libavcodec/mpc7.c

   1 /*
   2  * Musepack SV7 decoder
   3  * Copyright (c) 2006 Konstantin Shishkov
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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/internal.h"
  30 #include "libavutil/lfg.h"
  31 #include "avcodec.h"
  32 #include "get_bits.h"
  33 #include "dsputil.h"
  34 #include "internal.h"
  35 #include "mpegaudiodsp.h"
  36
  37 #include "mpc.h"
  38 #include "mpc7data.h"
  39
  40 #define BANDS            32
  41 #define SAMPLES_PER_BAND 36
  42 #define MPC_FRAME_SIZE   (BANDS * SAMPLES_PER_BAND)
  43
  44 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
  45
  46 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
  47 {
  48        0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
  49        5636, 6164, 6676, 7224
  50 };
  51
  52
  53 static av_cold int mpc7_decode_init(AVCodecContext * avctx)
  54 {
  55     int i, j;
  56     MPCContext *c = avctx->priv_data;
  57     GetBitContext gb;
  58     LOCAL_ALIGNED_16(uint8_t, buf, [16]);
  59     static int vlc_initialized = 0;
  60
  61     static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
  62     static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
  63     static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
  64     static VLC_TYPE quant_tables[7224][2];
  65
  66     /* Musepack SV7 is always stereo */
  67     if (avctx->channels != 2) {
  68         av_log_ask_for_sample(avctx, "Unsupported number of channels: %d\n",
  69                               avctx->channels);
  70         return AVERROR_PATCHWELCOME;
  71     }
  72
  73     if(avctx->extradata_size < 16){
  74         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
  75         return -1;
  76     }
  77     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
  78     av_lfg_init(&c->rnd, 0xDEADBEEF);
  79     ff_dsputil_init(&c->dsp, avctx);
  80     ff_mpadsp_init(&c->mpadsp);
  81     c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
  82     ff_mpc_init();
  83     init_get_bits(&gb, buf, 128);
  84
  85     c->IS = get_bits1(&gb);
  86     c->MSS = get_bits1(&gb);
  87     c->maxbands = get_bits(&gb, 6);
  88     if(c->maxbands >= BANDS){
  89         av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
  90         return -1;
  91     }
  92     skip_bits_long(&gb, 88);
  93     c->gapless = get_bits1(&gb);
  94     c->lastframelen = get_bits(&gb, 11);
  95     av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
  96             c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
  97     c->frames_to_skip = 0;
  98
  99     avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
 100     avctx->channel_layout = AV_CH_LAYOUT_STEREO;
 101
 102     if(vlc_initialized) return 0;
 103     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
 104     scfi_vlc.table = scfi_table;
 105     scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
 106     if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
 107                 &mpc7_scfi[1], 2, 1,
 108                 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
 109         av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
 110         return -1;
 111     }
 112     dscf_vlc.table = dscf_table;
 113     dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
 114     if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
 115                 &mpc7_dscf[1], 2, 1,
 116                 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
 117         av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
 118         return -1;
 119     }
 120     hdr_vlc.table = hdr_table;
 121     hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
 122     if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
 123                 &mpc7_hdr[1], 2, 1,
 124                 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
 125         av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
 126         return -1;
 127     }
 128     for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
 129         for(j = 0; j < 2; j++){
 130             quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
 131             quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
 132             if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
 133                         &mpc7_quant_vlc[i][j][1], 4, 2,
 134                         &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
 135                 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
 136                 return -1;
 137             }
 138         }
 139     }
 140     vlc_initialized = 1;
 141
 142     return 0;
 143 }
 144
 145 /**
 146  * Fill samples for given subband
 147  */
 148 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
 149 {
 150     int i, i1, t;
 151     switch(idx){
 152     case -1:
 153         for(i = 0; i < SAMPLES_PER_BAND; i++){
 154             *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
 155         }
 156         break;
 157     case 1:
 158         i1 = get_bits1(gb);
 159         for(i = 0; i < SAMPLES_PER_BAND/3; i++){
 160             t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
 161             *dst++ = mpc7_idx30[t];
 162             *dst++ = mpc7_idx31[t];
 163             *dst++ = mpc7_idx32[t];
 164         }
 165         break;
 166     case 2:
 167         i1 = get_bits1(gb);
 168         for(i = 0; i < SAMPLES_PER_BAND/2; i++){
 169             t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
 170             *dst++ = mpc7_idx50[t];
 171             *dst++ = mpc7_idx51[t];
 172         }
 173         break;
 174     case  3: case  4: case  5: case  6: case  7:
 175         i1 = get_bits1(gb);
 176         for(i = 0; i < SAMPLES_PER_BAND; i++)
 177             *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
 178         break;
 179     case  8: case  9: case 10: case 11: case 12:
 180     case 13: case 14: case 15: case 16: case 17:
 181         t = (1 << (idx - 2)) - 1;
 182         for(i = 0; i < SAMPLES_PER_BAND; i++)
 183             *dst++ = get_bits(gb, idx - 1) - t;
 184         break;
 185     default: // case 0 and -2..-17
 186         return;
 187     }
 188 }
 189
 190 static int get_scale_idx(GetBitContext *gb, int ref)
 191 {
 192     int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
 193     if (t == 8)
 194         return get_bits(gb, 6);
 195     return av_clip_uintp2(ref + t, 7);
 196 }
 197
 198 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
 199                              int *got_frame_ptr, AVPacket *avpkt)
 200 {
 201     AVFrame *frame     = data;
 202     const uint8_t *buf = avpkt->data;
 203     int buf_size;
 204     MPCContext *c = avctx->priv_data;
 205     GetBitContext gb;
 206     int i, ch;
 207     int mb = -1;
 208     Band *bands = c->bands;
 209     int off, ret, last_frame, skip;
 210     int bits_used, bits_avail;
 211
 212     memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
 213
 214     buf_size = avpkt->size & ~3;
 215     if (buf_size <= 0) {
 216         av_log(avctx, AV_LOG_ERROR, "packet size is too small (%i bytes)\n",
 217                avpkt->size);
 218         return AVERROR_INVALIDDATA;
 219     }
 220     if (buf_size != avpkt->size) {
 221         av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
 222                "extra bytes at the end will be skipped.\n");
 223     }
 224
 225     skip       = buf[0];
 226     last_frame = buf[1];
 227     buf       += 4;
 228     buf_size  -= 4;
 229
 230     /* get output buffer */
 231     frame->nb_samples = last_frame ? c->lastframelen : MPC_FRAME_SIZE;
 232     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
 233         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 234         return ret;
 235     }
 236
 237     av_fast_padded_malloc(&c->bits, &c->buf_size, buf_size);
 238     if (!c->bits)
 239         return AVERROR(ENOMEM);
 240     c->dsp.bswap_buf((uint32_t *)c->bits, (const uint32_t *)buf, buf_size >> 2);
 241     init_get_bits(&gb, c->bits, buf_size * 8);
 242     skip_bits_long(&gb, skip);
 243
 244     /* read subband indexes */
 245     for(i = 0; i <= c->maxbands; i++){
 246         for(ch = 0; ch < 2; ch++){
 247             int t = 4;
 248             if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
 249             if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
 250             else bands[i].res[ch] = av_clip(bands[i-1].res[ch] + t, 0, 17);
 251         }
 252
 253         if(bands[i].res[0] || bands[i].res[1]){
 254             mb = i;
 255             if(c->MSS) bands[i].msf = get_bits1(&gb);
 256         }
 257     }
 258     /* get scale indexes coding method */
 259     for(i = 0; i <= mb; i++)
 260         for(ch = 0; ch < 2; ch++)
 261             if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
 262     /* get scale indexes */
 263     for(i = 0; i <= mb; i++){
 264         for(ch = 0; ch < 2; ch++){
 265             if(bands[i].res[ch]){
 266                 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
 267                 bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
 268                 switch(bands[i].scfi[ch]){
 269                 case 0:
 270                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
 271                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
 272                     break;
 273                 case 1:
 274                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
 275                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
 276                     break;
 277                 case 2:
 278                     bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
 279                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
 280                     break;
 281                 case 3:
 282                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
 283                     break;
 284                 }
 285                 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
 286             }
 287         }
 288     }
 289     /* get quantizers */
 290     memset(c->Q, 0, sizeof(c->Q));
 291     off = 0;
 292     for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
 293         for(ch = 0; ch < 2; ch++)
 294             idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
 295
 296     ff_mpc_dequantize_and_synth(c, mb, (int16_t **)frame->extended_data, 2);
 297
 298     bits_used = get_bits_count(&gb);
 299     bits_avail = buf_size * 8;
 300     if (!last_frame && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))) {
 301         av_log(avctx, AV_LOG_ERROR, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
 302         return -1;
 303     }
 304     if(c->frames_to_skip){
 305         c->frames_to_skip--;
 306         *got_frame_ptr = 0;
 307         return avpkt->size;
 308     }
 309
 310     *got_frame_ptr = 1;
 311
 312     return avpkt->size;
 313 }
 314
 315 static void mpc7_decode_flush(AVCodecContext *avctx)
 316 {
 317     MPCContext *c = avctx->priv_data;
 318
 319     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
 320     c->frames_to_skip = 32;
 321 }
 322
 323 static av_cold int mpc7_decode_close(AVCodecContext *avctx)
 324 {
 325     MPCContext *c = avctx->priv_data;
 326     av_freep(&c->bits);
 327     c->buf_size = 0;
 328     return 0;
 329 }
 330
 331 AVCodec ff_mpc7_decoder = {
 332     .name           = "mpc7",
 333     .type           = AVMEDIA_TYPE_AUDIO,
 334     .id             = AV_CODEC_ID_MUSEPACK7,
 335     .priv_data_size = sizeof(MPCContext),
 336     .init           = mpc7_decode_init,
 337     .close          = mpc7_decode_close,
 338     .decode         = mpc7_decode_frame,
 339     .flush          = mpc7_decode_flush,
 340     .capabilities   = CODEC_CAP_DR1,
 341     .long_name      = NULL_IF_CONFIG_SMALL("Musepack SV7"),
 342     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
 343                                                       AV_SAMPLE_FMT_NONE },
 344 };