FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/af_drmeter.c
Date: 2024-04-19 07:31:02
Exec Total Coverage
Lines: 0 79 0.0%
Functions: 0 6 0.0%
Branches: 0 37 0.0%

Line Branch Exec Source
1 /*
2 * Copyright (c) 2018 Paul B Mahol
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <float.h>
22
23 #include "libavutil/ffmath.h"
24 #include "libavutil/mem.h"
25 #include "libavutil/opt.h"
26 #include "audio.h"
27 #include "avfilter.h"
28 #include "internal.h"
29
30 #define BINS 32768
31
32 typedef struct ChannelStats {
33 uint64_t nb_samples;
34 uint64_t blknum;
35 float peak;
36 float sum;
37 uint32_t peaks[BINS+1];
38 uint32_t rms[BINS+1];
39 } ChannelStats;
40
41 typedef struct DRMeterContext {
42 const AVClass *class;
43 ChannelStats *chstats;
44 int nb_channels;
45 int64_t tc_samples;
46 double time_constant;
47 } DRMeterContext;
48
49 #define OFFSET(x) offsetof(DRMeterContext, x)
50 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
51
52 static const AVOption drmeter_options[] = {
53 { "length", "set the window length", OFFSET(time_constant), AV_OPT_TYPE_DOUBLE, {.dbl=3}, .01, 10, FLAGS },
54 { NULL }
55 };
56
57 AVFILTER_DEFINE_CLASS(drmeter);
58
59 static int config_output(AVFilterLink *outlink)
60 {
61 DRMeterContext *s = outlink->src->priv;
62
63 s->chstats = av_calloc(outlink->ch_layout.nb_channels, sizeof(*s->chstats));
64 if (!s->chstats)
65 return AVERROR(ENOMEM);
66 s->nb_channels = outlink->ch_layout.nb_channels;
67 s->tc_samples = lrint(s->time_constant * outlink->sample_rate);
68
69 return 0;
70 }
71
72 static void finish_block(ChannelStats *p)
73 {
74 int peak_bin, rms_bin;
75 float peak, rms;
76
77 rms = sqrtf(2.f * p->sum / p->nb_samples);
78 peak = p->peak;
79 rms_bin = av_clip(lrintf(rms * BINS), 0, BINS);
80 peak_bin = av_clip(lrintf(peak * BINS), 0, BINS);
81 p->rms[rms_bin]++;
82 p->peaks[peak_bin]++;
83
84 p->peak = 0;
85 p->sum = 0;
86 p->nb_samples = 0;
87 p->blknum++;
88 }
89
90 static void update_stat(DRMeterContext *s, ChannelStats *p, float sample)
91 {
92 p->peak = fmaxf(fabsf(sample), p->peak);
93 p->sum += sample * sample;
94 p->nb_samples++;
95 if (p->nb_samples >= s->tc_samples)
96 finish_block(p);
97 }
98
99 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
100 {
101 DRMeterContext *s = inlink->dst->priv;
102 const int channels = s->nb_channels;
103
104 switch (inlink->format) {
105 case AV_SAMPLE_FMT_FLTP:
106 for (int c = 0; c < channels; c++) {
107 ChannelStats *p = &s->chstats[c];
108 const float *src = (const float *)buf->extended_data[c];
109
110 for (int i = 0; i < buf->nb_samples; i++, src++)
111 update_stat(s, p, *src);
112 }
113 break;
114 case AV_SAMPLE_FMT_FLT: {
115 const float *src = (const float *)buf->extended_data[0];
116
117 for (int i = 0; i < buf->nb_samples; i++) {
118 for (int c = 0; c < channels; c++, src++)
119 update_stat(s, &s->chstats[c], *src);
120 }}
121 break;
122 }
123
124 return ff_filter_frame(inlink->dst->outputs[0], buf);
125 }
126
127 #define SQR(a) ((a)*(a))
128
129 static void print_stats(AVFilterContext *ctx)
130 {
131 DRMeterContext *s = ctx->priv;
132 float dr = 0.f;
133
134 for (int ch = 0; ch < s->nb_channels; ch++) {
135 ChannelStats *p = &s->chstats[ch];
136 float chdr, secondpeak, rmssum = 0.f;
137 int first = 0, last = lrintf(0.2f * p->blknum);
138 int peak_bin = BINS;
139
140 if (!p->nb_samples) {
141 av_log(ctx, AV_LOG_INFO, "No data, dynamic range not meassurable\n");
142 return;
143 }
144
145 if (p->nb_samples)
146 finish_block(p);
147
148 for (int i = BINS; i >= 0; i--) {
149 if (p->peaks[i]) {
150 if (first || p->peaks[i] > 1) {
151 peak_bin = i;
152 break;
153 }
154 first = 1;
155 }
156 }
157
158 secondpeak = peak_bin / (float)BINS;
159
160 for (int64_t i = BINS, j = 0; i >= 0 && j < last; i--) {
161 if (p->rms[i]) {
162 rmssum += SQR(i / (float)BINS) * p->rms[i];
163 j += p->rms[i];
164 }
165 }
166
167 chdr = 20.f * log10f(secondpeak / sqrtf(rmssum / (float)last));
168 dr += chdr;
169 av_log(ctx, AV_LOG_INFO, "Channel %d: DR: %g\n", ch + 1, chdr);
170 }
171
172 av_log(ctx, AV_LOG_INFO, "Overall DR: %g\n", dr / s->nb_channels);
173 }
174
175 static av_cold void uninit(AVFilterContext *ctx)
176 {
177 DRMeterContext *s = ctx->priv;
178
179 if (s->nb_channels)
180 print_stats(ctx);
181 av_freep(&s->chstats);
182 }
183
184 static const AVFilterPad drmeter_inputs[] = {
185 {
186 .name = "default",
187 .type = AVMEDIA_TYPE_AUDIO,
188 .filter_frame = filter_frame,
189 },
190 };
191
192 static const AVFilterPad drmeter_outputs[] = {
193 {
194 .name = "default",
195 .type = AVMEDIA_TYPE_AUDIO,
196 .config_props = config_output,
197 },
198 };
199
200 const AVFilter ff_af_drmeter = {
201 .name = "drmeter",
202 .description = NULL_IF_CONFIG_SMALL("Measure audio dynamic range."),
203 .priv_size = sizeof(DRMeterContext),
204 .priv_class = &drmeter_class,
205 .uninit = uninit,
206 .flags = AVFILTER_FLAG_METADATA_ONLY,
207 FILTER_INPUTS(drmeter_inputs),
208 FILTER_OUTPUTS(drmeter_outputs),
209 FILTER_SAMPLEFMTS(AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_FLT),
210 };
211