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mpc8.c
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1 /*
2  * Musepack SV8 decoder
3  * Copyright (c) 2007 Konstantin Shishkov
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 
22 /**
23  * @file
24  * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
25  * divided into 32 subbands.
26  */
27 
29 #include "libavutil/lfg.h"
30 #include "avcodec.h"
31 #include "get_bits.h"
32 #include "internal.h"
33 #include "mpegaudiodsp.h"
34 
35 #include "mpc.h"
36 #include "mpc8data.h"
37 #include "mpc8huff.h"
38 
39 static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
40 static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
41 
42 static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET };
44 
45 static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
46 {
47  int len = mpc8_cnk_len[k-1][n-1] - 1;
48  int code = len ? get_bits_long(gb, len) : 0;
49 
50  if (code >= mpc8_cnk_lost[k-1][n-1])
51  code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
52 
53  return code;
54 }
55 
56 static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
57 {
58  int bits = 0;
59  const uint32_t * C = mpc8_cnk[k-1];
60  int code = mpc8_dec_base(gb, k, n);
61 
62  do {
63  n--;
64  if (code >= C[n]) {
65  bits |= 1 << n;
66  code -= C[n];
67  C -= 32;
68  k--;
69  }
70  } while(k > 0);
71 
72  return bits;
73 }
74 
75 static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
76 {
77  if(mpc8_cnk_len[0][m] < 1) return 0;
78  return mpc8_dec_base(gb, 1, m+1);
79 }
80 
81 static int mpc8_get_mask(GetBitContext *gb, int size, int t)
82 {
83  int mask = 0;
84 
85  if(t && t != size)
86  mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
87  if((t << 1) > size) mask = ~mask;
88 
89  return mask;
90 }
91 
92 static const uint16_t vlc_offsets[13] = {
93  0, 640, 1184, 1748, 2298, 2426, 2554, 3066, 3578, 4106, 4618, 5196, 5708
94 };
95 
97 {
98  int i;
99  MPCContext *c = avctx->priv_data;
100  GetBitContext gb;
101  static int vlc_initialized = 0;
102  int channels;
103 
104  static VLC_TYPE band_table[542][2];
105  static VLC_TYPE q1_table[520][2];
106  static VLC_TYPE q9up_table[524][2];
107  static VLC_TYPE scfi0_table[1 << MPC8_SCFI0_BITS][2];
108  static VLC_TYPE scfi1_table[1 << MPC8_SCFI1_BITS][2];
109  static VLC_TYPE dscf0_table[560][2];
110  static VLC_TYPE dscf1_table[598][2];
111  static VLC_TYPE q3_0_table[512][2];
112  static VLC_TYPE q3_1_table[516][2];
113  static VLC_TYPE codes_table[5708][2];
114 
115  if(avctx->extradata_size < 2){
116  av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
117  return -1;
118  }
119  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
120  av_lfg_init(&c->rnd, 0xDEADBEEF);
121  ff_mpadsp_init(&c->mpadsp);
122 
123  ff_mpc_init();
124 
125  init_get_bits(&gb, avctx->extradata, 16);
126 
127  skip_bits(&gb, 3);//sample rate
128  c->maxbands = get_bits(&gb, 5) + 1;
129  if (c->maxbands >= BANDS) {
130  av_log(avctx,AV_LOG_ERROR, "maxbands %d too high\n", c->maxbands);
131  return AVERROR_INVALIDDATA;
132  }
133  channels = get_bits(&gb, 4) + 1;
134  if (channels > 2) {
135  avpriv_request_sample(avctx, "Multichannel MPC SV8");
136  return AVERROR_PATCHWELCOME;
137  }
138  c->MSS = get_bits1(&gb);
139  c->frames = 1 << (get_bits(&gb, 3) * 2);
140 
142  avctx->channel_layout = (channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
143  avctx->channels = channels;
144 
145  if(vlc_initialized) return 0;
146  av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
147 
148  band_vlc.table = band_table;
149  band_vlc.table_allocated = 542;
151  mpc8_bands_bits, 1, 1,
153 
154  q1_vlc.table = q1_table;
155  q1_vlc.table_allocated = 520;
157  mpc8_q1_bits, 1, 1,
159  q9up_vlc.table = q9up_table;
160  q9up_vlc.table_allocated = 524;
162  mpc8_q9up_bits, 1, 1,
164 
165  scfi_vlc[0].table = scfi0_table;
166  scfi_vlc[0].table_allocated = 1 << MPC8_SCFI0_BITS;
168  mpc8_scfi0_bits, 1, 1,
170  scfi_vlc[1].table = scfi1_table;
171  scfi_vlc[1].table_allocated = 1 << MPC8_SCFI1_BITS;
173  mpc8_scfi1_bits, 1, 1,
175 
176  dscf_vlc[0].table = dscf0_table;
177  dscf_vlc[0].table_allocated = 560;
179  mpc8_dscf0_bits, 1, 1,
181  dscf_vlc[1].table = dscf1_table;
182  dscf_vlc[1].table_allocated = 598;
184  mpc8_dscf1_bits, 1, 1,
186 
187  q3_vlc[0].table = q3_0_table;
188  q3_vlc[0].table_allocated = 512;
190  mpc8_q3_bits, 1, 1,
191  mpc8_q3_codes, 1, 1,
193  q3_vlc[1].table = q3_1_table;
194  q3_vlc[1].table_allocated = 516;
196  mpc8_q4_bits, 1, 1,
197  mpc8_q4_codes, 1, 1,
199 
200  for(i = 0; i < 2; i++){
201  res_vlc[i].table = &codes_table[vlc_offsets[0+i]];
202  res_vlc[i].table_allocated = vlc_offsets[1+i] - vlc_offsets[0+i];
203  init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,
204  &mpc8_res_bits[i], 1, 1,
206 
207  q2_vlc[i].table = &codes_table[vlc_offsets[2+i]];
208  q2_vlc[i].table_allocated = vlc_offsets[3+i] - vlc_offsets[2+i];
209  init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,
210  &mpc8_q2_bits[i], 1, 1,
212 
213  quant_vlc[0][i].table = &codes_table[vlc_offsets[4+i]];
214  quant_vlc[0][i].table_allocated = vlc_offsets[5+i] - vlc_offsets[4+i];
215  init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,
216  &mpc8_q5_bits[i], 1, 1,
218  quant_vlc[1][i].table = &codes_table[vlc_offsets[6+i]];
219  quant_vlc[1][i].table_allocated = vlc_offsets[7+i] - vlc_offsets[6+i];
220  init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,
221  &mpc8_q6_bits[i], 1, 1,
223  quant_vlc[2][i].table = &codes_table[vlc_offsets[8+i]];
224  quant_vlc[2][i].table_allocated = vlc_offsets[9+i] - vlc_offsets[8+i];
225  init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,
226  &mpc8_q7_bits[i], 1, 1,
228  quant_vlc[3][i].table = &codes_table[vlc_offsets[10+i]];
229  quant_vlc[3][i].table_allocated = vlc_offsets[11+i] - vlc_offsets[10+i];
230  init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,
231  &mpc8_q8_bits[i], 1, 1,
233  }
234  vlc_initialized = 1;
235 
236  return 0;
237 }
238 
239 static int mpc8_decode_frame(AVCodecContext * avctx, void *data,
240  int *got_frame_ptr, AVPacket *avpkt)
241 {
242  AVFrame *frame = data;
243  const uint8_t *buf = avpkt->data;
244  int buf_size = avpkt->size;
245  MPCContext *c = avctx->priv_data;
246  GetBitContext gb2, *gb = &gb2;
247  int i, j, k, ch, cnt, res, t;
248  Band *bands = c->bands;
249  int off;
250  int maxband, keyframe;
251  int last[2];
252 
253  /* get output buffer */
254  frame->nb_samples = MPC_FRAME_SIZE;
255  if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
256  return res;
257 
258  keyframe = c->cur_frame == 0;
259 
260  if(keyframe){
261  memset(c->Q, 0, sizeof(c->Q));
262  c->last_bits_used = 0;
263  }
264  init_get_bits(gb, buf, buf_size * 8);
265  skip_bits(gb, c->last_bits_used & 7);
266 
267  if(keyframe)
268  maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
269  else{
270  maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
271  if(maxband > 32) maxband -= 33;
272  }
273 
274  if(maxband > c->maxbands + 1) {
275  av_log(avctx, AV_LOG_ERROR, "maxband %d too large\n",maxband);
276  return AVERROR_INVALIDDATA;
277  }
278  c->last_max_band = maxband;
279 
280  /* read subband indexes */
281  if(maxband){
282  last[0] = last[1] = 0;
283  for(i = maxband - 1; i >= 0; i--){
284  for(ch = 0; ch < 2; ch++){
285  last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
286  if(last[ch] > 15) last[ch] -= 17;
287  bands[i].res[ch] = last[ch];
288  }
289  }
290  if(c->MSS){
291  int mask;
292 
293  cnt = 0;
294  for(i = 0; i < maxband; i++)
295  if(bands[i].res[0] || bands[i].res[1])
296  cnt++;
297  t = mpc8_get_mod_golomb(gb, cnt);
298  mask = mpc8_get_mask(gb, cnt, t);
299  for(i = maxband - 1; i >= 0; i--)
300  if(bands[i].res[0] || bands[i].res[1]){
301  bands[i].msf = mask & 1;
302  mask >>= 1;
303  }
304  }
305  }
306  for(i = maxband; i < c->maxbands; i++)
307  bands[i].res[0] = bands[i].res[1] = 0;
308 
309  if(keyframe){
310  for(i = 0; i < 32; i++)
311  c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
312  }
313 
314  for(i = 0; i < maxband; i++){
315  if(bands[i].res[0] || bands[i].res[1]){
316  cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
317  if(cnt >= 0){
318  t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
319  if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
320  if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
321  }
322  }
323  }
324 
325  for(i = 0; i < maxband; i++){
326  for(ch = 0; ch < 2; ch++){
327  if(!bands[i].res[ch]) continue;
328 
329  if(c->oldDSCF[ch][i]){
330  bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
331  c->oldDSCF[ch][i] = 0;
332  }else{
333  t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
334  if(t == 64)
335  t += get_bits(gb, 6);
336  bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
337  }
338  for(j = 0; j < 2; j++){
339  if((bands[i].scfi[ch] << j) & 2)
340  bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
341  else{
342  t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
343  if(t == 31)
344  t = 64 + get_bits(gb, 6);
345  bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
346  }
347  }
348  }
349  }
350 
351  for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
352  for(ch = 0; ch < 2; ch++){
353  res = bands[i].res[ch];
354  switch(res){
355  case -1:
356  for(j = 0; j < SAMPLES_PER_BAND; j++)
357  c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
358  break;
359  case 0:
360  break;
361  case 1:
362  for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
363  cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
364  t = mpc8_get_mask(gb, 18, cnt);
365  for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)
366  c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;
367  }
368  break;
369  case 2:
370  cnt = 6;//2*mpc8_thres[res]
371  for(j = 0; j < SAMPLES_PER_BAND; j += 3){
372  t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
373  c->Q[ch][off + j + 0] = mpc8_idx50[t];
374  c->Q[ch][off + j + 1] = mpc8_idx51[t];
375  c->Q[ch][off + j + 2] = mpc8_idx52[t];
376  cnt = (cnt >> 1) + mpc8_huffq2[t];
377  }
378  break;
379  case 3:
380  case 4:
381  for(j = 0; j < SAMPLES_PER_BAND; j += 2){
382  t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];
383  c->Q[ch][off + j + 1] = t >> 4;
384  c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);
385  }
386  break;
387  case 5:
388  case 6:
389  case 7:
390  case 8:
391  cnt = 2 * mpc8_thres[res];
392  for(j = 0; j < SAMPLES_PER_BAND; j++){
393  t = get_vlc2(gb, quant_vlc[res - 5][cnt > mpc8_thres[res]].table, quant_vlc[res - 5][cnt > mpc8_thres[res]].bits, 2) + quant_offsets[res - 5];
394  c->Q[ch][off + j] = t;
395  cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
396  }
397  break;
398  default:
399  for(j = 0; j < SAMPLES_PER_BAND; j++){
400  c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
401  if(res != 9){
402  c->Q[ch][off + j] <<= res - 9;
403  c->Q[ch][off + j] |= get_bits(gb, res - 9);
404  }
405  c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
406  }
407  }
408  }
409  }
410 
411  ff_mpc_dequantize_and_synth(c, maxband - 1,
412  (int16_t **)frame->extended_data,
413  avctx->channels);
414 
415  c->cur_frame++;
416 
418  if(get_bits_left(gb) < 8) // we have only padding left
419  c->last_bits_used = buf_size << 3;
420  if(c->cur_frame >= c->frames)
421  c->cur_frame = 0;
422 
423  *got_frame_ptr = 1;
424 
425  return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
426 }
427 
429 {
430  MPCContext *c = avctx->priv_data;
431  c->cur_frame = 0;
432 }
433 
435  .name = "mpc8",
436  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
437  .type = AVMEDIA_TYPE_AUDIO,
438  .id = AV_CODEC_ID_MUSEPACK8,
439  .priv_data_size = sizeof(MPCContext),
443  .capabilities = CODEC_CAP_DR1,
444  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
446 };