FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/vf_backgroundkey.c
Date: 2024-07-17 14:05:47
Exec Total Coverage
Lines: 0 109 0.0%
Functions: 0 5 0.0%
Branches: 0 34 0.0%

Line Branch Exec Source
1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include "libavutil/mem.h"
20 #include "libavutil/opt.h"
21 #include "libavutil/pixdesc.h"
22 #include "avfilter.h"
23 #include "internal.h"
24 #include "video.h"
25
26 typedef struct BackgroundkeyContext {
27 const AVClass *class;
28
29 float threshold;
30 float similarity;
31 float blend;
32 int max;
33
34 int nb_threads;
35 int hsub_log2;
36 int vsub_log2;
37
38 int64_t max_sum;
39 int64_t *sums;
40
41 AVFrame *background;
42
43 int (*do_slice)(AVFilterContext *avctx, void *arg,
44 int jobnr, int nb_jobs);
45 } BackgroundkeyContext;
46
47 static int do_backgroundkey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
48 {
49 BackgroundkeyContext *s = avctx->priv;
50 AVFrame *frame = arg;
51 const int slice_start = (frame->height * jobnr) / nb_jobs;
52 const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
53 const int min_diff = (255 + 255 + 255) * s->similarity;
54 const float blend = s->blend;
55 const int hsub = s->hsub_log2;
56 const int vsub = s->vsub_log2;
57 int64_t sum = 0;
58
59 for (int y = slice_start; y < slice_end; y++) {
60 const uint8_t *srcy = frame->data[0] + frame->linesize[0] * y;
61 const uint8_t *srcu = frame->data[1] + frame->linesize[1] * (y >> vsub);
62 const uint8_t *srcv = frame->data[2] + frame->linesize[2] * (y >> vsub);
63 const uint8_t *bsrcy = s->background->data[0] + s->background->linesize[0] * y;
64 const uint8_t *bsrcu = s->background->data[1] + s->background->linesize[1] * (y >> vsub);
65 const uint8_t *bsrcv = s->background->data[2] + s->background->linesize[2] * (y >> vsub);
66 uint8_t *dst = frame->data[3] + frame->linesize[3] * y;
67 for (int x = 0; x < frame->width; x++) {
68 const int xx = x >> hsub;
69 const int diff = FFABS(srcy[x] - bsrcy[x]) +
70 FFABS(srcu[xx] - bsrcu[xx]) +
71 FFABS(srcv[xx] - bsrcv[xx]);
72 int A;
73
74 sum += diff;
75 if (blend > 0.f) {
76 A = 255 - av_clipf((min_diff - diff) / blend, 0.f, 255.f);
77 } else {
78 A = (diff > min_diff) ? 255 : 0;
79 }
80
81 dst[x] = A;
82 }
83 }
84
85 s->sums[jobnr] = sum;
86
87 return 0;
88 }
89
90 static int do_backgroundkey16_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
91 {
92 BackgroundkeyContext *s = avctx->priv;
93 AVFrame *frame = arg;
94 const int slice_start = (frame->height * jobnr) / nb_jobs;
95 const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
96 const int hsub = s->hsub_log2;
97 const int vsub = s->vsub_log2;
98 const int max = s->max;
99 const int min_diff = s->similarity * (s->max + s->max + s->max);
100 const float blend = s->blend;
101 int64_t sum = 0;
102
103 for (int y = slice_start; y < slice_end; y++) {
104 const uint16_t *srcy = (const uint16_t *)(frame->data[0] + frame->linesize[0] * y);
105 const uint16_t *srcu = (const uint16_t *)(frame->data[1] + frame->linesize[1] * (y >> vsub));
106 const uint16_t *srcv = (const uint16_t *)(frame->data[2] + frame->linesize[2] * (y >> vsub));
107 const uint16_t *bsrcy = (const uint16_t *)(s->background->data[0] + s->background->linesize[0] * y);
108 const uint16_t *bsrcu = (const uint16_t *)(s->background->data[1] + s->background->linesize[1] * (y >> vsub));
109 const uint16_t *bsrcv = (const uint16_t *)(s->background->data[2] + s->background->linesize[2] * (y >> vsub));
110 uint16_t *dst = (uint16_t *)(frame->data[3] + frame->linesize[3] * y);
111 for (int x = 0; x < frame->width; x++) {
112 const int xx = x >> hsub;
113 const int diff = FFABS(srcy[x] - bsrcy[x] ) +
114 FFABS(srcu[xx] - bsrcu[xx]) +
115 FFABS(srcv[xx] - bsrcv[xx]);
116 int A;
117
118 sum += diff;
119 if (blend > 0.f) {
120 A = max - av_clipf((min_diff - diff) / blend, 0.f, max);
121 } else {
122 A = (diff > min_diff) ? max : 0;
123 }
124
125 dst[x] = A;
126 }
127 }
128
129 s->sums[jobnr] = sum;
130
131 return 0;
132 }
133
134 static int filter_frame(AVFilterLink *link, AVFrame *frame)
135 {
136 AVFilterContext *avctx = link->dst;
137 BackgroundkeyContext *s = avctx->priv;
138 int64_t sum = 0;
139 int ret = 0;
140
141 if (!s->background) {
142 s->background = ff_get_video_buffer(link, frame->width, frame->height);
143 if (!s->background) {
144 ret = AVERROR(ENOMEM);
145 goto fail;
146 }
147 ret = av_frame_copy(s->background, frame);
148 if (ret < 0)
149 goto fail;
150 }
151
152 if (ret = ff_filter_execute(avctx, s->do_slice, frame, NULL,
153 FFMIN(frame->height, s->nb_threads)))
154 goto fail;
155
156 for (int n = 0; n < s->nb_threads; n++)
157 sum += s->sums[n];
158 if (s->max_sum * s->threshold < sum) {
159 ret = av_frame_copy(s->background, frame);
160 if (ret < 0)
161 goto fail;
162 }
163
164 return ff_filter_frame(avctx->outputs[0], frame);
165 fail:
166 av_frame_free(&frame);
167 return ret;
168 }
169
170 static av_cold int config_output(AVFilterLink *outlink)
171 {
172 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
173 AVFilterContext *avctx = outlink->src;
174 AVFilterLink *inlink = avctx->inputs[0];
175 BackgroundkeyContext *s = avctx->priv;
176 int depth;
177
178 s->nb_threads = ff_filter_get_nb_threads(avctx);
179 depth = desc->comp[0].depth;
180 s->do_slice = depth <= 8 ? do_backgroundkey_slice : do_backgroundkey16_slice;
181 s->max = (1 << depth) - 1;
182 s->hsub_log2 = desc->log2_chroma_w;
183 s->vsub_log2 = desc->log2_chroma_h;
184 s->max_sum = (int64_t)(inlink->w) * inlink->h * s->max;
185 s->max_sum += 2LL * (inlink->w >> s->hsub_log2) * (inlink->h >> s->vsub_log2) * s->max;
186
187 s->sums = av_calloc(s->nb_threads, sizeof(*s->sums));
188 if (!s->sums)
189 return AVERROR(ENOMEM);
190
191 return 0;
192 }
193
194 static av_cold void uninit(AVFilterContext *ctx)
195 {
196 BackgroundkeyContext *s = ctx->priv;
197
198 av_frame_free(&s->background);
199 av_freep(&s->sums);
200 }
201
202 static const AVFilterPad backgroundkey_inputs[] = {
203 {
204 .name = "default",
205 .type = AVMEDIA_TYPE_VIDEO,
206 .flags = AVFILTERPAD_FLAG_NEEDS_WRITABLE,
207 .filter_frame = filter_frame,
208 },
209 };
210
211 static const AVFilterPad backgroundkey_outputs[] = {
212 {
213 .name = "default",
214 .type = AVMEDIA_TYPE_VIDEO,
215 .config_props = config_output,
216 },
217 };
218
219 #define OFFSET(x) offsetof(BackgroundkeyContext, x)
220 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
221
222 static const AVOption backgroundkey_options[] = {
223 { "threshold", "set the scene change threshold", OFFSET(threshold), AV_OPT_TYPE_FLOAT, { .dbl = 0.08}, 0.0, 1.0, FLAGS },
224 { "similarity", "set the similarity", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.1 }, 0.0, 1.0, FLAGS },
225 { "blend", "set the blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
226 { NULL }
227 };
228
229 static const enum AVPixelFormat backgroundkey_fmts[] = {
230 AV_PIX_FMT_YUVA420P,
231 AV_PIX_FMT_YUVA422P,
232 AV_PIX_FMT_YUVA444P,
233 AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
234 AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
235 AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
236 AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
237 AV_PIX_FMT_GBRAP,
238 AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
239 AV_PIX_FMT_NONE
240 };
241
242 AVFILTER_DEFINE_CLASS(backgroundkey);
243
244 const AVFilter ff_vf_backgroundkey = {
245 .name = "backgroundkey",
246 .description = NULL_IF_CONFIG_SMALL("Turns a static background into transparency."),
247 .priv_size = sizeof(BackgroundkeyContext),
248 .priv_class = &backgroundkey_class,
249 .uninit = uninit,
250 FILTER_INPUTS(backgroundkey_inputs),
251 FILTER_OUTPUTS(backgroundkey_outputs),
252 FILTER_PIXFMTS_ARRAY(backgroundkey_fmts),
253 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
254 .process_command = ff_filter_process_command,
255 };
256