptr, pcm + 1);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
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pcm += 32;
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}
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}
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/*------------------------------------------------------------*/
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void sbt16_dual_mono(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct16_dual_mono(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
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pcm += 16;
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}
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}
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/*------------------------------------------------------------*/
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void sbt16_dual_left(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct16_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
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pcm += 16;
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}
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}
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/*------------------------------------------------------------*/
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void sbt16_dual_right(float *sample, short *pcm, int n)
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{
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int i;
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sample++;
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for (i = 0; i < n; i++)
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{
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fdct16_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window16(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 16) & 255;
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pcm += 16;
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}
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}
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/*------------------------------------------------------------*/
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/*---------------- 8 pt sbt's -------------------------------*/
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/*------------------------------------------------------------*/
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void sbt8_mono(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct8(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
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pcm += 8;
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}
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}
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/*------------------------------------------------------------*/
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void sbt8_dual(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct8_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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fdct8_dual(sample + 1, pMP3Stream->vbuf2 + pMP3Stream->vb_ptr);
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window8_dual(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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window8_dual(pMP3Stream->vbuf2, pMP3Stream->vb_ptr, pcm + 1);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
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pcm += 16;
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}
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}
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/*------------------------------------------------------------*/
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void sbt8_dual_mono(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct8_dual_mono(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
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pcm += 8;
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}
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}
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/*------------------------------------------------------------*/
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void sbt8_dual_left(float *sample, short *pcm, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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{
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fdct8_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
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pcm += 8;
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}
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}
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/*------------------------------------------------------------*/
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void sbt8_dual_right(float *sample, short *pcm, int n)
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{
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int i;
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sample++;
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for (i = 0; i < n; i++)
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{
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fdct8_dual(sample, pMP3Stream->vbuf + pMP3Stream->vb_ptr);
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window8(pMP3Stream->vbuf, pMP3Stream->vb_ptr, pcm);
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sample += 64;
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pMP3Stream->vb_ptr = (pMP3Stream->vb_ptr - 8) & 127;
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pcm += 8;
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}
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}
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/*------------------------------------------------------------*/
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/*------------------------------------------------------------*/
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#define COMPILE_ME
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#include "csbtb.c" /* 8 bit output */
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#include "csbtL3.c" /* Layer III */
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/*------------------------------------------------------------*/
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