yading@10: /*
yading@10:  * Musepack decoder core
yading@10:  * Copyright (c) 2006 Konstantin Shishkov
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * Musepack decoder core
yading@10:  * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
yading@10:  * divided into 32 subbands.
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "get_bits.h"
yading@10: #include "mpegaudiodsp.h"
yading@10: #include "mpegaudio.h"
yading@10: 
yading@10: #include "mpc.h"
yading@10: #include "mpcdata.h"
yading@10: 
yading@10: void ff_mpc_init(void)
yading@10: {
yading@10:     ff_mpa_synth_init_fixed(ff_mpa_synth_window_fixed);
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Process decoded Musepack data and produce PCM
yading@10:  */
yading@10: static void mpc_synth(MPCContext *c, int16_t **out, int channels)
yading@10: {
yading@10:     int dither_state = 0;
yading@10:     int i, ch;
yading@10: 
yading@10:     for(ch = 0;  ch < channels; ch++){
yading@10:         for(i = 0; i < SAMPLES_PER_BAND; i++) {
yading@10:             ff_mpa_synth_filter_fixed(&c->mpadsp,
yading@10:                                 c->synth_buf[ch], &(c->synth_buf_offset[ch]),
yading@10:                                 ff_mpa_synth_window_fixed, &dither_state,
yading@10:                                 out[ch] + 32 * i, 1,
yading@10:                                 c->sb_samples[ch][i]);
yading@10:         }
yading@10:     }
yading@10: }
yading@10: 
yading@10: void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, int16_t **out,
yading@10:                                  int channels)
yading@10: {
yading@10:     int i, j, ch;
yading@10:     Band *bands = c->bands;
yading@10:     int off;
yading@10:     float mul;
yading@10: 
yading@10:     /* dequantize */
yading@10:     memset(c->sb_samples, 0, sizeof(c->sb_samples));
yading@10:     off = 0;
yading@10:     for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){
yading@10:         for(ch = 0; ch < 2; ch++){
yading@10:             if(bands[i].res[ch]){
yading@10:                 j = 0;
yading@10:                 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0] & 0xFF];
yading@10:                 for(; j < 12; j++)
yading@10:                     c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
yading@10:                 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1] & 0xFF];
yading@10:                 for(; j < 24; j++)
yading@10:                     c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
yading@10:                 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2] & 0xFF];
yading@10:                 for(; j < 36; j++)
yading@10:                     c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
yading@10:             }
yading@10:         }
yading@10:         if(bands[i].msf){
yading@10:             int t1, t2;
yading@10:             for(j = 0; j < SAMPLES_PER_BAND; j++){
yading@10:                 t1 = c->sb_samples[0][j][i];
yading@10:                 t2 = c->sb_samples[1][j][i];
yading@10:                 c->sb_samples[0][j][i] = t1 + t2;
yading@10:                 c->sb_samples[1][j][i] = t1 - t2;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     mpc_synth(c, out, channels);
yading@10: }