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  mul <<= shift;
111  for (i=0; i<len; i+=8) {
112 
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;
121  }
122  }
123 }
124 
125 /**
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).
128  */
129 static void ac3_downmix_c_fixed16(int16_t **samples, int16_t **matrix,
130  int out_ch, int in_ch, int len)
131 {
132  int i, j;
133  int v0, v1;
134  if (out_ch == 2) {
135  for (i = 0; i < len; i++) {
136  v0 = v1 = 0;
137  for (j = 0; j < in_ch; j++) {
138  v0 += samples[j][i] * matrix[0][j];
139  v1 += samples[j][i] * matrix[1][j];
140  }
141  samples[0][i] = (v0+2048)>>12;
142  samples[1][i] = (v1+2048)>>12;
143  }
144  } else if (out_ch == 1) {
145  for (i = 0; i < len; i++) {
146  v0 = 0;
147  for (j = 0; j < in_ch; j++)
148  v0 += samples[j][i] * matrix[0][j];
149  samples[0][i] = (v0+2048)>>12;
150  }
151  }
152 }
153 
154 #include "eac3dec.c"
155 #include "ac3dec.c"
156 
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 },
161  { NULL},
162 };
163 
164 static const AVClass ac3_decoder_class = {
165  .class_name = "Fixed-Point AC-3 Decoder",
166  .item_name = av_default_item_name,
167  .option = options,
168  .version = LIBAVUTIL_VERSION_INT,
169 };
170 
172  .name = "ac3_fixed",
173  .type = AVMEDIA_TYPE_AUDIO,
174  .id = AV_CODEC_ID_AC3,
175  .priv_data_size = sizeof (AC3DecodeContext),
177  .close = ac3_decode_end,
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,
184  .priv_class = &ac3_decoder_class,
185 };
static const AVClass ac3_decoder_class
Definition: ac3dec_fixed.c:164
#define NULL
Definition: coverity.c:32
static int shift(int a, int b)
Definition: sonic.c:82
AVOption.
Definition: opt.h:248
#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:235
#define AV_CODEC_CAP_CHANNEL_CONF
Codec should fill in channel configuration and samplerate instead of container.
Definition: codec.h:102
GLfloat v0
Definition: opengl_enc.c:106
AVCodec.
Definition: codec.h:190
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 src
Definition: vp8dsp.c:254
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
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: codec.h:197
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
static float mul(float src0, float src1)
AVCodec ff_ac3_fixed_decoder
Definition: ac3dec_fixed.c:171
int32_t
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
static const AVOption options[]
Definition: ac3dec_fixed.c:157
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:129
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: codec.h:50
int i
Definition: input.c:407