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 "avcodec.h" 30#include "get_bits.h" 31#include "dsputil.h" 32#include "mpegaudio.h" 33 34#include "mpc.h" 35#include "mpcdata.h" 36 37void ff_mpc_init(void) 38{ 39 ff_mpa_synth_init(ff_mpa_synth_window); 40} 41 42/** 43 * Process decoded Musepack data and produce PCM 44 */ 45static void mpc_synth(MPCContext *c, int16_t *out) 46{ 47 int dither_state = 0; 48 int i, ch; 49 OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE], *samples_ptr; 50 51 for(ch = 0; ch < 2; ch++){ 52 samples_ptr = samples + ch; 53 for(i = 0; i < SAMPLES_PER_BAND; i++) { 54 ff_mpa_synth_filter(c->synth_buf[ch], &(c->synth_buf_offset[ch]), 55 ff_mpa_synth_window, &dither_state, 56 samples_ptr, 2, 57 c->sb_samples[ch][i]); 58 samples_ptr += 64; 59 } 60 } 61 for(i = 0; i < MPC_FRAME_SIZE*2; i++) 62 *out++=samples[i]; 63} 64 65void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data) 66{ 67 int i, j, ch; 68 Band *bands = c->bands; 69 int off; 70 float mul; 71 72 /* dequantize */ 73 memset(c->sb_samples, 0, sizeof(c->sb_samples)); 74 off = 0; 75 for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){ 76 for(ch = 0; ch < 2; ch++){ 77 if(bands[i].res[ch]){ 78 j = 0; 79 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0]]; 80 for(; j < 12; j++) 81 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 82 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1]]; 83 for(; j < 24; j++) 84 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 85 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2]]; 86 for(; j < 36; j++) 87 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 88 } 89 } 90 if(bands[i].msf){ 91 int t1, t2; 92 for(j = 0; j < SAMPLES_PER_BAND; j++){ 93 t1 = c->sb_samples[0][j][i]; 94 t2 = c->sb_samples[1][j][i]; 95 c->sb_samples[0][j][i] = t1 + t2; 96 c->sb_samples[1][j][i] = t1 - t2; 97 } 98 } 99 } 100 101 mpc_synth(c, data); 102} 103