1/*
2 * Musepack decoder core
3 * Copyright (c) 2006 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 * Musepack decoder core
25 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
26 * divided into 32 subbands.
27 */
28
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
37void ff_mpc_init(void)
38{
39    ff_mpa_synth_init(ff_mpa_synth_window);
40}
41
42/**
43 * Process decoded Musepack data and produce PCM
44 */
45static void mpc_synth(MPCContext *c, int16_t *out)
46{
47    int dither_state = 0;
48    int i, ch;
49    OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE], *samples_ptr;
50
51    for(ch = 0;  ch < 2; ch++){
52        samples_ptr = samples + ch;
53        for(i = 0; i < SAMPLES_PER_BAND; i++) {
54            ff_mpa_synth_filter(c->synth_buf[ch], &(c->synth_buf_offset[ch]),
55                                ff_mpa_synth_window, &dither_state,
56                                samples_ptr, 2,
57                                c->sb_samples[ch][i]);
58            samples_ptr += 64;
59        }
60    }
61    for(i = 0; i < MPC_FRAME_SIZE*2; i++)
62        *out++=samples[i];
63}
64
65void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data)
66{
67    int i, j, ch;
68    Band *bands = c->bands;
69    int off;
70    float mul;
71
72    /* dequantize */
73    memset(c->sb_samples, 0, sizeof(c->sb_samples));
74    off = 0;
75    for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){
76        for(ch = 0; ch < 2; ch++){
77            if(bands[i].res[ch]){
78                j = 0;
79                mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0]];
80                for(; j < 12; j++)
81                    c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
82                mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1]];
83                for(; j < 24; j++)
84                    c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
85                mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2]];
86                for(; j < 36; j++)
87                    c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
88            }
89        }
90        if(bands[i].msf){
91            int t1, t2;
92            for(j = 0; j < SAMPLES_PER_BAND; j++){
93                t1 = c->sb_samples[0][j][i];
94                t2 = c->sb_samples[1][j][i];
95                c->sb_samples[0][j][i] = t1 + t2;
96                c->sb_samples[1][j][i] = t1 - t2;
97            }
98        }
99    }
100
101    mpc_synth(c, data);
102}
103