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.
29 #include "bitstream.h"
31 #include "mpegaudio.h"
36 static DECLARE_ALIGNED_16(MPA_INT, mpa_window[512]);
38 void ff_mpc_init(void)
40 ff_mpa_synth_init(mpa_window);
44 * Process decoded Musepack data and produce PCM
46 static void mpc_synth(MPCContext *c, int16_t *out)
50 OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE], *samples_ptr;
52 for(ch = 0; ch < 2; ch++){
53 samples_ptr = samples + ch;
54 for(i = 0; i < SAMPLES_PER_BAND; i++) {
55 ff_mpa_synth_filter(c->synth_buf[ch], &(c->synth_buf_offset[ch]),
56 mpa_window, &dither_state,
58 c->sb_samples[ch][i]);
62 for(i = 0; i < MPC_FRAME_SIZE*2; i++)
66 void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data)
69 Band *bands = c->bands;
74 memset(c->sb_samples, 0, sizeof(c->sb_samples));
76 for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){
77 for(ch = 0; ch < 2; ch++){
80 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0]];
82 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
83 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1]];
85 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
86 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2]];
88 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
93 for(j = 0; j < SAMPLES_PER_BAND; j++){
94 t1 = c->sb_samples[0][j][i];
95 t2 = c->sb_samples[1][j][i];
96 c->sb_samples[0][j][i] = t1 + t2;
97 c->sb_samples[1][j][i] = t1 - t2;