1/* 2 * Copyright (c) 2012 3 * MIPS Technologies, Inc., California. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the MIPS Technologies, Inc., nor the names of its 14 * contributors may be used to endorse or promote products derived from 15 * this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * Author: Stanislav Ocovaj (socovaj@mips.com) 30 * 31 * AC3 fixed-point decoder for MIPS platforms 32 * 33 * This file is part of FFmpeg. 34 * 35 * FFmpeg is free software; you can redistribute it and/or 36 * modify it under the terms of the GNU Lesser General Public 37 * License as published by the Free Software Foundation; either 38 * version 2.1 of the License, or (at your option) any later version. 39 * 40 * FFmpeg is distributed in the hope that it will be useful, 41 * but WITHOUT ANY WARRANTY; without even the implied warranty of 42 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 43 * Lesser General Public License for more details. 44 * 45 * You should have received a copy of the GNU Lesser General Public 46 * License along with FFmpeg; if not, write to the Free Software 47 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 48 */ 49 50#define FFT_FLOAT 0 51#define USE_FIXED 1 52#define FFT_FIXED_32 1 53#include "ac3dec.h" 54 55 56/** 57 * Table for center mix levels 58 * reference: Section 5.4.2.4 cmixlev 59 */ 60static const uint8_t center_levels[4] = { 4, 5, 6, 5 }; 61 62/** 63 * Table for surround mix levels 64 * reference: Section 5.4.2.5 surmixlev 65 */ 66static const uint8_t surround_levels[4] = { 4, 6, 7, 6 }; 67 68int end_freq_inv_tab[8] = 69{ 70 50529027, 44278013, 39403370, 32292987, 27356480, 23729101, 20951060, 18755316 71}; 72 73static void scale_coefs ( 74 int32_t *dst, 75 const int32_t *src, 76 int dynrng, 77 int len) 78{ 79 int i, shift, round; 80 int16_t mul; 81 int temp, temp1, temp2, temp3, temp4, temp5, temp6, temp7; 82 83 mul = (dynrng & 0x1f) + 0x20; 84 shift = 4 - ((dynrng << 24) >> 29); 85 round = 1 << (shift-1); 86 for (i=0; i<len; i+=8) { 87 88 temp = src[i] * mul; 89 temp1 = src[i+1] * mul; 90 temp = temp + round; 91 temp2 = src[i+2] * mul; 92 93 temp1 = temp1 + round; 94 dst[i] = temp >> shift; 95 temp3 = src[i+3] * mul; 96 temp2 = temp2 + round; 97 98 dst[i+1] = temp1 >> shift; 99 temp4 = src[i + 4] * mul; 100 temp3 = temp3 + round; 101 dst[i+2] = temp2 >> shift; 102 103 temp5 = src[i+5] * mul; 104 temp4 = temp4 + round; 105 dst[i+3] = temp3 >> shift; 106 temp6 = src[i+6] * mul; 107 108 dst[i+4] = temp4 >> shift; 109 temp5 = temp5 + round; 110 temp7 = src[i+7] * mul; 111 temp6 = temp6 + round; 112 113 dst[i+5] = temp5 >> shift; 114 temp7 = temp7 + round; 115 dst[i+6] = temp6 >> shift; 116 dst[i+7] = temp7 >> shift; 117 118 } 119} 120 121/** 122 * Downmix samples from original signal to stereo or mono (this is for 16-bit samples 123 * and fixed point decoder - original (for 32-bit samples) is in ac3dsp.c). 124 */ 125static void ac3_downmix_c_fixed16(int16_t **samples, int16_t (*matrix)[2], 126 int out_ch, int in_ch, int len) 127{ 128 int i, j; 129 int v0, v1; 130 if (out_ch == 2) { 131 for (i = 0; i < len; i++) { 132 v0 = v1 = 0; 133 for (j = 0; j < in_ch; j++) { 134 v0 += samples[j][i] * matrix[j][0]; 135 v1 += samples[j][i] * matrix[j][1]; 136 } 137 samples[0][i] = (v0+2048)>>12; 138 samples[1][i] = (v1+2048)>>12; 139 } 140 } else if (out_ch == 1) { 141 for (i = 0; i < len; i++) { 142 v0 = 0; 143 for (j = 0; j < in_ch; j++) 144 v0 += samples[j][i] * matrix[j][0]; 145 samples[0][i] = (v0+2048)>>12; 146 } 147 } 148} 149 150#include "ac3dec.c" 151 152static const AVOption options[] = { 153 { NULL}, 154}; 155 156static const AVClass ac3_decoder_class = { 157 .class_name = "Fixed-Point AC-3 Decoder", 158 .item_name = av_default_item_name, 159 .option = options, 160 .version = LIBAVUTIL_VERSION_INT, 161}; 162 163AVCodec ff_ac3_fixed_decoder = { 164 .name = "ac3_fixed", 165 .type = AVMEDIA_TYPE_AUDIO, 166 .id = AV_CODEC_ID_AC3, 167 .priv_data_size = sizeof (AC3DecodeContext), 168 .init = ac3_decode_init, 169 .close = ac3_decode_end, 170 .decode = ac3_decode_frame, 171 .capabilities = CODEC_CAP_DR1, 172 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"), 173 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P, 174 AV_SAMPLE_FMT_NONE }, 175 .priv_class = &ac3_decoder_class, 176}; 177