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