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 "libavutil/attributes.h" 30#include "avcodec.h" 31#include "get_bits.h" 32#include "mpegaudiodsp.h" 33#include "mpegaudio.h" 34 35#include "mpc.h" 36#include "mpcdata.h" 37 38av_cold void 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 51 for(ch = 0; ch < channels; ch++){ 52 for(i = 0; i < SAMPLES_PER_BAND; i++) { 53 ff_mpa_synth_filter_fixed(&c->mpadsp, 54 c->synth_buf[ch], &(c->synth_buf_offset[ch]), 55 ff_mpa_synth_window_fixed, &dither_state, 56 out[ch] + 32 * i, 1, 57 c->sb_samples[ch][i]); 58 } 59 } 60} 61 62void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, int16_t **out, 63 int channels) 64{ 65 int i, j, ch; 66 Band *bands = c->bands; 67 int off; 68 float mul; 69 70 /* dequantize */ 71 memset(c->sb_samples, 0, sizeof(c->sb_samples)); 72 off = 0; 73 for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){ 74 for(ch = 0; ch < 2; ch++){ 75 if(bands[i].res[ch]){ 76 j = 0; 77 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0] & 0xFF]; 78 for(; j < 12; j++) 79 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 80 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1] & 0xFF]; 81 for(; j < 24; j++) 82 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 83 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2] & 0xFF]; 84 for(; j < 36; j++) 85 c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; 86 } 87 } 88 if(bands[i].msf){ 89 int t1, t2; 90 for(j = 0; j < SAMPLES_PER_BAND; j++){ 91 t1 = c->sb_samples[0][j][i]; 92 t2 = c->sb_samples[1][j][i]; 93 c->sb_samples[0][j][i] = t1 + t2; 94 c->sb_samples[1][j][i] = t1 - t2; 95 } 96 } 97 } 98 99 mpc_synth(c, out, channels); 100} 101