2 * Musepack decoder core
3 * Copyright (c) 2006 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
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.
31 #include "mpegaudio.h"
36 void ff_mpc_init(void)
38 ff_mpa_synth_init(ff_mpa_synth_window);
42 * Process decoded Musepack data and produce PCM
44 static void mpc_synth(MPCContext *c, int16_t *out)
48 OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE], *samples_ptr;
50 for(ch = 0; ch < 2; ch++){
51 samples_ptr = samples + ch;
52 for(i = 0; i < SAMPLES_PER_BAND; i++) {
53 ff_mpa_synth_filter(c->synth_buf[ch], &(c->synth_buf_offset[ch]),
54 ff_mpa_synth_window, &dither_state,
56 c->sb_samples[ch][i]);
60 for(i = 0; i < MPC_FRAME_SIZE*2; i++)
64 void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data)
67 Band *bands = c->bands;
72 memset(c->sb_samples, 0, sizeof(c->sb_samples));
74 for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){
75 for(ch = 0; ch < 2; ch++){
78 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0]];
80 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
81 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1]];
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][2]];
86 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
91 for(j = 0; j < SAMPLES_PER_BAND; j++){
92 t1 = c->sb_samples[0][j][i];
93 t2 = c->sb_samples[1][j][i];
94 c->sb_samples[0][j][i] = t1 + t2;
95 c->sb_samples[1][j][i] = t1 - t2;