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 static const int end_freq_inv_tab[8] =
57 {
58 50529027, 44278013, 39403370, 32292987, 27356480, 23729101, 20951060, 18755316
59 };
60
scale_coefs(int32_t * dst,const int32_t * src,int dynrng,int len)61 static void scale_coefs (
62 int32_t *dst,
63 const int32_t *src,
64 int dynrng,
65 int len)
66 {
67 int i, shift, round;
68 int16_t mul;
69 int temp, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
70
71 mul = (dynrng & 0x1f) + 0x20;
72 shift = 4 - ((dynrng << 23) >> 28);
73 if (shift > 0 ) {
74 round = 1 << (shift-1);
75 for (i=0; i<len; i+=8) {
76
77 temp = src[i] * mul;
78 temp1 = src[i+1] * mul;
79 temp = temp + round;
80 temp2 = src[i+2] * mul;
81
82 temp1 = temp1 + round;
83 dst[i] = temp >> shift;
84 temp3 = src[i+3] * mul;
85 temp2 = temp2 + round;
86
87 dst[i+1] = temp1 >> shift;
88 temp4 = src[i + 4] * mul;
89 temp3 = temp3 + round;
90 dst[i+2] = temp2 >> shift;
91
92 temp5 = src[i+5] * mul;
93 temp4 = temp4 + round;
94 dst[i+3] = temp3 >> shift;
95 temp6 = src[i+6] * mul;
96
97 dst[i+4] = temp4 >> shift;
98 temp5 = temp5 + round;
99 temp7 = src[i+7] * mul;
100 temp6 = temp6 + round;
101
102 dst[i+5] = temp5 >> shift;
103 temp7 = temp7 + round;
104 dst[i+6] = temp6 >> shift;
105 dst[i+7] = temp7 >> shift;
106
107 }
108 } else {
109 shift = -shift;
110 for (i=0; i<len; i+=8) {
111
112 temp = src[i] * mul;
113 temp1 = src[i+1] * mul;
114 temp2 = src[i+2] * mul;
115
116 dst[i] = temp << shift;
117 temp3 = src[i+3] * mul;
118
119 dst[i+1] = temp1 << shift;
120 temp4 = src[i + 4] * mul;
121 dst[i+2] = temp2 << shift;
122
123 temp5 = src[i+5] * mul;
124 dst[i+3] = temp3 << shift;
125 temp6 = src[i+6] * mul;
126
127 dst[i+4] = temp4 << shift;
128 temp7 = src[i+7] * mul;
129
130 dst[i+5] = temp5 << shift;
131 dst[i+6] = temp6 << shift;
132 dst[i+7] = temp7 << shift;
133
134 }
135 }
136 }
137
138 /**
139 * Downmix samples from original signal to stereo or mono (this is for 16-bit samples
140 * and fixed point decoder - original (for 32-bit samples) is in ac3dsp.c).
141 */
ac3_downmix_c_fixed16(int16_t ** samples,int16_t (* matrix)[2],int out_ch,int in_ch,int len)142 static void ac3_downmix_c_fixed16(int16_t **samples, int16_t (*matrix)[2],
143 int out_ch, int in_ch, int len)
144 {
145 int i, j;
146 int v0, v1;
147 if (out_ch == 2) {
148 for (i = 0; i < len; i++) {
149 v0 = v1 = 0;
150 for (j = 0; j < in_ch; j++) {
151 v0 += samples[j][i] * matrix[j][0];
152 v1 += samples[j][i] * matrix[j][1];
153 }
154 samples[0][i] = (v0+2048)>>12;
155 samples[1][i] = (v1+2048)>>12;
156 }
157 } else if (out_ch == 1) {
158 for (i = 0; i < len; i++) {
159 v0 = 0;
160 for (j = 0; j < in_ch; j++)
161 v0 += samples[j][i] * matrix[j][0];
162 samples[0][i] = (v0+2048)>>12;
163 }
164 }
165 }
166
167 #include "ac3dec.c"
168
169 static const AVOption options[] = {
170 { "drc_scale", "percentage of dynamic range compression to apply", OFFSET(drc_scale), AV_OPT_TYPE_FLOAT, {.dbl = 1.0}, 0.0, 6.0, PAR },
171 { "heavy_compr", "heavy dynamic range compression enabled", OFFSET(heavy_compression), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, PAR },
172 { NULL},
173 };
174
175 static const AVClass ac3_decoder_class = {
176 .class_name = "Fixed-Point AC-3 Decoder",
177 .item_name = av_default_item_name,
178 .option = options,
179 .version = LIBAVUTIL_VERSION_INT,
180 };
181
182 AVCodec ff_ac3_fixed_decoder = {
183 .name = "ac3_fixed",
184 .type = AVMEDIA_TYPE_AUDIO,
185 .id = AV_CODEC_ID_AC3,
186 .priv_data_size = sizeof (AC3DecodeContext),
187 .init = ac3_decode_init,
188 .close = ac3_decode_end,
189 .decode = ac3_decode_frame,
190 .capabilities = CODEC_CAP_DR1,
191 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
192 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
193 AV_SAMPLE_FMT_NONE },
194 .priv_class = &ac3_decoder_class,
195 };
196