libavcodec/mpc7.c
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00001 /*
00002  * Musepack SV7 decoder
00003  * Copyright (c) 2006 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 "internal.h"
00031 #include "get_bits.h"
00032 #include "dsputil.h"
00033 #include "mpegaudiodsp.h"
00034 #include "libavutil/audioconvert.h"
00035 
00036 #include "mpc.h"
00037 #include "mpc7data.h"
00038 
00039 #define BANDS            32
00040 #define SAMPLES_PER_BAND 36
00041 #define MPC_FRAME_SIZE   (BANDS * SAMPLES_PER_BAND)
00042 
00043 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
00044 
00045 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
00046 {
00047        0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
00048        5636, 6164, 6676, 7224
00049 };
00050 
00051 
00052 static av_cold int mpc7_decode_init(AVCodecContext * avctx)
00053 {
00054     int i, j;
00055     MPCContext *c = avctx->priv_data;
00056     GetBitContext gb;
00057     uint8_t buf[16];
00058     static int vlc_initialized = 0;
00059 
00060     static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
00061     static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
00062     static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
00063     static VLC_TYPE quant_tables[7224][2];
00064 
00065     /* Musepack SV7 is always stereo */
00066     if (avctx->channels != 2) {
00067         av_log_ask_for_sample(avctx, "Unsupported number of channels: %d\n",
00068                               avctx->channels);
00069         return AVERROR_PATCHWELCOME;
00070     }
00071 
00072     if(avctx->extradata_size < 16){
00073         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
00074         return -1;
00075     }
00076     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
00077     av_lfg_init(&c->rnd, 0xDEADBEEF);
00078     dsputil_init(&c->dsp, avctx);
00079     ff_mpadsp_init(&c->mpadsp);
00080     c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
00081     ff_mpc_init();
00082     init_get_bits(&gb, buf, 128);
00083 
00084     c->IS = get_bits1(&gb);
00085     c->MSS = get_bits1(&gb);
00086     c->maxbands = get_bits(&gb, 6);
00087     if(c->maxbands >= BANDS){
00088         av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
00089         return -1;
00090     }
00091     skip_bits_long(&gb, 88);
00092     c->gapless = get_bits1(&gb);
00093     c->lastframelen = get_bits(&gb, 11);
00094     av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
00095             c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
00096     c->frames_to_skip = 0;
00097 
00098     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00099     avctx->channel_layout = AV_CH_LAYOUT_STEREO;
00100 
00101     if(vlc_initialized) return 0;
00102     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
00103     scfi_vlc.table = scfi_table;
00104     scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
00105     if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
00106                 &mpc7_scfi[1], 2, 1,
00107                 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
00108         av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
00109         return -1;
00110     }
00111     dscf_vlc.table = dscf_table;
00112     dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
00113     if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
00114                 &mpc7_dscf[1], 2, 1,
00115                 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
00116         av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
00117         return -1;
00118     }
00119     hdr_vlc.table = hdr_table;
00120     hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
00121     if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
00122                 &mpc7_hdr[1], 2, 1,
00123                 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
00124         av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
00125         return -1;
00126     }
00127     for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
00128         for(j = 0; j < 2; j++){
00129             quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
00130             quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
00131             if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
00132                         &mpc7_quant_vlc[i][j][1], 4, 2,
00133                         &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
00134                 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
00135                 return -1;
00136             }
00137         }
00138     }
00139     vlc_initialized = 1;
00140 
00141     avcodec_get_frame_defaults(&c->frame);
00142     avctx->coded_frame = &c->frame;
00143 
00144     return 0;
00145 }
00146 
00150 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
00151 {
00152     int i, i1, t;
00153     switch(idx){
00154     case -1:
00155         for(i = 0; i < SAMPLES_PER_BAND; i++){
00156             *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
00157         }
00158         break;
00159     case 1:
00160         i1 = get_bits1(gb);
00161         for(i = 0; i < SAMPLES_PER_BAND/3; i++){
00162             t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
00163             *dst++ = mpc7_idx30[t];
00164             *dst++ = mpc7_idx31[t];
00165             *dst++ = mpc7_idx32[t];
00166         }
00167         break;
00168     case 2:
00169         i1 = get_bits1(gb);
00170         for(i = 0; i < SAMPLES_PER_BAND/2; i++){
00171             t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
00172             *dst++ = mpc7_idx50[t];
00173             *dst++ = mpc7_idx51[t];
00174         }
00175         break;
00176     case  3: case  4: case  5: case  6: case  7:
00177         i1 = get_bits1(gb);
00178         for(i = 0; i < SAMPLES_PER_BAND; i++)
00179             *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
00180         break;
00181     case  8: case  9: case 10: case 11: case 12:
00182     case 13: case 14: case 15: case 16: case 17:
00183         t = (1 << (idx - 2)) - 1;
00184         for(i = 0; i < SAMPLES_PER_BAND; i++)
00185             *dst++ = get_bits(gb, idx - 1) - t;
00186         break;
00187     default: // case 0 and -2..-17
00188         return;
00189     }
00190 }
00191 
00192 static int get_scale_idx(GetBitContext *gb, int ref)
00193 {
00194     int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
00195     if (t == 8)
00196         return get_bits(gb, 6);
00197     return av_clip_uintp2(ref + t, 7);
00198 }
00199 
00200 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
00201                              int *got_frame_ptr, AVPacket *avpkt)
00202 {
00203     const uint8_t *buf = avpkt->data;
00204     int buf_size = avpkt->size;
00205     MPCContext *c = avctx->priv_data;
00206     GetBitContext gb;
00207     uint8_t *bits;
00208     int i, ch;
00209     int mb = -1;
00210     Band *bands = c->bands;
00211     int off, ret;
00212     int bits_used, bits_avail;
00213 
00214     memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
00215     if(buf_size <= 4){
00216         av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);
00217         return AVERROR(EINVAL);
00218     }
00219 
00220     /* get output buffer */
00221     c->frame.nb_samples = buf[1] ? c->lastframelen : MPC_FRAME_SIZE;
00222     if ((ret = ff_get_buffer(avctx, &c->frame)) < 0) {
00223         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00224         return ret;
00225     }
00226 
00227     bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);
00228     c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);
00229     init_get_bits(&gb, bits, (buf_size - 4)* 8);
00230     skip_bits_long(&gb, buf[0]);
00231 
00232     /* read subband indexes */
00233     for(i = 0; i <= c->maxbands; i++){
00234         for(ch = 0; ch < 2; ch++){
00235             int t = 4;
00236             if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
00237             if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
00238             else bands[i].res[ch] = av_clip(bands[i-1].res[ch] + t, 0, 17);
00239         }
00240 
00241         if(bands[i].res[0] || bands[i].res[1]){
00242             mb = i;
00243             if(c->MSS) bands[i].msf = get_bits1(&gb);
00244         }
00245     }
00246     /* get scale indexes coding method */
00247     for(i = 0; i <= mb; i++)
00248         for(ch = 0; ch < 2; ch++)
00249             if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
00250     /* get scale indexes */
00251     for(i = 0; i <= mb; i++){
00252         for(ch = 0; ch < 2; ch++){
00253             if(bands[i].res[ch]){
00254                 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
00255                 bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
00256                 switch(bands[i].scfi[ch]){
00257                 case 0:
00258                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
00259                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
00260                     break;
00261                 case 1:
00262                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
00263                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
00264                     break;
00265                 case 2:
00266                     bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
00267                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
00268                     break;
00269                 case 3:
00270                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
00271                     break;
00272                 }
00273                 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
00274             }
00275         }
00276     }
00277     /* get quantizers */
00278     memset(c->Q, 0, sizeof(c->Q));
00279     off = 0;
00280     for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
00281         for(ch = 0; ch < 2; ch++)
00282             idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
00283 
00284     ff_mpc_dequantize_and_synth(c, mb, c->frame.data[0], 2);
00285 
00286     av_free(bits);
00287 
00288     bits_used = get_bits_count(&gb);
00289     bits_avail = (buf_size - 4) * 8;
00290     if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){
00291         av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
00292         return -1;
00293     }
00294     if(c->frames_to_skip){
00295         c->frames_to_skip--;
00296         *got_frame_ptr = 0;
00297         return buf_size;
00298     }
00299 
00300     *got_frame_ptr   = 1;
00301     *(AVFrame *)data = c->frame;
00302 
00303     return buf_size;
00304 }
00305 
00306 static void mpc7_decode_flush(AVCodecContext *avctx)
00307 {
00308     MPCContext *c = avctx->priv_data;
00309 
00310     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
00311     c->frames_to_skip = 32;
00312 }
00313 
00314 AVCodec ff_mpc7_decoder = {
00315     .name           = "mpc7",
00316     .type           = AVMEDIA_TYPE_AUDIO,
00317     .id             = CODEC_ID_MUSEPACK7,
00318     .priv_data_size = sizeof(MPCContext),
00319     .init           = mpc7_decode_init,
00320     .decode         = mpc7_decode_frame,
00321     .flush = mpc7_decode_flush,
00322     .capabilities   = CODEC_CAP_DR1,
00323     .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
00324 };