1 /*
2 synth.h: generic synth functions
3
4 copyright 1995-2008 by the mpg123 project - free software under the terms of the LGPL 2.1
5 see COPYING and AUTHORS files in distribution or http://mpg123.org
6 initially written by Michael Hipp, generalized by Thomas Orgis
7
8 This header is used multiple times to create different variants of these functions.
9 See decode.c and friends.
10 Hint: BLOCK, MONO_NAME, MONO2STEREO_NAME, SYNTH_NAME and SAMPLE_T as well as WRITE_SAMPLE do vary.
11
12 Thomas looked closely at the decode_1to1, decode_2to1 and decode_4to1 contents, seeing that they are too similar to be separate files.
13 This is what resulted...
14
15 Basically, you need one set of these functions for each output sample type.
16 That currently means signed short, 8bit or float/double; though unsigned short may come, too.
17
18 Define NO_AUTOINCREMENT i386 code that shall not rely on autoincrement.
19 Actual benefit of this has to be examined; may apply to specific (old) compilers, only.
20 */
21
22
23 /* Main synth function, uses the plain dct64 or dct64_i386. */
SYNTH_NAME(real * bandPtr,int channel,mpg123_handle * fr,int final)24 int SYNTH_NAME(real *bandPtr, int channel, mpg123_handle *fr, int final)
25 {
26 #ifndef NO_AUTOINCREMENT
27 #define BACKPEDAL 0x10 /* We use autoincrement and thus need this re-adjustment for window/b0. */
28 #define MY_DCT64 dct64
29 #else
30 #define BACKPEDAL 0x00 /* i386 code does not need that. */
31 #define MY_DCT64 dct64_i386
32 #endif
33 static const int step = 2;
34 SAMPLE_T *samples = (SAMPLE_T *) (fr->buffer.data + fr->buffer.fill);
35
36 real *b0, **buf; /* (*buf)[0x110]; */
37 int clip = 0;
38 int bo1;
39 #ifndef NO_EQUALIZER
40 if(fr->have_eq_settings) do_equalizer(bandPtr,channel,fr->equalizer);
41 #endif
42 if(!channel)
43 {
44 fr->bo--;
45 fr->bo &= 0xf;
46 buf = fr->real_buffs[0];
47 }
48 else
49 {
50 #ifdef USE_DITHER
51 /* We always go forward 32 dither points (and back again for the second channel),
52 (re)sampling the noise the same way as the original signal. */
53 fr->ditherindex -= 32;
54 #endif
55 samples++;
56 buf = fr->real_buffs[1];
57 }
58 #ifdef USE_DITHER
59 /* We check only once for the overflow of dither index here ...
60 this wraps differently than the original i586 dither code, in theory (but when DITHERSIZE % BLOCK/2 == 0 it's the same). */
61 if(DITHERSIZE-fr->ditherindex < 32) fr->ditherindex = 0;
62 /* And we define a macro for the dither action... */
63 #define ADD_DITHER(fr,sum) sum+=fr->dithernoise[fr->ditherindex]; fr->ditherindex += 64/BLOCK;
64 #else
65 #define ADD_DITHER(fr,sum)
66 #endif
67
68 if(fr->bo & 0x1)
69 {
70 b0 = buf[0];
71 bo1 = fr->bo;
72 MY_DCT64(buf[1]+((fr->bo+1)&0xf),buf[0]+fr->bo,bandPtr);
73 }
74 else
75 {
76 b0 = buf[1];
77 bo1 = fr->bo+1;
78 MY_DCT64(buf[0]+fr->bo,buf[1]+fr->bo+1,bandPtr);
79 }
80
81 {
82 register int j;
83 real *window = fr->decwin + 16 - bo1;
84
85 for(j=(BLOCK/4); j; j--, b0+=0x400/BLOCK-BACKPEDAL, window+=0x800/BLOCK-BACKPEDAL, samples+=step)
86 {
87 real sum;
88 #ifndef NO_AUTOINCREMENT
89 sum = REAL_MUL_SYNTH(*window++, *b0++);
90 sum -= REAL_MUL_SYNTH(*window++, *b0++);
91 sum += REAL_MUL_SYNTH(*window++, *b0++);
92 sum -= REAL_MUL_SYNTH(*window++, *b0++);
93 sum += REAL_MUL_SYNTH(*window++, *b0++);
94 sum -= REAL_MUL_SYNTH(*window++, *b0++);
95 sum += REAL_MUL_SYNTH(*window++, *b0++);
96 sum -= REAL_MUL_SYNTH(*window++, *b0++);
97 sum += REAL_MUL_SYNTH(*window++, *b0++);
98 sum -= REAL_MUL_SYNTH(*window++, *b0++);
99 sum += REAL_MUL_SYNTH(*window++, *b0++);
100 sum -= REAL_MUL_SYNTH(*window++, *b0++);
101 sum += REAL_MUL_SYNTH(*window++, *b0++);
102 sum -= REAL_MUL_SYNTH(*window++, *b0++);
103 sum += REAL_MUL_SYNTH(*window++, *b0++);
104 sum -= REAL_MUL_SYNTH(*window++, *b0++);
105 #else
106 sum = REAL_MUL_SYNTH(window[0x0], b0[0x0]);
107 sum -= REAL_MUL_SYNTH(window[0x1], b0[0x1]);
108 sum += REAL_MUL_SYNTH(window[0x2], b0[0x2]);
109 sum -= REAL_MUL_SYNTH(window[0x3], b0[0x3]);
110 sum += REAL_MUL_SYNTH(window[0x4], b0[0x4]);
111 sum -= REAL_MUL_SYNTH(window[0x5], b0[0x5]);
112 sum += REAL_MUL_SYNTH(window[0x6], b0[0x6]);
113 sum -= REAL_MUL_SYNTH(window[0x7], b0[0x7]);
114 sum += REAL_MUL_SYNTH(window[0x8], b0[0x8]);
115 sum -= REAL_MUL_SYNTH(window[0x9], b0[0x9]);
116 sum += REAL_MUL_SYNTH(window[0xA], b0[0xA]);
117 sum -= REAL_MUL_SYNTH(window[0xB], b0[0xB]);
118 sum += REAL_MUL_SYNTH(window[0xC], b0[0xC]);
119 sum -= REAL_MUL_SYNTH(window[0xD], b0[0xD]);
120 sum += REAL_MUL_SYNTH(window[0xE], b0[0xE]);
121 sum -= REAL_MUL_SYNTH(window[0xF], b0[0xF]);
122 #endif
123
124 ADD_DITHER(fr,sum)
125 WRITE_SAMPLE(samples,sum,clip);
126 }
127
128 {
129 real sum;
130 sum = REAL_MUL_SYNTH(window[0x0], b0[0x0]);
131 sum += REAL_MUL_SYNTH(window[0x2], b0[0x2]);
132 sum += REAL_MUL_SYNTH(window[0x4], b0[0x4]);
133 sum += REAL_MUL_SYNTH(window[0x6], b0[0x6]);
134 sum += REAL_MUL_SYNTH(window[0x8], b0[0x8]);
135 sum += REAL_MUL_SYNTH(window[0xA], b0[0xA]);
136 sum += REAL_MUL_SYNTH(window[0xC], b0[0xC]);
137 sum += REAL_MUL_SYNTH(window[0xE], b0[0xE]);
138
139 ADD_DITHER(fr,sum)
140 WRITE_SAMPLE(samples,sum,clip);
141 samples += step;
142 b0-=0x400/BLOCK;
143 window-=0x800/BLOCK;
144 }
145 window += bo1<<1;
146
147 for(j=(BLOCK/4)-1; j; j--, b0-=0x400/BLOCK+BACKPEDAL, window-=0x800/BLOCK-BACKPEDAL, samples+=step)
148 {
149 real sum;
150 #ifndef NO_AUTOINCREMENT
151 sum = -REAL_MUL_SYNTH(*(--window), *b0++);
152 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
153 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
154 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
155 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
156 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
157 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
158 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
159 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
160 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
161 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
162 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
163 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
164 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
165 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
166 sum -= REAL_MUL_SYNTH(*(--window), *b0++);
167 #else
168 sum = -REAL_MUL_SYNTH(window[-0x1], b0[0x0]);
169 sum -= REAL_MUL_SYNTH(window[-0x2], b0[0x1]);
170 sum -= REAL_MUL_SYNTH(window[-0x3], b0[0x2]);
171 sum -= REAL_MUL_SYNTH(window[-0x4], b0[0x3]);
172 sum -= REAL_MUL_SYNTH(window[-0x5], b0[0x4]);
173 sum -= REAL_MUL_SYNTH(window[-0x6], b0[0x5]);
174 sum -= REAL_MUL_SYNTH(window[-0x7], b0[0x6]);
175 sum -= REAL_MUL_SYNTH(window[-0x8], b0[0x7]);
176 sum -= REAL_MUL_SYNTH(window[-0x9], b0[0x8]);
177 sum -= REAL_MUL_SYNTH(window[-0xA], b0[0x9]);
178 sum -= REAL_MUL_SYNTH(window[-0xB], b0[0xA]);
179 sum -= REAL_MUL_SYNTH(window[-0xC], b0[0xB]);
180 sum -= REAL_MUL_SYNTH(window[-0xD], b0[0xC]);
181 sum -= REAL_MUL_SYNTH(window[-0xE], b0[0xD]);
182 sum -= REAL_MUL_SYNTH(window[-0xF], b0[0xE]);
183 sum -= REAL_MUL_SYNTH(window[-0x0], b0[0xF]); /* Is that right? 0x0? Just wondering... */
184 #endif
185 ADD_DITHER(fr,sum)
186 WRITE_SAMPLE(samples,sum,clip);
187 }
188 }
189
190 if(final) fr->buffer.fill += BLOCK*sizeof(SAMPLE_T);
191
192 return clip;
193 #undef ADD_DITHER
194 #undef BACKPEDAL
195 #undef MY_DCT64
196 }
197