Libav 0.7.1
libavcodec/mpc8.c
Go to the documentation of this file.
00001 /*
00002  * Musepack SV8 decoder
00003  * Copyright (c) 2007 Konstantin Shishkov
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #include "libavutil/lfg.h"
00029 #include "avcodec.h"
00030 #include "get_bits.h"
00031 #include "dsputil.h"
00032 #include "mpegaudiodsp.h"
00033 #include "libavutil/audioconvert.h"
00034 
00035 #include "mpc.h"
00036 #include "mpc8data.h"
00037 #include "mpc8huff.h"
00038 
00039 static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
00040 static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
00041 
00042 static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET };
00043 static const int quant_offsets[6] = { MPC8_Q5_OFFSET, MPC8_Q6_OFFSET, MPC8_Q7_OFFSET, MPC8_Q8_OFFSET };
00044 
00045 static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
00046 {
00047     int len = mpc8_cnk_len[k-1][n-1] - 1;
00048     int code = len ? get_bits_long(gb, len) : 0;
00049 
00050     if (code >= mpc8_cnk_lost[k-1][n-1])
00051         code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
00052 
00053     return code;
00054 }
00055 
00056 static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
00057 {
00058     int bits = 0;
00059     const uint32_t * C = mpc8_cnk[k-1];
00060     int code = mpc8_dec_base(gb, k, n);
00061 
00062     do {
00063         n--;
00064         if (code >= C[n]) {
00065             bits |= 1 << n;
00066             code -= C[n];
00067             C -= 32;
00068             k--;
00069         }
00070     } while(k > 0);
00071 
00072     return bits;
00073 }
00074 
00075 static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
00076 {
00077     if(mpc8_cnk_len[0][m] < 1) return 0;
00078     return mpc8_dec_base(gb, 1, m+1);
00079 }
00080 
00081 static int mpc8_get_mask(GetBitContext *gb, int size, int t)
00082 {
00083     int mask = 0;
00084 
00085     if(t && t != size)
00086          mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
00087     if((t << 1) > size) mask = ~mask;
00088 
00089     return mask;
00090 }
00091 
00092 static const uint16_t vlc_offsets[13] = {
00093     0, 640, 1184, 1748, 2298, 2426, 2554, 3066, 3578, 4106, 4618, 5196, 5708
00094 };
00095 
00096 static av_cold int mpc8_decode_init(AVCodecContext * avctx)
00097 {
00098     int i;
00099     MPCContext *c = avctx->priv_data;
00100     GetBitContext gb;
00101     static int vlc_initialized = 0;
00102     int channels;
00103 
00104     static VLC_TYPE band_table[542][2];
00105     static VLC_TYPE q1_table[520][2];
00106     static VLC_TYPE q9up_table[524][2];
00107     static VLC_TYPE scfi0_table[1 << MPC8_SCFI0_BITS][2];
00108     static VLC_TYPE scfi1_table[1 << MPC8_SCFI1_BITS][2];
00109     static VLC_TYPE dscf0_table[560][2];
00110     static VLC_TYPE dscf1_table[598][2];
00111     static VLC_TYPE q3_0_table[512][2];
00112     static VLC_TYPE q3_1_table[516][2];
00113     static VLC_TYPE codes_table[5708][2];
00114 
00115     if(avctx->extradata_size < 2){
00116         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
00117         return -1;
00118     }
00119     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
00120     av_lfg_init(&c->rnd, 0xDEADBEEF);
00121     dsputil_init(&c->dsp, avctx);
00122     ff_mpadsp_init(&c->mpadsp);
00123 
00124     ff_mpc_init();
00125 
00126     init_get_bits(&gb, avctx->extradata, 16);
00127 
00128     skip_bits(&gb, 3);//sample rate
00129     c->maxbands = get_bits(&gb, 5) + 1;
00130     channels = get_bits(&gb, 4) + 1;
00131     if (channels > 2) {
00132         av_log_missing_feature(avctx, "Multichannel MPC SV8", 1);
00133         return -1;
00134     }
00135     c->MSS = get_bits1(&gb);
00136     c->frames = 1 << (get_bits(&gb, 3) * 2);
00137 
00138     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00139     avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
00140 
00141     if(vlc_initialized) return 0;
00142     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
00143 
00144     band_vlc.table = band_table;
00145     band_vlc.table_allocated = 542;
00146     init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE,
00147              mpc8_bands_bits,  1, 1,
00148              mpc8_bands_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00149 
00150     q1_vlc.table = q1_table;
00151     q1_vlc.table_allocated = 520;
00152     init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE,
00153              mpc8_q1_bits,  1, 1,
00154              mpc8_q1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00155     q9up_vlc.table = q9up_table;
00156     q9up_vlc.table_allocated = 524;
00157     init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE,
00158              mpc8_q9up_bits,  1, 1,
00159              mpc8_q9up_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00160 
00161     scfi_vlc[0].table = scfi0_table;
00162     scfi_vlc[0].table_allocated = 1 << MPC8_SCFI0_BITS;
00163     init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE,
00164              mpc8_scfi0_bits,  1, 1,
00165              mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00166     scfi_vlc[1].table = scfi1_table;
00167     scfi_vlc[1].table_allocated = 1 << MPC8_SCFI1_BITS;
00168     init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE,
00169              mpc8_scfi1_bits,  1, 1,
00170              mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00171 
00172     dscf_vlc[0].table = dscf0_table;
00173     dscf_vlc[0].table_allocated = 560;
00174     init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE,
00175              mpc8_dscf0_bits,  1, 1,
00176              mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00177     dscf_vlc[1].table = dscf1_table;
00178     dscf_vlc[1].table_allocated = 598;
00179     init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE,
00180              mpc8_dscf1_bits,  1, 1,
00181              mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00182 
00183     q3_vlc[0].table = q3_0_table;
00184     q3_vlc[0].table_allocated = 512;
00185     init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE,
00186              mpc8_q3_bits,  1, 1,
00187              mpc8_q3_codes, 1, 1,
00188              mpc8_q3_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);
00189     q3_vlc[1].table = q3_1_table;
00190     q3_vlc[1].table_allocated = 516;
00191     init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE,
00192              mpc8_q4_bits,  1, 1,
00193              mpc8_q4_codes, 1, 1,
00194              mpc8_q4_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);
00195 
00196     for(i = 0; i < 2; i++){
00197         res_vlc[i].table = &codes_table[vlc_offsets[0+i]];
00198         res_vlc[i].table_allocated = vlc_offsets[1+i] - vlc_offsets[0+i];
00199         init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,
00200                  &mpc8_res_bits[i],  1, 1,
00201                  &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00202 
00203         q2_vlc[i].table = &codes_table[vlc_offsets[2+i]];
00204         q2_vlc[i].table_allocated = vlc_offsets[3+i] - vlc_offsets[2+i];
00205         init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,
00206                  &mpc8_q2_bits[i],  1, 1,
00207                  &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00208 
00209         quant_vlc[0][i].table = &codes_table[vlc_offsets[4+i]];
00210         quant_vlc[0][i].table_allocated = vlc_offsets[5+i] - vlc_offsets[4+i];
00211         init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,
00212                  &mpc8_q5_bits[i],  1, 1,
00213                  &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00214         quant_vlc[1][i].table = &codes_table[vlc_offsets[6+i]];
00215         quant_vlc[1][i].table_allocated = vlc_offsets[7+i] - vlc_offsets[6+i];
00216         init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,
00217                  &mpc8_q6_bits[i],  1, 1,
00218                  &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00219         quant_vlc[2][i].table = &codes_table[vlc_offsets[8+i]];
00220         quant_vlc[2][i].table_allocated = vlc_offsets[9+i] - vlc_offsets[8+i];
00221         init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,
00222                  &mpc8_q7_bits[i],  1, 1,
00223                  &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00224         quant_vlc[3][i].table = &codes_table[vlc_offsets[10+i]];
00225         quant_vlc[3][i].table_allocated = vlc_offsets[11+i] - vlc_offsets[10+i];
00226         init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,
00227                  &mpc8_q8_bits[i],  1, 1,
00228                  &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00229     }
00230     vlc_initialized = 1;
00231     return 0;
00232 }
00233 
00234 static int mpc8_decode_frame(AVCodecContext * avctx,
00235                             void *data, int *data_size,
00236                             AVPacket *avpkt)
00237 {
00238     const uint8_t *buf = avpkt->data;
00239     int buf_size = avpkt->size;
00240     MPCContext *c = avctx->priv_data;
00241     GetBitContext gb2, *gb = &gb2;
00242     int i, j, k, ch, cnt, res, t;
00243     Band *bands = c->bands;
00244     int off;
00245     int maxband, keyframe;
00246     int last[2];
00247 
00248     keyframe = c->cur_frame == 0;
00249 
00250     if(keyframe){
00251         memset(c->Q, 0, sizeof(c->Q));
00252         c->last_bits_used = 0;
00253     }
00254     init_get_bits(gb, buf, buf_size * 8);
00255     skip_bits(gb, c->last_bits_used & 7);
00256 
00257     if(keyframe)
00258         maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
00259     else{
00260         maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
00261         if(maxband > 32) maxband -= 33;
00262     }
00263     c->last_max_band = maxband;
00264 
00265     /* read subband indexes */
00266     if(maxband){
00267         last[0] = last[1] = 0;
00268         for(i = maxband - 1; i >= 0; i--){
00269             for(ch = 0; ch < 2; ch++){
00270                 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
00271                 if(last[ch] > 15) last[ch] -= 17;
00272                 bands[i].res[ch] = last[ch];
00273             }
00274         }
00275         if(c->MSS){
00276             int mask;
00277 
00278             cnt = 0;
00279             for(i = 0; i < maxband; i++)
00280                 if(bands[i].res[0] || bands[i].res[1])
00281                     cnt++;
00282             t = mpc8_get_mod_golomb(gb, cnt);
00283             mask = mpc8_get_mask(gb, cnt, t);
00284             for(i = maxband - 1; i >= 0; i--)
00285                 if(bands[i].res[0] || bands[i].res[1]){
00286                     bands[i].msf = mask & 1;
00287                     mask >>= 1;
00288                 }
00289         }
00290     }
00291     for(i = maxband; i < c->maxbands; i++)
00292         bands[i].res[0] = bands[i].res[1] = 0;
00293 
00294     if(keyframe){
00295         for(i = 0; i < 32; i++)
00296             c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
00297     }
00298 
00299     for(i = 0; i < maxband; i++){
00300         if(bands[i].res[0] || bands[i].res[1]){
00301             cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
00302             if(cnt >= 0){
00303                 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
00304                 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
00305                 if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
00306             }
00307         }
00308     }
00309 
00310     for(i = 0; i < maxband; i++){
00311         for(ch = 0; ch < 2; ch++){
00312             if(!bands[i].res[ch]) continue;
00313 
00314             if(c->oldDSCF[ch][i]){
00315                 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
00316                 c->oldDSCF[ch][i] = 0;
00317             }else{
00318                 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
00319                 if(t == 64)
00320                     t += get_bits(gb, 6);
00321                 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
00322             }
00323             for(j = 0; j < 2; j++){
00324                 if((bands[i].scfi[ch] << j) & 2)
00325                     bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
00326                 else{
00327                     t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
00328                     if(t == 31)
00329                         t = 64 + get_bits(gb, 6);
00330                     bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
00331                 }
00332             }
00333         }
00334     }
00335 
00336     for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
00337         for(ch = 0; ch < 2; ch++){
00338             res = bands[i].res[ch];
00339             switch(res){
00340             case -1:
00341                 for(j = 0; j < SAMPLES_PER_BAND; j++)
00342                     c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
00343                 break;
00344             case 0:
00345                 break;
00346             case 1:
00347                 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
00348                     cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
00349                     t = mpc8_get_mask(gb, 18, cnt);
00350                     for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)
00351                         c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;
00352                 }
00353                 break;
00354             case 2:
00355                 cnt = 6;//2*mpc8_thres[res]
00356                 for(j = 0; j < SAMPLES_PER_BAND; j += 3){
00357                     t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
00358                     c->Q[ch][off + j + 0] = mpc8_idx50[t];
00359                     c->Q[ch][off + j + 1] = mpc8_idx51[t];
00360                     c->Q[ch][off + j + 2] = mpc8_idx52[t];
00361                     cnt = (cnt >> 1) + mpc8_huffq2[t];
00362                 }
00363                 break;
00364             case 3:
00365             case 4:
00366                 for(j = 0; j < SAMPLES_PER_BAND; j += 2){
00367                     t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];
00368                     c->Q[ch][off + j + 1] = t >> 4;
00369                     c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);
00370                 }
00371                 break;
00372             case 5:
00373             case 6:
00374             case 7:
00375             case 8:
00376                 cnt = 2 * mpc8_thres[res];
00377                 for(j = 0; j < SAMPLES_PER_BAND; j++){
00378                     t = get_vlc2(gb, quant_vlc[res - 5][cnt > mpc8_thres[res]].table, quant_vlc[res - 5][cnt > mpc8_thres[res]].bits, 2) + quant_offsets[res - 5];
00379                     c->Q[ch][off + j] = t;
00380                     cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
00381                 }
00382                 break;
00383             default:
00384                 for(j = 0; j < SAMPLES_PER_BAND; j++){
00385                     c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
00386                     if(res != 9){
00387                         c->Q[ch][off + j] <<= res - 9;
00388                         c->Q[ch][off + j] |= get_bits(gb, res - 9);
00389                     }
00390                     c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
00391                 }
00392             }
00393         }
00394     }
00395 
00396     ff_mpc_dequantize_and_synth(c, maxband, data, avctx->channels);
00397 
00398     c->cur_frame++;
00399 
00400     c->last_bits_used = get_bits_count(gb);
00401     if(c->cur_frame >= c->frames)
00402         c->cur_frame = 0;
00403     *data_size =  MPC_FRAME_SIZE * 2 * avctx->channels;
00404 
00405     return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
00406 }
00407 
00408 AVCodec ff_mpc8_decoder = {
00409     "mpc8",
00410     AVMEDIA_TYPE_AUDIO,
00411     CODEC_ID_MUSEPACK8,
00412     sizeof(MPCContext),
00413     mpc8_decode_init,
00414     NULL,
00415     NULL,
00416     mpc8_decode_frame,
00417     .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
00418 };