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 - ((dynrng
<< 23) >> 28);
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
;
110 for (i
=0; i
<len
; i
+=8) {
113 temp1
= src
[i
+1] * mul
;
114 temp2
= src
[i
+2] * mul
;
116 dst
[i
] = temp
<< shift
;
117 temp3
= src
[i
+3] * mul
;
119 dst
[i
+1] = temp1
<< shift
;
120 temp4
= src
[i
+ 4] * mul
;
121 dst
[i
+2] = temp2
<< shift
;
123 temp5
= src
[i
+5] * mul
;
124 dst
[i
+3] = temp3
<< shift
;
125 temp6
= src
[i
+6] * mul
;
127 dst
[i
+4] = temp4
<< shift
;
128 temp7
= src
[i
+7] * mul
;
130 dst
[i
+5] = temp5
<< shift
;
131 dst
[i
+6] = temp6
<< shift
;
132 dst
[i
+7] = temp7
<< shift
;
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).
142 static void ac3_downmix_c_fixed16(int16_t **samples
, int16_t (*matrix
)[2],
143 int out_ch
, int in_ch
, int len
)
148 for (i
= 0; i
< len
; i
++) {
150 for (j
= 0; j
< in_ch
; j
++) {
151 v0
+= samples
[j
][i
] * matrix
[j
][0];
152 v1
+= samples
[j
][i
] * matrix
[j
][1];
154 samples
[0][i
] = (v0
+2048)>>12;
155 samples
[1][i
] = (v1
+2048)>>12;
157 } else if (out_ch
== 1) {
158 for (i
= 0; i
< len
; i
++) {
160 for (j
= 0; j
< in_ch
; j
++)
161 v0
+= samples
[j
][i
] * matrix
[j
][0];
162 samples
[0][i
] = (v0
+2048)>>12;
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
},
175 static const AVClass ac3_decoder_class
= {
176 .class_name
= "Fixed-Point AC-3 Decoder",
177 .item_name
= av_default_item_name
,
179 .version
= LIBAVUTIL_VERSION_INT
,
182 AVCodec ff_ac3_fixed_decoder
= {
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
,