Nellymoser ASAO decoder
[libav.git] / libavcodec / nellymoserdec.c
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636b13c5
BL
1/*
2 * NellyMoser audio decoder
3 * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
4 * 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
5 * 520e17cd55896441042b14df2566a6eb610ed444
6 * Copyright (c) 2007 Loic Minier <lool at dooz.org>
7 * Benjamin Larsson
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 * DEALINGS IN THE SOFTWARE.
26 */
27
28/**
29 * @file nellymoserdec.c
30 * The 3 alphanumeric copyright notices are md5summed they are from the original
31 * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
32 */
33#include "avcodec.h"
34#include "random.h"
35#include "dsputil.h"
36
37#define ALT_BITSTREAM_READER_LE
38#include "bitstream.h"
39
40#define NELLY_BANDS 23
41#define NELLY_BLOCK_LEN 64
42#define NELLY_HEADER_BITS 116
43#define NELLY_DETAIL_BITS 198
44#define NELLY_BUF_LEN 128
45#define NELLY_FILL_LEN 124
46#define NELLY_BIT_CAP 6
47#define NELLY_BASE_OFF 4228
48#define NELLY_BASE_SHIFT 19
49#define NELLY_SAMPLES 256
50
51static const float dequantization_table[127] = {
520.0000000000,-0.8472560048, 0.7224709988, -1.5247479677, -0.4531480074, 0.3753609955, 1.4717899561,
53-1.9822579622, -1.1929379702, -0.5829370022, -0.0693780035, 0.3909569979,0.9069200158, 1.4862740040,
54 2.2215409279, -2.3887870312, -1.8067539930, -1.4105420113, -1.0773609877, -0.7995010018,-0.5558109879,
55-0.3334020078, -0.1324490011, 0.0568020009, 0.2548770010, 0.4773550034, 0.7386850119, 1.0443060398,
561.3954459429, 1.8098750114, 2.3918759823,-2.3893830776, -1.9884680510, -1.7514040470, -1.5643119812,
57-1.3922129869,-1.2164649963, -1.0469499826, -0.8905100226, -0.7645580173, -0.6454579830, -0.5259280205,
58-0.4059549868, -0.3029719889, -0.2096900046, -0.1239869967, -0.0479229987, 0.0257730000, 0.1001340002,
590.1737180054, 0.2585540116, 0.3522900045, 0.4569880068, 0.5767750144, 0.7003160119, 0.8425520062,
601.0093879700, 1.1821349859, 1.3534560204, 1.5320819616, 1.7332619429, 1.9722349644, 2.3978140354,
61-2.5756309032, -2.0573320389, -1.8984919786, -1.7727810144, -1.6662600040, -1.5742180347, -1.4993319511,
62-1.4316639900, -1.3652280569, -1.3000990152, -1.2280930281, -1.1588579416, -1.0921250582, -1.0135740042,
63-0.9202849865, -0.8287050128, -0.7374889851, -0.6447759867, -0.5590940118, -0.4857139885, -0.4110319912,
64-0.3459700048, -0.2851159871, -0.2341620028, -0.1870580018, -0.1442500055, -0.1107169986, -0.0739680007,
65-0.0365610011, -0.0073290002, 0.0203610007, 0.0479039997, 0.0751969963, 0.0980999991, 0.1220389977,
660.1458999962, 0.1694349945, 0.1970459968, 0.2252430022, 0.2556869984, 0.2870100141, 0.3197099864,
670.3525829911, 0.3889069855, 0.4334920049, 0.4769459963, 0.5204820037, 0.5644530058, 0.6122040153,
680.6685929894, 0.7341650128, 0.8032159805, 0.8784040213, 0.9566209912, 1.0397069454, 1.1293770075,
691.2211159468, 1.3080279827, 1.4024800062, 1.5056819916, 1.6227730513, 1.7724959850, 1.9430880547,
70 2.2903931141
71};
72
73static const uint8_t nelly_band_sizes_table[NELLY_BANDS] = {
742, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 9, 10, 12, 14, 15
75};
76
77static const uint16_t nelly_init_table[64] = {
783134, 5342, 6870, 7792, 8569, 9185, 9744, 10191, 10631, 11061, 11434, 11770,
7912116, 12513, 12925, 13300, 13674, 14027, 14352, 14716, 15117, 15477, 15824,
8016157, 16513, 16804, 17090, 17401, 17679, 17948, 18238, 18520, 18764, 19078,
8119381, 19640, 19921, 20205, 20500, 20813, 21162, 21465, 21794, 22137, 22453,
8222756, 23067, 23350, 23636, 23926, 24227, 24521, 24819, 25107, 25414, 25730,
8326120, 26497, 26895, 27344, 27877, 28463, 29426, 31355
84};
85
86static const int16_t nelly_delta_table[32] = {
87-11725, -9420, -7910, -6801, -5948, -5233, -4599, -4039, -3507, -3030, -2596,
88-2170, -1774, -1383, -1016, -660, -329, -1, 337, 696, 1085, 1512, 1962, 2433,
892968, 3569, 4314, 5279, 6622, 8154, 10076, 12975
90};
91
92typedef struct NellyMoserDecodeContext {
93 AVCodecContext* avctx;
94 float float_buf[NELLY_SAMPLES];
95 float state[64];
96 AVRandomState random_state;
97 GetBitContext gb;
98 int add_bias;
99 int scale_bias;
100 DSPContext dsp;
101 FFTContext fftc;
102} NellyMoserDecodeContext;
103
104
105DECLARE_ALIGNED_16(float,sine_window[128]);
106DECLARE_ALIGNED_16(float,tcos[64]);
107DECLARE_ALIGNED_16(float,tsin[64]);
108DECLARE_ALIGNED_16(float,cos_tab[64]);
109
110static inline int signed_shift(int i, int shift) {
111 if (shift > 0)
112 return i << shift;
113 return i >> -shift;
114}
115
116static void antialias(float *buf, float *audio)
117{
118 int i, end, mid_hi, mid_lo;
119
120 end = NELLY_BUF_LEN-1;
121 mid_hi = NELLY_BUF_LEN/2;
122 mid_lo = mid_hi-1;
123
124 for (i = 0; i < NELLY_BUF_LEN/4; i++) {
125 audio[2*i] = buf[2*i ]*tcos[i ] - buf[end-2*i]*tsin[i];
126 audio[2*i+1] = -(buf[end-2*i ]*tcos[i ] + buf[2*i ]*tsin[i]);
127 audio[end-2*i-1]= buf[end-2*i-1]*tcos[mid_lo-i] - buf[2*i+1 ]*tsin[mid_lo-i];
128 audio[end-2*i ]= -(buf[2*i+1 ]*tcos[mid_lo-i] + buf[end-2*i]*tsin[mid_lo-i]);
129 }
130}
131
132static void complex2signal(float *audio)
133{
134 int i, end, mid_hi, mid_lo;
135 float *aptr, *sigptr, a, b, c, d, e, f, g;
136
137 end = NELLY_BUF_LEN-1;
138 mid_hi = NELLY_BUF_LEN/2;
139 mid_lo = mid_hi-1;
140
141 a = -audio[end];
142 b = audio[end-1];
143 c = -audio[1];
144 d = cos_tab[0];
145 e = audio[0];
146 f = cos_tab[mid_lo];
147 g = cos_tab[1];
148
149 audio[0] = d*e;
150 audio[1] = b*g-a*f;
151 audio[end-1] = a*g+b*f;
152 audio[end] = c*(-d);
153
154 aptr = audio+end-2;
155 sigptr = cos_tab+mid_hi-1;
156
157 for (i = 3; i < NELLY_BUF_LEN/2; i += 2) {
158 a = audio[i-1];
159 b = -audio[i];
160 c = cos_tab[i/2];
161 d = *sigptr;
162 e = *(aptr-1);
163 f = -(*aptr);
164
165 audio[i-1] = a*c+b*d;
166 *aptr = a*d-b*c;
167
168 a = cos_tab[(i/2)+1];
169 b = *(sigptr-1);
170
171 *(aptr-1) = b*e+a*f;
172 audio[i] = a*e-b*f;
173
174 sigptr--;
175 aptr -= 2;
176 }
177}
178
179static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio)
180{
181 int bot, mid_up, mid_down, top;
182 float s_bot, s_top;
183
184 bot = 0;
185 top = NELLY_BUF_LEN-1;
186 mid_up = NELLY_BUF_LEN/2;
187 mid_down = (NELLY_BUF_LEN/2)-1;
188
189 while (bot < NELLY_BUF_LEN/4) {
190 s_bot = audio[bot];
191 s_top = audio[top];
192 audio[bot] = (audio[mid_up]*sine_window[bot]-state[bot ]*sine_window[top])/s->scale_bias + s->add_bias;
193 audio[top] = (-state[bot ]*sine_window[bot]-audio[mid_up]*sine_window[top])/s->scale_bias + s->add_bias;
194 state[bot] = audio[mid_down];
195
196 audio[mid_down] = (s_top *sine_window[mid_down]-state[mid_down]*sine_window[mid_up])/s->scale_bias + s->add_bias;
197 audio[mid_up ] = (-state[mid_down]*sine_window[mid_down]-s_top *sine_window[mid_up])/s->scale_bias + s->add_bias;
198 state[mid_down] = s_bot;
199
200 bot++;
201 mid_up++;
202 mid_down--;
203 top--;
204 }
205}
206
207static int sum_bits(short *buf, short shift, short off)
208{
209 int b, i = 0, ret = 0;
210
211 for (i = 0; i < NELLY_FILL_LEN; i++) {
212 b = buf[i]-off;
213 b = ((b>>(shift-1))+1)>>1;
214 ret += av_clip(b, 0, NELLY_BIT_CAP);
215 }
216
217 return ret;
218}
219
220static int headroom(int *la)
221{
222 int l;
223 if (*la == 0) {
224 return 31;
225 }
226 l = 30 - av_log2(FFABS(*la));
227 *la <<= l;
228 return l;
229}
230
231
232static void get_sample_bits(float *buf, int *bits)
233{
234 int i, j;
235 short sbuf[128];
236 int bitsum = 0, last_bitsum, small_bitsum, big_bitsum;
237 short shift, shift_saved;
238 int max, sum, last_off, tmp;
239 int big_off, small_off;
240 int off;
241
242 max = 0;
243 for (i = 0; i < NELLY_FILL_LEN; i++) {
244 max = FFMAX(max, buf[i]);
245 }
246 shift = -16;
247 shift += headroom(&max);
248
249 sum = 0;
250 for (i = 0; i < NELLY_FILL_LEN; i++) {
251 sbuf[i] = signed_shift(buf[i], shift);
252 sbuf[i] = (3*sbuf[i])>>2;
253 sum += sbuf[i];
254 }
255
256 shift += 11;
257 shift_saved = shift;
258 sum -= NELLY_DETAIL_BITS << shift;
259 shift += headroom(&sum);
260 small_off = (NELLY_BASE_OFF * (sum>>16)) >> 15;
261 shift = shift_saved - (NELLY_BASE_SHIFT+shift-31);
262
263 small_off = signed_shift(small_off, shift);
264
265 bitsum = sum_bits(sbuf, shift_saved, small_off);
266
267 if (bitsum != NELLY_DETAIL_BITS) {
268 shift = 0;
269 off = bitsum - NELLY_DETAIL_BITS;
270
271 for(shift=0; FFABS(off) <= 16383; shift++)
272 off *= 2;
273
274 off = (off * NELLY_BASE_OFF) >> 15;
275 shift = shift_saved-(NELLY_BASE_SHIFT+shift-15);
276
277 off = signed_shift(off, shift);
278
279 for (j = 1; j < 20; j++) {
280 last_off = small_off;
281 small_off += off;
282 last_bitsum = bitsum;
283
284 bitsum = sum_bits(sbuf, shift_saved, small_off);
285
286 if ((bitsum-NELLY_DETAIL_BITS) * (last_bitsum-NELLY_DETAIL_BITS) <= 0)
287 break;
288 }
289
290 if (bitsum > NELLY_DETAIL_BITS) {
291 big_off = small_off;
292 small_off = last_off;
293 big_bitsum=bitsum;
294 small_bitsum=last_bitsum;
295 } else {
296 big_off = last_off;
297 big_bitsum=last_bitsum;
298 small_bitsum=bitsum;
299 }
300
301 while (bitsum != NELLY_DETAIL_BITS && j <= 19) {
302 off = (big_off+small_off)>>1;
303 bitsum = sum_bits(sbuf, shift_saved, off);
304 if (bitsum > NELLY_DETAIL_BITS) {
305 big_off=off;
306 big_bitsum=bitsum;
307 } else {
308 small_off = off;
309 small_bitsum=bitsum;
310 }
311 j++;
312 }
313
314 if (abs(big_bitsum-NELLY_DETAIL_BITS) >=
315 abs(small_bitsum-NELLY_DETAIL_BITS)) {
316 bitsum = small_bitsum;
317 } else {
318 small_off = big_off;
319 bitsum = big_bitsum;
320 }
321 }
322
323 for (i = 0; i < NELLY_FILL_LEN; i++) {
324 tmp = sbuf[i]-small_off;
325 tmp = ((tmp>>(shift_saved-1))+1)>>1;
326 bits[i] = av_clip(tmp, 0, NELLY_BIT_CAP);
327 }
328
329 if (bitsum > NELLY_DETAIL_BITS) {
330 tmp = i = 0;
331 while (tmp < NELLY_DETAIL_BITS) {
332 tmp += bits[i];
333 i++;
334 }
335
336 bits[i-1] -= tmp - NELLY_DETAIL_BITS;
337 for(; i < NELLY_FILL_LEN; i++)
338 bits[i] = 0;
339 }
340}
341
342void nelly_decode_block(NellyMoserDecodeContext *s, unsigned char block[NELLY_BLOCK_LEN], float audio[NELLY_SAMPLES])
343{
344 int i,j;
345 float buf[NELLY_BUF_LEN], pows[NELLY_BUF_LEN];
346 float *aptr, *bptr, *pptr, val, pval;
347 int bits[NELLY_BUF_LEN];
348 unsigned char v;
349
350 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
351
352 bptr = buf;
353 pptr = pows;
354 val = nelly_init_table[get_bits(&s->gb, 6)];
355 for (i=0 ; i<NELLY_BANDS ; i++) {
356 if (i > 0)
357 val += nelly_delta_table[get_bits(&s->gb, 5)];
358 pval = pow(2, val/2048);
359 for (j = 0; j < nelly_band_sizes_table[i]; j++) {
360 *bptr++ = val;
361 *pptr++ = pval;
362 }
363
364 }
365
366 memset(&buf[NELLY_FILL_LEN],0,4*sizeof(float));
367 memset(&pows[NELLY_FILL_LEN],0,4*sizeof(float));
368
369 get_sample_bits(buf, bits);
370
371 for (i = 0; i < 2; i++) {
372 aptr = audio+i*128;
373 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
374 skip_bits(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
375
376 for (j = 0; j < NELLY_FILL_LEN; j++) {
377 if (bits[j] <= 0) {
378 buf[j] = M_SQRT1_2*pows[j];
379 if (av_random(&s->random_state) & 1)
380 buf[j] *= -1.0;
381 } else {
382 v = get_bits(&s->gb, bits[j]);
383 buf[j] = dequantization_table[(1<<bits[j])-1+v]*pows[j];
384 }
385 }
386
387 antialias(buf, aptr);
388 ff_fft_permute(&s->fftc, (FFTComplex*)aptr);
389 ff_fft_calc(&s->fftc, (FFTComplex*)aptr);
390 complex2signal(aptr);
391 overlap_and_window(s, s->state, aptr);
392 }
393}
394
395static int decode_init(AVCodecContext * avctx) {
396 NellyMoserDecodeContext *s = avctx->priv_data;
397 int i;
398 float alpha;
399
400 s->avctx = avctx;
401 av_init_random(0, &s->random_state);
402 ff_fft_init(&s->fftc, 6, 1);
403 dsputil_init(&s->dsp, avctx);
404
405 if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
406 s->add_bias = 385;
407 s->scale_bias = 32768;
408 } else {
409 s->add_bias = 0;
410 s->scale_bias = 1;
411 }
412
413 /* Generate overlap window */
414 if (!sine_window[0])
415 for (i=0 ; i<128; i++) {
416 sine_window[i] = sin((i + 0.5) / 256.0 * M_PI);
417 }
418
419 /* Generate tables */
420 if (!tcos[0])
421 for(i=0;i<64;i++) {
422 alpha = 2*M_PI * (i + 1.0 / 4.0) / 256;
423 tcos[i] = cos(alpha);
424 tsin[i] = -sin(alpha);
425 cos_tab[i] = cos(i/128.0*M_PI)/8.0;
426 }
427
428 return 0;
429}
430
431static int decode_tag(AVCodecContext * avctx,
432 void *data, int *data_size,
433 uint8_t * buf, int buf_size) {
434 NellyMoserDecodeContext *s = avctx->priv_data;
435 int blocks, i;
436 int16_t* samples;
437 *data_size = 0;
438 samples = (int16_t*)data;
439
440 if (buf_size < avctx->block_align)
441 return buf_size;
442
443 switch (buf_size) {
444 case 64: // 8000Hz
445 blocks = 1; break;
446 case 128: // 11025Hz
447 blocks = 2; break;
448 case 256: // 22050Hz
449 blocks = 4; break;
450 default:
451 av_log(avctx, AV_LOG_DEBUG, "Tag size %d unknown, report sample!\n", buf_size);
452 return buf_size;
453 }
454
455 for (i=0 ; i<blocks ; i++) {
456 nelly_decode_block(s, &buf[i*NELLY_BLOCK_LEN], s->float_buf);
457 s->dsp.float_to_int16(&samples[i*NELLY_SAMPLES], s->float_buf, NELLY_SAMPLES);
458 *data_size += NELLY_SAMPLES*sizeof(int16_t);
459 }
460
461 return blocks*NELLY_SAMPLES*sizeof(int16_t);
462}
463
464static int decode_end(AVCodecContext * avctx) {
465 NellyMoserDecodeContext *s = avctx->priv_data;
466
467 ff_fft_end(&s->fftc);
468 return 0;
469}
470
471AVCodec nellymoser_decoder = {
472 "nellymoser",
473 CODEC_TYPE_AUDIO,
474 CODEC_ID_NELLYMOSER,
475 sizeof(NellyMoserDecodeContext),
476 decode_init,
477 NULL,
478 decode_end,
479 decode_tag,
480};
481