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 libavcodec/mpc.c Musepack decoder core
24 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
25 * divided into 32 subbands.
26 */
27
28#include "libavutil/random.h"
29#include "avcodec.h"
30#include "bitstream.h"
31#include "dsputil.h"
32#include "mpegaudio.h"
33
34#include "mpc.h"
35#include "mpcdata.h"
36
37static DECLARE_ALIGNED_16(MPA_INT, mpa_window[512]);
38
39void ff_mpc_init(void)
40{
41    ff_mpa_synth_init(mpa_window);
42}
43
44/**
45 * Process decoded Musepack data and produce PCM
46 */
47static void mpc_synth(MPCContext *c, int16_t *out)
48{
49    int dither_state = 0;
50    int i, ch;
51    OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE], *samples_ptr;
52
53    for(ch = 0;  ch < 2; ch++){
54        samples_ptr = samples + ch;
55        for(i = 0; i < SAMPLES_PER_BAND; i++) {
56            ff_mpa_synth_filter(c->synth_buf[ch], &(c->synth_buf_offset[ch]),
57                                mpa_window, &dither_state,
58                                samples_ptr, 2,
59                                c->sb_samples[ch][i]);
60            samples_ptr += 64;
61        }
62    }
63    for(i = 0; i < MPC_FRAME_SIZE*2; i++)
64        *out++=samples[i];
65}
66
67void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data)
68{
69    int i, j, ch;
70    Band *bands = c->bands;
71    int off;
72    float mul;
73
74    /* dequantize */
75    memset(c->sb_samples, 0, sizeof(c->sb_samples));
76    off = 0;
77    for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){
78        for(ch = 0; ch < 2; ch++){
79            if(bands[i].res[ch]){
80                j = 0;
81                mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0]];
82                for(; j < 12; j++)
83                    c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
84                mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1]];
85                for(; j < 24; j++)
86                    c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
87                mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2]];
88                for(; j < 36; j++)
89                    c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
90            }
91        }
92        if(bands[i].msf){
93            int t1, t2;
94            for(j = 0; j < SAMPLES_PER_BAND; j++){
95                t1 = c->sb_samples[0][j][i];
96                t2 = c->sb_samples[1][j][i];
97                c->sb_samples[0][j][i] = t1 + t2;
98                c->sb_samples[1][j][i] = t1 - t2;
99            }
100        }
101    }
102
103    mpc_synth(c, data);
104}
105