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 28#include "libavutil/lfg.h" 29#include "avcodec.h" 30#include "get_bits.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 39static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2]; 40static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc; 41 42static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET }; 43static const int quant_offsets[6] = { MPC8_Q5_OFFSET, MPC8_Q6_OFFSET, MPC8_Q7_OFFSET, MPC8_Q8_OFFSET }; 44 45static 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 56static 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 75static 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 81static 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 92static const uint16_t vlc_offsets[13] = { 93 0, 640, 1184, 1748, 2298, 2426, 2554, 3066, 3578, 4106, 4618, 5196, 5708 94}; 95 96static av_cold int mpc8_decode_init(AVCodecContext * avctx) 97{ 98 int i; 99 MPCContext *c = avctx->priv_data; 100 GetBitContext gb; 101 static int vlc_initialized = 0; 102 103 static VLC_TYPE band_table[542][2]; 104 static VLC_TYPE q1_table[520][2]; 105 static VLC_TYPE q9up_table[524][2]; 106 static VLC_TYPE scfi0_table[1 << MPC8_SCFI0_BITS][2]; 107 static VLC_TYPE scfi1_table[1 << MPC8_SCFI1_BITS][2]; 108 static VLC_TYPE dscf0_table[560][2]; 109 static VLC_TYPE dscf1_table[598][2]; 110 static VLC_TYPE q3_0_table[512][2]; 111 static VLC_TYPE q3_1_table[516][2]; 112 static VLC_TYPE codes_table[5708][2]; 113 114 if(avctx->extradata_size < 2){ 115 av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size); 116 return -1; 117 } 118 memset(c->oldDSCF, 0, sizeof(c->oldDSCF)); 119 av_lfg_init(&c->rnd, 0xDEADBEEF); 120 dsputil_init(&c->dsp, avctx); 121 122 ff_mpc_init(); 123 124 init_get_bits(&gb, avctx->extradata, 16); 125 126 skip_bits(&gb, 3);//sample rate 127 c->maxbands = get_bits(&gb, 5) + 1; 128 skip_bits(&gb, 4);//channels 129 c->MSS = get_bits1(&gb); 130 c->frames = 1 << (get_bits(&gb, 3) * 2); 131 132 avctx->sample_fmt = SAMPLE_FMT_S16; 133 avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO; 134 135 if(vlc_initialized) return 0; 136 av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n"); 137 138 band_vlc.table = band_table; 139 band_vlc.table_allocated = 542; 140 init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE, 141 mpc8_bands_bits, 1, 1, 142 mpc8_bands_codes, 1, 1, INIT_VLC_USE_NEW_STATIC); 143 144 q1_vlc.table = q1_table; 145 q1_vlc.table_allocated = 520; 146 init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE, 147 mpc8_q1_bits, 1, 1, 148 mpc8_q1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC); 149 q9up_vlc.table = q9up_table; 150 q9up_vlc.table_allocated = 524; 151 init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE, 152 mpc8_q9up_bits, 1, 1, 153 mpc8_q9up_codes, 1, 1, INIT_VLC_USE_NEW_STATIC); 154 155 scfi_vlc[0].table = scfi0_table; 156 scfi_vlc[0].table_allocated = 1 << MPC8_SCFI0_BITS; 157 init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE, 158 mpc8_scfi0_bits, 1, 1, 159 mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC); 160 scfi_vlc[1].table = scfi1_table; 161 scfi_vlc[1].table_allocated = 1 << MPC8_SCFI1_BITS; 162 init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE, 163 mpc8_scfi1_bits, 1, 1, 164 mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC); 165 166 dscf_vlc[0].table = dscf0_table; 167 dscf_vlc[0].table_allocated = 560; 168 init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE, 169 mpc8_dscf0_bits, 1, 1, 170 mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC); 171 dscf_vlc[1].table = dscf1_table; 172 dscf_vlc[1].table_allocated = 598; 173 init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE, 174 mpc8_dscf1_bits, 1, 1, 175 mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC); 176 177 q3_vlc[0].table = q3_0_table; 178 q3_vlc[0].table_allocated = 512; 179 init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE, 180 mpc8_q3_bits, 1, 1, 181 mpc8_q3_codes, 1, 1, 182 mpc8_q3_syms, 1, 1, INIT_VLC_USE_NEW_STATIC); 183 q3_vlc[1].table = q3_1_table; 184 q3_vlc[1].table_allocated = 516; 185 init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE, 186 mpc8_q4_bits, 1, 1, 187 mpc8_q4_codes, 1, 1, 188 mpc8_q4_syms, 1, 1, INIT_VLC_USE_NEW_STATIC); 189 190 for(i = 0; i < 2; i++){ 191 res_vlc[i].table = &codes_table[vlc_offsets[0+i]]; 192 res_vlc[i].table_allocated = vlc_offsets[1+i] - vlc_offsets[0+i]; 193 init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE, 194 &mpc8_res_bits[i], 1, 1, 195 &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC); 196 197 q2_vlc[i].table = &codes_table[vlc_offsets[2+i]]; 198 q2_vlc[i].table_allocated = vlc_offsets[3+i] - vlc_offsets[2+i]; 199 init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE, 200 &mpc8_q2_bits[i], 1, 1, 201 &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC); 202 203 quant_vlc[0][i].table = &codes_table[vlc_offsets[4+i]]; 204 quant_vlc[0][i].table_allocated = vlc_offsets[5+i] - vlc_offsets[4+i]; 205 init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE, 206 &mpc8_q5_bits[i], 1, 1, 207 &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC); 208 quant_vlc[1][i].table = &codes_table[vlc_offsets[6+i]]; 209 quant_vlc[1][i].table_allocated = vlc_offsets[7+i] - vlc_offsets[6+i]; 210 init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE, 211 &mpc8_q6_bits[i], 1, 1, 212 &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC); 213 quant_vlc[2][i].table = &codes_table[vlc_offsets[8+i]]; 214 quant_vlc[2][i].table_allocated = vlc_offsets[9+i] - vlc_offsets[8+i]; 215 init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE, 216 &mpc8_q7_bits[i], 1, 1, 217 &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC); 218 quant_vlc[3][i].table = &codes_table[vlc_offsets[10+i]]; 219 quant_vlc[3][i].table_allocated = vlc_offsets[11+i] - vlc_offsets[10+i]; 220 init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE, 221 &mpc8_q8_bits[i], 1, 1, 222 &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC); 223 } 224 vlc_initialized = 1; 225 return 0; 226} 227 228static int mpc8_decode_frame(AVCodecContext * avctx, 229 void *data, int *data_size, 230 AVPacket *avpkt) 231{ 232 const uint8_t *buf = avpkt->data; 233 int buf_size = avpkt->size; 234 MPCContext *c = avctx->priv_data; 235 GetBitContext gb2, *gb = &gb2; 236 int i, j, k, ch, cnt, res, t; 237 Band *bands = c->bands; 238 int off; 239 int maxband, keyframe; 240 int last[2]; 241 242 keyframe = c->cur_frame == 0; 243 244 if(keyframe){ 245 memset(c->Q, 0, sizeof(c->Q)); 246 c->last_bits_used = 0; 247 } 248 init_get_bits(gb, buf, buf_size * 8); 249 skip_bits(gb, c->last_bits_used & 7); 250 251 if(keyframe) 252 maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1); 253 else{ 254 maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2); 255 if(maxband > 32) maxband -= 33; 256 } 257 c->last_max_band = maxband; 258 259 /* read subband indexes */ 260 if(maxband){ 261 last[0] = last[1] = 0; 262 for(i = maxband - 1; i >= 0; i--){ 263 for(ch = 0; ch < 2; ch++){ 264 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch]; 265 if(last[ch] > 15) last[ch] -= 17; 266 bands[i].res[ch] = last[ch]; 267 } 268 } 269 if(c->MSS){ 270 int mask; 271 272 cnt = 0; 273 for(i = 0; i < maxband; i++) 274 if(bands[i].res[0] || bands[i].res[1]) 275 cnt++; 276 t = mpc8_get_mod_golomb(gb, cnt); 277 mask = mpc8_get_mask(gb, cnt, t); 278 for(i = maxband - 1; i >= 0; i--) 279 if(bands[i].res[0] || bands[i].res[1]){ 280 bands[i].msf = mask & 1; 281 mask >>= 1; 282 } 283 } 284 } 285 for(i = maxband; i < c->maxbands; i++) 286 bands[i].res[0] = bands[i].res[1] = 0; 287 288 if(keyframe){ 289 for(i = 0; i < 32; i++) 290 c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1; 291 } 292 293 for(i = 0; i < maxband; i++){ 294 if(bands[i].res[0] || bands[i].res[1]){ 295 cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1; 296 if(cnt >= 0){ 297 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1); 298 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt); 299 if(bands[i].res[1]) bands[i].scfi[1] = t & 3; 300 } 301 } 302 } 303 304 for(i = 0; i < maxband; i++){ 305 for(ch = 0; ch < 2; ch++){ 306 if(!bands[i].res[ch]) continue; 307 308 if(c->oldDSCF[ch][i]){ 309 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6; 310 c->oldDSCF[ch][i] = 0; 311 }else{ 312 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2); 313 if(t == 64) 314 t += get_bits(gb, 6); 315 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6; 316 } 317 for(j = 0; j < 2; j++){ 318 if((bands[i].scfi[ch] << j) & 2) 319 bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j]; 320 else{ 321 t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2); 322 if(t == 31) 323 t = 64 + get_bits(gb, 6); 324 bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6; 325 } 326 } 327 } 328 } 329 330 for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){ 331 for(ch = 0; ch < 2; ch++){ 332 res = bands[i].res[ch]; 333 switch(res){ 334 case -1: 335 for(j = 0; j < SAMPLES_PER_BAND; j++) 336 c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510; 337 break; 338 case 0: 339 break; 340 case 1: 341 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){ 342 cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2); 343 t = mpc8_get_mask(gb, 18, cnt); 344 for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1) 345 c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0; 346 } 347 break; 348 case 2: 349 cnt = 6;//2*mpc8_thres[res] 350 for(j = 0; j < SAMPLES_PER_BAND; j += 3){ 351 t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2); 352 c->Q[ch][off + j + 0] = mpc8_idx50[t]; 353 c->Q[ch][off + j + 1] = mpc8_idx51[t]; 354 c->Q[ch][off + j + 2] = mpc8_idx52[t]; 355 cnt = (cnt >> 1) + mpc8_huffq2[t]; 356 } 357 break; 358 case 3: 359 case 4: 360 for(j = 0; j < SAMPLES_PER_BAND; j += 2){ 361 t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3]; 362 c->Q[ch][off + j + 1] = t >> 4; 363 c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF); 364 } 365 break; 366 case 5: 367 case 6: 368 case 7: 369 case 8: 370 cnt = 2 * mpc8_thres[res]; 371 for(j = 0; j < SAMPLES_PER_BAND; j++){ 372 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]; 373 c->Q[ch][off + j] = t; 374 cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]); 375 } 376 break; 377 default: 378 for(j = 0; j < SAMPLES_PER_BAND; j++){ 379 c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2); 380 if(res != 9){ 381 c->Q[ch][off + j] <<= res - 9; 382 c->Q[ch][off + j] |= get_bits(gb, res - 9); 383 } 384 c->Q[ch][off + j] -= (1 << (res - 2)) - 1; 385 } 386 } 387 } 388 } 389 390 ff_mpc_dequantize_and_synth(c, maxband, data); 391 392 c->cur_frame++; 393 394 c->last_bits_used = get_bits_count(gb); 395 if(c->cur_frame >= c->frames) 396 c->cur_frame = 0; 397 *data_size = MPC_FRAME_SIZE * 4; 398 399 return c->cur_frame ? c->last_bits_used >> 3 : buf_size; 400} 401 402AVCodec mpc8_decoder = { 403 "mpc8", 404 AVMEDIA_TYPE_AUDIO, 405 CODEC_ID_MUSEPACK8, 406 sizeof(MPCContext), 407 mpc8_decode_init, 408 NULL, 409 NULL, 410 mpc8_decode_frame, 411 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"), 412}; 413