blob: 6cf9b9d520855024e1210c83d827761c0756750d
| 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 "mpegaudiodsp.h" |
| 32 | #include "mpegaudio.h" |
| 33 | |
| 34 | #include "mpc.h" |
| 35 | #include "mpcdata.h" |
| 36 | |
| 37 | av_cold void ff_mpc_init(void) |
| 38 | { |
| 39 | ff_mpa_synth_init_fixed(ff_mpa_synth_window_fixed); |
| 40 | } |
| 41 | |
| 42 | /** |
| 43 | * Process decoded Musepack data and produce PCM |
| 44 | */ |
| 45 | static void mpc_synth(MPCContext *c, int16_t **out, int channels) |
| 46 | { |
| 47 | int dither_state = 0; |
| 48 | int i, ch; |
| 49 | |
| 50 | for(ch = 0; ch < channels; ch++){ |
| 51 | for(i = 0; i < SAMPLES_PER_BAND; i++) { |
| 52 | ff_mpa_synth_filter_fixed(&c->mpadsp, |
| 53 | c->synth_buf[ch], &(c->synth_buf_offset[ch]), |
| 54 | ff_mpa_synth_window_fixed, &dither_state, |
| 55 | out[ch] + 32 * i, 1, |
| 56 | c->sb_samples[ch][i]); |
| 57 | } |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, int16_t **out, |
| 62 | int channels) |
| 63 | { |
| 64 | int i, j, ch; |
| 65 | Band *bands = c->bands; |
| 66 | int off; |
| 67 | float mul; |
| 68 | |
| 69 | /* dequantize */ |
| 70 | memset(c->sb_samples, 0, sizeof(c->sb_samples)); |
| 71 | off = 0; |
| 72 | for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){ |
| 73 | for(ch = 0; ch < 2; ch++){ |
| 74 | if(bands[i].res[ch]){ |
| 75 | j = 0; |
| 76 | mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0] & 0xFF]; |
| 77 | for(; j < 12; j++) |
| 78 | c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; |
| 79 | mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1] & 0xFF]; |
| 80 | for(; j < 24; j++) |
| 81 | c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; |
| 82 | mul = (mpc_CC+1)[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2] & 0xFF]; |
| 83 | for(; j < 36; j++) |
| 84 | c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off]; |
| 85 | } |
| 86 | } |
| 87 | if(bands[i].msf){ |
| 88 | int t1, t2; |
| 89 | for(j = 0; j < SAMPLES_PER_BAND; j++){ |
| 90 | t1 = c->sb_samples[0][j][i]; |
| 91 | t2 = c->sb_samples[1][j][i]; |
| 92 | c->sb_samples[0][j][i] = t1 + t2; |
| 93 | c->sb_samples[1][j][i] = t1 - t2; |
| 94 | } |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | mpc_synth(c, out, channels); |
| 99 | } |
| 100 |