Mercurial > SDL_sound_CoreAudio
annotate decoders/mpglib/layer2.c @ 520:64ae7ac242b9
Fixed uninitialized buffer in mpglib. (Thanks, Phil!).
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Fri, 06 Jul 2007 11:29:02 +0000 |
parents | ad4c8f34136a |
children |
rev | line source |
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261 | 1 /* |
2 * Mpeg Layer-2 audio decoder | |
3 * -------------------------- | |
4 * copyright (c) 1995 by Michael Hipp, All rights reserved. See also 'README' | |
5 * | |
6 */ | |
7 | |
8 #include "mpg123_sdlsound.h" | |
9 #include "l2tables.h" | |
10 | |
11 static int grp_3tab[32 * 3] = { 0, }; /* used: 27 */ | |
12 static int grp_5tab[128 * 3] = { 0, }; /* used: 125 */ | |
13 static int grp_9tab[1024 * 3] = { 0, }; /* used: 729 */ | |
14 | |
15 real muls[27][64]; /* also used by layer 1 */ | |
16 | |
17 void init_layer2(void) | |
18 { | |
19 static double mulmul[27] = { | |
20 0.0 , -2.0/3.0 , 2.0/3.0 , | |
21 2.0/7.0 , 2.0/15.0 , 2.0/31.0, 2.0/63.0 , 2.0/127.0 , 2.0/255.0 , | |
22 2.0/511.0 , 2.0/1023.0 , 2.0/2047.0 , 2.0/4095.0 , 2.0/8191.0 , | |
23 2.0/16383.0 , 2.0/32767.0 , 2.0/65535.0 , | |
24 -4.0/5.0 , -2.0/5.0 , 2.0/5.0, 4.0/5.0 , | |
25 -8.0/9.0 , -4.0/9.0 , -2.0/9.0 , 2.0/9.0 , 4.0/9.0 , 8.0/9.0 }; | |
26 static int base[3][9] = { | |
27 { 1 , 0, 2 , } , | |
28 { 17, 18, 0 , 19, 20 , } , | |
29 { 21, 1, 22, 23, 0, 24, 25, 2, 26 } }; | |
30 int i,j,k,l,len; | |
31 real *table; | |
32 static int tablen[3] = { 3 , 5 , 9 }; | |
33 static int *itable,*tables[3] = { grp_3tab , grp_5tab , grp_9tab }; | |
34 | |
35 for(i=0;i<3;i++) | |
36 { | |
37 itable = tables[i]; | |
38 len = tablen[i]; | |
39 for(j=0;j<len;j++) | |
40 for(k=0;k<len;k++) | |
41 for(l=0;l<len;l++) | |
42 { | |
43 *itable++ = base[i][l]; | |
44 *itable++ = base[i][k]; | |
45 *itable++ = base[i][j]; | |
46 } | |
47 } | |
48 | |
49 for(k=0;k<27;k++) | |
50 { | |
51 double m=mulmul[k]; | |
52 table = muls[k]; | |
53 for(j=3,i=0;i<63;i++,j--) | |
54 *table++ = m * pow(2.0,(double) j / 3.0); | |
55 *table++ = 0.0; | |
56 } | |
57 } | |
58 | |
59 | |
60 void II_step_one(unsigned int *bit_alloc,int *scale,struct frame *fr) | |
61 { | |
62 int stereo = fr->stereo-1; | |
63 int sblimit = fr->II_sblimit; | |
64 int jsbound = fr->jsbound; | |
65 int sblimit2 = fr->II_sblimit<<stereo; | |
66 struct al_table *alloc1 = fr->alloc; | |
67 int i; | |
68 static unsigned int scfsi_buf[64]; | |
69 unsigned int *scfsi,*bita; | |
70 int sc,step; | |
71 | |
72 bita = bit_alloc; | |
73 if(stereo) | |
74 { | |
75 for (i=jsbound;i;i--,alloc1+=(1<<step)) | |
76 { | |
77 *bita++ = (char) getbits(step=alloc1->bits); | |
78 *bita++ = (char) getbits(step); | |
79 } | |
80 for (i=sblimit-jsbound;i;i--,alloc1+=(1<<step)) | |
81 { | |
82 bita[0] = (char) getbits(step=alloc1->bits); | |
83 bita[1] = bita[0]; | |
84 bita+=2; | |
85 } | |
86 bita = bit_alloc; | |
87 scfsi=scfsi_buf; | |
88 for (i=sblimit2;i;i--) | |
89 if (*bita++) | |
90 *scfsi++ = (char) getbits_fast(2); | |
91 } | |
92 else /* mono */ | |
93 { | |
94 for (i=sblimit;i;i--,alloc1+=(1<<step)) | |
95 *bita++ = (char) getbits(step=alloc1->bits); | |
96 bita = bit_alloc; | |
97 scfsi=scfsi_buf; | |
98 for (i=sblimit;i;i--) | |
99 if (*bita++) | |
100 *scfsi++ = (char) getbits_fast(2); | |
101 } | |
102 | |
103 bita = bit_alloc; | |
104 scfsi=scfsi_buf; | |
105 for (i=sblimit2;i;i--) | |
106 if (*bita++) | |
107 switch (*scfsi++) | |
108 { | |
109 case 0: | |
110 *scale++ = getbits_fast(6); | |
111 *scale++ = getbits_fast(6); | |
112 *scale++ = getbits_fast(6); | |
113 break; | |
114 case 1 : | |
115 *scale++ = sc = getbits_fast(6); | |
116 *scale++ = sc; | |
117 *scale++ = getbits_fast(6); | |
118 break; | |
119 case 2: | |
120 *scale++ = sc = getbits_fast(6); | |
121 *scale++ = sc; | |
122 *scale++ = sc; | |
123 break; | |
124 default: /* case 3 */ | |
125 *scale++ = getbits_fast(6); | |
126 *scale++ = sc = getbits_fast(6); | |
127 *scale++ = sc; | |
128 break; | |
129 } | |
130 | |
131 } | |
132 | |
133 void II_step_two(unsigned int *bit_alloc,real fraction[2][4][SBLIMIT],int *scale,struct frame *fr,int x1) | |
134 { | |
135 int i,j,k,ba; | |
136 int stereo = fr->stereo; | |
137 int sblimit = fr->II_sblimit; | |
138 int jsbound = fr->jsbound; | |
139 struct al_table *alloc2,*alloc1 = fr->alloc; | |
140 unsigned int *bita=bit_alloc; | |
141 int d1,step; | |
142 | |
143 for (i=0;i<jsbound;i++,alloc1+=(1<<step)) | |
144 { | |
145 step = alloc1->bits; | |
146 for (j=0;j<stereo;j++) | |
147 { | |
148 if ( (ba=*bita++) ) | |
149 { | |
150 k=(alloc2 = alloc1+ba)->bits; | |
151 if( (d1=alloc2->d) < 0) | |
152 { | |
153 real cm=muls[k][scale[x1]]; | |
154 fraction[j][0][i] = ((real) ((int)getbits(k) + d1)) * cm; | |
155 fraction[j][1][i] = ((real) ((int)getbits(k) + d1)) * cm; | |
156 fraction[j][2][i] = ((real) ((int)getbits(k) + d1)) * cm; | |
157 } | |
158 else | |
159 { | |
160 static int *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab }; | |
161 unsigned int idx,*tab,m=scale[x1]; | |
162 idx = (unsigned int) getbits(k); | |
163 tab = (unsigned int *) (table[d1] + idx + idx + idx); | |
164 fraction[j][0][i] = muls[*tab++][m]; | |
165 fraction[j][1][i] = muls[*tab++][m]; | |
166 fraction[j][2][i] = muls[*tab][m]; | |
167 } | |
168 scale+=3; | |
169 } | |
170 else | |
171 fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0; | |
172 } | |
173 } | |
174 | |
175 for (i=jsbound;i<sblimit;i++,alloc1+=(1<<step)) | |
176 { | |
177 step = alloc1->bits; | |
178 bita++; /* channel 1 and channel 2 bitalloc are the same */ | |
179 if ( (ba=*bita++) ) | |
180 { | |
181 k=(alloc2 = alloc1+ba)->bits; | |
182 if( (d1=alloc2->d) < 0) | |
183 { | |
184 real cm; | |
185 cm=muls[k][scale[x1+3]]; | |
186 fraction[1][0][i] = (fraction[0][0][i] = (real) ((int)getbits(k) + d1) ) * cm; | |
187 fraction[1][1][i] = (fraction[0][1][i] = (real) ((int)getbits(k) + d1) ) * cm; | |
188 fraction[1][2][i] = (fraction[0][2][i] = (real) ((int)getbits(k) + d1) ) * cm; | |
189 cm=muls[k][scale[x1]]; | |
190 fraction[0][0][i] *= cm; fraction[0][1][i] *= cm; fraction[0][2][i] *= cm; | |
191 } | |
192 else | |
193 { | |
194 static int *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab }; | |
195 unsigned int idx,*tab,m1,m2; | |
196 m1 = scale[x1]; m2 = scale[x1+3]; | |
197 idx = (unsigned int) getbits(k); | |
198 tab = (unsigned int *) (table[d1] + idx + idx + idx); | |
199 fraction[0][0][i] = muls[*tab][m1]; fraction[1][0][i] = muls[*tab++][m2]; | |
200 fraction[0][1][i] = muls[*tab][m1]; fraction[1][1][i] = muls[*tab++][m2]; | |
201 fraction[0][2][i] = muls[*tab][m1]; fraction[1][2][i] = muls[*tab][m2]; | |
202 } | |
203 scale+=6; | |
204 } | |
205 else { | |
206 fraction[0][0][i] = fraction[0][1][i] = fraction[0][2][i] = | |
207 fraction[1][0][i] = fraction[1][1][i] = fraction[1][2][i] = 0.0; | |
208 } | |
209 /* | |
210 should we use individual scalefac for channel 2 or | |
211 is the current way the right one , where we just copy channel 1 to | |
212 channel 2 ?? | |
213 The current 'strange' thing is, that we throw away the scalefac | |
214 values for the second channel ...!! | |
215 -> changed .. now we use the scalefac values of channel one !! | |
216 */ | |
217 } | |
218 | |
219 for(i=sblimit;i<SBLIMIT;i++) | |
220 for (j=0;j<stereo;j++) | |
221 fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0; | |
222 | |
223 } | |
224 | |
225 static void II_select_table(struct frame *fr) | |
226 { | |
227 static int translate[3][2][16] = | |
228 { { { 0,2,2,2,2,2,2,0,0,0,1,1,1,1,1,0 } , | |
229 { 0,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0 } } , | |
230 { { 0,2,2,2,2,2,2,0,0,0,0,0,0,0,0,0 } , | |
231 { 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0 } } , | |
232 { { 0,3,3,3,3,3,3,0,0,0,1,1,1,1,1,0 } , | |
233 { 0,3,3,0,0,0,1,1,1,1,1,1,1,1,1,0 } } }; | |
234 | |
235 int table,sblim; | |
236 static struct al_table *tables[5] = | |
237 { alloc_0, alloc_1, alloc_2, alloc_3 , alloc_4 }; | |
238 static int sblims[5] = { 27 , 30 , 8, 12 , 30 }; | |
239 | |
240 if(fr->lsf) | |
241 table = 4; | |
242 else | |
243 table = translate[fr->sampling_frequency][2-fr->stereo][fr->bitrate_index]; | |
244 sblim = sblims[table]; | |
245 | |
246 fr->alloc = tables[table]; | |
247 fr->II_sblimit = sblim; | |
248 } | |
249 | |
281
ad4c8f34136a
Minor formatting updates.
Ryan C. Gordon <icculus@icculus.org>
parents:
279
diff
changeset
|
250 int do_layer2(struct frame *fr,unsigned char *pcm_sample, |
ad4c8f34136a
Minor formatting updates.
Ryan C. Gordon <icculus@icculus.org>
parents:
279
diff
changeset
|
251 int *pcm_point,struct mpstr *mp) |
261 | 252 { |
253 int clip=0; | |
254 int i,j; | |
255 int stereo = fr->stereo; | |
256 real fraction[2][4][SBLIMIT]; /* pick_table clears unused subbands */ | |
257 unsigned int bit_alloc[64]; | |
258 int scale[192]; | |
259 int single = fr->single; | |
260 | |
261 II_select_table(fr); | |
262 fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ? | |
263 (fr->mode_ext<<2)+4 : fr->II_sblimit; | |
264 | |
265 if(stereo == 1 || single == 3) | |
266 single = 0; | |
267 | |
268 II_step_one(bit_alloc, scale, fr); | |
269 | |
270 for (i=0;i<SCALE_BLOCK;i++) | |
271 { | |
272 II_step_two(bit_alloc,fraction,scale,fr,i>>2); | |
273 for (j=0;j<3;j++) { | |
274 if(single >= 0) { | |
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
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275 clip += synth_1to1_mono(fraction[0][j],pcm_sample,pcm_point,mp); |
261 | 276 } |
277 else { | |
278 int p1 = *pcm_point; | |
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
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279 clip += synth_1to1(fraction[0][j],0,pcm_sample,&p1,mp); |
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
280 clip += synth_1to1(fraction[1][j],1,pcm_sample,pcm_point,mp); |
261 | 281 } |
282 | |
283 } | |
284 } | |
285 | |
286 return clip; | |
287 } | |
288 | |
289 |