FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavfilter/vf_chromakey.c
Date: 2026-09-26 05:01:43
Exec Total Coverage
Lines: 0 148 0.0%
Functions: 0 12 0.0%
Branches: 0 78 0.0%
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1 /*
2 * Copyright (c) 2015 Timo Rothenpieler <timo@rothenpieler.org>
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/opt.h"
22 #include "libavutil/intreadwrite.h"
23 #include "libavutil/pixdesc.h"
24 #include "avfilter.h"
25 #include "filters.h"
26
27 typedef struct ChromakeyContext {
28 const AVClass *class;
29
30 uint8_t chromakey_rgba[4];
31 uint16_t chromakey_uv[2];
32
33 float similarity;
34 float blend;
35
36 int is_yuv;
37 int depth;
38 int mid;
39 int max;
40
41 int hsub_log2;
42 int vsub_log2;
43
44 int (*do_slice)(AVFilterContext *ctx, void *arg,
45 int jobnr, int nb_jobs);
46 } ChromakeyContext;
47
48 ✗ static uint8_t do_chromakey_pixel(ChromakeyContext *ctx, uint8_t u[9], uint8_t v[9])
49 {
50 ✗ double diff = 0.0;
51 int du, dv, i;
52
53 ✗ for (i = 0; i < 9; ++i) {
54 ✗ du = (int)u[i] - ctx->chromakey_uv[0];
55 ✗ dv = (int)v[i] - ctx->chromakey_uv[1];
56
57 ✗ diff += sqrt((du * du + dv * dv) / (255.0 * 255.0 * 2));
58 }
59
60 ✗ diff /= 9.0;
61
62 ✗ if (ctx->blend > 0.0001) {
63 ✗ return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * 255.0;
64 } else {
65 ✗ return (diff > ctx->similarity) ? 255 : 0;
66 }
67 }
68
69 ✗ static uint16_t do_chromakey_pixel16(ChromakeyContext *ctx, uint16_t u[9], uint16_t v[9])
70 {
71 ✗ double max = ctx->max;
72 ✗ double diff = 0.0;
73 int du, dv, i;
74
75 ✗ for (i = 0; i < 9; ++i) {
76 ✗ du = (int)u[i] - ctx->chromakey_uv[0];
77 ✗ dv = (int)v[i] - ctx->chromakey_uv[1];
78
79 ✗ diff += sqrt((du * du + dv * dv) / (max * max * 2));
80 }
81
82 ✗ diff /= 9.0;
83
84 ✗ if (ctx->blend > 0.0001) {
85 ✗ return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * max;
86 } else {
87 ✗ return (diff > ctx->similarity) ? max : 0;
88 }
89 }
90
91 ✗ static av_always_inline void get_pixel_uv(AVFrame *frame, int hsub_log2, int vsub_log2, int x, int y, uint8_t *u, uint8_t *v)
92 {
93 ✗ if (x < 0 || x >= frame->width || y < 0 || y >= frame->height)
94 ✗ return;
95
96 ✗ x >>= hsub_log2;
97 ✗ y >>= vsub_log2;
98
99 ✗ *u = frame->data[1][frame->linesize[1] * y + x];
100 ✗ *v = frame->data[2][frame->linesize[2] * y + x];
101 }
102
103 ✗ static av_always_inline void get_pixel16_uv(AVFrame *frame, int hsub_log2, int vsub_log2, int x, int y, uint16_t *u, uint16_t *v)
104 {
105 ✗ if (x < 0 || x >= frame->width || y < 0 || y >= frame->height)
106 ✗ return;
107
108 ✗ x >>= hsub_log2;
109 ✗ y >>= vsub_log2;
110
111 ✗ *u = AV_RN16(&frame->data[1][frame->linesize[1] * y + 2 * x]);
112 ✗ *v = AV_RN16(&frame->data[2][frame->linesize[2] * y + 2 * x]);
113 }
114
115 ✗ static int do_chromakey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
116 {
117 ✗ AVFrame *frame = arg;
118
119 ✗ const int slice_start = ff_slice_pos(frame->height, jobnr, nb_jobs);
120 ✗ const int slice_end = ff_slice_pos(frame->height, jobnr + 1, nb_jobs);
121
122 ✗ ChromakeyContext *ctx = avctx->priv;
123
124 int x, y, xo, yo;
125 uint8_t u[9], v[9];
126
127 ✗ memset(u, ctx->chromakey_uv[0], sizeof(u));
128 ✗ memset(v, ctx->chromakey_uv[1], sizeof(v));
129
130 ✗ for (y = slice_start; y < slice_end; ++y) {
131 ✗ for (x = 0; x < frame->width; ++x) {
132 ✗ for (yo = 0; yo < 3; ++yo) {
133 ✗ for (xo = 0; xo < 3; ++xo) {
134 ✗ get_pixel_uv(frame, ctx->hsub_log2, ctx->vsub_log2, x + xo - 1, y + yo - 1, &u[yo * 3 + xo], &v[yo * 3 + xo]);
135 }
136 }
137
138 ✗ frame->data[3][frame->linesize[3] * y + x] = do_chromakey_pixel(ctx, u, v);
139 }
140 }
141
142 ✗ return 0;
143 }
144
145 ✗ static int do_chromakey16_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
146 {
147 ✗ AVFrame *frame = arg;
148
149 ✗ const int slice_start = ff_slice_pos(frame->height, jobnr, nb_jobs);
150 ✗ const int slice_end = ff_slice_pos(frame->height, jobnr + 1, nb_jobs);
151
152 ✗ ChromakeyContext *ctx = avctx->priv;
153
154 int x, y, xo, yo;
155 uint16_t u[9], v[9];
156
157 ✗ for (int i = 0; i < 9; i++) {
158 ✗ u[i] = ctx->chromakey_uv[0];
159 ✗ v[i] = ctx->chromakey_uv[1];
160 }
161
162 ✗ for (y = slice_start; y < slice_end; ++y) {
163 ✗ for (x = 0; x < frame->width; ++x) {
164 ✗ uint16_t *dst = (uint16_t *)(frame->data[3] + frame->linesize[3] * y);
165
166 ✗ for (yo = 0; yo < 3; ++yo) {
167 ✗ for (xo = 0; xo < 3; ++xo) {
168 ✗ get_pixel16_uv(frame, ctx->hsub_log2, ctx->vsub_log2, x + xo - 1, y + yo - 1, &u[yo * 3 + xo], &v[yo * 3 + xo]);
169 }
170 }
171
172 ✗ dst[x] = do_chromakey_pixel16(ctx, u, v);
173 }
174 }
175
176 ✗ return 0;
177 }
178
179 ✗ static int do_chromahold_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
180 {
181 ✗ ChromakeyContext *ctx = avctx->priv;
182 ✗ AVFrame *frame = arg;
183 ✗ const int slice_start = ff_slice_pos(frame->height >> ctx->vsub_log2, jobnr, nb_jobs);
184 ✗ const int slice_end = ff_slice_pos(frame->height >> ctx->vsub_log2, jobnr + 1, nb_jobs);
185
186 int x, y, alpha;
187
188 ✗ for (y = slice_start; y < slice_end; ++y) {
189 ✗ for (x = 0; x < frame->width >> ctx->hsub_log2; ++x) {
190 ✗ int u = frame->data[1][frame->linesize[1] * y + x];
191 ✗ int v = frame->data[2][frame->linesize[2] * y + x];
192 double diff;
193 int du, dv;
194
195 ✗ du = u - ctx->chromakey_uv[0];
196 ✗ dv = v - ctx->chromakey_uv[1];
197
198 ✗ diff = sqrt((du * du + dv * dv) / (255.0 * 255.0 * 2.0));
199
200 ✗ alpha = diff > ctx->similarity;
201 ✗ if (ctx->blend > 0.0001) {
202 ✗ double f = 1. - av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0);
203
204 ✗ frame->data[1][frame->linesize[1] * y + x] = 128 + (u - 128) * f;
205 ✗ frame->data[2][frame->linesize[2] * y + x] = 128 + (v - 128) * f;
206 ✗ } else if (alpha) {
207 ✗ frame->data[1][frame->linesize[1] * y + x] = 128;
208 ✗ frame->data[2][frame->linesize[2] * y + x] = 128;
209 }
210 }
211 }
212
213 ✗ return 0;
214 }
215
216 ✗ static int do_chromahold16_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
217 {
218 ✗ ChromakeyContext *ctx = avctx->priv;
219 ✗ AVFrame *frame = arg;
220 ✗ const int slice_start = ff_slice_pos(frame->height >> ctx->vsub_log2, jobnr, nb_jobs);
221 ✗ const int slice_end = ff_slice_pos(frame->height >> ctx->vsub_log2, jobnr + 1, nb_jobs);
222 ✗ const int mid = ctx->mid;
223 ✗ double max = ctx->max;
224
225 int x, y, alpha;
226
227 ✗ for (y = slice_start; y < slice_end; ++y) {
228 ✗ for (x = 0; x < frame->width >> ctx->hsub_log2; ++x) {
229 ✗ int u = AV_RN16(&frame->data[1][frame->linesize[1] * y + 2 * x]);
230 ✗ int v = AV_RN16(&frame->data[2][frame->linesize[2] * y + 2 * x]);
231 double diff;
232 int du, dv;
233
234 ✗ du = u - ctx->chromakey_uv[0];
235 ✗ dv = v - ctx->chromakey_uv[1];
236
237 ✗ diff = sqrt((du * du + dv * dv) / (max * max * 2.0));
238
239 ✗ alpha = diff > ctx->similarity;
240 ✗ if (ctx->blend > 0.0001) {
241 ✗ double f = 1. - av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0);
242
243 ✗ AV_WN16(&frame->data[1][frame->linesize[1] * y + 2 * x], mid + (u - mid) * f);
244 ✗ AV_WN16(&frame->data[2][frame->linesize[2] * y + 2 * x], mid + (v - mid) * f);
245 ✗ } else if (alpha) {
246 ✗ AV_WN16(&frame->data[1][frame->linesize[1] * y + 2 * x], mid);
247 ✗ AV_WN16(&frame->data[2][frame->linesize[2] * y + 2 * x], mid);
248 }
249 }
250 }
251
252 ✗ return 0;
253 }
254
255 ✗ static int filter_frame(AVFilterLink *link, AVFrame *frame)
256 {
257 ✗ AVFilterContext *avctx = link->dst;
258 ✗ ChromakeyContext *ctx = avctx->priv;
259 int res;
260
261 ✗ if (res = ff_filter_execute(avctx, ctx->do_slice, frame, NULL,
262 ✗ FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
263 ✗ return res;
264
265 ✗ if (!strcmp(avctx->filter->name, "chromakey"))
266 ✗ frame->alpha_mode = avctx->outputs[0]->alpha_mode;
267 ✗ return ff_filter_frame(avctx->outputs[0], frame);
268 }
269
270 #define FIXNUM(x) lrint((x) * (1 << 10))
271 #define RGB_TO_U(rgb) (((- FIXNUM(0.16874) * rgb[0] - FIXNUM(0.33126) * rgb[1] + FIXNUM(0.50000) * rgb[2] + (1 << 9) - 1) >> 10) + 128)
272 #define RGB_TO_V(rgb) ((( FIXNUM(0.50000) * rgb[0] - FIXNUM(0.41869) * rgb[1] - FIXNUM(0.08131) * rgb[2] + (1 << 9) - 1) >> 10) + 128)
273
274 ✗ static av_cold int config_output(AVFilterLink *outlink)
275 {
276 ✗ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
277 ✗ AVFilterContext *avctx = outlink->src;
278 ✗ ChromakeyContext *ctx = avctx->priv;
279 int factor;
280
281 ✗ ctx->depth = desc->comp[0].depth;
282 ✗ ctx->mid = 1 << (ctx->depth - 1);
283 ✗ ctx->max = (1 << ctx->depth) - 1;
284
285 ✗ factor = 1 << (ctx->depth - 8);
286
287 ✗ if (ctx->is_yuv) {
288 ✗ ctx->chromakey_uv[0] = ctx->chromakey_rgba[1] * factor;
289 ✗ ctx->chromakey_uv[1] = ctx->chromakey_rgba[2] * factor;
290 } else {
291 ✗ ctx->chromakey_uv[0] = RGB_TO_U(ctx->chromakey_rgba) * factor;
292 ✗ ctx->chromakey_uv[1] = RGB_TO_V(ctx->chromakey_rgba) * factor;
293 }
294
295 ✗ if (!strcmp(avctx->filter->name, "chromakey")) {
296 ✗ outlink->alpha_mode = AVALPHA_MODE_STRAIGHT;
297 ✗ ctx->do_slice = ctx->depth <= 8 ? do_chromakey_slice : do_chromakey16_slice;
298 } else {
299 ✗ ctx->do_slice = ctx->depth <= 8 ? do_chromahold_slice: do_chromahold16_slice;
300 }
301
302 ✗ return 0;
303 }
304
305 ✗ static av_cold int config_input(AVFilterLink *inlink)
306 {
307 ✗ AVFilterContext *avctx = inlink->dst;
308 ✗ ChromakeyContext *ctx = avctx->priv;
309 ✗ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
310
311 ✗ ctx->hsub_log2 = desc->log2_chroma_w;
312 ✗ ctx->vsub_log2 = desc->log2_chroma_h;
313
314 ✗ return 0;
315 }
316
317 ✗ static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
318 char *res, int res_len, int flags)
319 {
320 int ret;
321
322 ✗ ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
323 ✗ if (ret < 0)
324 ✗ return ret;
325
326 ✗ return config_output(ctx->outputs[0]);
327 }
328
329 static const AVFilterPad inputs[] = {
330 {
331 .name = "default",
332 .type = AVMEDIA_TYPE_VIDEO,
333 .flags = AVFILTERPAD_FLAG_NEEDS_WRITABLE,
334 .filter_frame = filter_frame,
335 .config_props = config_input,
336 },
337 };
338
339 static const AVFilterPad outputs[] = {
340 {
341 .name = "default",
342 .type = AVMEDIA_TYPE_VIDEO,
343 .config_props = config_output,
344 },
345 };
346
347 #define OFFSET(x) offsetof(ChromakeyContext, x)
348 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
349
350 static const AVOption chromakey_options[] = {
351 { "color", "set the chromakey key color", OFFSET(chromakey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, 0, 0, FLAGS },
352 { "similarity", "set the chromakey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.00001, 1.0, FLAGS },
353 { "blend", "set the chromakey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
354 { "yuv", "color parameter is in yuv instead of rgb", OFFSET(is_yuv), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
355 { NULL }
356 };
357
358 static const enum AVPixelFormat chromakey_fmts[] = {
359 AV_PIX_FMT_YUVA420P,
360 AV_PIX_FMT_YUVA422P,
361 AV_PIX_FMT_YUVA444P,
362 AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
363 AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
364 AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
365 AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
366 AV_PIX_FMT_NONE
367 };
368
369 AVFILTER_DEFINE_CLASS(chromakey);
370
371 const FFFilter ff_vf_chromakey = {
372 .p.name = "chromakey",
373 .p.description = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on YUV colors."),
374 .p.priv_class = &chromakey_class,
375 .p.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
376 .priv_size = sizeof(ChromakeyContext),
377 FILTER_INPUTS(inputs),
378 FILTER_OUTPUTS(outputs),
379 FILTER_PIXFMTS_ARRAY(chromakey_fmts),
380 .process_command = process_command,
381 };
382
383 static const AVOption chromahold_options[] = {
384 { "color", "set the chromahold key color", OFFSET(chromakey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, 0, 0, FLAGS },
385 { "similarity", "set the chromahold similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.00001, 1.0, FLAGS },
386 { "blend", "set the chromahold blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
387 { "yuv", "color parameter is in yuv instead of rgb", OFFSET(is_yuv), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
388 { NULL }
389 };
390
391 static const enum AVPixelFormat hold_pixel_fmts[] = {
392 AV_PIX_FMT_YUV420P,
393 AV_PIX_FMT_YUV422P,
394 AV_PIX_FMT_YUV444P,
395 AV_PIX_FMT_YUVA420P,
396 AV_PIX_FMT_YUVA422P,
397 AV_PIX_FMT_YUVA444P,
398 AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
399 AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
400 AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12,
401 AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14,
402 AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
403 AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
404 AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
405 AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
406 AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
407 AV_PIX_FMT_NONE
408 };
409
410 AVFILTER_DEFINE_CLASS(chromahold);
411
412 const FFFilter ff_vf_chromahold = {
413 .p.name = "chromahold",
414 .p.description = NULL_IF_CONFIG_SMALL("Turns a certain color range into gray."),
415 .p.priv_class = &chromahold_class,
416 .p.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
417 .priv_size = sizeof(ChromakeyContext),
418 FILTER_INPUTS(inputs),
419 FILTER_OUTPUTS(outputs),
420 FILTER_PIXFMTS_ARRAY(hold_pixel_fmts),
421 .process_command = process_command,
422 };
423