libavcodec/mpc8.c

   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 mpc8.c Musepack SV8 decoder
  24  * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
  25  * divided into 32 subbands.
  26  */
  27
  28 #include "libavutil/random.h"
  29 #include "avcodec.h"
  30 #include "bitstream.h"
  31 #include "dsputil.h"
  32
  33 #ifdef CONFIG_MPEGAUDIO_HP
  34 #define USE_HIGHPRECISION
  35 #endif
  36 #include "mpegaudio.h"
  37
  38 #include "mpc.h"
  39 #include "mpcdata.h"
  40 #include "mpc8data.h"
  41 #include "mpc8huff.h"
  42
  43 static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
  44 static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
  45
  46 static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET };
  47 static const int quant_offsets[6] = { MPC8_Q5_OFFSET, MPC8_Q6_OFFSET, MPC8_Q7_OFFSET, MPC8_Q8_OFFSET };
  48
  49 static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
  50 {
  51     int code = get_bits(gb, mpc8_cnk_len[k-1][n-1] - 1);
  52
  53     if (code >= mpc8_cnk_lost[k-1][n-1])
  54         code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
  55
  56     return code;
  57 }
  58
  59 static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
  60 {
  61     int bits = 0;
  62     const uint32_t * C = mpc8_cnk[k-1];
  63     int code = mpc8_dec_base(gb, k, n);
  64
  65     do {
  66         n--;
  67         if (code >= C[n]) {
  68             bits |= 1 << n;
  69             code -= C[n];
  70             C -= 32;
  71             k--;
  72         }
  73     } while(k > 0);
  74
  75     return bits;
  76 }
  77
  78 static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
  79 {
  80     if(mpc8_cnk_len[0][m] < 1) return 0;
  81     return mpc8_dec_base(gb, 1, m+1);
  82 }
  83
  84 static int mpc8_get_mask(GetBitContext *gb, int size, int t)
  85 {
  86     int mask = 0;
  87
  88     if(t && t != size)
  89          mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
  90     if((t << 1) > size) mask = ~mask;
  91
  92     return mask;
  93 }
  94
  95 static av_cold int mpc8_decode_init(AVCodecContext * avctx)
  96 {
  97     int i;
  98     MPCContext *c = avctx->priv_data;
  99     GetBitContext gb;
 100     static int vlc_initialized = 0;
 101
 102     if(avctx->extradata_size < 2){
 103         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
 104         return -1;
 105     }
 106     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
 107     av_init_random(0xDEADBEEF, &c->rnd);
 108     dsputil_init(&c->dsp, avctx);
 109
 110     ff_mpc_init();
 111
 112     init_get_bits(&gb, avctx->extradata, 16);
 113
 114     skip_bits(&gb, 3);//sample rate
 115     c->maxbands = get_bits(&gb, 5) + 1;
 116     skip_bits(&gb, 4);//channels
 117     c->MSS = get_bits1(&gb);
 118     c->frames = 1 << (get_bits(&gb, 3) * 2);
 119
 120     if(vlc_initialized) return 0;
 121     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
 122
 123     init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE,
 124              mpc8_bands_bits,  1, 1,
 125              mpc8_bands_codes, 1, 1, INIT_VLC_USE_STATIC);
 126
 127     init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE,
 128              mpc8_q1_bits,  1, 1,
 129              mpc8_q1_codes, 1, 1, INIT_VLC_USE_STATIC);
 130     init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE,
 131              mpc8_q9up_bits,  1, 1,
 132              mpc8_q9up_codes, 1, 1, INIT_VLC_USE_STATIC);
 133
 134     init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE,
 135              mpc8_scfi0_bits,  1, 1,
 136              mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_STATIC);
 137     init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE,
 138              mpc8_scfi1_bits,  1, 1,
 139              mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_STATIC);
 140
 141     init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE,
 142              mpc8_dscf0_bits,  1, 1,
 143              mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_STATIC);
 144     init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE,
 145              mpc8_dscf1_bits,  1, 1,
 146              mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_STATIC);
 147
 148     init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE,
 149              mpc8_q3_bits,  1, 1,
 150              mpc8_q3_codes, 1, 1,
 151              mpc8_q3_syms,  1, 1, INIT_VLC_USE_STATIC);
 152     init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE,
 153              mpc8_q4_bits,  1, 1,
 154              mpc8_q4_codes, 1, 1,
 155              mpc8_q4_syms,  1, 1, INIT_VLC_USE_STATIC);
 156
 157     for(i = 0; i < 2; i++){
 158         init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,
 159                  &mpc8_res_bits[i],  1, 1,
 160                  &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_STATIC);
 161
 162         init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,
 163                  &mpc8_q2_bits[i],  1, 1,
 164                  &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_STATIC);
 165
 166         init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,
 167                  &mpc8_q5_bits[i],  1, 1,
 168                  &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_STATIC);
 169         init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,
 170                  &mpc8_q6_bits[i],  1, 1,
 171                  &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_STATIC);
 172         init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,
 173                  &mpc8_q7_bits[i],  1, 1,
 174                  &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_STATIC);
 175         init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,
 176                  &mpc8_q8_bits[i],  1, 1,
 177                  &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_STATIC);
 178     }
 179     vlc_initialized = 1;
 180     avctx->sample_fmt = SAMPLE_FMT_S16;
 181     return 0;
 182 }
 183
 184 static int mpc8_decode_frame(AVCodecContext * avctx,
 185                             void *data, int *data_size,
 186                             const uint8_t * buf, int buf_size)
 187 {
 188     MPCContext *c = avctx->priv_data;
 189     GetBitContext gb2, *gb = &gb2;
 190     int i, j, k, ch, cnt, res, t;
 191     Band *bands = c->bands;
 192     int off;
 193     int maxband, keyframe;
 194     int last[2];
 195
 196     keyframe = c->cur_frame == 0;
 197
 198     if(keyframe){
 199         memset(c->Q, 0, sizeof(c->Q));
 200         c->last_bits_used = 0;
 201     }
 202     init_get_bits(gb, buf, buf_size * 8);
 203     skip_bits(gb, c->last_bits_used & 7);
 204
 205     if(keyframe)
 206         maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
 207     else{
 208         maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
 209         if(maxband > 32) maxband -= 33;
 210     }
 211     c->last_max_band = maxband;
 212
 213     /* read subband indexes */
 214     if(maxband){
 215         last[0] = last[1] = 0;
 216         for(i = maxband - 1; i >= 0; i--){
 217             for(ch = 0; ch < 2; ch++){
 218                 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
 219                 if(last[ch] > 15) last[ch] -= 17;
 220                 bands[i].res[ch] = last[ch];
 221             }
 222         }
 223         if(c->MSS){
 224             int mask;
 225
 226             cnt = 0;
 227             for(i = 0; i < maxband; i++)
 228                 if(bands[i].res[0] || bands[i].res[1])
 229                     cnt++;
 230             t = mpc8_get_mod_golomb(gb, cnt);
 231             mask = mpc8_get_mask(gb, cnt, t);
 232             for(i = maxband - 1; i >= 0; i--)
 233                 if(bands[i].res[0] || bands[i].res[1]){
 234                     bands[i].msf = mask & 1;
 235                     mask >>= 1;
 236                 }
 237         }
 238     }
 239     for(i = maxband; i < c->maxbands; i++)
 240         bands[i].res[0] = bands[i].res[1] = 0;
 241
 242     if(keyframe){
 243         for(i = 0; i < 32; i++)
 244             c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
 245     }
 246
 247     for(i = 0; i < maxband; i++){
 248         if(bands[i].res[0] || bands[i].res[1]){
 249             cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
 250             if(cnt >= 0){
 251                 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
 252                 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
 253                 if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
 254             }
 255         }
 256     }
 257
 258     for(i = 0; i < maxband; i++){
 259         for(ch = 0; ch < 2; ch++){
 260             if(!bands[i].res[ch]) continue;
 261
 262             if(c->oldDSCF[ch][i]){
 263                 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
 264                 c->oldDSCF[ch][i] = 0;
 265             }else{
 266                 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
 267                 if(t == 64)
 268                     t += get_bits(gb, 6);
 269                 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
 270             }
 271             for(j = 0; j < 2; j++){
 272                 if((bands[i].scfi[ch] << j) & 2)
 273                     bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
 274                 else{
 275                     t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
 276                     if(t == 31)
 277                         t = 64 + get_bits(gb, 6);
 278                     bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
 279                 }
 280             }
 281         }
 282     }
 283
 284     for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
 285         for(ch = 0; ch < 2; ch++){
 286             res = bands[i].res[ch];
 287             switch(res){
 288             case -1:
 289                 for(j = 0; j < SAMPLES_PER_BAND; j++)
 290                     c->Q[ch][off + j] = (av_random(&c->rnd) & 0x3FC) - 510;
 291                 break;
 292             case 0:
 293                 break;
 294             case 1:
 295                 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
 296                     cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
 297                     t = mpc8_get_mask(gb, 18, cnt);
 298                     for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)
 299                         c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;
 300                 }
 301                 break;
 302             case 2:
 303                 cnt = 6;//2*mpc8_thres[res]
 304                 for(j = 0; j < SAMPLES_PER_BAND; j += 3){
 305                     t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
 306                     c->Q[ch][off + j + 0] = mpc8_idx50[t];
 307                     c->Q[ch][off + j + 1] = mpc8_idx51[t];
 308                     c->Q[ch][off + j + 2] = mpc8_idx52[t];
 309                     cnt = (cnt >> 1) + mpc8_huffq2[t];
 310                 }
 311                 break;
 312             case 3:
 313             case 4:
 314                 for(j = 0; j < SAMPLES_PER_BAND; j += 2){
 315                     t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];
 316                     c->Q[ch][off + j + 1] = t >> 4;
 317                     c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);
 318                 }
 319                 break;
 320             case 5:
 321             case 6:
 322             case 7:
 323             case 8:
 324                 cnt = 2 * mpc8_thres[res];
 325                 for(j = 0; j < SAMPLES_PER_BAND; j++){
 326                     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];
 327                     c->Q[ch][off + j] = t;
 328                     cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
 329                 }
 330                 break;
 331             default:
 332                 for(j = 0; j < SAMPLES_PER_BAND; j++){
 333                     c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
 334                     if(res != 9){
 335                         c->Q[ch][off + j] <<= res - 9;
 336                         c->Q[ch][off + j] |= get_bits(gb, res - 9);
 337                     }
 338                     c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
 339                 }
 340             }
 341         }
 342     }
 343
 344     ff_mpc_dequantize_and_synth(c, maxband, data);
 345
 346     c->cur_frame++;
 347
 348     c->last_bits_used = get_bits_count(gb);
 349     if(c->cur_frame >= c->frames)
 350         c->cur_frame = 0;
 351     *data_size =  MPC_FRAME_SIZE * 4;
 352
 353     return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
 354 }
 355
 356 AVCodec mpc8_decoder = {
 357     "mpc8",
 358     CODEC_TYPE_AUDIO,
 359     CODEC_ID_MUSEPACK8,
 360     sizeof(MPCContext),
 361     mpc8_decode_init,
 362     NULL,
 363     NULL,
 364     mpc8_decode_frame,
 365     .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
 366 };