libavcodec/mpc7.c

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