1/*
2 * Musepack SV8 decoder
3 * Copyright (c) 2007 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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/lfg.h"
29#include "avcodec.h"
30#include "get_bits.h"
31#include "dsputil.h"
32#include "mpegaudio.h"
33
34#include "mpc.h"
35#include "mpcdata.h"
36#include "mpc8data.h"
37#include "mpc8huff.h"
38
39static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
40static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
41
42static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET };
43static const int quant_offsets[6] = { MPC8_Q5_OFFSET, MPC8_Q6_OFFSET, MPC8_Q7_OFFSET, MPC8_Q8_OFFSET };
44
45static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
46{
47    int len = mpc8_cnk_len[k-1][n-1] - 1;
48    int code = len ? get_bits_long(gb, len) : 0;
49
50    if (code >= mpc8_cnk_lost[k-1][n-1])
51        code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
52
53    return code;
54}
55
56static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
57{
58    int bits = 0;
59    const uint32_t * C = mpc8_cnk[k-1];
60    int code = mpc8_dec_base(gb, k, n);
61
62    do {
63        n--;
64        if (code >= C[n]) {
65            bits |= 1 << n;
66            code -= C[n];
67            C -= 32;
68            k--;
69        }
70    } while(k > 0);
71
72    return bits;
73}
74
75static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
76{
77    if(mpc8_cnk_len[0][m] < 1) return 0;
78    return mpc8_dec_base(gb, 1, m+1);
79}
80
81static int mpc8_get_mask(GetBitContext *gb, int size, int t)
82{
83    int mask = 0;
84
85    if(t && t != size)
86         mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
87    if((t << 1) > size) mask = ~mask;
88
89    return mask;
90}
91
92static const uint16_t vlc_offsets[13] = {
93    0, 640, 1184, 1748, 2298, 2426, 2554, 3066, 3578, 4106, 4618, 5196, 5708
94};
95
96static av_cold int mpc8_decode_init(AVCodecContext * avctx)
97{
98    int i;
99    MPCContext *c = avctx->priv_data;
100    GetBitContext gb;
101    static int vlc_initialized = 0;
102
103    static VLC_TYPE band_table[542][2];
104    static VLC_TYPE q1_table[520][2];
105    static VLC_TYPE q9up_table[524][2];
106    static VLC_TYPE scfi0_table[1 << MPC8_SCFI0_BITS][2];
107    static VLC_TYPE scfi1_table[1 << MPC8_SCFI1_BITS][2];
108    static VLC_TYPE dscf0_table[560][2];
109    static VLC_TYPE dscf1_table[598][2];
110    static VLC_TYPE q3_0_table[512][2];
111    static VLC_TYPE q3_1_table[516][2];
112    static VLC_TYPE codes_table[5708][2];
113
114    if(avctx->extradata_size < 2){
115        av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
116        return -1;
117    }
118    memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
119    av_lfg_init(&c->rnd, 0xDEADBEEF);
120    dsputil_init(&c->dsp, avctx);
121
122    ff_mpc_init();
123
124    init_get_bits(&gb, avctx->extradata, 16);
125
126    skip_bits(&gb, 3);//sample rate
127    c->maxbands = get_bits(&gb, 5) + 1;
128    skip_bits(&gb, 4);//channels
129    c->MSS = get_bits1(&gb);
130    c->frames = 1 << (get_bits(&gb, 3) * 2);
131
132    avctx->sample_fmt = SAMPLE_FMT_S16;
133    avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
134
135    if(vlc_initialized) return 0;
136    av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
137
138    band_vlc.table = band_table;
139    band_vlc.table_allocated = 542;
140    init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE,
141             mpc8_bands_bits,  1, 1,
142             mpc8_bands_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
143
144    q1_vlc.table = q1_table;
145    q1_vlc.table_allocated = 520;
146    init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE,
147             mpc8_q1_bits,  1, 1,
148             mpc8_q1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
149    q9up_vlc.table = q9up_table;
150    q9up_vlc.table_allocated = 524;
151    init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE,
152             mpc8_q9up_bits,  1, 1,
153             mpc8_q9up_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
154
155    scfi_vlc[0].table = scfi0_table;
156    scfi_vlc[0].table_allocated = 1 << MPC8_SCFI0_BITS;
157    init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE,
158             mpc8_scfi0_bits,  1, 1,
159             mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
160    scfi_vlc[1].table = scfi1_table;
161    scfi_vlc[1].table_allocated = 1 << MPC8_SCFI1_BITS;
162    init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE,
163             mpc8_scfi1_bits,  1, 1,
164             mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
165
166    dscf_vlc[0].table = dscf0_table;
167    dscf_vlc[0].table_allocated = 560;
168    init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE,
169             mpc8_dscf0_bits,  1, 1,
170             mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
171    dscf_vlc[1].table = dscf1_table;
172    dscf_vlc[1].table_allocated = 598;
173    init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE,
174             mpc8_dscf1_bits,  1, 1,
175             mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
176
177    q3_vlc[0].table = q3_0_table;
178    q3_vlc[0].table_allocated = 512;
179    init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE,
180             mpc8_q3_bits,  1, 1,
181             mpc8_q3_codes, 1, 1,
182             mpc8_q3_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);
183    q3_vlc[1].table = q3_1_table;
184    q3_vlc[1].table_allocated = 516;
185    init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE,
186             mpc8_q4_bits,  1, 1,
187             mpc8_q4_codes, 1, 1,
188             mpc8_q4_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);
189
190    for(i = 0; i < 2; i++){
191        res_vlc[i].table = &codes_table[vlc_offsets[0+i]];
192        res_vlc[i].table_allocated = vlc_offsets[1+i] - vlc_offsets[0+i];
193        init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,
194                 &mpc8_res_bits[i],  1, 1,
195                 &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
196
197        q2_vlc[i].table = &codes_table[vlc_offsets[2+i]];
198        q2_vlc[i].table_allocated = vlc_offsets[3+i] - vlc_offsets[2+i];
199        init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,
200                 &mpc8_q2_bits[i],  1, 1,
201                 &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
202
203        quant_vlc[0][i].table = &codes_table[vlc_offsets[4+i]];
204        quant_vlc[0][i].table_allocated = vlc_offsets[5+i] - vlc_offsets[4+i];
205        init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,
206                 &mpc8_q5_bits[i],  1, 1,
207                 &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
208        quant_vlc[1][i].table = &codes_table[vlc_offsets[6+i]];
209        quant_vlc[1][i].table_allocated = vlc_offsets[7+i] - vlc_offsets[6+i];
210        init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,
211                 &mpc8_q6_bits[i],  1, 1,
212                 &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
213        quant_vlc[2][i].table = &codes_table[vlc_offsets[8+i]];
214        quant_vlc[2][i].table_allocated = vlc_offsets[9+i] - vlc_offsets[8+i];
215        init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,
216                 &mpc8_q7_bits[i],  1, 1,
217                 &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
218        quant_vlc[3][i].table = &codes_table[vlc_offsets[10+i]];
219        quant_vlc[3][i].table_allocated = vlc_offsets[11+i] - vlc_offsets[10+i];
220        init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,
221                 &mpc8_q8_bits[i],  1, 1,
222                 &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
223    }
224    vlc_initialized = 1;
225    return 0;
226}
227
228static int mpc8_decode_frame(AVCodecContext * avctx,
229                            void *data, int *data_size,
230                            AVPacket *avpkt)
231{
232    const uint8_t *buf = avpkt->data;
233    int buf_size = avpkt->size;
234    MPCContext *c = avctx->priv_data;
235    GetBitContext gb2, *gb = &gb2;
236    int i, j, k, ch, cnt, res, t;
237    Band *bands = c->bands;
238    int off;
239    int maxband, keyframe;
240    int last[2];
241
242    keyframe = c->cur_frame == 0;
243
244    if(keyframe){
245        memset(c->Q, 0, sizeof(c->Q));
246        c->last_bits_used = 0;
247    }
248    init_get_bits(gb, buf, buf_size * 8);
249    skip_bits(gb, c->last_bits_used & 7);
250
251    if(keyframe)
252        maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
253    else{
254        maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
255        if(maxband > 32) maxband -= 33;
256    }
257    c->last_max_band = maxband;
258
259    /* read subband indexes */
260    if(maxband){
261        last[0] = last[1] = 0;
262        for(i = maxband - 1; i >= 0; i--){
263            for(ch = 0; ch < 2; ch++){
264                last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
265                if(last[ch] > 15) last[ch] -= 17;
266                bands[i].res[ch] = last[ch];
267            }
268        }
269        if(c->MSS){
270            int mask;
271
272            cnt = 0;
273            for(i = 0; i < maxband; i++)
274                if(bands[i].res[0] || bands[i].res[1])
275                    cnt++;
276            t = mpc8_get_mod_golomb(gb, cnt);
277            mask = mpc8_get_mask(gb, cnt, t);
278            for(i = maxband - 1; i >= 0; i--)
279                if(bands[i].res[0] || bands[i].res[1]){
280                    bands[i].msf = mask & 1;
281                    mask >>= 1;
282                }
283        }
284    }
285    for(i = maxband; i < c->maxbands; i++)
286        bands[i].res[0] = bands[i].res[1] = 0;
287
288    if(keyframe){
289        for(i = 0; i < 32; i++)
290            c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
291    }
292
293    for(i = 0; i < maxband; i++){
294        if(bands[i].res[0] || bands[i].res[1]){
295            cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
296            if(cnt >= 0){
297                t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
298                if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
299                if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
300            }
301        }
302    }
303
304    for(i = 0; i < maxband; i++){
305        for(ch = 0; ch < 2; ch++){
306            if(!bands[i].res[ch]) continue;
307
308            if(c->oldDSCF[ch][i]){
309                bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
310                c->oldDSCF[ch][i] = 0;
311            }else{
312                t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
313                if(t == 64)
314                    t += get_bits(gb, 6);
315                bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
316            }
317            for(j = 0; j < 2; j++){
318                if((bands[i].scfi[ch] << j) & 2)
319                    bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
320                else{
321                    t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
322                    if(t == 31)
323                        t = 64 + get_bits(gb, 6);
324                    bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
325                }
326            }
327        }
328    }
329
330    for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
331        for(ch = 0; ch < 2; ch++){
332            res = bands[i].res[ch];
333            switch(res){
334            case -1:
335                for(j = 0; j < SAMPLES_PER_BAND; j++)
336                    c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
337                break;
338            case 0:
339                break;
340            case 1:
341                for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
342                    cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
343                    t = mpc8_get_mask(gb, 18, cnt);
344                    for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)
345                        c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;
346                }
347                break;
348            case 2:
349                cnt = 6;//2*mpc8_thres[res]
350                for(j = 0; j < SAMPLES_PER_BAND; j += 3){
351                    t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
352                    c->Q[ch][off + j + 0] = mpc8_idx50[t];
353                    c->Q[ch][off + j + 1] = mpc8_idx51[t];
354                    c->Q[ch][off + j + 2] = mpc8_idx52[t];
355                    cnt = (cnt >> 1) + mpc8_huffq2[t];
356                }
357                break;
358            case 3:
359            case 4:
360                for(j = 0; j < SAMPLES_PER_BAND; j += 2){
361                    t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];
362                    c->Q[ch][off + j + 1] = t >> 4;
363                    c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);
364                }
365                break;
366            case 5:
367            case 6:
368            case 7:
369            case 8:
370                cnt = 2 * mpc8_thres[res];
371                for(j = 0; j < SAMPLES_PER_BAND; j++){
372                    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];
373                    c->Q[ch][off + j] = t;
374                    cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
375                }
376                break;
377            default:
378                for(j = 0; j < SAMPLES_PER_BAND; j++){
379                    c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
380                    if(res != 9){
381                        c->Q[ch][off + j] <<= res - 9;
382                        c->Q[ch][off + j] |= get_bits(gb, res - 9);
383                    }
384                    c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
385                }
386            }
387        }
388    }
389
390    ff_mpc_dequantize_and_synth(c, maxband, data);
391
392    c->cur_frame++;
393
394    c->last_bits_used = get_bits_count(gb);
395    if(c->cur_frame >= c->frames)
396        c->cur_frame = 0;
397    *data_size =  MPC_FRAME_SIZE * 4;
398
399    return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
400}
401
402AVCodec mpc8_decoder = {
403    "mpc8",
404    AVMEDIA_TYPE_AUDIO,
405    CODEC_ID_MUSEPACK8,
406    sizeof(MPCContext),
407    mpc8_decode_init,
408    NULL,
409    NULL,
410    mpc8_decode_frame,
411    .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
412};
413