3 * MIPS Technologies, Inc., California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 * Author: Stanislav Ocovaj (socovaj@mips.com)
31 * AC3 fixed-point decoder for MIPS platforms
33 * This file is part of FFmpeg.
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.
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.
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
52 #define FFT_FIXED_32 1
56 static const int end_freq_inv_tab[8] =
58 50529027, 44278013, 39403370, 32292987, 27356480, 23729101, 20951060, 18755316
61 static void scale_coefs (
69 int temp, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
71 mul = (dynrng & 0x1f) + 0x20;
72 shift = 4 - (sign_extend(dynrng, 9) >> 5);
74 round = 1 << (shift-1);
75 for (i=0; i<len; i+=8) {
78 temp1 = src[i+1] * mul;
80 temp2 = src[i+2] * mul;
82 temp1 = temp1 + round;
83 dst[i] = temp >> shift;
84 temp3 = src[i+3] * mul;
85 temp2 = temp2 + round;
87 dst[i+1] = temp1 >> shift;
88 temp4 = src[i + 4] * mul;
89 temp3 = temp3 + round;
90 dst[i+2] = temp2 >> shift;
92 temp5 = src[i+5] * mul;
93 temp4 = temp4 + round;
94 dst[i+3] = temp3 >> shift;
95 temp6 = src[i+6] * mul;
97 dst[i+4] = temp4 >> shift;
98 temp5 = temp5 + round;
99 temp7 = src[i+7] * mul;
100 temp6 = temp6 + round;
102 dst[i+5] = temp5 >> shift;
103 temp7 = temp7 + round;
104 dst[i+6] = temp6 >> shift;
105 dst[i+7] = temp7 >> shift;
111 for (i=0; i<len; i+=8) {
113 dst[i] = src[i ] * mul;
114 dst[i+1] = src[i+1] * mul;
115 dst[i+2] = src[i+2] * mul;
116 dst[i+3] = src[i+3] * mul;
117 dst[i+4] = src[i+4] * mul;
118 dst[i+5] = src[i+5] * mul;
119 dst[i+6] = src[i+6] * mul;
120 dst[i+7] = src[i+7] * mul;
126 * Downmix samples from original signal to stereo or mono (this is for 16-bit samples
127 * and fixed point decoder - original (for 32-bit samples) is in ac3dsp.c).
129 static void ac3_downmix_c_fixed16(int16_t **samples, int16_t **matrix,
130 int out_ch, int in_ch, int len)
135 for (i = 0; i < len; i++) {
137 for (j = 0; j < in_ch; j++) {
138 v0 += samples[j][i] * matrix[0][j];
139 v1 += samples[j][i] * matrix[1][j];
141 samples[0][i] = (v0+2048)>>12;
142 samples[1][i] = (v1+2048)>>12;
144 } else if (out_ch == 1) {
145 for (i = 0; i < len; i++) {
147 for (j = 0; j < in_ch; j++)
148 v0 += samples[j][i] * matrix[0][j];
149 samples[0][i] = (v0+2048)>>12;
157 static const AVOption options[] = {
158 { "cons_noisegen", "enable consistent noise generation", OFFSET(consistent_noise_generation), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
159 { "drc_scale", "percentage of dynamic range compression to apply", OFFSET(drc_scale), AV_OPT_TYPE_FLOAT, {.dbl = 1.0}, 0.0, 6.0, PAR },
160 { "heavy_compr", "enable heavy dynamic range compression", OFFSET(heavy_compression), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
164 static const AVClass ac3_decoder_class = {
165 .class_name = "Fixed-Point AC-3 Decoder",
166 .item_name = av_default_item_name,
168 .version = LIBAVUTIL_VERSION_INT,
171 AVCodec ff_ac3_fixed_decoder = {
173 .type = AVMEDIA_TYPE_AUDIO,
174 .id = AV_CODEC_ID_AC3,
175 .priv_data_size = sizeof (AC3DecodeContext),
176 .init = ac3_decode_init,
177 .close = ac3_decode_end,
178 .decode = ac3_decode_frame,
179 .capabilities = AV_CODEC_CAP_CHANNEL_CONF |
181 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
182 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
183 AV_SAMPLE_FMT_NONE },
184 .priv_class = &ac3_decoder_class,