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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/*
* Copyright (c) 2018 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 <float.h>
#include "libavutil/ffmath.h"
#include "libavutil/opt.h"
#include "audio.h"
#include "avfilter.h"
#include "internal.h"
typedef struct ChannelStats {
uint64_t nb_samples;
uint64_t blknum;
float peak;
float sum;
uint32_t peaks[10001];
uint32_t rms[10001];
} ChannelStats;
typedef struct DRMeterContext {
const AVClass *class;
ChannelStats *chstats;
int nb_channels;
uint64_t tc_samples;
double time_constant;
} DRMeterContext;
#define OFFSET(x) offsetof(DRMeterContext, x)
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption drmeter_options[] = {
{ "length", "set the window length", OFFSET(time_constant), AV_OPT_TYPE_DOUBLE, {.dbl=3}, .01, 10, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(drmeter);
static int query_formats(AVFilterContext *ctx)
{
AVFilterFormats *formats;
AVFilterChannelLayouts *layouts;
static const enum AVSampleFormat sample_fmts[] = {
AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_FLT,
AV_SAMPLE_FMT_NONE
};
int ret;
layouts = ff_all_channel_counts();
if (!layouts)
return AVERROR(ENOMEM);
ret = ff_set_common_channel_layouts(ctx, layouts);
if (ret < 0)
return ret;
formats = ff_make_format_list(sample_fmts);
if (!formats)
return AVERROR(ENOMEM);
ret = ff_set_common_formats(ctx, formats);
if (ret < 0)
return ret;
formats = ff_all_samplerates();
if (!formats)
return AVERROR(ENOMEM);
return ff_set_common_samplerates(ctx, formats);
}
static int config_output(AVFilterLink *outlink)
{
DRMeterContext *s = outlink->src->priv;
s->chstats = av_calloc(sizeof(*s->chstats), outlink->channels);
if (!s->chstats)
return AVERROR(ENOMEM);
s->nb_channels = outlink->channels;
s->tc_samples = s->time_constant * outlink->sample_rate + .5;
return 0;
}
static void finish_block(ChannelStats *p)
{
int peak_bin, rms_bin;
float peak, rms;
rms = sqrt(2 * p->sum / p->nb_samples);
peak = p->peak;
rms_bin = av_clip(rms * 10000, 0, 10000);
peak_bin = av_clip(peak * 10000, 0, 10000);
p->rms[rms_bin]++;
p->peaks[peak_bin]++;
p->peak = 0;
p->sum = 0;
p->nb_samples = 0;
p->blknum++;
}
static void update_stat(DRMeterContext *s, ChannelStats *p, float sample)
{
if (p->nb_samples >= s->tc_samples) {
finish_block(p);
}
p->peak = FFMAX(FFABS(sample), p->peak);
p->sum += sample * sample;
p->nb_samples++;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
{
DRMeterContext *s = inlink->dst->priv;
const int channels = s->nb_channels;
int i, c;
switch (inlink->format) {
case AV_SAMPLE_FMT_FLTP:
for (c = 0; c < channels; c++) {
ChannelStats *p = &s->chstats[c];
const float *src = (const float *)buf->extended_data[c];
for (i = 0; i < buf->nb_samples; i++, src++)
update_stat(s, p, *src);
}
break;
case AV_SAMPLE_FMT_FLT: {
const float *src = (const float *)buf->extended_data[0];
for (i = 0; i < buf->nb_samples; i++) {
for (c = 0; c < channels; c++, src++)
update_stat(s, &s->chstats[c], *src);
}}
break;
}
return ff_filter_frame(inlink->dst->outputs[0], buf);
}
#define SQR(a) ((a)*(a))
static void print_stats(AVFilterContext *ctx)
{
DRMeterContext *s = ctx->priv;
float dr = 0;
int ch;
for (ch = 0; ch < s->nb_channels; ch++) {
ChannelStats *p = &s->chstats[ch];
float chdr, secondpeak, rmssum = 0;
int i, j, first = 0;
if (!p->nb_samples) {
av_log(ctx, AV_LOG_INFO, "No data, dynamic range not meassurable\n");
return;
}
finish_block(p);
for (i = 0; i <= 10000; i++) {
if (p->peaks[10000 - i]) {
if (first)
break;
first = 1;
}
}
secondpeak = (10000 - i) / 10000.;
for (i = 10000, j = 0; i >= 0 && j < 0.2 * p->blknum; i--) {
if (p->rms[i]) {
rmssum += SQR(i / 10000.) * p->rms[i];
j += p->rms[i];
}
}
chdr = 20 * log10(secondpeak / sqrt(rmssum / (0.2 * p->blknum)));
dr += chdr;
av_log(ctx, AV_LOG_INFO, "Channel %d: DR: %.1f\n", ch + 1, chdr);
}
av_log(ctx, AV_LOG_INFO, "Overall DR: %.1f\n", dr / s->nb_channels);
}
static av_cold void uninit(AVFilterContext *ctx)
{
DRMeterContext *s = ctx->priv;
if (s->nb_channels)
print_stats(ctx);
av_freep(&s->chstats);
}
static const AVFilterPad drmeter_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad drmeter_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_output,
},
{ NULL }
};
AVFilter ff_af_drmeter = {
.name = "drmeter",
.description = NULL_IF_CONFIG_SMALL("Measure audio dynamic range."),
.query_formats = query_formats,
.priv_size = sizeof(DRMeterContext),
.priv_class = &drmeter_class,
.uninit = uninit,
.inputs = drmeter_inputs,
.outputs = drmeter_outputs,
};
|
