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/channel_layout.h" 29#include "libavutil/lfg.h" 30#include "libavutil/thread.h" 31#include "avcodec.h" 32#include "codec_internal.h" 33#include "get_bits.h" 34#include "internal.h" 35#include "mpegaudiodsp.h" 36 37#include "mpc.h" 38#include "mpc8data.h" 39#include "mpc8huff.h" 40 41static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2]; 42static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc; 43 44static inline int mpc8_dec_base(GetBitContext *gb, int k, int n) 45{ 46 int len = mpc8_cnk_len[k-1][n-1] - 1; 47 int code = len ? get_bits_long(gb, len) : 0; 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 55static 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 |= 1U << n; 65 code -= C[n]; 66 C -= 32; 67 k--; 68 } 69 } while(k > 0); 70 71 return bits; 72} 73 74static 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 80static 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 91static av_cold void build_vlc(VLC *vlc, unsigned *buf_offset, 92 const uint8_t codes_counts[16], 93 const uint8_t **syms, int offset) 94{ 95 static VLCElem vlc_buf[9296]; 96 uint8_t len[MPC8_MAX_VLC_SIZE]; 97 unsigned num = 0; 98 99 vlc->table = &vlc_buf[*buf_offset]; 100 vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *buf_offset; 101 102 for (int i = 16; i > 0; i--) 103 for (unsigned tmp = num + codes_counts[i - 1]; num < tmp; num++) 104 len[num] = i; 105 106 ff_init_vlc_from_lengths(vlc, FFMIN(len[0], 9), num, len, 1, 107 *syms, 1, 1, offset, INIT_VLC_STATIC_OVERLONG, NULL); 108 *buf_offset += vlc->table_size; 109 *syms += num; 110} 111 112static av_cold void mpc8_init_static(void) 113{ 114 const uint8_t *q_syms = mpc8_q_syms, *bands_syms = mpc8_bands_syms; 115 const uint8_t *res_syms = mpc8_res_syms, *scfi_syms = mpc8_scfi_syms; 116 const uint8_t *dscf_syms = mpc8_dscf_syms; 117 unsigned offset = 0; 118 119 build_vlc(&band_vlc, &offset, mpc8_bands_len_counts, &bands_syms, 0); 120 121 build_vlc(&q1_vlc, &offset, mpc8_q1_len_counts, &q_syms, 0); 122 build_vlc(&q9up_vlc, &offset, mpc8_q9up_len_counts, &q_syms, 0); 123 124 for (int i = 0; i < 2; i++){ 125 build_vlc(&scfi_vlc[i], &offset, mpc8_scfi_len_counts[i], &scfi_syms, 0); 126 127 build_vlc(&dscf_vlc[i], &offset, mpc8_dscf_len_counts[i], &dscf_syms, 0); 128 129 build_vlc(&res_vlc[i], &offset, mpc8_res_len_counts[i], &res_syms, 0); 130 131 build_vlc(&q2_vlc[i], &offset, mpc8_q2_len_counts[i], &q_syms, 0); 132 build_vlc(&q3_vlc[i], &offset, mpc8_q34_len_counts[i], 133 &q_syms, -48 - 16 * i); 134 for (int j = 0; j < 4; j++) 135 build_vlc(&quant_vlc[j][i], &offset, mpc8_q5_8_len_counts[i][j], 136 &q_syms, -((8 << j) - 1)); 137 } 138 ff_mpa_synth_init_fixed(); 139} 140 141static av_cold int mpc8_decode_init(AVCodecContext * avctx) 142{ 143 static AVOnce init_static_once = AV_ONCE_INIT; 144 MPCContext *c = avctx->priv_data; 145 GetBitContext gb; 146 int channels; 147 148 if(avctx->extradata_size < 2){ 149 av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size); 150 return -1; 151 } 152 memset(c->oldDSCF, 0, sizeof(c->oldDSCF)); 153 av_lfg_init(&c->rnd, 0xDEADBEEF); 154 ff_mpadsp_init(&c->mpadsp); 155 156 init_get_bits(&gb, avctx->extradata, 16); 157 158 skip_bits(&gb, 3);//sample rate 159 c->maxbands = get_bits(&gb, 5) + 1; 160 if (c->maxbands >= BANDS) { 161 av_log(avctx,AV_LOG_ERROR, "maxbands %d too high\n", c->maxbands); 162 return AVERROR_INVALIDDATA; 163 } 164 channels = get_bits(&gb, 4) + 1; 165 if (channels > 2) { 166 avpriv_request_sample(avctx, "Multichannel MPC SV8"); 167 return AVERROR_PATCHWELCOME; 168 } 169 c->MSS = get_bits1(&gb); 170 c->frames = 1 << (get_bits(&gb, 3) * 2); 171 172 avctx->sample_fmt = AV_SAMPLE_FMT_S16P; 173 av_channel_layout_uninit(&avctx->ch_layout); 174 av_channel_layout_default(&avctx->ch_layout, channels); 175 176 ff_thread_once(&init_static_once, mpc8_init_static); 177 178 return 0; 179} 180 181static int mpc8_decode_frame(AVCodecContext *avctx, AVFrame *frame, 182 int *got_frame_ptr, AVPacket *avpkt) 183{ 184 const uint8_t *buf = avpkt->data; 185 int buf_size = avpkt->size; 186 MPCContext *c = avctx->priv_data; 187 GetBitContext gb2, *gb = &gb2; 188 int i, j, k, ch, cnt, res, t; 189 Band *bands = c->bands; 190 int off; 191 int maxband, keyframe; 192 int last[2]; 193 194 keyframe = c->cur_frame == 0; 195 196 if(keyframe){ 197 memset(c->Q, 0, sizeof(c->Q)); 198 c->last_bits_used = 0; 199 } 200 if ((res = init_get_bits8(gb, buf, buf_size)) < 0) 201 return res; 202 203 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 } 211 212 if (get_bits_left(gb) < 0) { 213 *got_frame_ptr = 0; 214 return buf_size; 215 } 216 217 if(maxband > c->maxbands + 1) { 218 av_log(avctx, AV_LOG_ERROR, "maxband %d too large\n",maxband); 219 return AVERROR_INVALIDDATA; 220 } 221 c->last_max_band = maxband; 222 223 /* read subband indexes */ 224 if(maxband){ 225 last[0] = last[1] = 0; 226 for(i = maxband - 1; i >= 0; i--){ 227 for(ch = 0; ch < 2; ch++){ 228 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch]; 229 if(last[ch] > 15) last[ch] -= 17; 230 bands[i].res[ch] = last[ch]; 231 } 232 } 233 if(c->MSS){ 234 int mask; 235 236 cnt = 0; 237 for(i = 0; i < maxband; i++) 238 if(bands[i].res[0] || bands[i].res[1]) 239 cnt++; 240 t = mpc8_get_mod_golomb(gb, cnt); 241 mask = mpc8_get_mask(gb, cnt, t); 242 for(i = maxband - 1; i >= 0; i--) 243 if(bands[i].res[0] || bands[i].res[1]){ 244 bands[i].msf = mask & 1; 245 mask >>= 1; 246 } 247 } 248 } 249 for(i = maxband; i < c->maxbands; i++) 250 bands[i].res[0] = bands[i].res[1] = 0; 251 252 if(keyframe){ 253 for(i = 0; i < 32; i++) 254 c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1; 255 } 256 257 for(i = 0; i < maxband; i++){ 258 if(bands[i].res[0] || bands[i].res[1]){ 259 cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1; 260 if(cnt >= 0){ 261 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1); 262 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt); 263 if(bands[i].res[1]) bands[i].scfi[1] = t & 3; 264 } 265 } 266 } 267 268 for(i = 0; i < maxband; i++){ 269 for(ch = 0; ch < 2; ch++){ 270 if(!bands[i].res[ch]) continue; 271 272 if(c->oldDSCF[ch][i]){ 273 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6; 274 c->oldDSCF[ch][i] = 0; 275 }else{ 276 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2); 277 if(t == 64) 278 t += get_bits(gb, 6); 279 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6; 280 } 281 for(j = 0; j < 2; j++){ 282 if((bands[i].scfi[ch] << j) & 2) 283 bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j]; 284 else{ 285 t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2); 286 if(t == 31) 287 t = 64 + get_bits(gb, 6); 288 bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6; 289 } 290 } 291 } 292 } 293 294 for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){ 295 for(ch = 0; ch < 2; ch++){ 296 res = bands[i].res[ch]; 297 switch(res){ 298 case -1: 299 for(j = 0; j < SAMPLES_PER_BAND; j++) 300 c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510; 301 break; 302 case 0: 303 break; 304 case 1: 305 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){ 306 cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2); 307 t = mpc8_get_mask(gb, 18, cnt); 308 for(k = 0; k < SAMPLES_PER_BAND / 2; k++) 309 c->Q[ch][off + j + k] = t & (1 << (SAMPLES_PER_BAND / 2 - k - 1)) 310 ? (get_bits1(gb) << 1) - 1 : 0; 311 } 312 break; 313 case 2: 314 cnt = 6;//2*mpc8_thres[res] 315 for(j = 0; j < SAMPLES_PER_BAND; j += 3){ 316 t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2); 317 c->Q[ch][off + j + 0] = mpc8_idx50[t]; 318 c->Q[ch][off + j + 1] = mpc8_idx51[t]; 319 c->Q[ch][off + j + 2] = mpc8_idx52[t]; 320 cnt = (cnt >> 1) + mpc8_huffq2[t]; 321 } 322 break; 323 case 3: 324 case 4: 325 for(j = 0; j < SAMPLES_PER_BAND; j += 2){ 326 t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2); 327 c->Q[ch][off + j + 1] = t >> 4; 328 c->Q[ch][off + j + 0] = sign_extend(t, 4); 329 } 330 break; 331 case 5: 332 case 6: 333 case 7: 334 case 8: 335 cnt = 2 * mpc8_thres[res]; 336 for(j = 0; j < SAMPLES_PER_BAND; j++){ 337 const VLC *vlc = &quant_vlc[res - 5][cnt > mpc8_thres[res]]; 338 c->Q[ch][off + j] = get_vlc2(gb, vlc->table, vlc->bits, 2); 339 cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]); 340 } 341 break; 342 default: 343 for(j = 0; j < SAMPLES_PER_BAND; j++){ 344 c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2); 345 if(res != 9){ 346 c->Q[ch][off + j] <<= res - 9; 347 c->Q[ch][off + j] |= get_bits(gb, res - 9); 348 } 349 c->Q[ch][off + j] -= (1 << (res - 2)) - 1; 350 } 351 } 352 } 353 } 354 355 frame->nb_samples = MPC_FRAME_SIZE; 356 if ((res = ff_get_buffer(avctx, frame, 0)) < 0) 357 return res; 358 359 ff_mpc_dequantize_and_synth(c, maxband - 1, 360 (int16_t **)frame->extended_data, 361 avctx->ch_layout.nb_channels); 362 363 c->cur_frame++; 364 365 c->last_bits_used = get_bits_count(gb); 366 if(c->cur_frame >= c->frames) 367 c->cur_frame = 0; 368 if (get_bits_left(gb) < 0) { 369 av_log(avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb)); 370 c->last_bits_used = buf_size << 3; 371 } else if (c->cur_frame == 0 && get_bits_left(gb) < 8) {// we have only padding left 372 c->last_bits_used = buf_size << 3; 373 } 374 375 *got_frame_ptr = 1; 376 377 return c->cur_frame ? c->last_bits_used >> 3 : buf_size; 378} 379 380static av_cold void mpc8_decode_flush(AVCodecContext *avctx) 381{ 382 MPCContext *c = avctx->priv_data; 383 c->cur_frame = 0; 384} 385 386const FFCodec ff_mpc8_decoder = { 387 .p.name = "mpc8", 388 .p.long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"), 389 .p.type = AVMEDIA_TYPE_AUDIO, 390 .p.id = AV_CODEC_ID_MUSEPACK8, 391 .priv_data_size = sizeof(MPCContext), 392 .init = mpc8_decode_init, 393 FF_CODEC_DECODE_CB(mpc8_decode_frame), 394 .flush = mpc8_decode_flush, 395 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF, 396 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P, 397 AV_SAMPLE_FMT_NONE }, 398 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 399}; 400