1/* 2 * Musepack SV7 decoder 3 * Copyright (c) 2006 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 "mpc7data.h" 36 37#define BANDS 32 38#define SAMPLES_PER_BAND 36 39#define MPC_FRAME_SIZE (BANDS * SAMPLES_PER_BAND) 40 41static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2]; 42 43static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] = 44{ 45 0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124, 46 5636, 6164, 6676, 7224 47}; 48 49 50static av_cold int mpc7_decode_init(AVCodecContext * avctx) 51{ 52 int i, j; 53 MPCContext *c = avctx->priv_data; 54 GetBitContext gb; 55 uint8_t buf[16]; 56 static int vlc_initialized = 0; 57 58 static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2]; 59 static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2]; 60 static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2]; 61 static VLC_TYPE quant_tables[7224][2]; 62 63 if(avctx->extradata_size < 16){ 64 av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size); 65 return -1; 66 } 67 memset(c->oldDSCF, 0, sizeof(c->oldDSCF)); 68 av_lfg_init(&c->rnd, 0xDEADBEEF); 69 dsputil_init(&c->dsp, avctx); 70 c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4); 71 ff_mpc_init(); 72 init_get_bits(&gb, buf, 128); 73 74 c->IS = get_bits1(&gb); 75 c->MSS = get_bits1(&gb); 76 c->maxbands = get_bits(&gb, 6); 77 if(c->maxbands >= BANDS){ 78 av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands); 79 return -1; 80 } 81 skip_bits_long(&gb, 88); 82 c->gapless = get_bits1(&gb); 83 c->lastframelen = get_bits(&gb, 11); 84 av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n", 85 c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands); 86 c->frames_to_skip = 0; 87 88 avctx->sample_fmt = SAMPLE_FMT_S16; 89 avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO; 90 91 if(vlc_initialized) return 0; 92 av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n"); 93 scfi_vlc.table = scfi_table; 94 scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS; 95 if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE, 96 &mpc7_scfi[1], 2, 1, 97 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){ 98 av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n"); 99 return -1; 100 } 101 dscf_vlc.table = dscf_table; 102 dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS; 103 if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE, 104 &mpc7_dscf[1], 2, 1, 105 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){ 106 av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n"); 107 return -1; 108 } 109 hdr_vlc.table = hdr_table; 110 hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS; 111 if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE, 112 &mpc7_hdr[1], 2, 1, 113 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){ 114 av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n"); 115 return -1; 116 } 117 for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){ 118 for(j = 0; j < 2; j++){ 119 quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]]; 120 quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j]; 121 if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i], 122 &mpc7_quant_vlc[i][j][1], 4, 2, 123 &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){ 124 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j); 125 return -1; 126 } 127 } 128 } 129 vlc_initialized = 1; 130 return 0; 131} 132 133/** 134 * Fill samples for given subband 135 */ 136static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst) 137{ 138 int i, i1, t; 139 switch(idx){ 140 case -1: 141 for(i = 0; i < SAMPLES_PER_BAND; i++){ 142 *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510; 143 } 144 break; 145 case 1: 146 i1 = get_bits1(gb); 147 for(i = 0; i < SAMPLES_PER_BAND/3; i++){ 148 t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2); 149 *dst++ = mpc7_idx30[t]; 150 *dst++ = mpc7_idx31[t]; 151 *dst++ = mpc7_idx32[t]; 152 } 153 break; 154 case 2: 155 i1 = get_bits1(gb); 156 for(i = 0; i < SAMPLES_PER_BAND/2; i++){ 157 t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2); 158 *dst++ = mpc7_idx50[t]; 159 *dst++ = mpc7_idx51[t]; 160 } 161 break; 162 case 3: case 4: case 5: case 6: case 7: 163 i1 = get_bits1(gb); 164 for(i = 0; i < SAMPLES_PER_BAND; i++) 165 *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1]; 166 break; 167 case 8: case 9: case 10: case 11: case 12: 168 case 13: case 14: case 15: case 16: case 17: 169 t = (1 << (idx - 2)) - 1; 170 for(i = 0; i < SAMPLES_PER_BAND; i++) 171 *dst++ = get_bits(gb, idx - 1) - t; 172 break; 173 default: // case 0 and -2..-17 174 return; 175 } 176} 177 178static int get_scale_idx(GetBitContext *gb, int ref) 179{ 180 int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7; 181 if (t == 8) 182 return get_bits(gb, 6); 183 return ref + t; 184} 185 186static int mpc7_decode_frame(AVCodecContext * avctx, 187 void *data, int *data_size, 188 AVPacket *avpkt) 189{ 190 const uint8_t *buf = avpkt->data; 191 int buf_size = avpkt->size; 192 MPCContext *c = avctx->priv_data; 193 GetBitContext gb; 194 uint8_t *bits; 195 int i, ch; 196 int mb = -1; 197 Band *bands = c->bands; 198 int off; 199 int bits_used, bits_avail; 200 201 memset(bands, 0, sizeof(bands)); 202 if(buf_size <= 4){ 203 av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size); 204 } 205 206 bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE); 207 c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2); 208 init_get_bits(&gb, bits, (buf_size - 4)* 8); 209 skip_bits(&gb, buf[0]); 210 211 /* read subband indexes */ 212 for(i = 0; i <= c->maxbands; i++){ 213 for(ch = 0; ch < 2; ch++){ 214 int t = 4; 215 if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5; 216 if(t == 4) bands[i].res[ch] = get_bits(&gb, 4); 217 else bands[i].res[ch] = bands[i-1].res[ch] + t; 218 } 219 220 if(bands[i].res[0] || bands[i].res[1]){ 221 mb = i; 222 if(c->MSS) bands[i].msf = get_bits1(&gb); 223 } 224 } 225 /* get scale indexes coding method */ 226 for(i = 0; i <= mb; i++) 227 for(ch = 0; ch < 2; ch++) 228 if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1); 229 /* get scale indexes */ 230 for(i = 0; i <= mb; i++){ 231 for(ch = 0; ch < 2; ch++){ 232 if(bands[i].res[ch]){ 233 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i]; 234 bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]); 235 switch(bands[i].scfi[ch]){ 236 case 0: 237 bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]); 238 bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]); 239 break; 240 case 1: 241 bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]); 242 bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1]; 243 break; 244 case 2: 245 bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0]; 246 bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]); 247 break; 248 case 3: 249 bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0]; 250 break; 251 } 252 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2]; 253 } 254 } 255 } 256 /* get quantizers */ 257 memset(c->Q, 0, sizeof(c->Q)); 258 off = 0; 259 for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND) 260 for(ch = 0; ch < 2; ch++) 261 idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off); 262 263 ff_mpc_dequantize_and_synth(c, mb, data); 264 265 av_free(bits); 266 267 bits_used = get_bits_count(&gb); 268 bits_avail = (buf_size - 4) * 8; 269 if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){ 270 av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail); 271 return -1; 272 } 273 if(c->frames_to_skip){ 274 c->frames_to_skip--; 275 *data_size = 0; 276 return buf_size; 277 } 278 *data_size = (buf[1] ? c->lastframelen : MPC_FRAME_SIZE) * 4; 279 280 return buf_size; 281} 282 283static void mpc7_decode_flush(AVCodecContext *avctx) 284{ 285 MPCContext *c = avctx->priv_data; 286 287 memset(c->oldDSCF, 0, sizeof(c->oldDSCF)); 288 c->frames_to_skip = 32; 289} 290 291AVCodec mpc7_decoder = { 292 "mpc7", 293 AVMEDIA_TYPE_AUDIO, 294 CODEC_ID_MUSEPACK7, 295 sizeof(MPCContext), 296 mpc7_decode_init, 297 NULL, 298 NULL, 299 mpc7_decode_frame, 300 .flush = mpc7_decode_flush, 301 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"), 302}; 303