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
ff_mpc_init(void)37 av_cold void ff_mpc_init(void)
38 {
39 ff_mpa_synth_init_fixed(ff_mpa_synth_window_fixed);
40 }
41
42 /**
43 * Process decoded Musepack data and produce PCM
44 */
mpc_synth(MPCContext * c,int16_t ** out,int channels)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++) {
52 ff_mpa_synth_filter_fixed(&c->mpadsp,
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
ff_mpc_dequantize_and_synth(MPCContext * c,int maxband,int16_t ** out,int channels)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] = av_clipf(mul * c->Q[ch][j + off], INT32_MIN, INT32_MAX);
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] = av_clipf(mul * c->Q[ch][j + off], INT32_MIN, INT32_MAX);
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] = av_clipf(mul * c->Q[ch][j + off], INT32_MIN, INT32_MAX);
85 }
86 }
87 if(bands[i].msf){
88 unsigned 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 }
100