FFmpeg: libavcodec/mpc8.c Source File

00001 /*
00002  * Musepack SV8 decoder
00003  * Copyright (c) 2007 Konstantin Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "mpegaudio.h"
00033 
00034 #include "mpc.h"
00035 #include "mpcdata.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 
00103     static VLC_TYPE band_table[542][2];
00104     static VLC_TYPE q1_table[520][2];
00105     static VLC_TYPE q9up_table[524][2];
00106     static VLC_TYPE scfi0_table[1 << MPC8_SCFI0_BITS][2];
00107     static VLC_TYPE scfi1_table[1 << MPC8_SCFI1_BITS][2];
00108     static VLC_TYPE dscf0_table[560][2];
00109     static VLC_TYPE dscf1_table[598][2];
00110     static VLC_TYPE q3_0_table[512][2];
00111     static VLC_TYPE q3_1_table[516][2];
00112     static VLC_TYPE codes_table[5708][2];
00113 
00114     if(avctx->extradata_size < 2){
00115         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
00116         return -1;
00117     }
00118     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
00119     av_lfg_init(&c->rnd, 0xDEADBEEF);
00120     dsputil_init(&c->dsp, avctx);
00121 
00122     ff_mpc_init();
00123 
00124     init_get_bits(&gb, avctx->extradata, 16);
00125 
00126     skip_bits(&gb, 3);//sample rate
00127     c->maxbands = get_bits(&gb, 5) + 1;
00128     skip_bits(&gb, 4);//channels
00129     c->MSS = get_bits1(&gb);
00130     c->frames = 1 << (get_bits(&gb, 3) * 2);
00131 
00132     avctx->sample_fmt = SAMPLE_FMT_S16;
00133     avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
00134 
00135     if(vlc_initialized) return 0;
00136     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
00137 
00138     band_vlc.table = band_table;
00139     band_vlc.table_allocated = 542;
00140     init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE,
00141              mpc8_bands_bits,  1, 1,
00142              mpc8_bands_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00143 
00144     q1_vlc.table = q1_table;
00145     q1_vlc.table_allocated = 520;
00146     init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE,
00147              mpc8_q1_bits,  1, 1,
00148              mpc8_q1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00149     q9up_vlc.table = q9up_table;
00150     q9up_vlc.table_allocated = 524;
00151     init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE,
00152              mpc8_q9up_bits,  1, 1,
00153              mpc8_q9up_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00154 
00155     scfi_vlc[0].table = scfi0_table;
00156     scfi_vlc[0].table_allocated = 1 << MPC8_SCFI0_BITS;
00157     init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE,
00158              mpc8_scfi0_bits,  1, 1,
00159              mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00160     scfi_vlc[1].table = scfi1_table;
00161     scfi_vlc[1].table_allocated = 1 << MPC8_SCFI1_BITS;
00162     init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE,
00163              mpc8_scfi1_bits,  1, 1,
00164              mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00165 
00166     dscf_vlc[0].table = dscf0_table;
00167     dscf_vlc[0].table_allocated = 560;
00168     init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE,
00169              mpc8_dscf0_bits,  1, 1,
00170              mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00171     dscf_vlc[1].table = dscf1_table;
00172     dscf_vlc[1].table_allocated = 598;
00173     init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE,
00174              mpc8_dscf1_bits,  1, 1,
00175              mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
00176 
00177     q3_vlc[0].table = q3_0_table;
00178     q3_vlc[0].table_allocated = 512;
00179     init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE,
00180              mpc8_q3_bits,  1, 1,
00181              mpc8_q3_codes, 1, 1,
00182              mpc8_q3_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);
00183     q3_vlc[1].table = q3_1_table;
00184     q3_vlc[1].table_allocated = 516;
00185     init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE,
00186              mpc8_q4_bits,  1, 1,
00187              mpc8_q4_codes, 1, 1,
00188              mpc8_q4_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);
00189 
00190     for(i = 0; i < 2; i++){
00191         res_vlc[i].table = &codes_table[vlc_offsets[0+i]];
00192         res_vlc[i].table_allocated = vlc_offsets[1+i] - vlc_offsets[0+i];
00193         init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,
00194                  &mpc8_res_bits[i],  1, 1,
00195                  &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00196 
00197         q2_vlc[i].table = &codes_table[vlc_offsets[2+i]];
00198         q2_vlc[i].table_allocated = vlc_offsets[3+i] - vlc_offsets[2+i];
00199         init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,
00200                  &mpc8_q2_bits[i],  1, 1,
00201                  &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00202 
00203         quant_vlc[0][i].table = &codes_table[vlc_offsets[4+i]];
00204         quant_vlc[0][i].table_allocated = vlc_offsets[5+i] - vlc_offsets[4+i];
00205         init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,
00206                  &mpc8_q5_bits[i],  1, 1,
00207                  &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00208         quant_vlc[1][i].table = &codes_table[vlc_offsets[6+i]];
00209         quant_vlc[1][i].table_allocated = vlc_offsets[7+i] - vlc_offsets[6+i];
00210         init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,
00211                  &mpc8_q6_bits[i],  1, 1,
00212                  &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00213         quant_vlc[2][i].table = &codes_table[vlc_offsets[8+i]];
00214         quant_vlc[2][i].table_allocated = vlc_offsets[9+i] - vlc_offsets[8+i];
00215         init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,
00216                  &mpc8_q7_bits[i],  1, 1,
00217                  &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00218         quant_vlc[3][i].table = &codes_table[vlc_offsets[10+i]];
00219         quant_vlc[3][i].table_allocated = vlc_offsets[11+i] - vlc_offsets[10+i];
00220         init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,
00221                  &mpc8_q8_bits[i],  1, 1,
00222                  &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
00223     }
00224     vlc_initialized = 1;
00225     return 0;
00226 }
00227 
00228 static int mpc8_decode_frame(AVCodecContext * avctx,
00229                             void *data, int *data_size,
00230                             AVPacket *avpkt)
00231 {
00232     const uint8_t *buf = avpkt->data;
00233     int buf_size = avpkt->size;
00234     MPCContext *c = avctx->priv_data;
00235     GetBitContext gb2, *gb = &gb2;
00236     int i, j, k, ch, cnt, res, t;
00237     Band *bands = c->bands;
00238     int off;
00239     int maxband, keyframe;
00240     int last[2];
00241 
00242     keyframe = c->cur_frame == 0;
00243 
00244     if(keyframe){
00245         memset(c->Q, 0, sizeof(c->Q));
00246         c->last_bits_used = 0;
00247     }
00248     init_get_bits(gb, buf, buf_size * 8);
00249     skip_bits(gb, c->last_bits_used & 7);
00250 
00251     if(keyframe)
00252         maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
00253     else{
00254         maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
00255         if(maxband > 32) maxband -= 33;
00256     }
00257     c->last_max_band = maxband;
00258 
00259     /* read subband indexes */
00260     if(maxband){
00261         last[0] = last[1] = 0;
00262         for(i = maxband - 1; i >= 0; i--){
00263             for(ch = 0; ch < 2; ch++){
00264                 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
00265                 if(last[ch] > 15) last[ch] -= 17;
00266                 bands[i].res[ch] = last[ch];
00267             }
00268         }
00269         if(c->MSS){
00270             int mask;
00271 
00272             cnt = 0;
00273             for(i = 0; i < maxband; i++)
00274                 if(bands[i].res[0] || bands[i].res[1])
00275                     cnt++;
00276             t = mpc8_get_mod_golomb(gb, cnt);
00277             mask = mpc8_get_mask(gb, cnt, t);
00278             for(i = maxband - 1; i >= 0; i--)
00279                 if(bands[i].res[0] || bands[i].res[1]){
00280                     bands[i].msf = mask & 1;
00281                     mask >>= 1;
00282                 }
00283         }
00284     }
00285     for(i = maxband; i < c->maxbands; i++)
00286         bands[i].res[0] = bands[i].res[1] = 0;
00287 
00288     if(keyframe){
00289         for(i = 0; i < 32; i++)
00290             c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
00291     }
00292 
00293     for(i = 0; i < maxband; i++){
00294         if(bands[i].res[0] || bands[i].res[1]){
00295             cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
00296             if(cnt >= 0){
00297                 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
00298                 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
00299                 if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
00300             }
00301         }
00302     }
00303 
00304     for(i = 0; i < maxband; i++){
00305         for(ch = 0; ch < 2; ch++){
00306             if(!bands[i].res[ch]) continue;
00307 
00308             if(c->oldDSCF[ch][i]){
00309                 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
00310                 c->oldDSCF[ch][i] = 0;
00311             }else{
00312                 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
00313                 if(t == 64)
00314                     t += get_bits(gb, 6);
00315                 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
00316             }
00317             for(j = 0; j < 2; j++){
00318                 if((bands[i].scfi[ch] << j) & 2)
00319                     bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
00320                 else{
00321                     t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
00322                     if(t == 31)
00323                         t = 64 + get_bits(gb, 6);
00324                     bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
00325                 }
00326             }
00327         }
00328     }
00329 
00330     for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
00331         for(ch = 0; ch < 2; ch++){
00332             res = bands[i].res[ch];
00333             switch(res){
00334             case -1:
00335                 for(j = 0; j < SAMPLES_PER_BAND; j++)
00336                     c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
00337                 break;
00338             case 0:
00339                 break;
00340             case 1:
00341                 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
00342                     cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
00343                     t = mpc8_get_mask(gb, 18, cnt);
00344                     for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)
00345                         c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;
00346                 }
00347                 break;
00348             case 2:
00349                 cnt = 6;//2*mpc8_thres[res]
00350                 for(j = 0; j < SAMPLES_PER_BAND; j += 3){
00351                     t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
00352                     c->Q[ch][off + j + 0] = mpc8_idx50[t];
00353                     c->Q[ch][off + j + 1] = mpc8_idx51[t];
00354                     c->Q[ch][off + j + 2] = mpc8_idx52[t];
00355                     cnt = (cnt >> 1) + mpc8_huffq2[t];
00356                 }
00357                 break;
00358             case 3:
00359             case 4:
00360                 for(j = 0; j < SAMPLES_PER_BAND; j += 2){
00361                     t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];
00362                     c->Q[ch][off + j + 1] = t >> 4;
00363                     c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);
00364                 }
00365                 break;
00366             case 5:
00367             case 6:
00368             case 7:
00369             case 8:
00370                 cnt = 2 * mpc8_thres[res];
00371                 for(j = 0; j < SAMPLES_PER_BAND; j++){
00372                     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];
00373                     c->Q[ch][off + j] = t;
00374                     cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
00375                 }
00376                 break;
00377             default:
00378                 for(j = 0; j < SAMPLES_PER_BAND; j++){
00379                     c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
00380                     if(res != 9){
00381                         c->Q[ch][off + j] <<= res - 9;
00382                         c->Q[ch][off + j] |= get_bits(gb, res - 9);
00383                     }
00384                     c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
00385                 }
00386             }
00387         }
00388     }
00389 
00390     ff_mpc_dequantize_and_synth(c, maxband, data);
00391 
00392     c->cur_frame++;
00393 
00394     c->last_bits_used = get_bits_count(gb);
00395     if(c->cur_frame >= c->frames)
00396         c->cur_frame = 0;
00397     *data_size =  MPC_FRAME_SIZE * 4;
00398 
00399     return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
00400 }
00401 
00402 AVCodec mpc8_decoder = {
00403     "mpc8",
00404     AVMEDIA_TYPE_AUDIO,
00405     CODEC_ID_MUSEPACK8,
00406     sizeof(MPCContext),
00407     mpc8_decode_init,
00408     NULL,
00409     NULL,
00410     mpc8_decode_frame,
00411     .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
00412 };