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mpc.c
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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 "libavutil/attributes.h"
30 #include "avcodec.h"
31 #include "mpegaudiodsp.h"
32 #include "mpegaudio.h"
33 
34 #include "mpc.h"
35 #include "mpcdata.h"
36 
37 av_cold void ff_mpc_init(void)
38 {
40 }
41 
42 /**
43  * Process decoded Musepack data and produce PCM
44  */
45 static void mpc_synth(MPCContext *c, int16_t **out, int channels)
46 {
47  int dither_state = 0;
48  int i, ch;
49 
50  for(ch = 0; ch < channels; ch++){
51  for(i = 0; i < SAMPLES_PER_BAND; i++) {
53  c->synth_buf[ch], &(c->synth_buf_offset[ch]),
54  ff_mpa_synth_window_fixed, &dither_state,
55  out[ch] + 32 * i, 1,
56  c->sb_samples[ch][i]);
57  }
58  }
59 }
60 
61 void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, int16_t **out,
62  int channels)
63 {
64  int i, j, ch;
65  Band *bands = c->bands;
66  int off;
67  float mul;
68 
69  /* dequantize */
70  memset(c->sb_samples, 0, sizeof(c->sb_samples));
71  off = 0;
72  for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){
73  for(ch = 0; ch < 2; ch++){
74  if(bands[i].res[ch]){
75  j = 0;
76  mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0] & 0xFF];
77  for(; j < 12; j++)
78  c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
79  mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1] & 0xFF];
80  for(; j < 24; j++)
81  c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
82  mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2] & 0xFF];
83  for(; j < 36; j++)
84  c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
85  }
86  }
87  if(bands[i].msf){
88  int t1, t2;
89  for(j = 0; j < SAMPLES_PER_BAND; j++){
90  t1 = c->sb_samples[0][j][i];
91  t2 = c->sb_samples[1][j][i];
92  c->sb_samples[0][j][i] = t1 + t2;
93  c->sb_samples[1][j][i] = t1 - t2;
94  }
95  }
96  }
97 
98  mpc_synth(c, out, channels);
99 }
int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT]
Definition: mpc.h:70
void ff_mpc_dequantize_and_synth(MPCContext *c, int maxband, int16_t **out, int channels)
Definition: mpc.c:61
MPADSPContext mpadsp
Definition: mpc.h:54
MPA_INT synth_buf[MPA_MAX_CHANNELS][512 *2]
Definition: mpc.h:68
int32_t ff_mpa_synth_window_fixed[]
int Q[2][MPC_FRAME_SIZE]
Definition: mpc.h:61
static const float mpc_CC[18+1]
Definition: mpcdata.h:25
int res[2]
Definition: mpc.h:46
Macro definitions for various function/variable attributes.
#define av_cold
Definition: attributes.h:82
void ff_mpa_synth_init_fixed(int32_t *window)
int scf_idx[2][3]
Definition: mpc.h:48
static const float mpc_SCF[256]
Definition: mpcdata.h:33
#define t1
Definition: regdef.h:29
#define SAMPLES_PER_BAND
Definition: mpc.h:40
void ff_mpa_synth_filter_fixed(MPADSPContext *s, int32_t *synth_buf_ptr, int *synth_buf_offset, int32_t *window, int *dither_state, int16_t *samples, int incr, int32_t *sb_samples)
Libavcodec external API header.
Musepack decoder MPEG Audio Layer 1/2 -like codec with frames of 1152 samples divided into 32 subband...
av_cold void ff_mpc_init(void)
Definition: mpc.c:37
static void mpc_synth(MPCContext *c, int16_t **out, int channels)
Process decoded Musepack data and produce PCM.
Definition: mpc.c:45
Band bands[BANDS]
Definition: mpc.h:60
static double c[64]
mpeg audio declarations for both encoder and decoder.
int synth_buf_offset[MPA_MAX_CHANNELS]
Definition: mpc.h:69
FILE * out
Definition: movenc.c:54
Subband structure - hold all variables for each subband.
Definition: mpc.h:44
#define t2
Definition: regdef.h:30
Definition: mpc.h:52