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 #include "ac3dec.h"
53 
54 
55 static const int end_freq_inv_tab[8] =
56 {
57  50529027, 44278013, 39403370, 32292987, 27356480, 23729101, 20951060, 18755316
58 };
59 
60 static void scale_coefs (
61  int32_t *dst,
62  const int32_t *src,
63  int dynrng,
64  int len)
65 {
66  int i, shift;
67  unsigned mul, round;
68  int temp, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
69 
70  mul = (dynrng & 0x1f) + 0x20;
71  shift = 4 - (sign_extend(dynrng, 9) >> 5);
72  if (shift > 0 ) {
73  round = 1 << (shift-1);
74  for (i=0; i<len; i+=8) {
75 
76  temp = src[i] * mul;
77  temp1 = src[i+1] * mul;
78  temp = temp + round;
79  temp2 = src[i+2] * mul;
80 
81  temp1 = temp1 + round;
82  dst[i] = temp >> shift;
83  temp3 = src[i+3] * mul;
84  temp2 = temp2 + round;
85 
86  dst[i+1] = temp1 >> shift;
87  temp4 = src[i + 4] * mul;
88  temp3 = temp3 + round;
89  dst[i+2] = temp2 >> shift;
90 
91  temp5 = src[i+5] * mul;
92  temp4 = temp4 + round;
93  dst[i+3] = temp3 >> shift;
94  temp6 = src[i+6] * mul;
95 
96  dst[i+4] = temp4 >> shift;
97  temp5 = temp5 + round;
98  temp7 = src[i+7] * mul;
99  temp6 = temp6 + round;
100 
101  dst[i+5] = temp5 >> shift;
102  temp7 = temp7 + round;
103  dst[i+6] = temp6 >> shift;
104  dst[i+7] = temp7 >> shift;
105 
106  }
107  } else {
108  shift = -shift;
109  mul <<= shift;
110  for (i=0; i<len; i+=8) {
111 
112  dst[i] = src[i ] * mul;
113  dst[i+1] = src[i+1] * mul;
114  dst[i+2] = src[i+2] * mul;
115  dst[i+3] = src[i+3] * mul;
116  dst[i+4] = src[i+4] * mul;
117  dst[i+5] = src[i+5] * mul;
118  dst[i+6] = src[i+6] * mul;
119  dst[i+7] = src[i+7] * mul;
120  }
121  }
122 }
123 
124 /**
125  * Downmix samples from original signal to stereo or mono (this is for 16-bit samples
126  * and fixed point decoder - original (for 32-bit samples) is in ac3dsp.c).
127  */
128 static void ac3_downmix_c_fixed16(int16_t **samples, int16_t **matrix,
129  int out_ch, int in_ch, int len)
130 {
131  int i, j;
132  int v0, v1;
133  if (out_ch == 2) {
134  for (i = 0; i < len; i++) {
135  v0 = v1 = 0;
136  for (j = 0; j < in_ch; j++) {
137  v0 += samples[j][i] * matrix[0][j];
138  v1 += samples[j][i] * matrix[1][j];
139  }
140  samples[0][i] = (v0+2048)>>12;
141  samples[1][i] = (v1+2048)>>12;
142  }
143  } else if (out_ch == 1) {
144  for (i = 0; i < len; i++) {
145  v0 = 0;
146  for (j = 0; j < in_ch; j++)
147  v0 += samples[j][i] * matrix[0][j];
148  samples[0][i] = (v0+2048)>>12;
149  }
150  }
151 }
152 
153 #include "eac3dec.c"
154 #include "ac3dec.c"
155 
156 static const AVOption options[] = {
157  { "cons_noisegen", "enable consistent noise generation", OFFSET(consistent_noise_generation), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
158  { "drc_scale", "percentage of dynamic range compression to apply", OFFSET(drc_scale), AV_OPT_TYPE_FLOAT, {.dbl = 1.0}, 0.0, 6.0, PAR },
159  { "heavy_compr", "enable heavy dynamic range compression", OFFSET(heavy_compression), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
160  { NULL},
161 };
162 
163 static const AVClass ac3_decoder_class = {
164  .class_name = "Fixed-Point AC-3 Decoder",
165  .item_name = av_default_item_name,
166  .option = options,
167  .version = LIBAVUTIL_VERSION_INT,
168 };
169 
171  .name = "ac3_fixed",
172  .type = AVMEDIA_TYPE_AUDIO,
173  .id = AV_CODEC_ID_AC3,
174  .priv_data_size = sizeof (AC3DecodeContext),
176  .close = ac3_decode_end,
178  .capabilities = AV_CODEC_CAP_CHANNEL_CONF |
180  .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
181  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
183  .priv_class = &ac3_decoder_class,
185 };
AVCodec
AVCodec.
Definition: codec.h:202
FF_CODEC_CAP_INIT_THREADSAFE
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:42
AV_CODEC_ID_AC3
@ AV_CODEC_ID_AC3
Definition: codec_id.h:426
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
ac3_decoder_class
static const AVClass ac3_decoder_class
Definition: ac3dec_fixed.c:163
AVOption
AVOption.
Definition: opt.h:247
v0
#define v0
Definition: regdef.h:26
ac3dec.h
scale_coefs
static void scale_coefs(int32_t *dst, const int32_t *src, int dynrng, int len)
Definition: ac3dec_fixed.c:60
ac3dec.c
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
ac3_decode_init
static av_cold int ac3_decode_init(AVCodecContext *avctx)
AVCodec initialization.
Definition: ac3dec.c:185
mul
static float mul(float src0, float src1)
Definition: dnn_backend_native_layer_mathbinary.c:39
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
src
#define src
Definition: vp8dsp.c:255
ff_ac3_fixed_decoder
const AVCodec ff_ac3_fixed_decoder
Definition: ac3dec_fixed.c:170
eac3dec.c
AV_CODEC_CAP_CHANNEL_CONF
#define AV_CODEC_CAP_CHANNEL_CONF
Codec should fill in channel configuration and samplerate instead of container.
Definition: codec.h:109
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:59
end_freq_inv_tab
static const int end_freq_inv_tab[8]
Definition: ac3dec_fixed.c:55
AV_SAMPLE_FMT_S16P
@ AV_SAMPLE_FMT_S16P
signed 16 bits, planar
Definition: samplefmt.h:67
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:227
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
round
static av_always_inline av_const double round(double x)
Definition: libm.h:444
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: internal.h:50
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
ac3_decode_end
static av_cold int ac3_decode_end(AVCodecContext *avctx)
Uninitialize the AC-3 decoder.
Definition: ac3dec.c:1837
options
static const AVOption options[]
Definition: ac3dec_fixed.c:156
ac3_downmix_c_fixed16
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:128
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
len
int len
Definition: vorbis_enc_data.h:426
AVClass::class_name
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:71
OFFSET
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 see the OFFSET() macro
sign_extend
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:130
temp
else temp
Definition: vf_mcdeint.c:248
samples
Filter the word “frame” indicates either a video frame or a group of audio samples
Definition: filter_design.txt:8
shift
static int shift(int a, int b)
Definition: sonic.c:83
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:241
int32_t
int32_t
Definition: audioconvert.c:56
PAR
@ PAR
Definition: af_afade.c:54
ac3_decode_frame
static int ac3_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Decode a single AC-3 frame.
Definition: ac3dec.c:1468