FFmpeg
ac3dec_fixed.c
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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 
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;
68  unsigned mul, round;
69  int temp, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
70 
71  mul = (dynrng & 0x1f) + 0x20;
72  shift = 4 - (sign_extend(dynrng, 9) >> 5);
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  */
142 static void ac3_downmix_c_fixed16(int16_t **samples, int16_t **matrix,
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[0][j];
152  v1 += samples[j][i] * matrix[1][j];
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[0][j];
162  samples[0][i] = (v0+2048)>>12;
163  }
164  }
165 }
166 
167 #include "eac3dec.c"
168 #include "ac3dec.c"
169 
170 static const AVOption options[] = {
171  { "cons_noisegen", "enable consistent noise generation", OFFSET(consistent_noise_generation), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
172  { "drc_scale", "percentage of dynamic range compression to apply", OFFSET(drc_scale), AV_OPT_TYPE_FLOAT, {.dbl = 1.0}, 0.0, 6.0, PAR },
173  { "heavy_compr", "enable heavy dynamic range compression", OFFSET(heavy_compression), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
174  { NULL},
175 };
176 
177 static const AVClass ac3_decoder_class = {
178  .class_name = "Fixed-Point AC-3 Decoder",
179  .item_name = av_default_item_name,
180  .option = options,
181  .version = LIBAVUTIL_VERSION_INT,
182 };
183 
185  .name = "ac3_fixed",
186  .type = AVMEDIA_TYPE_AUDIO,
187  .id = AV_CODEC_ID_AC3,
188  .priv_data_size = sizeof (AC3DecodeContext),
190  .close = ac3_decode_end,
192  .capabilities = AV_CODEC_CAP_DR1,
193  .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
194  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
196  .priv_class = &ac3_decoder_class,
197 };
static const AVClass ac3_decoder_class
Definition: ac3dec_fixed.c:177
#define NULL
Definition: coverity.c:32
static int shift(int a, int b)
Definition: sonic.c:82
AVOption.
Definition: opt.h:246
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
else temp
Definition: vf_mcdeint.c:256
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:191
GLfloat v0
Definition: opengl_enc.c:106
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3494
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
static void scale_coefs(int32_t *dst, const int32_t *src, int dynrng, int len)
Definition: ac3dec_fixed.c:61
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
static av_cold int ac3_decode_end(AVCodecContext *avctx)
Uninitialize the AC-3 decoder.
Definition: ac3dec.c:1831
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option keep it simple and lowercase description are in without and describe what they for example set the foo of the bar offset is the offset of the field in your local see the OFFSET() macro
const char * name
Name of the codec implementation.
Definition: avcodec.h:3501
static av_always_inline av_const double round(double x)
Definition: libm.h:444
static int ac3_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Decode a single AC-3 frame.
Definition: ac3dec.c:1462
AVCodec ff_ac3_fixed_decoder
Definition: ac3dec_fixed.c:184
int32_t
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
static const AVOption options[]
Definition: ac3dec_fixed.c:170
static const int end_freq_inv_tab[8]
Definition: ac3dec_fixed.c:56
Describe the class of an AVClass context structure.
Definition: log.h:67
Definition: af_afade.c:54
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:130
static void ac3_downmix_c_fixed16(int16_t **samples, int16_t **matrix, int out_ch, int in_ch, int len)
Downmix samples from original signal to stereo or mono (this is for 16-bit samples and fixed point de...
Definition: ac3dec_fixed.c:142
int len
Filter the word “frame” indicates either a video frame or a group of audio samples
signed 16 bits, planar
Definition: samplefmt.h:67
static av_cold int ac3_decode_init(AVCodecContext *avctx)
AVCodec initialization.
Definition: ac3dec.c:184
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:986