mpc.c
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1 /*
2  * Musepack decoder core
3  * Copyright (c) 2006 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
29 #include "avcodec.h"
30 #include "get_bits.h"
31 #include "dsputil.h"
32 #include "mpegaudiodsp.h"
33 #include "mpegaudio.h"
34 
35 #include "mpc.h"
36 #include "mpcdata.h"
37 
38 void ff_mpc_init(void)
39 {
41 }
42 
46 static void mpc_synth(MPCContext *c, int16_t *out, int channels)
47 {
48  int dither_state = 0;
49  int i, ch;
51 
52  for(ch = 0; ch < channels; ch++){
53  samples_ptr = samples + ch;
54  for(i = 0; i < SAMPLES_PER_BAND; i++) {
56  c->synth_buf[ch], &(c->synth_buf_offset[ch]),
57  ff_mpa_synth_window_fixed, &dither_state,
58  samples_ptr, channels,
59  c->sb_samples[ch][i]);
60  samples_ptr += 32 * channels;
61  }
62  }
63  for(i = 0; i < MPC_FRAME_SIZE*channels; i++)
64  *out++=samples[i];
65 }
66 
67 void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data, int channels)
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] + 1] * mpc_SCF[bands[i].scf_idx[ch][0]+6];
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] + 1] * mpc_SCF[bands[i].scf_idx[ch][1]+6];
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] + 1] * mpc_SCF[bands[i].scf_idx[ch][2]+6];
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, channels);
104 }