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sonic.c
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1 /*
2  * Simple free lossless/lossy audio codec
3  * Copyright (c) 2004 Alex Beregszaszi
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 #include "avcodec.h"
22 #include "get_bits.h"
23 #include "golomb.h"
24 #include "internal.h"
25 #include "rangecoder.h"
26 
27 
28 /**
29  * @file
30  * Simple free lossless/lossy audio codec
31  * Based on Paul Francis Harrison's Bonk (http://www.logarithmic.net/pfh/bonk)
32  * Written and designed by Alex Beregszaszi
33  *
34  * TODO:
35  * - CABAC put/get_symbol
36  * - independent quantizer for channels
37  * - >2 channels support
38  * - more decorrelation types
39  * - more tap_quant tests
40  * - selectable intlist writers/readers (bonk-style, golomb, cabac)
41  */
42 
43 #define MAX_CHANNELS 2
44 
45 #define MID_SIDE 0
46 #define LEFT_SIDE 1
47 #define RIGHT_SIDE 2
48 
49 typedef struct SonicContext {
50  int version;
53 
55  double quantization;
56 
58 
59  int *tap_quant;
62 
63  // for encoding
64  int *tail;
65  int tail_size;
66  int *window;
68 
69  // for decoding
72 } SonicContext;
73 
74 #define LATTICE_SHIFT 10
75 #define SAMPLE_SHIFT 4
76 #define LATTICE_FACTOR (1 << LATTICE_SHIFT)
77 #define SAMPLE_FACTOR (1 << SAMPLE_SHIFT)
78 
79 #define BASE_QUANT 0.6
80 #define RATE_VARIATION 3.0
81 
82 static inline int shift(int a,int b)
83 {
84  return (a+(1<<(b-1))) >> b;
85 }
86 
87 static inline int shift_down(int a,int b)
88 {
89  return (a>>b)+(a<0);
90 }
91 
92 static av_always_inline av_flatten void put_symbol(RangeCoder *c, uint8_t *state, int v, int is_signed, uint64_t rc_stat[256][2], uint64_t rc_stat2[32][2]){
93  int i;
94 
95 #define put_rac(C,S,B) \
96 do{\
97  if(rc_stat){\
98  rc_stat[*(S)][B]++;\
99  rc_stat2[(S)-state][B]++;\
100  }\
101  put_rac(C,S,B);\
102 }while(0)
103 
104  if(v){
105  const int a= FFABS(v);
106  const int e= av_log2(a);
107  put_rac(c, state+0, 0);
108  if(e<=9){
109  for(i=0; i<e; i++){
110  put_rac(c, state+1+i, 1); //1..10
111  }
112  put_rac(c, state+1+i, 0);
113 
114  for(i=e-1; i>=0; i--){
115  put_rac(c, state+22+i, (a>>i)&1); //22..31
116  }
117 
118  if(is_signed)
119  put_rac(c, state+11 + e, v < 0); //11..21
120  }else{
121  for(i=0; i<e; i++){
122  put_rac(c, state+1+FFMIN(i,9), 1); //1..10
123  }
124  put_rac(c, state+1+9, 0);
125 
126  for(i=e-1; i>=0; i--){
127  put_rac(c, state+22+FFMIN(i,9), (a>>i)&1); //22..31
128  }
129 
130  if(is_signed)
131  put_rac(c, state+11 + 10, v < 0); //11..21
132  }
133  }else{
134  put_rac(c, state+0, 1);
135  }
136 #undef put_rac
137 }
138 
139 static inline av_flatten int get_symbol(RangeCoder *c, uint8_t *state, int is_signed){
140  if(get_rac(c, state+0))
141  return 0;
142  else{
143  int i, e, a;
144  e= 0;
145  while(get_rac(c, state+1 + FFMIN(e,9))){ //1..10
146  e++;
147  }
148 
149  a= 1;
150  for(i=e-1; i>=0; i--){
151  a += a + get_rac(c, state+22 + FFMIN(i,9)); //22..31
152  }
153 
154  e= -(is_signed && get_rac(c, state+11 + FFMIN(e, 10))); //11..21
155  return (a^e)-e;
156  }
157 }
158 
159 #if 1
160 static inline int intlist_write(RangeCoder *c, uint8_t *state, int *buf, int entries, int base_2_part)
161 {
162  int i;
163 
164  for (i = 0; i < entries; i++)
165  put_symbol(c, state, buf[i], 1, NULL, NULL);
166 
167  return 1;
168 }
169 
170 static inline int intlist_read(RangeCoder *c, uint8_t *state, int *buf, int entries, int base_2_part)
171 {
172  int i;
173 
174  for (i = 0; i < entries; i++)
175  buf[i] = get_symbol(c, state, 1);
176 
177  return 1;
178 }
179 #elif 1
180 static inline int intlist_write(PutBitContext *pb, int *buf, int entries, int base_2_part)
181 {
182  int i;
183 
184  for (i = 0; i < entries; i++)
185  set_se_golomb(pb, buf[i]);
186 
187  return 1;
188 }
189 
190 static inline int intlist_read(GetBitContext *gb, int *buf, int entries, int base_2_part)
191 {
192  int i;
193 
194  for (i = 0; i < entries; i++)
195  buf[i] = get_se_golomb(gb);
196 
197  return 1;
198 }
199 
200 #else
201 
202 #define ADAPT_LEVEL 8
203 
204 static int bits_to_store(uint64_t x)
205 {
206  int res = 0;
207 
208  while(x)
209  {
210  res++;
211  x >>= 1;
212  }
213  return res;
214 }
215 
216 static void write_uint_max(PutBitContext *pb, unsigned int value, unsigned int max)
217 {
218  int i, bits;
219 
220  if (!max)
221  return;
222 
223  bits = bits_to_store(max);
224 
225  for (i = 0; i < bits-1; i++)
226  put_bits(pb, 1, value & (1 << i));
227 
228  if ( (value | (1 << (bits-1))) <= max)
229  put_bits(pb, 1, value & (1 << (bits-1)));
230 }
231 
232 static unsigned int read_uint_max(GetBitContext *gb, int max)
233 {
234  int i, bits, value = 0;
235 
236  if (!max)
237  return 0;
238 
239  bits = bits_to_store(max);
240 
241  for (i = 0; i < bits-1; i++)
242  if (get_bits1(gb))
243  value += 1 << i;
244 
245  if ( (value | (1<<(bits-1))) <= max)
246  if (get_bits1(gb))
247  value += 1 << (bits-1);
248 
249  return value;
250 }
251 
252 static int intlist_write(PutBitContext *pb, int *buf, int entries, int base_2_part)
253 {
254  int i, j, x = 0, low_bits = 0, max = 0;
255  int step = 256, pos = 0, dominant = 0, any = 0;
256  int *copy, *bits;
257 
258  copy = av_calloc(entries, sizeof(*copy));
259  if (!copy)
260  return AVERROR(ENOMEM);
261 
262  if (base_2_part)
263  {
264  int energy = 0;
265 
266  for (i = 0; i < entries; i++)
267  energy += abs(buf[i]);
268 
269  low_bits = bits_to_store(energy / (entries * 2));
270  if (low_bits > 15)
271  low_bits = 15;
272 
273  put_bits(pb, 4, low_bits);
274  }
275 
276  for (i = 0; i < entries; i++)
277  {
278  put_bits(pb, low_bits, abs(buf[i]));
279  copy[i] = abs(buf[i]) >> low_bits;
280  if (copy[i] > max)
281  max = abs(copy[i]);
282  }
283 
284  bits = av_calloc(entries*max, sizeof(*bits));
285  if (!bits)
286  {
287  av_free(copy);
288  return AVERROR(ENOMEM);
289  }
290 
291  for (i = 0; i <= max; i++)
292  {
293  for (j = 0; j < entries; j++)
294  if (copy[j] >= i)
295  bits[x++] = copy[j] > i;
296  }
297 
298  // store bitstream
299  while (pos < x)
300  {
301  int steplet = step >> 8;
302 
303  if (pos + steplet > x)
304  steplet = x - pos;
305 
306  for (i = 0; i < steplet; i++)
307  if (bits[i+pos] != dominant)
308  any = 1;
309 
310  put_bits(pb, 1, any);
311 
312  if (!any)
313  {
314  pos += steplet;
315  step += step / ADAPT_LEVEL;
316  }
317  else
318  {
319  int interloper = 0;
320 
321  while (((pos + interloper) < x) && (bits[pos + interloper] == dominant))
322  interloper++;
323 
324  // note change
325  write_uint_max(pb, interloper, (step >> 8) - 1);
326 
327  pos += interloper + 1;
328  step -= step / ADAPT_LEVEL;
329  }
330 
331  if (step < 256)
332  {
333  step = 65536 / step;
334  dominant = !dominant;
335  }
336  }
337 
338  // store signs
339  for (i = 0; i < entries; i++)
340  if (buf[i])
341  put_bits(pb, 1, buf[i] < 0);
342 
343  av_free(bits);
344  av_free(copy);
345 
346  return 0;
347 }
348 
349 static int intlist_read(GetBitContext *gb, int *buf, int entries, int base_2_part)
350 {
351  int i, low_bits = 0, x = 0;
352  int n_zeros = 0, step = 256, dominant = 0;
353  int pos = 0, level = 0;
354  int *bits = av_calloc(entries, sizeof(*bits));
355 
356  if (!bits)
357  return AVERROR(ENOMEM);
358 
359  if (base_2_part)
360  {
361  low_bits = get_bits(gb, 4);
362 
363  if (low_bits)
364  for (i = 0; i < entries; i++)
365  buf[i] = get_bits(gb, low_bits);
366  }
367 
368 // av_log(NULL, AV_LOG_INFO, "entries: %d, low bits: %d\n", entries, low_bits);
369 
370  while (n_zeros < entries)
371  {
372  int steplet = step >> 8;
373 
374  if (!get_bits1(gb))
375  {
376  for (i = 0; i < steplet; i++)
377  bits[x++] = dominant;
378 
379  if (!dominant)
380  n_zeros += steplet;
381 
382  step += step / ADAPT_LEVEL;
383  }
384  else
385  {
386  int actual_run = read_uint_max(gb, steplet-1);
387 
388 // av_log(NULL, AV_LOG_INFO, "actual run: %d\n", actual_run);
389 
390  for (i = 0; i < actual_run; i++)
391  bits[x++] = dominant;
392 
393  bits[x++] = !dominant;
394 
395  if (!dominant)
396  n_zeros += actual_run;
397  else
398  n_zeros++;
399 
400  step -= step / ADAPT_LEVEL;
401  }
402 
403  if (step < 256)
404  {
405  step = 65536 / step;
406  dominant = !dominant;
407  }
408  }
409 
410  // reconstruct unsigned values
411  n_zeros = 0;
412  for (i = 0; n_zeros < entries; i++)
413  {
414  while(1)
415  {
416  if (pos >= entries)
417  {
418  pos = 0;
419  level += 1 << low_bits;
420  }
421 
422  if (buf[pos] >= level)
423  break;
424 
425  pos++;
426  }
427 
428  if (bits[i])
429  buf[pos] += 1 << low_bits;
430  else
431  n_zeros++;
432 
433  pos++;
434  }
435  av_free(bits);
436 
437  // read signs
438  for (i = 0; i < entries; i++)
439  if (buf[i] && get_bits1(gb))
440  buf[i] = -buf[i];
441 
442 // av_log(NULL, AV_LOG_INFO, "zeros: %d pos: %d\n", n_zeros, pos);
443 
444  return 0;
445 }
446 #endif
447 
448 static void predictor_init_state(int *k, int *state, int order)
449 {
450  int i;
451 
452  for (i = order-2; i >= 0; i--)
453  {
454  int j, p, x = state[i];
455 
456  for (j = 0, p = i+1; p < order; j++,p++)
457  {
458  int tmp = x + shift_down(k[j] * state[p], LATTICE_SHIFT);
459  state[p] += shift_down(k[j]*x, LATTICE_SHIFT);
460  x = tmp;
461  }
462  }
463 }
464 
465 static int predictor_calc_error(int *k, int *state, int order, int error)
466 {
467  int i, x = error - shift_down(k[order-1] * state[order-1], LATTICE_SHIFT);
468 
469 #if 1
470  int *k_ptr = &(k[order-2]),
471  *state_ptr = &(state[order-2]);
472  for (i = order-2; i >= 0; i--, k_ptr--, state_ptr--)
473  {
474  int k_value = *k_ptr, state_value = *state_ptr;
475  x -= shift_down(k_value * state_value, LATTICE_SHIFT);
476  state_ptr[1] = state_value + shift_down(k_value * x, LATTICE_SHIFT);
477  }
478 #else
479  for (i = order-2; i >= 0; i--)
480  {
481  x -= shift_down(k[i] * state[i], LATTICE_SHIFT);
482  state[i+1] = state[i] + shift_down(k[i] * x, LATTICE_SHIFT);
483  }
484 #endif
485 
486  // don't drift too far, to avoid overflows
487  if (x > (SAMPLE_FACTOR<<16)) x = (SAMPLE_FACTOR<<16);
488  if (x < -(SAMPLE_FACTOR<<16)) x = -(SAMPLE_FACTOR<<16);
489 
490  state[0] = x;
491 
492  return x;
493 }
494 
495 #if CONFIG_SONIC_ENCODER || CONFIG_SONIC_LS_ENCODER
496 // Heavily modified Levinson-Durbin algorithm which
497 // copes better with quantization, and calculates the
498 // actual whitened result as it goes.
499 
500 static void modified_levinson_durbin(int *window, int window_entries,
501  int *out, int out_entries, int channels, int *tap_quant)
502 {
503  int i;
504  int *state = av_calloc(window_entries, sizeof(*state));
505 
506  memcpy(state, window, 4* window_entries);
507 
508  for (i = 0; i < out_entries; i++)
509  {
510  int step = (i+1)*channels, k, j;
511  double xx = 0.0, xy = 0.0;
512 #if 1
513  int *x_ptr = &(window[step]);
514  int *state_ptr = &(state[0]);
515  j = window_entries - step;
516  for (;j>0;j--,x_ptr++,state_ptr++)
517  {
518  double x_value = *x_ptr;
519  double state_value = *state_ptr;
520  xx += state_value*state_value;
521  xy += x_value*state_value;
522  }
523 #else
524  for (j = 0; j <= (window_entries - step); j++);
525  {
526  double stepval = window[step+j];
527  double stateval = window[j];
528 // xx += (double)window[j]*(double)window[j];
529 // xy += (double)window[step+j]*(double)window[j];
530  xx += stateval*stateval;
531  xy += stepval*stateval;
532  }
533 #endif
534  if (xx == 0.0)
535  k = 0;
536  else
537  k = (int)(floor(-xy/xx * (double)LATTICE_FACTOR / (double)(tap_quant[i]) + 0.5));
538 
539  if (k > (LATTICE_FACTOR/tap_quant[i]))
540  k = LATTICE_FACTOR/tap_quant[i];
541  if (-k > (LATTICE_FACTOR/tap_quant[i]))
542  k = -(LATTICE_FACTOR/tap_quant[i]);
543 
544  out[i] = k;
545  k *= tap_quant[i];
546 
547 #if 1
548  x_ptr = &(window[step]);
549  state_ptr = &(state[0]);
550  j = window_entries - step;
551  for (;j>0;j--,x_ptr++,state_ptr++)
552  {
553  int x_value = *x_ptr;
554  int state_value = *state_ptr;
555  *x_ptr = x_value + shift_down(k*state_value,LATTICE_SHIFT);
556  *state_ptr = state_value + shift_down(k*x_value, LATTICE_SHIFT);
557  }
558 #else
559  for (j=0; j <= (window_entries - step); j++)
560  {
561  int stepval = window[step+j];
562  int stateval=state[j];
563  window[step+j] += shift_down(k * stateval, LATTICE_SHIFT);
564  state[j] += shift_down(k * stepval, LATTICE_SHIFT);
565  }
566 #endif
567  }
568 
569  av_free(state);
570 }
571 
572 static inline int code_samplerate(int samplerate)
573 {
574  switch (samplerate)
575  {
576  case 44100: return 0;
577  case 22050: return 1;
578  case 11025: return 2;
579  case 96000: return 3;
580  case 48000: return 4;
581  case 32000: return 5;
582  case 24000: return 6;
583  case 16000: return 7;
584  case 8000: return 8;
585  }
586  return AVERROR(EINVAL);
587 }
588 
589 static av_cold int sonic_encode_init(AVCodecContext *avctx)
590 {
591  SonicContext *s = avctx->priv_data;
592  PutBitContext pb;
593  int i;
594 
595  s->version = 2;
596 
597  if (avctx->channels > MAX_CHANNELS)
598  {
599  av_log(avctx, AV_LOG_ERROR, "Only mono and stereo streams are supported by now\n");
600  return AVERROR(EINVAL); /* only stereo or mono for now */
601  }
602 
603  if (avctx->channels == 2)
604  s->decorrelation = MID_SIDE;
605  else
606  s->decorrelation = 3;
607 
608  if (avctx->codec->id == AV_CODEC_ID_SONIC_LS)
609  {
610  s->lossless = 1;
611  s->num_taps = 32;
612  s->downsampling = 1;
613  s->quantization = 0.0;
614  }
615  else
616  {
617  s->num_taps = 128;
618  s->downsampling = 2;
619  s->quantization = 1.0;
620  }
621 
622  // max tap 2048
623  if (s->num_taps < 32 || s->num_taps > 1024 || s->num_taps % 32) {
624  av_log(avctx, AV_LOG_ERROR, "Invalid number of taps\n");
625  return AVERROR_INVALIDDATA;
626  }
627 
628  // generate taps
629  s->tap_quant = av_calloc(s->num_taps, sizeof(*s->tap_quant));
630  for (i = 0; i < s->num_taps; i++)
631  s->tap_quant[i] = ff_sqrt(i+1);
632 
633  s->channels = avctx->channels;
634  s->samplerate = avctx->sample_rate;
635 
636  s->block_align = 2048LL*s->samplerate/(44100*s->downsampling);
638 
639  s->tail_size = s->num_taps*s->channels;
640  s->tail = av_calloc(s->tail_size, sizeof(*s->tail));
641  if (!s->tail)
642  return AVERROR(ENOMEM);
643 
644  s->predictor_k = av_calloc(s->num_taps, sizeof(*s->predictor_k) );
645  if (!s->predictor_k)
646  return AVERROR(ENOMEM);
647 
648  for (i = 0; i < s->channels; i++)
649  {
650  s->coded_samples[i] = av_calloc(s->block_align, sizeof(**s->coded_samples));
651  if (!s->coded_samples[i])
652  return AVERROR(ENOMEM);
653  }
654 
655  s->int_samples = av_calloc(s->frame_size, sizeof(*s->int_samples));
656 
657  s->window_size = ((2*s->tail_size)+s->frame_size);
658  s->window = av_calloc(s->window_size, sizeof(*s->window));
659  if (!s->window)
660  return AVERROR(ENOMEM);
661 
662  avctx->extradata = av_mallocz(16);
663  if (!avctx->extradata)
664  return AVERROR(ENOMEM);
665  init_put_bits(&pb, avctx->extradata, 16*8);
666 
667  put_bits(&pb, 2, s->version); // version
668  if (s->version >= 1)
669  {
670  if (s->version >= 2) {
671  put_bits(&pb, 8, s->version);
672  put_bits(&pb, 8, s->minor_version);
673  }
674  put_bits(&pb, 2, s->channels);
675  put_bits(&pb, 4, code_samplerate(s->samplerate));
676  }
677  put_bits(&pb, 1, s->lossless);
678  if (!s->lossless)
679  put_bits(&pb, 3, SAMPLE_SHIFT); // XXX FIXME: sample precision
680  put_bits(&pb, 2, s->decorrelation);
681  put_bits(&pb, 2, s->downsampling);
682  put_bits(&pb, 5, (s->num_taps >> 5)-1); // 32..1024
683  put_bits(&pb, 1, 0); // XXX FIXME: no custom tap quant table
684 
685  flush_put_bits(&pb);
686  avctx->extradata_size = put_bits_count(&pb)/8;
687 
688  av_log(avctx, AV_LOG_INFO, "Sonic: ver: %d.%d ls: %d dr: %d taps: %d block: %d frame: %d downsamp: %d\n",
690 
691  avctx->frame_size = s->block_align*s->downsampling;
692 
693  return 0;
694 }
695 
696 static av_cold int sonic_encode_close(AVCodecContext *avctx)
697 {
698  SonicContext *s = avctx->priv_data;
699  int i;
700 
701  for (i = 0; i < s->channels; i++)
702  av_freep(&s->coded_samples[i]);
703 
704  av_freep(&s->predictor_k);
705  av_freep(&s->tail);
706  av_freep(&s->tap_quant);
707  av_freep(&s->window);
708  av_freep(&s->int_samples);
709 
710  return 0;
711 }
712 
713 static int sonic_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
714  const AVFrame *frame, int *got_packet_ptr)
715 {
716  SonicContext *s = avctx->priv_data;
717  RangeCoder c;
718  int i, j, ch, quant = 0, x = 0;
719  int ret;
720  const short *samples = (const int16_t*)frame->data[0];
721  uint8_t state[32];
722 
723  if ((ret = ff_alloc_packet2(avctx, avpkt, s->frame_size * 5 + 1000)) < 0)
724  return ret;
725 
726  ff_init_range_encoder(&c, avpkt->data, avpkt->size);
727  ff_build_rac_states(&c, 0.05*(1LL<<32), 256-8);
728  memset(state, 128, sizeof(state));
729 
730  // short -> internal
731  for (i = 0; i < s->frame_size; i++)
732  s->int_samples[i] = samples[i];
733 
734  if (!s->lossless)
735  for (i = 0; i < s->frame_size; i++)
736  s->int_samples[i] = s->int_samples[i] << SAMPLE_SHIFT;
737 
738  switch(s->decorrelation)
739  {
740  case MID_SIDE:
741  for (i = 0; i < s->frame_size; i += s->channels)
742  {
743  s->int_samples[i] += s->int_samples[i+1];
744  s->int_samples[i+1] -= shift(s->int_samples[i], 1);
745  }
746  break;
747  case LEFT_SIDE:
748  for (i = 0; i < s->frame_size; i += s->channels)
749  s->int_samples[i+1] -= s->int_samples[i];
750  break;
751  case RIGHT_SIDE:
752  for (i = 0; i < s->frame_size; i += s->channels)
753  s->int_samples[i] -= s->int_samples[i+1];
754  break;
755  }
756 
757  memset(s->window, 0, 4* s->window_size);
758 
759  for (i = 0; i < s->tail_size; i++)
760  s->window[x++] = s->tail[i];
761 
762  for (i = 0; i < s->frame_size; i++)
763  s->window[x++] = s->int_samples[i];
764 
765  for (i = 0; i < s->tail_size; i++)
766  s->window[x++] = 0;
767 
768  for (i = 0; i < s->tail_size; i++)
769  s->tail[i] = s->int_samples[s->frame_size - s->tail_size + i];
770 
771  // generate taps
772  modified_levinson_durbin(s->window, s->window_size,
773  s->predictor_k, s->num_taps, s->channels, s->tap_quant);
774  if ((ret = intlist_write(&c, state, s->predictor_k, s->num_taps, 0)) < 0)
775  return ret;
776 
777  for (ch = 0; ch < s->channels; ch++)
778  {
779  x = s->tail_size+ch;
780  for (i = 0; i < s->block_align; i++)
781  {
782  int sum = 0;
783  for (j = 0; j < s->downsampling; j++, x += s->channels)
784  sum += s->window[x];
785  s->coded_samples[ch][i] = sum;
786  }
787  }
788 
789  // simple rate control code
790  if (!s->lossless)
791  {
792  double energy1 = 0.0, energy2 = 0.0;
793  for (ch = 0; ch < s->channels; ch++)
794  {
795  for (i = 0; i < s->block_align; i++)
796  {
797  double sample = s->coded_samples[ch][i];
798  energy2 += sample*sample;
799  energy1 += fabs(sample);
800  }
801  }
802 
803  energy2 = sqrt(energy2/(s->channels*s->block_align));
804  energy1 = M_SQRT2*energy1/(s->channels*s->block_align);
805 
806  // increase bitrate when samples are like a gaussian distribution
807  // reduce bitrate when samples are like a two-tailed exponential distribution
808 
809  if (energy2 > energy1)
810  energy2 += (energy2-energy1)*RATE_VARIATION;
811 
812  quant = (int)(BASE_QUANT*s->quantization*energy2/SAMPLE_FACTOR);
813 // av_log(avctx, AV_LOG_DEBUG, "quant: %d energy: %f / %f\n", quant, energy1, energy2);
814 
815  quant = av_clip(quant, 1, 65534);
816 
817  put_symbol(&c, state, quant, 0, NULL, NULL);
818 
819  quant *= SAMPLE_FACTOR;
820  }
821 
822  // write out coded samples
823  for (ch = 0; ch < s->channels; ch++)
824  {
825  if (!s->lossless)
826  for (i = 0; i < s->block_align; i++)
827  s->coded_samples[ch][i] = ROUNDED_DIV(s->coded_samples[ch][i], quant);
828 
829  if ((ret = intlist_write(&c, state, s->coded_samples[ch], s->block_align, 1)) < 0)
830  return ret;
831  }
832 
833 // av_log(avctx, AV_LOG_DEBUG, "used bytes: %d\n", (put_bits_count(&pb)+7)/8);
834 
835  avpkt->size = ff_rac_terminate(&c);
836  *got_packet_ptr = 1;
837  return 0;
838 
839 }
840 #endif /* CONFIG_SONIC_ENCODER || CONFIG_SONIC_LS_ENCODER */
841 
842 #if CONFIG_SONIC_DECODER
843 static const int samplerate_table[] =
844  { 44100, 22050, 11025, 96000, 48000, 32000, 24000, 16000, 8000 };
845 
846 static av_cold int sonic_decode_init(AVCodecContext *avctx)
847 {
848  SonicContext *s = avctx->priv_data;
849  GetBitContext gb;
850  int i;
851 
852  s->channels = avctx->channels;
853  s->samplerate = avctx->sample_rate;
854 
855  if (!avctx->extradata)
856  {
857  av_log(avctx, AV_LOG_ERROR, "No mandatory headers present\n");
858  return AVERROR_INVALIDDATA;
859  }
860 
861  init_get_bits8(&gb, avctx->extradata, avctx->extradata_size);
862 
863  s->version = get_bits(&gb, 2);
864  if (s->version >= 2) {
865  s->version = get_bits(&gb, 8);
866  s->minor_version = get_bits(&gb, 8);
867  }
868  if (s->version != 2)
869  {
870  av_log(avctx, AV_LOG_ERROR, "Unsupported Sonic version, please report\n");
871  return AVERROR_INVALIDDATA;
872  }
873 
874  if (s->version >= 1)
875  {
876  s->channels = get_bits(&gb, 2);
877  s->samplerate = samplerate_table[get_bits(&gb, 4)];
878  av_log(avctx, AV_LOG_INFO, "Sonicv2 chans: %d samprate: %d\n",
879  s->channels, s->samplerate);
880  }
881 
882  if (s->channels > MAX_CHANNELS)
883  {
884  av_log(avctx, AV_LOG_ERROR, "Only mono and stereo streams are supported by now\n");
885  return AVERROR_INVALIDDATA;
886  }
887 
888  s->lossless = get_bits1(&gb);
889  if (!s->lossless)
890  skip_bits(&gb, 3); // XXX FIXME
891  s->decorrelation = get_bits(&gb, 2);
892  if (s->decorrelation != 3 && s->channels != 2) {
893  av_log(avctx, AV_LOG_ERROR, "invalid decorrelation %d\n", s->decorrelation);
894  return AVERROR_INVALIDDATA;
895  }
896 
897  s->downsampling = get_bits(&gb, 2);
898  if (!s->downsampling) {
899  av_log(avctx, AV_LOG_ERROR, "invalid downsampling value\n");
900  return AVERROR_INVALIDDATA;
901  }
902 
903  s->num_taps = (get_bits(&gb, 5)+1)<<5;
904  if (get_bits1(&gb)) // XXX FIXME
905  av_log(avctx, AV_LOG_INFO, "Custom quant table\n");
906 
907  s->block_align = 2048LL*s->samplerate/(44100*s->downsampling);
909 // avctx->frame_size = s->block_align;
910 
911  av_log(avctx, AV_LOG_INFO, "Sonic: ver: %d.%d ls: %d dr: %d taps: %d block: %d frame: %d downsamp: %d\n",
913 
914  // generate taps
915  s->tap_quant = av_calloc(s->num_taps, sizeof(*s->tap_quant));
916  for (i = 0; i < s->num_taps; i++)
917  s->tap_quant[i] = ff_sqrt(i+1);
918 
919  s->predictor_k = av_calloc(s->num_taps, sizeof(*s->predictor_k));
920 
921  for (i = 0; i < s->channels; i++)
922  {
923  s->predictor_state[i] = av_calloc(s->num_taps, sizeof(**s->predictor_state));
924  if (!s->predictor_state[i])
925  return AVERROR(ENOMEM);
926  }
927 
928  for (i = 0; i < s->channels; i++)
929  {
930  s->coded_samples[i] = av_calloc(s->block_align, sizeof(**s->coded_samples));
931  if (!s->coded_samples[i])
932  return AVERROR(ENOMEM);
933  }
934  s->int_samples = av_calloc(s->frame_size, sizeof(*s->int_samples));
935 
936  avctx->sample_fmt = AV_SAMPLE_FMT_S16;
937  return 0;
938 }
939 
940 static av_cold int sonic_decode_close(AVCodecContext *avctx)
941 {
942  SonicContext *s = avctx->priv_data;
943  int i;
944 
945  av_freep(&s->int_samples);
946  av_freep(&s->tap_quant);
947  av_freep(&s->predictor_k);
948 
949  for (i = 0; i < s->channels; i++)
950  {
951  av_freep(&s->predictor_state[i]);
952  av_freep(&s->coded_samples[i]);
953  }
954 
955  return 0;
956 }
957 
958 static int sonic_decode_frame(AVCodecContext *avctx,
959  void *data, int *got_frame_ptr,
960  AVPacket *avpkt)
961 {
962  const uint8_t *buf = avpkt->data;
963  int buf_size = avpkt->size;
964  SonicContext *s = avctx->priv_data;
965  RangeCoder c;
966  uint8_t state[32];
967  int i, quant, ch, j, ret;
968  int16_t *samples;
969  AVFrame *frame = data;
970 
971  if (buf_size == 0) return 0;
972 
973  frame->nb_samples = s->frame_size / avctx->channels;
974  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
975  return ret;
976  samples = (int16_t *)frame->data[0];
977 
978 // av_log(NULL, AV_LOG_INFO, "buf_size: %d\n", buf_size);
979 
980  memset(state, 128, sizeof(state));
981  ff_init_range_decoder(&c, buf, buf_size);
982  ff_build_rac_states(&c, 0.05*(1LL<<32), 256-8);
983 
984  intlist_read(&c, state, s->predictor_k, s->num_taps, 0);
985 
986  // dequantize
987  for (i = 0; i < s->num_taps; i++)
988  s->predictor_k[i] *= s->tap_quant[i];
989 
990  if (s->lossless)
991  quant = 1;
992  else
993  quant = get_symbol(&c, state, 0) * SAMPLE_FACTOR;
994 
995 // av_log(NULL, AV_LOG_INFO, "quant: %d\n", quant);
996 
997  for (ch = 0; ch < s->channels; ch++)
998  {
999  int x = ch;
1000 
1002 
1003  intlist_read(&c, state, s->coded_samples[ch], s->block_align, 1);
1004 
1005  for (i = 0; i < s->block_align; i++)
1006  {
1007  for (j = 0; j < s->downsampling - 1; j++)
1008  {
1010  x += s->channels;
1011  }
1012 
1013  s->int_samples[x] = predictor_calc_error(s->predictor_k, s->predictor_state[ch], s->num_taps, s->coded_samples[ch][i] * quant);
1014  x += s->channels;
1015  }
1016 
1017  for (i = 0; i < s->num_taps; i++)
1018  s->predictor_state[ch][i] = s->int_samples[s->frame_size - s->channels + ch - i*s->channels];
1019  }
1020 
1021  switch(s->decorrelation)
1022  {
1023  case MID_SIDE:
1024  for (i = 0; i < s->frame_size; i += s->channels)
1025  {
1026  s->int_samples[i+1] += shift(s->int_samples[i], 1);
1027  s->int_samples[i] -= s->int_samples[i+1];
1028  }
1029  break;
1030  case LEFT_SIDE:
1031  for (i = 0; i < s->frame_size; i += s->channels)
1032  s->int_samples[i+1] += s->int_samples[i];
1033  break;
1034  case RIGHT_SIDE:
1035  for (i = 0; i < s->frame_size; i += s->channels)
1036  s->int_samples[i] += s->int_samples[i+1];
1037  break;
1038  }
1039 
1040  if (!s->lossless)
1041  for (i = 0; i < s->frame_size; i++)
1042  s->int_samples[i] = shift(s->int_samples[i], SAMPLE_SHIFT);
1043 
1044  // internal -> short
1045  for (i = 0; i < s->frame_size; i++)
1046  samples[i] = av_clip_int16(s->int_samples[i]);
1047 
1048  *got_frame_ptr = 1;
1049 
1050  return buf_size;
1051 }
1052 
1053 AVCodec ff_sonic_decoder = {
1054  .name = "sonic",
1055  .long_name = NULL_IF_CONFIG_SMALL("Sonic"),
1056  .type = AVMEDIA_TYPE_AUDIO,
1057  .id = AV_CODEC_ID_SONIC,
1058  .priv_data_size = sizeof(SonicContext),
1059  .init = sonic_decode_init,
1060  .close = sonic_decode_close,
1061  .decode = sonic_decode_frame,
1062  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_EXPERIMENTAL,
1063 };
1064 #endif /* CONFIG_SONIC_DECODER */
1065 
1066 #if CONFIG_SONIC_ENCODER
1067 AVCodec ff_sonic_encoder = {
1068  .name = "sonic",
1069  .long_name = NULL_IF_CONFIG_SMALL("Sonic"),
1070  .type = AVMEDIA_TYPE_AUDIO,
1071  .id = AV_CODEC_ID_SONIC,
1072  .priv_data_size = sizeof(SonicContext),
1073  .init = sonic_encode_init,
1074  .encode2 = sonic_encode_frame,
1076  .capabilities = CODEC_CAP_EXPERIMENTAL,
1077  .close = sonic_encode_close,
1078 };
1079 #endif
1080 
1081 #if CONFIG_SONIC_LS_ENCODER
1082 AVCodec ff_sonic_ls_encoder = {
1083  .name = "sonicls",
1084  .long_name = NULL_IF_CONFIG_SMALL("Sonic lossless"),
1085  .type = AVMEDIA_TYPE_AUDIO,
1086  .id = AV_CODEC_ID_SONIC_LS,
1087  .priv_data_size = sizeof(SonicContext),
1088  .init = sonic_encode_init,
1089  .encode2 = sonic_encode_frame,
1091  .capabilities = CODEC_CAP_EXPERIMENTAL,
1092  .close = sonic_encode_close,
1093 };
1094 #endif