aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/vf_chromakey.c
blob: 3781506ca27234f7ebcca75168b8a44450347536 (plain) (blame)
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
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
/*
 * Copyright (c) 2015 Timo Rothenpieler <timo@rothenpieler.org>
 *
 * 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 "libavutil/opt.h"
#include "libavutil/imgutils.h"
#include "libavutil/intreadwrite.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

typedef struct ChromakeyContext {
    const AVClass *class;

    uint8_t chromakey_rgba[4];
    uint16_t chromakey_uv[2];

    float similarity;
    float blend;

    int is_yuv;
    int depth;
    int mid;
    int max;

    int hsub_log2;
    int vsub_log2;

    int (*do_slice)(AVFilterContext *ctx, void *arg,
                    int jobnr, int nb_jobs);
} ChromakeyContext;

static uint8_t do_chromakey_pixel(ChromakeyContext *ctx, uint8_t u[9], uint8_t v[9])
{
    double diff = 0.0;
    int du, dv, i;

    for (i = 0; i < 9; ++i) {
        du = (int)u[i] - ctx->chromakey_uv[0];
        dv = (int)v[i] - ctx->chromakey_uv[1];

        diff += sqrt((du * du + dv * dv) / (255.0 * 255.0));
    }

    diff /= 9.0;

    if (ctx->blend > 0.0001) {
        return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * 255.0;
    } else {
        return (diff > ctx->similarity) ? 255 : 0;
    }
}

static uint16_t do_chromakey_pixel16(ChromakeyContext *ctx, uint16_t u[9], uint16_t v[9])
{
    double max = ctx->max;
    double diff = 0.0;
    int du, dv, i;

    for (i = 0; i < 9; ++i) {
        du = (int)u[i] - ctx->chromakey_uv[0];
        dv = (int)v[i] - ctx->chromakey_uv[1];

        diff += sqrt((du * du + dv * dv) / (max * max));
    }

    diff /= 9.0;

    if (ctx->blend > 0.0001) {
        return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * max;
    } else {
        return (diff > ctx->similarity) ? max : 0;
    }
}

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)
{
    if (x < 0 || x >= frame->width || y < 0 || y >= frame->height)
        return;

    x >>= hsub_log2;
    y >>= vsub_log2;

    *u = frame->data[1][frame->linesize[1] * y + x];
    *v = frame->data[2][frame->linesize[2] * y + x];
}

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)
{
    if (x < 0 || x >= frame->width || y < 0 || y >= frame->height)
        return;

    x >>= hsub_log2;
    y >>= vsub_log2;

    *u = AV_RN16(&frame->data[1][frame->linesize[1] * y + 2 * x]);
    *v = AV_RN16(&frame->data[2][frame->linesize[2] * y + 2 * x]);
}

static int do_chromakey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
{
    AVFrame *frame = arg;

    const int slice_start = (frame->height * jobnr) / nb_jobs;
    const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;

    ChromakeyContext *ctx = avctx->priv;

    int x, y, xo, yo;
    uint8_t u[9], v[9];

    memset(u, ctx->chromakey_uv[0], sizeof(u));
    memset(v, ctx->chromakey_uv[1], sizeof(v));

    for (y = slice_start; y < slice_end; ++y) {
        for (x = 0; x < frame->width; ++x) {
            for (yo = 0; yo < 3; ++yo) {
                for (xo = 0; xo < 3; ++xo) {
                    get_pixel_uv(frame, ctx->hsub_log2, ctx->vsub_log2, x + xo - 1, y + yo - 1, &u[yo * 3 + xo], &v[yo * 3 + xo]);
                }
            }

            frame->data[3][frame->linesize[3] * y + x] = do_chromakey_pixel(ctx, u, v);
        }
    }

    return 0;
}

static int do_chromakey16_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
{
    AVFrame *frame = arg;

    const int slice_start = (frame->height * jobnr) / nb_jobs;
    const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;

    ChromakeyContext *ctx = avctx->priv;

    int x, y, xo, yo;
    uint16_t u[9], v[9];

    for (int i = 0; i < 9; i++) {
        u[i] = ctx->chromakey_uv[0];
        v[i] = ctx->chromakey_uv[1];
    }

    for (y = slice_start; y < slice_end; ++y) {
        for (x = 0; x < frame->width; ++x) {
            uint16_t *dst = (uint16_t *)(frame->data[3] + frame->linesize[3] * y);

            for (yo = 0; yo < 3; ++yo) {
                for (xo = 0; xo < 3; ++xo) {
                    get_pixel16_uv(frame, ctx->hsub_log2, ctx->vsub_log2, x + xo - 1, y + yo - 1, &u[yo * 3 + xo], &v[yo * 3 + xo]);
                }
            }

            dst[x] = do_chromakey_pixel16(ctx, u, v);
        }
    }

    return 0;
}

static int do_chromahold_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
{
    ChromakeyContext *ctx = avctx->priv;
    AVFrame *frame = arg;
    const int slice_start = ((frame->height >> ctx->vsub_log2) * jobnr) / nb_jobs;
    const int slice_end = ((frame->height >> ctx->vsub_log2) * (jobnr + 1)) / nb_jobs;

    int x, y, alpha;

    for (y = slice_start; y < slice_end; ++y) {
        for (x = 0; x < frame->width >> ctx->hsub_log2; ++x) {
            int u = frame->data[1][frame->linesize[1] * y + x];
            int v = frame->data[2][frame->linesize[2] * y + x];
            double diff;
            int du, dv;

            du = u - ctx->chromakey_uv[0];
            dv = v - ctx->chromakey_uv[1];

            diff = sqrt((du * du + dv * dv) / (255.0 * 255.0));

            alpha = diff > ctx->similarity;
            if (ctx->blend > 0.0001) {
                double f = 1. - av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0);

                frame->data[1][frame->linesize[1] * y + x] = 128 + (u - 128) * f;
                frame->data[2][frame->linesize[2] * y + x] = 128 + (v - 128) * f;
            } else if (alpha) {
                frame->data[1][frame->linesize[1] * y + x] = 128;
                frame->data[2][frame->linesize[2] * y + x] = 128;
            }
        }
    }

    return 0;
}

static int do_chromahold16_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
{
    ChromakeyContext *ctx = avctx->priv;
    AVFrame *frame = arg;
    const int slice_start = ((frame->height >> ctx->vsub_log2) * jobnr) / nb_jobs;
    const int slice_end = ((frame->height >> ctx->vsub_log2) * (jobnr + 1)) / nb_jobs;
    const int mid = ctx->mid;
    double max = ctx->max;

    int x, y, alpha;

    for (y = slice_start; y < slice_end; ++y) {
        for (x = 0; x < frame->width >> ctx->hsub_log2; ++x) {
            int u = AV_RN16(&frame->data[1][frame->linesize[1] * y + 2 * x]);
            int v = AV_RN16(&frame->data[2][frame->linesize[2] * y + 2 * x]);
            double diff;
            int du, dv;

            du = u - ctx->chromakey_uv[0];
            dv = v - ctx->chromakey_uv[1];

            diff = sqrt((du * du + dv * dv) / (max * max));

            alpha = diff > ctx->similarity;
            if (ctx->blend > 0.0001) {
                double f = 1. - av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0);

                AV_WN16(&frame->data[1][frame->linesize[1] * y + 2 * x], mid + (u - mid) * f);
                AV_WN16(&frame->data[2][frame->linesize[2] * y + 2 * x], mid + (v - mid) * f);
            } else if (alpha) {
                AV_WN16(&frame->data[1][frame->linesize[1] * y + 2 * x], mid);
                AV_WN16(&frame->data[2][frame->linesize[2] * y + 2 * x], mid);
            }
        }
    }

    return 0;
}

static int filter_frame(AVFilterLink *link, AVFrame *frame)
{
    AVFilterContext *avctx = link->dst;
    ChromakeyContext *ctx = avctx->priv;
    int res;

    if (res = avctx->internal->execute(avctx, ctx->do_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
        return res;

    return ff_filter_frame(avctx->outputs[0], frame);
}

#define FIXNUM(x) lrint((x) * (1 << 10))
#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)
#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)

static av_cold int config_output(AVFilterLink *outlink)
{
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
    AVFilterContext *avctx = outlink->src;
    ChromakeyContext *ctx = avctx->priv;
    int factor;

    ctx->depth = desc->comp[0].depth;
    ctx->mid = 1 << (ctx->depth - 1);
    ctx->max = (1 << ctx->depth) - 1;

    factor = 1 << (ctx->depth - 8);

    if (ctx->is_yuv) {
        ctx->chromakey_uv[0] = ctx->chromakey_rgba[1] * factor;
        ctx->chromakey_uv[1] = ctx->chromakey_rgba[2] * factor;
    } else {
        ctx->chromakey_uv[0] = RGB_TO_U(ctx->chromakey_rgba) * factor;
        ctx->chromakey_uv[1] = RGB_TO_V(ctx->chromakey_rgba) * factor;
    }

    if (!strcmp(avctx->filter->name, "chromakey")) {
        ctx->do_slice = ctx->depth <= 8 ? do_chromakey_slice : do_chromakey16_slice;
    } else {
        ctx->do_slice = ctx->depth <= 8 ? do_chromahold_slice: do_chromahold16_slice;
    }

    return 0;
}

static av_cold int query_formats(AVFilterContext *avctx)
{
    static const enum AVPixelFormat pixel_fmts[] = {
        AV_PIX_FMT_YUVA420P,
        AV_PIX_FMT_YUVA422P,
        AV_PIX_FMT_YUVA444P,
        AV_PIX_FMT_YUVA420P9,  AV_PIX_FMT_YUVA422P9,  AV_PIX_FMT_YUVA444P9,
        AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
        AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
        AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
        AV_PIX_FMT_NONE
    };

    static const enum AVPixelFormat hold_pixel_fmts[] = {
        AV_PIX_FMT_YUV420P,
        AV_PIX_FMT_YUV422P,
        AV_PIX_FMT_YUV444P,
        AV_PIX_FMT_YUVA420P,
        AV_PIX_FMT_YUVA422P,
        AV_PIX_FMT_YUVA444P,
        AV_PIX_FMT_YUV420P9,   AV_PIX_FMT_YUV422P9,   AV_PIX_FMT_YUV444P9,
        AV_PIX_FMT_YUV420P10,  AV_PIX_FMT_YUV422P10,  AV_PIX_FMT_YUV444P10,
        AV_PIX_FMT_YUV444P12,  AV_PIX_FMT_YUV422P12,  AV_PIX_FMT_YUV420P12,
        AV_PIX_FMT_YUV444P14,  AV_PIX_FMT_YUV422P14,  AV_PIX_FMT_YUV420P14,
        AV_PIX_FMT_YUV420P16,  AV_PIX_FMT_YUV422P16,  AV_PIX_FMT_YUV444P16,
        AV_PIX_FMT_YUVA420P9,  AV_PIX_FMT_YUVA422P9,  AV_PIX_FMT_YUVA444P9,
        AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
        AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
        AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
        AV_PIX_FMT_NONE
    };

    AVFilterFormats *formats = NULL;

    formats = ff_make_format_list(!strcmp(avctx->filter->name, "chromahold") ? hold_pixel_fmts : pixel_fmts);
    if (!formats)
        return AVERROR(ENOMEM);

    return ff_set_common_formats(avctx, formats);
}

static av_cold int config_input(AVFilterLink *inlink)
{
    AVFilterContext *avctx = inlink->dst;
    ChromakeyContext *ctx = avctx->priv;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

    ctx->hsub_log2 = desc->log2_chroma_w;
    ctx->vsub_log2 = desc->log2_chroma_h;

    return 0;
}

static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                           char *res, int res_len, int flags)
{
    int ret;

    ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
    if (ret < 0)
        return ret;

    return config_output(ctx->outputs[0]);
}

static const AVFilterPad chromakey_inputs[] = {
    {
        .name           = "default",
        .type           = AVMEDIA_TYPE_VIDEO,
        .needs_writable = 1,
        .filter_frame   = filter_frame,
        .config_props   = config_input,
    },
    { NULL }
};

static const AVFilterPad chromakey_outputs[] = {
    {
        .name           = "default",
        .type           = AVMEDIA_TYPE_VIDEO,
        .config_props   = config_output,
    },
    { NULL }
};

#define OFFSET(x) offsetof(ChromakeyContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM

static const AVOption chromakey_options[] = {
    { "color", "set the chromakey key color", OFFSET(chromakey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
    { "similarity", "set the chromakey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
    { "blend", "set the chromakey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
    { "yuv", "color parameter is in yuv instead of rgb", OFFSET(is_yuv), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
    { NULL }
};

AVFILTER_DEFINE_CLASS(chromakey);

AVFilter ff_vf_chromakey = {
    .name          = "chromakey",
    .description   = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on YUV colors."),
    .priv_size     = sizeof(ChromakeyContext),
    .priv_class    = &chromakey_class,
    .query_formats = query_formats,
    .inputs        = chromakey_inputs,
    .outputs       = chromakey_outputs,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
    .process_command = process_command,
};

static const AVOption chromahold_options[] = {
    { "color", "set the chromahold key color", OFFSET(chromakey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
    { "similarity", "set the chromahold similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
    { "blend", "set the chromahold blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
    { "yuv", "color parameter is in yuv instead of rgb", OFFSET(is_yuv), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
    { NULL }
};

static const AVFilterPad chromahold_inputs[] = {
    {
        .name           = "default",
        .type           = AVMEDIA_TYPE_VIDEO,
        .needs_writable = 1,
        .filter_frame   = filter_frame,
        .config_props   = config_input,
    },
    { NULL }
};

static const AVFilterPad chromahold_outputs[] = {
    {
        .name           = "default",
        .type           = AVMEDIA_TYPE_VIDEO,
        .config_props   = config_output,
    },
    { NULL }
};

AVFILTER_DEFINE_CLASS(chromahold);

AVFilter ff_vf_chromahold = {
    .name          = "chromahold",
    .description   = NULL_IF_CONFIG_SMALL("Turns a certain color range into gray."),
    .priv_size     = sizeof(ChromakeyContext),
    .priv_class    = &chromahold_class,
    .query_formats = query_formats,
    .inputs        = chromahold_inputs,
    .outputs       = chromahold_outputs,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
    .process_command = process_command,
};