1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
/*
* Copyright (c) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen, Vladimir Sadovnikov and others
* Copyright (c) 2015 Paul B Mahol
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/opt.h"
#include "libavutil/samplefmt.h"
#include "avfilter.h"
#include "audio.h"
#include "internal.h"
typedef struct CompensationDelayContext {
const AVClass *class;
int distance_mm;
int distance_cm;
int distance_m;
double dry, wet;
int temp;
unsigned delay;
unsigned w_ptr;
unsigned buf_size;
AVFrame *delay_frame;
} CompensationDelayContext;
#define OFFSET(x) offsetof(CompensationDelayContext, x)
#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption compensationdelay_options[] = {
{ "mm", "set mm distance", OFFSET(distance_mm), AV_OPT_TYPE_INT, {.i64=0}, 0, 10, A },
{ "cm", "set cm distance", OFFSET(distance_cm), AV_OPT_TYPE_INT, {.i64=0}, 0, 100, A },
{ "m", "set meter distance", OFFSET(distance_m), AV_OPT_TYPE_INT, {.i64=0}, 0, 100, A },
{ "dry", "set dry amount", OFFSET(dry), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 1, A },
{ "wet", "set wet amount", OFFSET(wet), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, A },
{ "temp", "set temperature °C", OFFSET(temp), AV_OPT_TYPE_INT, {.i64=20}, -50, 50, A },
{ NULL }
};
AVFILTER_DEFINE_CLASS(compensationdelay);
// The maximum distance for options
#define COMP_DELAY_MAX_DISTANCE (100.0 * 100.0 + 100.0 * 1.0 + 1.0)
// The actual speed of sound in normal conditions
#define COMP_DELAY_SOUND_SPEED_KM_H(temp) 1.85325 * (643.95 * sqrt(((temp + 273.15) / 273.15)))
#define COMP_DELAY_SOUND_SPEED_CM_S(temp) (COMP_DELAY_SOUND_SPEED_KM_H(temp) * (1000.0 * 100.0) /* cm/km */ / (60.0 * 60.0) /* s/h */)
#define COMP_DELAY_SOUND_FRONT_DELAY(temp) (1.0 / COMP_DELAY_SOUND_SPEED_CM_S(temp))
// The maximum delay may be reached by this filter
#define COMP_DELAY_MAX_DELAY (COMP_DELAY_MAX_DISTANCE * COMP_DELAY_SOUND_FRONT_DELAY(50))
static int query_formats(AVFilterContext *ctx)
{
static const enum AVSampleFormat sample_fmts[] = {
AV_SAMPLE_FMT_DBLP,
AV_SAMPLE_FMT_NONE
};
int ret = ff_set_common_all_channel_counts(ctx);
if (ret < 0)
return ret;
ret = ff_set_common_formats_from_list(ctx, sample_fmts);
if (ret < 0)
return ret;
return ff_set_common_all_samplerates(ctx);
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
CompensationDelayContext *s = ctx->priv;
unsigned min_size, new_size = 1;
s->delay = (s->distance_m * 100. + s->distance_cm * 1. + s->distance_mm * .1) *
COMP_DELAY_SOUND_FRONT_DELAY(s->temp) * inlink->sample_rate;
min_size = inlink->sample_rate * COMP_DELAY_MAX_DELAY;
while (new_size < min_size)
new_size <<= 1;
s->delay_frame = av_frame_alloc();
if (!s->delay_frame)
return AVERROR(ENOMEM);
s->buf_size = new_size;
s->delay_frame->format = inlink->format;
s->delay_frame->nb_samples = new_size;
s->delay_frame->channel_layout = inlink->channel_layout;
return av_frame_get_buffer(s->delay_frame, 0);
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
CompensationDelayContext *s = ctx->priv;
const unsigned b_mask = s->buf_size - 1;
const unsigned buf_size = s->buf_size;
const unsigned delay = s->delay;
const double dry = s->dry;
const double wet = s->wet;
unsigned r_ptr, w_ptr = 0;
AVFrame *out;
int n, ch;
out = ff_get_audio_buffer(ctx->outputs[0], in->nb_samples);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, in);
for (ch = 0; ch < inlink->channels; ch++) {
const double *src = (const double *)in->extended_data[ch];
double *dst = (double *)out->extended_data[ch];
double *buffer = (double *)s->delay_frame->extended_data[ch];
w_ptr = s->w_ptr;
r_ptr = (w_ptr + buf_size - delay) & b_mask;
for (n = 0; n < in->nb_samples; n++) {
const double sample = src[n];
buffer[w_ptr] = sample;
dst[n] = dry * sample + wet * buffer[r_ptr];
w_ptr = (w_ptr + 1) & b_mask;
r_ptr = (r_ptr + 1) & b_mask;
}
}
s->w_ptr = w_ptr;
av_frame_free(&in);
return ff_filter_frame(ctx->outputs[0], out);
}
static av_cold void uninit(AVFilterContext *ctx)
{
CompensationDelayContext *s = ctx->priv;
av_frame_free(&s->delay_frame);
}
static const AVFilterPad compensationdelay_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_input,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad compensationdelay_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
},
{ NULL }
};
const AVFilter ff_af_compensationdelay = {
.name = "compensationdelay",
.description = NULL_IF_CONFIG_SMALL("Audio Compensation Delay Line."),
.query_formats = query_formats,
.priv_size = sizeof(CompensationDelayContext),
.priv_class = &compensationdelay_class,
.uninit = uninit,
.inputs = compensationdelay_inputs,
.outputs = compensationdelay_outputs,
};
|
