1 /******************************************************************** |
|
2 * * |
|
3 * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. * |
|
4 * * |
|
5 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * |
|
6 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * |
|
7 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * |
|
8 * * |
|
9 * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002 * |
|
10 * BY THE Xiph.Org FOUNDATION http://www.xiph.org/ * |
|
11 * * |
|
12 ******************************************************************** |
|
13 |
|
14 function: floor backend 0 implementation |
|
15 |
|
16 ********************************************************************/ |
|
17 |
|
18 #include <stdlib.h> |
|
19 #include <string.h> |
|
20 #include <math.h> |
|
21 #include "ogg.h" |
|
22 #include "ivorbiscodec.h" |
|
23 #include "codec_internal.h" |
|
24 #include "registry.h" |
|
25 #include "codebook.h" |
|
26 #include "misc.h" |
|
27 #include "block.h" |
|
28 |
|
29 #define LSP_FRACBITS 14 |
|
30 |
|
31 typedef struct { |
|
32 long n; |
|
33 int ln; |
|
34 int m; |
|
35 int *linearmap; |
|
36 |
|
37 vorbis_info_floor0 *vi; |
|
38 ogg_int32_t *lsp_look; |
|
39 |
|
40 } vorbis_look_floor0; |
|
41 |
|
42 /*************** LSP decode ********************/ |
|
43 |
|
44 #include "lsp_lookup.h" |
|
45 |
|
46 /* interpolated 1./sqrt(p) where .5 <= a < 1. (.100000... to .111111...) in |
|
47 16.16 format |
|
48 returns in m.8 format */ |
|
49 |
|
50 static long ADJUST_SQRT2[2]={8192,5792}; |
|
51 STIN ogg_int32_t vorbis_invsqlook_i(long a,long e){ |
|
52 long i=(a&0x7fff)>>(INVSQ_LOOKUP_I_SHIFT-1); |
|
53 long d=a&INVSQ_LOOKUP_I_MASK; /* 0.10 */ |
|
54 long val=INVSQ_LOOKUP_I[i]- /* 1.16 */ |
|
55 ((INVSQ_LOOKUP_IDel[i]*d)>>INVSQ_LOOKUP_I_SHIFT); /* result 1.16 */ |
|
56 val*=ADJUST_SQRT2[e&1]; |
|
57 e=(e>>1)+21; |
|
58 return(val>>e); |
|
59 } |
|
60 |
|
61 /* interpolated lookup based fromdB function, domain -140dB to 0dB only */ |
|
62 /* a is in n.12 format */ |
|
63 STIN ogg_int32_t vorbis_fromdBlook_i(long a){ |
|
64 int i=(-a)>>(12-FROMdB2_SHIFT); |
|
65 if(i<0) return 0x7fffffff; |
|
66 if(i>=(FROMdB_LOOKUP_SZ<<FROMdB_SHIFT))return 0; |
|
67 |
|
68 return FROMdB_LOOKUP[i>>FROMdB_SHIFT] * FROMdB2_LOOKUP[i&FROMdB2_MASK]; |
|
69 } |
|
70 |
|
71 /* interpolated lookup based cos function, domain 0 to PI only */ |
|
72 /* a is in 0.16 format, where 0==0, 2^^16-1==PI, return 0.14 */ |
|
73 STIN ogg_int32_t vorbis_coslook_i(long a){ |
|
74 int i=a>>COS_LOOKUP_I_SHIFT; |
|
75 int d=a&COS_LOOKUP_I_MASK; |
|
76 return COS_LOOKUP_I[i]- ((d*(COS_LOOKUP_I[i]-COS_LOOKUP_I[i+1]))>> |
|
77 COS_LOOKUP_I_SHIFT); |
|
78 } |
|
79 |
|
80 /* interpolated lookup based cos function */ |
|
81 /* a is in 0.16 format, where 0==0, 2^^16==PI, return .LSP_FRACBITS */ |
|
82 STIN ogg_int32_t vorbis_coslook2_i(long a){ |
|
83 a=a&0x1ffff; |
|
84 |
|
85 if(a>0x10000)a=0x20000-a; |
|
86 { |
|
87 int i=a>>COS_LOOKUP_I_SHIFT; |
|
88 int d=a&COS_LOOKUP_I_MASK; |
|
89 a=((COS_LOOKUP_I[i]<<COS_LOOKUP_I_SHIFT)- |
|
90 d*(COS_LOOKUP_I[i]-COS_LOOKUP_I[i+1]))>> |
|
91 (COS_LOOKUP_I_SHIFT-LSP_FRACBITS+14); |
|
92 } |
|
93 |
|
94 return(a); |
|
95 } |
|
96 |
|
97 static const int barklook[28]={ |
|
98 0,100,200,301, 405,516,635,766, |
|
99 912,1077,1263,1476, 1720,2003,2333,2721, |
|
100 3184,3742,4428,5285, 6376,7791,9662,12181, |
|
101 15624,20397,27087,36554 |
|
102 }; |
|
103 |
|
104 /* used in init only; interpolate the long way */ |
|
105 STIN ogg_int32_t toBARK(int n){ |
|
106 int i; |
|
107 for(i=0;i<27;i++) |
|
108 if(n>=barklook[i] && n<barklook[i+1])break; |
|
109 |
|
110 if(i==27){ |
|
111 return 27<<15; |
|
112 }else{ |
|
113 int gap=barklook[i+1]-barklook[i]; |
|
114 int del=n-barklook[i]; |
|
115 |
|
116 return((i<<15)+((del<<15)/gap)); |
|
117 } |
|
118 } |
|
119 |
|
120 static const unsigned char MLOOP_1[64]={ |
|
121 0,10,11,11, 12,12,12,12, 13,13,13,13, 13,13,13,13, |
|
122 14,14,14,14, 14,14,14,14, 14,14,14,14, 14,14,14,14, |
|
123 15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15, |
|
124 15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15, |
|
125 }; |
|
126 |
|
127 static const unsigned char MLOOP_2[64]={ |
|
128 0,4,5,5, 6,6,6,6, 7,7,7,7, 7,7,7,7, |
|
129 8,8,8,8, 8,8,8,8, 8,8,8,8, 8,8,8,8, |
|
130 9,9,9,9, 9,9,9,9, 9,9,9,9, 9,9,9,9, |
|
131 9,9,9,9, 9,9,9,9, 9,9,9,9, 9,9,9,9, |
|
132 }; |
|
133 |
|
134 static const unsigned char MLOOP_3[8]={0,1,2,2,3,3,3,3}; |
|
135 |
|
136 void vorbis_lsp_to_curve(ogg_int32_t *curve,int *map,int n,int ln, |
|
137 ogg_int32_t *lsp,int m, |
|
138 ogg_int32_t amp, |
|
139 ogg_int32_t ampoffset, |
|
140 ogg_int32_t *icos){ |
|
141 |
|
142 /* 0 <= m < 256 */ |
|
143 |
|
144 /* set up for using all int later */ |
|
145 int i; |
|
146 int ampoffseti=ampoffset*4096; |
|
147 int ampi=amp; |
|
148 ogg_int32_t *ilsp=(ogg_int32_t *)alloca(m*sizeof(*ilsp)); |
|
149 /* lsp is in 8.24, range 0 to PI; coslook wants it in .16 0 to 1*/ |
|
150 for(i=0;i<m;i++){ |
|
151 #ifndef _LOW_ACCURACY_ |
|
152 ogg_int32_t val=MULT32(lsp[i],0x517cc2); |
|
153 #else |
|
154 ogg_int32_t val=((lsp[i]>>10)*0x517d)>>14; |
|
155 #endif |
|
156 |
|
157 /* safeguard against a malicious stream */ |
|
158 if(val<0 || (val>>COS_LOOKUP_I_SHIFT)>=COS_LOOKUP_I_SZ){ |
|
159 memset(curve,0,sizeof(*curve)*n); |
|
160 return; |
|
161 } |
|
162 |
|
163 ilsp[i]=vorbis_coslook_i(val); |
|
164 } |
|
165 |
|
166 i=0; |
|
167 while(i<n){ |
|
168 int j,k=map[i]; |
|
169 ogg_uint32_t pi=46341; /* 2**-.5 in 0.16 */ |
|
170 ogg_uint32_t qi=46341; |
|
171 ogg_int32_t qexp=0,shift; |
|
172 ogg_int32_t wi=icos[k]; |
|
173 |
|
174 #ifdef _V_LSP_MATH_ASM |
|
175 lsp_loop_asm(&qi,&pi,&qexp,ilsp,wi,m); |
|
176 |
|
177 pi=((pi*pi)>>16); |
|
178 qi=((qi*qi)>>16); |
|
179 |
|
180 if(m&1){ |
|
181 qexp= qexp*2-28*((m+1)>>1)+m; |
|
182 pi*=(1<<14)-((wi*wi)>>14); |
|
183 qi+=pi>>14; |
|
184 }else{ |
|
185 qexp= qexp*2-13*m; |
|
186 |
|
187 pi*=(1<<14)-wi; |
|
188 qi*=(1<<14)+wi; |
|
189 |
|
190 qi=(qi+pi)>>14; |
|
191 } |
|
192 |
|
193 if(qi&0xffff0000){ /* checks for 1.xxxxxxxxxxxxxxxx */ |
|
194 qi>>=1; qexp++; |
|
195 }else |
|
196 lsp_norm_asm(&qi,&qexp); |
|
197 |
|
198 #else |
|
199 |
|
200 qi*=labs(ilsp[0]-wi); |
|
201 pi*=labs(ilsp[1]-wi); |
|
202 |
|
203 for(j=3;j<m;j+=2){ |
|
204 if(!(shift=MLOOP_1[(pi|qi)>>25])) |
|
205 if(!(shift=MLOOP_2[(pi|qi)>>19])) |
|
206 shift=MLOOP_3[(pi|qi)>>16]; |
|
207 qi=(qi>>shift)*labs(ilsp[j-1]-wi); |
|
208 pi=(pi>>shift)*labs(ilsp[j]-wi); |
|
209 qexp+=shift; |
|
210 } |
|
211 if(!(shift=MLOOP_1[(pi|qi)>>25])) |
|
212 if(!(shift=MLOOP_2[(pi|qi)>>19])) |
|
213 shift=MLOOP_3[(pi|qi)>>16]; |
|
214 |
|
215 /* pi,qi normalized collectively, both tracked using qexp */ |
|
216 |
|
217 if(m&1){ |
|
218 /* odd order filter; slightly assymetric */ |
|
219 /* the last coefficient */ |
|
220 qi=(qi>>shift)*labs(ilsp[j-1]-wi); |
|
221 pi=(pi>>shift)<<14; |
|
222 qexp+=shift; |
|
223 |
|
224 if(!(shift=MLOOP_1[(pi|qi)>>25])) |
|
225 if(!(shift=MLOOP_2[(pi|qi)>>19])) |
|
226 shift=MLOOP_3[(pi|qi)>>16]; |
|
227 |
|
228 pi>>=shift; |
|
229 qi>>=shift; |
|
230 qexp+=shift-14*((m+1)>>1); |
|
231 |
|
232 pi=((pi*pi)>>16); |
|
233 qi=((qi*qi)>>16); |
|
234 qexp=qexp*2+m; |
|
235 |
|
236 pi*=(1<<14)-((wi*wi)>>14); |
|
237 qi+=pi>>14; |
|
238 |
|
239 }else{ |
|
240 /* even order filter; still symmetric */ |
|
241 |
|
242 /* p*=p(1-w), q*=q(1+w), let normalization drift because it isn't |
|
243 worth tracking step by step */ |
|
244 |
|
245 pi>>=shift; |
|
246 qi>>=shift; |
|
247 qexp+=shift-7*m; |
|
248 |
|
249 pi=((pi*pi)>>16); |
|
250 qi=((qi*qi)>>16); |
|
251 qexp=qexp*2+m; |
|
252 |
|
253 pi*=(1<<14)-wi; |
|
254 qi*=(1<<14)+wi; |
|
255 qi=(qi+pi)>>14; |
|
256 |
|
257 } |
|
258 |
|
259 |
|
260 /* we've let the normalization drift because it wasn't important; |
|
261 however, for the lookup, things must be normalized again. We |
|
262 need at most one right shift or a number of left shifts */ |
|
263 |
|
264 if(qi&0xffff0000){ /* checks for 1.xxxxxxxxxxxxxxxx */ |
|
265 qi>>=1; qexp++; |
|
266 }else |
|
267 while(qi && !(qi&0x8000)){ /* checks for 0.0xxxxxxxxxxxxxxx or less*/ |
|
268 qi<<=1; qexp--; |
|
269 } |
|
270 |
|
271 #endif |
|
272 |
|
273 amp=vorbis_fromdBlook_i(ampi* /* n.4 */ |
|
274 vorbis_invsqlook_i(qi,qexp)- |
|
275 /* m.8, m+n<=8 */ |
|
276 ampoffseti); /* 8.12[0] */ |
|
277 |
|
278 #ifdef _LOW_ACCURACY_ |
|
279 amp>>=9; |
|
280 #endif |
|
281 curve[i]= MULT31_SHIFT15(curve[i],amp); |
|
282 while(map[++i]==k) curve[i]= MULT31_SHIFT15(curve[i],amp); |
|
283 } |
|
284 } |
|
285 |
|
286 /*************** vorbis decode glue ************/ |
|
287 |
|
288 static void floor0_free_info(vorbis_info_floor *i){ |
|
289 vorbis_info_floor0 *info=(vorbis_info_floor0 *)i; |
|
290 if(info){ |
|
291 memset(info,0,sizeof(*info)); |
|
292 _ogg_free(info); |
|
293 } |
|
294 } |
|
295 |
|
296 static void floor0_free_look(vorbis_look_floor *i){ |
|
297 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i; |
|
298 if(look){ |
|
299 |
|
300 if(look->linearmap)_ogg_free(look->linearmap); |
|
301 if(look->lsp_look)_ogg_free(look->lsp_look); |
|
302 memset(look,0,sizeof(*look)); |
|
303 _ogg_free(look); |
|
304 } |
|
305 } |
|
306 |
|
307 static vorbis_info_floor *floor0_unpack (vorbis_info *vi,oggpack_buffer *opb){ |
|
308 codec_setup_info *ci=(codec_setup_info *)vi->codec_setup; |
|
309 int j; |
|
310 |
|
311 vorbis_info_floor0 *info=(vorbis_info_floor0 *)_ogg_malloc(sizeof(*info)); |
|
312 info->order=oggpack_read(opb,8); |
|
313 info->rate=oggpack_read(opb,16); |
|
314 info->barkmap=oggpack_read(opb,16); |
|
315 info->ampbits=oggpack_read(opb,6); |
|
316 info->ampdB=oggpack_read(opb,8); |
|
317 info->numbooks=oggpack_read(opb,4)+1; |
|
318 |
|
319 if(info->order<1)goto err_out; |
|
320 if(info->rate<1)goto err_out; |
|
321 if(info->barkmap<1)goto err_out; |
|
322 if(info->numbooks<1)goto err_out; |
|
323 |
|
324 for(j=0;j<info->numbooks;j++){ |
|
325 info->books[j]=oggpack_read(opb,8); |
|
326 if(info->books[j]<0 || info->books[j]>=ci->books)goto err_out; |
|
327 } |
|
328 return(info); |
|
329 |
|
330 err_out: |
|
331 floor0_free_info(info); |
|
332 return(NULL); |
|
333 } |
|
334 |
|
335 /* initialize Bark scale and normalization lookups. We could do this |
|
336 with static tables, but Vorbis allows a number of possible |
|
337 combinations, so it's best to do it computationally. |
|
338 |
|
339 The below is authoritative in terms of defining scale mapping. |
|
340 Note that the scale depends on the sampling rate as well as the |
|
341 linear block and mapping sizes */ |
|
342 |
|
343 static vorbis_look_floor *floor0_look (vorbis_dsp_state *vd,vorbis_info_mode *mi, |
|
344 vorbis_info_floor *i){ |
|
345 int j; |
|
346 vorbis_info *vi=vd->vi; |
|
347 codec_setup_info *ci=(codec_setup_info *)vi->codec_setup; |
|
348 vorbis_info_floor0 *info=(vorbis_info_floor0 *)i; |
|
349 vorbis_look_floor0 *look=(vorbis_look_floor0 *)_ogg_calloc(1,sizeof(*look)); |
|
350 look->m=info->order; |
|
351 look->n=ci->blocksizes[mi->blockflag]/2; |
|
352 look->ln=info->barkmap; |
|
353 look->vi=info; |
|
354 |
|
355 /* the mapping from a linear scale to a smaller bark scale is |
|
356 straightforward. We do *not* make sure that the linear mapping |
|
357 does not skip bark-scale bins; the decoder simply skips them and |
|
358 the encoder may do what it wishes in filling them. They're |
|
359 necessary in some mapping combinations to keep the scale spacing |
|
360 accurate */ |
|
361 look->linearmap=(int *)_ogg_malloc((look->n+1)*sizeof(*look->linearmap)); |
|
362 for(j=0;j<look->n;j++){ |
|
363 |
|
364 int val=(look->ln* |
|
365 ((toBARK(info->rate/2*j/look->n)<<11)/toBARK(info->rate/2)))>>11; |
|
366 |
|
367 if(val>=look->ln)val=look->ln-1; /* guard against the approximation */ |
|
368 look->linearmap[j]=val; |
|
369 } |
|
370 look->linearmap[j]=-1; |
|
371 |
|
372 look->lsp_look=(ogg_int32_t *)_ogg_malloc(look->ln*sizeof(*look->lsp_look)); |
|
373 for(j=0;j<look->ln;j++) |
|
374 look->lsp_look[j]=vorbis_coslook2_i(0x10000*j/look->ln); |
|
375 |
|
376 return look; |
|
377 } |
|
378 |
|
379 static void *floor0_inverse1(vorbis_block *vb,vorbis_look_floor *i){ |
|
380 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i; |
|
381 vorbis_info_floor0 *info=look->vi; |
|
382 int j,k; |
|
383 |
|
384 int ampraw=oggpack_read(&vb->opb,info->ampbits); |
|
385 if(ampraw>0){ /* also handles the -1 out of data case */ |
|
386 long maxval=(1<<info->ampbits)-1; |
|
387 int amp=((ampraw*info->ampdB)<<4)/maxval; |
|
388 int booknum=oggpack_read(&vb->opb,_ilog(info->numbooks)); |
|
389 |
|
390 if(booknum!=-1 && booknum<info->numbooks){ /* be paranoid */ |
|
391 codec_setup_info *ci=(codec_setup_info *)vb->vd->vi->codec_setup; |
|
392 codebook *b=ci->fullbooks+info->books[booknum]; |
|
393 ogg_int32_t last=0; |
|
394 ogg_int32_t *lsp=(ogg_int32_t *)_vorbis_block_alloc(vb,sizeof(*lsp)*(look->m+1)); |
|
395 |
|
396 for(j=0;j<look->m;j+=b->dim) |
|
397 if(vorbis_book_decodev_set(b,lsp+j,&vb->opb,b->dim,-24)==-1)goto eop; |
|
398 for(j=0;j<look->m;){ |
|
399 for(k=0;k<b->dim;k++,j++)lsp[j]+=last; |
|
400 last=lsp[j-1]; |
|
401 } |
|
402 |
|
403 lsp[look->m]=amp; |
|
404 return(lsp); |
|
405 } |
|
406 } |
|
407 eop: |
|
408 return(NULL); |
|
409 } |
|
410 |
|
411 static int floor0_inverse2(vorbis_block *vb,vorbis_look_floor *i, |
|
412 void *memo,ogg_int32_t *out){ |
|
413 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i; |
|
414 vorbis_info_floor0 *info=look->vi; |
|
415 |
|
416 if(memo){ |
|
417 ogg_int32_t *lsp=(ogg_int32_t *)memo; |
|
418 ogg_int32_t amp=lsp[look->m]; |
|
419 |
|
420 /* take the coefficients back to a spectral envelope curve */ |
|
421 vorbis_lsp_to_curve(out,look->linearmap,look->n,look->ln, |
|
422 lsp,look->m,amp,info->ampdB,look->lsp_look); |
|
423 return(1); |
|
424 } |
|
425 memset(out,0,sizeof(*out)*look->n); |
|
426 return(0); |
|
427 } |
|
428 |
|
429 /* export hooks */ |
|
430 vorbis_func_floor floor0_exportbundle={ |
|
431 &floor0_unpack,&floor0_look,&floor0_free_info, |
|
432 &floor0_free_look,&floor0_inverse1,&floor0_inverse2 |
|
433 }; |
|
434 |
|
435 |
|