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