source: golgotha/src/i4/loaders/mp3/decode_i386.cc @ 80

Last change on this file since 80 was 80, checked in by Sam Hocevar, 11 years ago
  • Adding the Golgotha source code. Not sure what's going to be interesting in there, but since it's all public domain, there's certainly stuff to pick up.
File size: 5.3 KB
Line 
1/********************************************************************** <BR>
2  This file is part of Crack dot Com's free source code release of
3  Golgotha. <a href="http://www.crack.com/golgotha_release"> <BR> for
4  information about compiling & licensing issues visit this URL</a>
5  <PRE> If that doesn't help, contact Jonathan Clark at
6  golgotha_source@usa.net (Subject should have "GOLG" in it)
7***********************************************************************/
8
9/*
10 * Mpeg Layer-1,2,3 audio decoder
11 * ------------------------------
12 * copyright (c) 1995,1996,1997 by Michael Hipp, All rights reserved.
13 * See also 'README'
14 *
15 * slighlty optimized for machines without autoincrement/decrement.
16 * The performance is highly compiler dependend. Maybe
17 * the decode.c version for 'normal' processor may be faster
18 * even for Intel processors.
19 */
20
21#include <stdlib.h>
22#include <math.h>
23#include <string.h>
24
25#include "mpg123.h"
26
27#define WRITE_SAMPLE(samples,sum,clip) \
28  if( (sum) > 32767.0) { *(samples) = 0x7fff; (clip)++; } \
29  else if( (sum) < -32768.0) { *(samples) = -0x8000; (clip)++; } \
30  else { *(samples) = sum; }
31
32static int bo = 1;
33
34void init_decode_i386(void)
35{
36        bo = 1;
37}
38
39int synth_1to1_8bit(real *bandPtr,int channel,unsigned char *samples)
40{
41  short samples_tmp[64];
42  short *tmp1 = samples_tmp + channel;
43  int i,ret;
44
45  samples += channel;
46  ret = synth_1to1(bandPtr,channel,(unsigned char *)samples_tmp);
47
48  for(i=0;i<32;i++) {
49    *samples = conv16to8[*tmp1>>4];
50    samples += 2;
51    tmp1 += 2;
52  }
53
54  return ret;
55}
56
57int synth_1to1_8bit_mono(real *bandPtr,unsigned char *samples)
58{
59  short samples_tmp[64];
60  short *tmp1 = samples_tmp;
61  int i,ret;
62
63  ret = synth_1to1(bandPtr,0,(unsigned char *)samples_tmp);
64
65  for(i=0;i<32;i++) {
66    *samples++ = conv16to8[*tmp1>>4];
67    tmp1+=2;
68  }
69
70  return ret;
71}
72
73int synth_1to1_8bit_mono2stereo(real *bandPtr,unsigned char *samples)
74{
75  short samples_tmp[64];
76  short *tmp1 = samples_tmp;
77  int i,ret;
78
79  ret = synth_1to1(bandPtr,0,(unsigned char *)samples_tmp);
80
81  for(i=0;i<32;i++) {
82    *samples++ = conv16to8[*tmp1>>4];
83    *samples++ = conv16to8[*tmp1>>4];
84    tmp1 += 2;
85  }
86
87  return ret;
88}
89
90int synth_1to1_mono(real *bandPtr,unsigned char *samples)
91{
92  short samples_tmp[64];
93  short *tmp1 = samples_tmp;
94
95  int i,ret;
96
97  ret = synth_1to1(bandPtr,0,(unsigned char *) samples_tmp);
98
99  for(i=0;i<32;i++) {
100        *( (short *) samples)++ = *tmp1;
101        tmp1 += 2;
102  }
103  return ret;
104}
105
106
107int synth_1to1_mono2stereo(real *bandPtr,unsigned char *samples)
108{
109  int i,ret = synth_1to1(bandPtr,0,samples);
110  for(i=0;i<32;i++) {
111    ((short *)samples)[1] = ((short *)samples)[0];
112    samples+=4;
113  }
114  return ret;
115}
116
117#ifndef PENTIUM_OPT
118int synth_1to1(real *bandPtr,int channel,unsigned char *out)
119{
120  static real buffs[2][2][0x110];
121  static const int step = 2;
122  short *samples = (short *) out;
123
124  real *b0,(*buf)[0x110];
125  int clip = 0;
126  int bo1;
127
128  if(flags.equalizer)
129        do_equalizer(bandPtr,channel);
130
131  if(!channel) {
132    bo--;
133    bo &= 0xf;
134    buf = buffs[0];
135  }
136  else {
137    samples++;
138    buf = buffs[1];
139  }
140
141  if(bo & 0x1) {
142    b0 = buf[0];
143    bo1 = bo;
144    dct64(buf[1]+((bo+1)&0xf),buf[0]+bo,bandPtr);
145  }
146  else {
147    b0 = buf[1];
148    bo1 = bo+1;
149    dct64(buf[0]+bo,buf[1]+bo+1,bandPtr);
150  }
151 
152  {
153    register int j;
154    real *window = decwin + 16 - bo1;
155
156    for (j=16;j;j--,b0+=0x10,window+=0x20,samples+=step)
157    {
158      real sum;
159      sum  = window[0x0] * b0[0x0];
160      sum -= window[0x1] * b0[0x1];
161      sum += window[0x2] * b0[0x2];
162      sum -= window[0x3] * b0[0x3];
163      sum += window[0x4] * b0[0x4];
164      sum -= window[0x5] * b0[0x5];
165      sum += window[0x6] * b0[0x6];
166      sum -= window[0x7] * b0[0x7];
167      sum += window[0x8] * b0[0x8];
168      sum -= window[0x9] * b0[0x9];
169      sum += window[0xA] * b0[0xA];
170      sum -= window[0xB] * b0[0xB];
171      sum += window[0xC] * b0[0xC];
172      sum -= window[0xD] * b0[0xD];
173      sum += window[0xE] * b0[0xE];
174      sum -= window[0xF] * b0[0xF];
175
176      WRITE_SAMPLE(samples,sum,clip);
177    }
178
179    {
180      real sum;
181      sum  = window[0x0] * b0[0x0];
182      sum += window[0x2] * b0[0x2];
183      sum += window[0x4] * b0[0x4];
184      sum += window[0x6] * b0[0x6];
185      sum += window[0x8] * b0[0x8];
186      sum += window[0xA] * b0[0xA];
187      sum += window[0xC] * b0[0xC];
188      sum += window[0xE] * b0[0xE];
189      WRITE_SAMPLE(samples,sum,clip);
190      b0-=0x10,window-=0x20,samples+=step;
191    }
192    window += bo1<<1;
193
194    for (j=15;j;j--,b0-=0x10,window-=0x20,samples+=step)
195    {
196      real sum;
197      sum = -window[-0x1] * b0[0x0];
198      sum -= window[-0x2] * b0[0x1];
199      sum -= window[-0x3] * b0[0x2];
200      sum -= window[-0x4] * b0[0x3];
201      sum -= window[-0x5] * b0[0x4];
202      sum -= window[-0x6] * b0[0x5];
203      sum -= window[-0x7] * b0[0x6];
204      sum -= window[-0x8] * b0[0x7];
205      sum -= window[-0x9] * b0[0x8];
206      sum -= window[-0xA] * b0[0x9];
207      sum -= window[-0xB] * b0[0xA];
208      sum -= window[-0xC] * b0[0xB];
209      sum -= window[-0xD] * b0[0xC];
210      sum -= window[-0xE] * b0[0xD];
211      sum -= window[-0xF] * b0[0xE];
212      sum -= window[-0x0] * b0[0xF];
213
214      WRITE_SAMPLE(samples,sum,clip);
215    }
216  }
217  return clip;
218}
219#endif
220
221
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