1 /*
2 * Copyright (c) 2017 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 "libavutil/imgutils.h"
22 #include "libavutil/opt.h"
23 #include "libavutil/pixdesc.h"
24 #include "avfilter.h"
25 #include "drawutils.h"
26 #include "formats.h"
27 #include "internal.h"
28 #include "video.h"
29
30 typedef struct EntropyContext {
31 const AVClass *class;
32
33 int mode;
34
35 int nb_planes;
36 int planeheight[4];
37 int planewidth[4];
38 int depth;
39 int is_rgb;
40 uint8_t rgba_map[4];
41 char planenames[4];
42 int64_t *histogram;
43 } EntropyContext;
44
45 #define OFFSET(x) offsetof(EntropyContext, x)
46 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
47 static const AVOption entropy_options[] = {
48 { "mode", "set kind of histogram entropy measurement", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "mode" },
49 { "normal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "mode" },
50 { "diff", NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "mode" },
51 { NULL }
52 };
53
54 AVFILTER_DEFINE_CLASS(entropy);
55
query_formats(AVFilterContext * ctx)56 static int query_formats(AVFilterContext *ctx)
57 {
58 static const enum AVPixelFormat pixfmts[] = {
59 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P,
60 AV_PIX_FMT_YUV440P,
61 AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
62 AV_PIX_FMT_YUVJ440P,
63 AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV420P9,
64 AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV420P10,
65 AV_PIX_FMT_YUV440P10,
66 AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12,
67 AV_PIX_FMT_YUV440P12,
68 AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14,
69 AV_PIX_FMT_YUV444P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV420P16,
70 AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
71 AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
72 AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16,
73 AV_PIX_FMT_NONE
74 };
75
76 AVFilterFormats *formats = ff_make_format_list(pixfmts);
77 if (!formats)
78 return AVERROR(ENOMEM);
79 return ff_set_common_formats(ctx, formats);
80 }
81
config_input(AVFilterLink * inlink)82 static int config_input(AVFilterLink *inlink)
83 {
84 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
85 AVFilterContext *ctx = inlink->dst;
86 EntropyContext *s = ctx->priv;
87
88 s->nb_planes = desc->nb_components;
89
90 s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
91 s->planeheight[0] = s->planeheight[3] = inlink->h;
92 s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
93 s->planewidth[0] = s->planewidth[3] = inlink->w;
94
95 s->depth = desc->comp[0].depth;
96 s->is_rgb = ff_fill_rgba_map(s->rgba_map, inlink->format) >= 0;
97
98 s->planenames[0] = s->is_rgb ? 'R' : 'Y';
99 s->planenames[1] = s->is_rgb ? 'G' : 'U';
100 s->planenames[2] = s->is_rgb ? 'B' : 'V';
101 s->planenames[3] = 'A';
102
103 s->histogram = av_malloc_array(1 << s->depth, sizeof(*s->histogram));
104 if (!s->histogram)
105 return AVERROR(ENOMEM);
106
107 return 0;
108 }
109
filter_frame(AVFilterLink * inlink,AVFrame * in)110 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
111 {
112 AVFilterContext *ctx = inlink->dst;
113 AVFilterLink *outlink = ctx->outputs[0];
114 EntropyContext *s = ctx->priv;
115 int plane, y, x;
116
117 for (plane = 0; plane < s->nb_planes; plane++) {
118 int cidx = s->is_rgb ? s->rgba_map[plane] : plane;
119 const uint8_t *src8 = in->data[plane];
120 const uint16_t *src16 = (const uint16_t *)in->data[plane];
121 float total = s->planewidth[plane] * s->planeheight[plane];
122 float entropy = 0;
123 char metabuf[128];
124 char key[128];
125
126 memset(s->histogram, 0, (1 << s->depth) * sizeof(*s->histogram));
127
128 if (s->depth <= 8) {
129 for (y = 0; y < s->planeheight[plane]; y++) {
130 for (x = 0; x < s->planewidth[plane]; x++) {
131 s->histogram[src8[x]]++;
132 }
133
134 src8 += in->linesize[plane];
135 }
136 } else {
137 for (y = 0; y < s->planeheight[plane]; y++) {
138 for (x = 0; x < s->planewidth[plane]; x++) {
139 s->histogram[src16[x]]++;
140 }
141
142 src16 += in->linesize[plane] / 2;
143 }
144 }
145
146 for (y = 0; y < 1 << s->depth; y++) {
147 if (s->mode == 0) {
148 if (s->histogram[y]) {
149 float p = s->histogram[y] / total;
150 entropy += -log2(p) * p;
151 }
152 } else if (s->mode == 1) {
153 if (y && (s->histogram[y] - s->histogram[y - 1]) != 0) {
154 float p = FFABS(s->histogram[y] - s->histogram[y - 1]) / total;
155 entropy += -log2(p) * p;
156 }
157 }
158 }
159
160 snprintf(key, sizeof(key), "lavfi.entropy.entropy.%s.%c", s->mode ? "diff" : "normal", s->planenames[cidx]);
161 snprintf(metabuf, sizeof(metabuf), "%f", entropy);
162 av_dict_set(&in->metadata, key, metabuf, 0);
163 snprintf(key, sizeof(key), "lavfi.entropy.normalized_entropy.%s.%c", s->mode ? "diff" : "normal", s->planenames[cidx]);
164 snprintf(metabuf, sizeof(metabuf), "%f", entropy / log2(1 << s->depth));
165 av_dict_set(&in->metadata, key, metabuf, 0);
166 }
167
168 return ff_filter_frame(outlink, in);
169 }
170
uninit(AVFilterContext * ctx)171 static av_cold void uninit(AVFilterContext *ctx)
172 {
173 EntropyContext *s = ctx->priv;
174
175 av_freep(&s->histogram);
176 }
177
178 static const AVFilterPad inputs[] = {
179 {
180 .name = "default",
181 .type = AVMEDIA_TYPE_VIDEO,
182 .filter_frame = filter_frame,
183 .config_props = config_input,
184 },
185 { NULL }
186 };
187
188 static const AVFilterPad outputs[] = {
189 {
190 .name = "default",
191 .type = AVMEDIA_TYPE_VIDEO,
192 },
193 { NULL }
194 };
195
196 AVFilter ff_vf_entropy = {
197 .name = "entropy",
198 .description = NULL_IF_CONFIG_SMALL("Measure video frames entropy."),
199 .priv_size = sizeof(EntropyContext),
200 .uninit = uninit,
201 .query_formats = query_formats,
202 .inputs = inputs,
203 .outputs = outputs,
204 .priv_class = &entropy_class,
205 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
206 };
207