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 <string.h> 30#include "libavutil/intmath.h" 31#include "mpegaudiodsp.h" 32 33#include "mpc.h" 34#include "mpcdata.h" 35 36/** 37 * Process decoded Musepack data and produce PCM 38 */ 39static void mpc_synth(MPCContext *c, int16_t **out, int channels) 40{ 41 int dither_state = 0; 42 int i, ch; 43 44 for(ch = 0; ch < channels; ch++){ 45 for(i = 0; i < SAMPLES_PER_BAND; i++) { 46 ff_mpa_synth_filter_fixed(&c->mpadsp, 47 c->synth_buf[ch], &(c->synth_buf_offset[ch]), 48 ff_mpa_synth_window_fixed, &dither_state, 49 out[ch] + 32 * i, 1, 50 c->sb_samples[ch][i]); 51 } 52 } 53} 54 55void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, int16_t **out, 56 int channels) 57{ 58 int i, j, ch; 59 Band *bands = c->bands; 60 int off; 61 float mul; 62 63 /* dequantize */ 64 memset(c->sb_samples, 0, sizeof(c->sb_samples)); 65 off = 0; 66 for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){ 67 for(ch = 0; ch < 2; ch++){ 68 if(bands[i].res[ch]){ 69 j = 0; 70 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0] & 0xFF]; 71 for(; j < 12; j++) 72 c->sb_samples[ch][j][i] = av_clipf(mul * c->Q[ch][j + off], INT32_MIN, INT32_MAX); 73 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1] & 0xFF]; 74 for(; j < 24; j++) 75 c->sb_samples[ch][j][i] = av_clipf(mul * c->Q[ch][j + off], INT32_MIN, INT32_MAX); 76 mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2] & 0xFF]; 77 for(; j < 36; j++) 78 c->sb_samples[ch][j][i] = av_clipf(mul * c->Q[ch][j + off], INT32_MIN, INT32_MAX); 79 } 80 } 81 if(bands[i].msf){ 82 unsigned t1, t2; 83 for(j = 0; j < SAMPLES_PER_BAND; j++){ 84 t1 = c->sb_samples[0][j][i]; 85 t2 = c->sb_samples[1][j][i]; 86 c->sb_samples[0][j][i] = t1 + t2; 87 c->sb_samples[1][j][i] = t1 - t2; 88 } 89 } 90 } 91 92 mpc_synth(c, out, channels); 93} 94