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