1/* 2 * Musepack decoder core 3 * Copyright (c) 2006 Konstantin Shishkov 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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 "mpegaudiodsp.h" 33#include "mpegaudio.h" 34 35#include "mpc.h" 36#include "mpcdata.h" 37 38void ff_mpc_init(void) 39{ 40 ff_mpa_synth_init_fixed(ff_mpa_synth_window_fixed); 41} 42 43/** 44 * Process decoded Musepack data and produce PCM 45 */ 46static void mpc_synth(MPCContext *c, int16_t *out, int channels) 47{ 48 int dither_state = 0; 49 int i, ch; 50 OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE], *samples_ptr; 51 52 for(ch = 0; ch < channels; ch++){ 53 samples_ptr = samples + ch; 54 for(i = 0; i < SAMPLES_PER_BAND; i++) { 55 ff_mpa_synth_filter_fixed(&c->mpadsp, 56 c->synth_buf[ch], &(c->synth_buf_offset[ch]), 57 ff_mpa_synth_window_fixed, &dither_state, 58 samples_ptr, channels, 59 c->sb_samples[ch][i]); 60 samples_ptr += 32 * channels; 61 } 62 } 63 for(i = 0; i < MPC_FRAME_SIZE*channels; i++) 64 *out++=samples[i]; 65} 66 67void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data, int channels) 68{ 69 int i, j, ch; 70 Band *bands = c->bands; 71 int off; 72 float mul; 73 74 /* dequantize */ 75 memset(c->sb_samples, 0, sizeof(c->sb_samples)); 76 off = 0; 77 for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){ 78 for(ch = 0; ch < 2; ch++){ 79 if(bands[i].res[ch]){ 80 j = 0; 81 mul = mpc_CC[bands[i].res[ch] + 1] * mpc_SCF[bands[i].scf_idx[ch][0]+6]; 82 for(; j < 12; j++) 83 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 84 mul = mpc_CC[bands[i].res[ch] + 1] * mpc_SCF[bands[i].scf_idx[ch][1]+6]; 85 for(; j < 24; j++) 86 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 87 mul = mpc_CC[bands[i].res[ch] + 1] * mpc_SCF[bands[i].scf_idx[ch][2]+6]; 88 for(; j < 36; j++) 89 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 90 } 91 } 92 if(bands[i].msf){ 93 int t1, t2; 94 for(j = 0; j < SAMPLES_PER_BAND; j++){ 95 t1 = c->sb_samples[0][j][i]; 96 t2 = c->sb_samples[1][j][i]; 97 c->sb_samples[0][j][i] = t1 + t2; 98 c->sb_samples[1][j][i] = t1 - t2; 99 } 100 } 101 } 102 103 mpc_synth(c, data, channels); 104} 105