FFmpeg: libavcodec/mpc7.c Source File

00001 /*
00002  * Musepack SV7 decoder
00003  * Copyright (c) 2006 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 "mpegaudiodsp.h"
00033 #include "libavutil/audioconvert.h"
00034 
00035 #include "mpc.h"
00036 #include "mpc7data.h"
00037 
00038 #define BANDS            32
00039 #define SAMPLES_PER_BAND 36
00040 #define MPC_FRAME_SIZE   (BANDS * SAMPLES_PER_BAND)
00041 
00042 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
00043 
00044 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
00045 {
00046        0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
00047        5636, 6164, 6676, 7224
00048 };
00049 
00050 
00051 static av_cold int mpc7_decode_init(AVCodecContext * avctx)
00052 {
00053     int i, j;
00054     MPCContext *c = avctx->priv_data;
00055     GetBitContext gb;
00056     uint8_t buf[16];
00057     static int vlc_initialized = 0;
00058 
00059     static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
00060     static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
00061     static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
00062     static VLC_TYPE quant_tables[7224][2];
00063 
00064     if(avctx->extradata_size < 16){
00065         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
00066         return -1;
00067     }
00068     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
00069     av_lfg_init(&c->rnd, 0xDEADBEEF);
00070     dsputil_init(&c->dsp, avctx);
00071     ff_mpadsp_init(&c->mpadsp);
00072     c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
00073     ff_mpc_init();
00074     init_get_bits(&gb, buf, 128);
00075 
00076     c->IS = get_bits1(&gb);
00077     c->MSS = get_bits1(&gb);
00078     c->maxbands = get_bits(&gb, 6);
00079     if(c->maxbands >= BANDS){
00080         av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
00081         return -1;
00082     }
00083     skip_bits_long(&gb, 88);
00084     c->gapless = get_bits1(&gb);
00085     c->lastframelen = get_bits(&gb, 11);
00086     av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
00087             c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
00088     c->frames_to_skip = 0;
00089 
00090     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00091     avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
00092 
00093     if(vlc_initialized) return 0;
00094     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
00095     scfi_vlc.table = scfi_table;
00096     scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
00097     if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
00098                 &mpc7_scfi[1], 2, 1,
00099                 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
00100         av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
00101         return -1;
00102     }
00103     dscf_vlc.table = dscf_table;
00104     dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
00105     if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
00106                 &mpc7_dscf[1], 2, 1,
00107                 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
00108         av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
00109         return -1;
00110     }
00111     hdr_vlc.table = hdr_table;
00112     hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
00113     if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
00114                 &mpc7_hdr[1], 2, 1,
00115                 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
00116         av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
00117         return -1;
00118     }
00119     for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
00120         for(j = 0; j < 2; j++){
00121             quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
00122             quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
00123             if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
00124                         &mpc7_quant_vlc[i][j][1], 4, 2,
00125                         &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
00126                 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
00127                 return -1;
00128             }
00129         }
00130     }
00131     vlc_initialized = 1;
00132     return 0;
00133 }
00134 
00138 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
00139 {
00140     int i, i1, t;
00141     switch(idx){
00142     case -1:
00143         for(i = 0; i < SAMPLES_PER_BAND; i++){
00144             *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
00145         }
00146         break;
00147     case 1:
00148         i1 = get_bits1(gb);
00149         for(i = 0; i < SAMPLES_PER_BAND/3; i++){
00150             t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
00151             *dst++ = mpc7_idx30[t];
00152             *dst++ = mpc7_idx31[t];
00153             *dst++ = mpc7_idx32[t];
00154         }
00155         break;
00156     case 2:
00157         i1 = get_bits1(gb);
00158         for(i = 0; i < SAMPLES_PER_BAND/2; i++){
00159             t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
00160             *dst++ = mpc7_idx50[t];
00161             *dst++ = mpc7_idx51[t];
00162         }
00163         break;
00164     case  3: case  4: case  5: case  6: case  7:
00165         i1 = get_bits1(gb);
00166         for(i = 0; i < SAMPLES_PER_BAND; i++)
00167             *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
00168         break;
00169     case  8: case  9: case 10: case 11: case 12:
00170     case 13: case 14: case 15: case 16: case 17:
00171         t = (1 << (idx - 2)) - 1;
00172         for(i = 0; i < SAMPLES_PER_BAND; i++)
00173             *dst++ = get_bits(gb, idx - 1) - t;
00174         break;
00175     default: // case 0 and -2..-17
00176         return;
00177     }
00178 }
00179 
00180 static int get_scale_idx(GetBitContext *gb, int ref)
00181 {
00182     int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
00183     if (t == 8)
00184         return get_bits(gb, 6);
00185     return ref + t;
00186 }
00187 
00188 static int mpc7_decode_frame(AVCodecContext * avctx,
00189                             void *data, int *data_size,
00190                             AVPacket *avpkt)
00191 {
00192     const uint8_t *buf = avpkt->data;
00193     int buf_size = avpkt->size;
00194     MPCContext *c = avctx->priv_data;
00195     GetBitContext gb;
00196     uint8_t *bits;
00197     int i, ch;
00198     int mb = -1;
00199     Band *bands = c->bands;
00200     int off, out_size;
00201     int bits_used, bits_avail;
00202 
00203     memset(bands, 0, sizeof(bands));
00204     if(buf_size <= 4){
00205         av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);
00206         return AVERROR(EINVAL);
00207     }
00208 
00209     out_size = (buf[1] ? c->lastframelen : MPC_FRAME_SIZE) * 4;
00210     if (*data_size < out_size) {
00211         av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
00212         return AVERROR(EINVAL);
00213     }
00214 
00215     bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);
00216     c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);
00217     init_get_bits(&gb, bits, (buf_size - 4)* 8);
00218     skip_bits_long(&gb, buf[0]);
00219 
00220     /* read subband indexes */
00221     for(i = 0; i <= c->maxbands; i++){
00222         for(ch = 0; ch < 2; ch++){
00223             int t = 4;
00224             if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
00225             if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
00226             else bands[i].res[ch] = bands[i-1].res[ch] + t;
00227         }
00228 
00229         if(bands[i].res[0] || bands[i].res[1]){
00230             mb = i;
00231             if(c->MSS) bands[i].msf = get_bits1(&gb);
00232         }
00233     }
00234     /* get scale indexes coding method */
00235     for(i = 0; i <= mb; i++)
00236         for(ch = 0; ch < 2; ch++)
00237             if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
00238     /* get scale indexes */
00239     for(i = 0; i <= mb; i++){
00240         for(ch = 0; ch < 2; ch++){
00241             if(bands[i].res[ch]){
00242                 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
00243                 bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
00244                 switch(bands[i].scfi[ch]){
00245                 case 0:
00246                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
00247                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
00248                     break;
00249                 case 1:
00250                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
00251                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
00252                     break;
00253                 case 2:
00254                     bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
00255                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
00256                     break;
00257                 case 3:
00258                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
00259                     break;
00260                 }
00261                 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
00262             }
00263         }
00264     }
00265     /* get quantizers */
00266     memset(c->Q, 0, sizeof(c->Q));
00267     off = 0;
00268     for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
00269         for(ch = 0; ch < 2; ch++)
00270             idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
00271 
00272     ff_mpc_dequantize_and_synth(c, mb, data, 2);
00273 
00274     av_free(bits);
00275 
00276     bits_used = get_bits_count(&gb);
00277     bits_avail = (buf_size - 4) * 8;
00278     if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){
00279         av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
00280         return -1;
00281     }
00282     if(c->frames_to_skip){
00283         c->frames_to_skip--;
00284         *data_size = 0;
00285         return buf_size;
00286     }
00287     *data_size = out_size;
00288 
00289     return buf_size;
00290 }
00291 
00292 static void mpc7_decode_flush(AVCodecContext *avctx)
00293 {
00294     MPCContext *c = avctx->priv_data;
00295 
00296     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
00297     c->frames_to_skip = 32;
00298 }
00299 
00300 AVCodec ff_mpc7_decoder = {
00301     "mpc7",
00302     AVMEDIA_TYPE_AUDIO,
00303     CODEC_ID_MUSEPACK7,
00304     sizeof(MPCContext),
00305     mpc7_decode_init,
00306     NULL,
00307     NULL,
00308     mpc7_decode_frame,
00309     .flush = mpc7_decode_flush,
00310     .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
00311 };