GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavfilter/vf_edgedetect.c Lines: 174 185 94.1 %
Date: 2020-08-13 15:06:06 Branches: 118 137 86.1 %

Line Branch Exec Source
1
/*
2
 * Copyright (c) 2012-2014 Clément Bœsch <u pkh me>
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
/**
22
 * @file
23
 * Edge detection filter
24
 *
25
 * @see https://en.wikipedia.org/wiki/Canny_edge_detector
26
 */
27
28
#include "libavutil/avassert.h"
29
#include "libavutil/imgutils.h"
30
#include "libavutil/opt.h"
31
#include "avfilter.h"
32
#include "formats.h"
33
#include "internal.h"
34
#include "video.h"
35
36
#define PLANE_R 0x4
37
#define PLANE_G 0x1
38
#define PLANE_B 0x2
39
#define PLANE_Y 0x1
40
#define PLANE_U 0x2
41
#define PLANE_V 0x4
42
#define PLANE_A 0x8
43
44
enum FilterMode {
45
    MODE_WIRES,
46
    MODE_COLORMIX,
47
    MODE_CANNY,
48
    NB_MODE
49
};
50
51
struct plane_info {
52
    uint8_t  *tmpbuf;
53
    uint16_t *gradients;
54
    char     *directions;
55
    int      width, height;
56
};
57
58
typedef struct EdgeDetectContext {
59
    const AVClass *class;
60
    struct plane_info planes[3];
61
    int filter_planes;
62
    int nb_planes;
63
    double   low, high;
64
    uint8_t  low_u8, high_u8;
65
    int mode;
66
} EdgeDetectContext;
67
68
#define OFFSET(x) offsetof(EdgeDetectContext, x)
69
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
70
static const AVOption edgedetect_options[] = {
71
    { "high", "set high threshold", OFFSET(high), AV_OPT_TYPE_DOUBLE, {.dbl=50/255.}, 0, 1, FLAGS },
72
    { "low",  "set low threshold",  OFFSET(low),  AV_OPT_TYPE_DOUBLE, {.dbl=20/255.}, 0, 1, FLAGS },
73
    { "mode", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=MODE_WIRES}, 0, NB_MODE-1, FLAGS, "mode" },
74
        { "wires",    "white/gray wires on black",  0, AV_OPT_TYPE_CONST, {.i64=MODE_WIRES},    INT_MIN, INT_MAX, FLAGS, "mode" },
75
        { "colormix", "mix colors",                 0, AV_OPT_TYPE_CONST, {.i64=MODE_COLORMIX}, INT_MIN, INT_MAX, FLAGS, "mode" },
76
        { "canny",    "detect edges on planes",     0, AV_OPT_TYPE_CONST, {.i64=MODE_CANNY},    INT_MIN, INT_MAX, FLAGS, "mode" },
77
    { "planes", "set planes to filter",  OFFSET(filter_planes), AV_OPT_TYPE_FLAGS, {.i64=7}, 1, 0x7, FLAGS, "flags" },
78
        { "y", "filter luma plane",  0, AV_OPT_TYPE_CONST, {.i64=PLANE_Y}, 0, 0, FLAGS, "flags" },
79
        { "u", "filter u plane",     0, AV_OPT_TYPE_CONST, {.i64=PLANE_U}, 0, 0, FLAGS, "flags" },
80
        { "v", "filter v plane",     0, AV_OPT_TYPE_CONST, {.i64=PLANE_V}, 0, 0, FLAGS, "flags" },
81
        { "r", "filter red plane",   0, AV_OPT_TYPE_CONST, {.i64=PLANE_R}, 0, 0, FLAGS, "flags" },
82
        { "g", "filter green plane", 0, AV_OPT_TYPE_CONST, {.i64=PLANE_G}, 0, 0, FLAGS, "flags" },
83
        { "b", "filter blue plane",  0, AV_OPT_TYPE_CONST, {.i64=PLANE_B}, 0, 0, FLAGS, "flags" },
84
    { NULL }
85
};
86
87
AVFILTER_DEFINE_CLASS(edgedetect);
88
89
2
static av_cold int init(AVFilterContext *ctx)
90
{
91
2
    EdgeDetectContext *edgedetect = ctx->priv;
92
93
2
    edgedetect->low_u8  = edgedetect->low  * 255. + .5;
94
2
    edgedetect->high_u8 = edgedetect->high * 255. + .5;
95
2
    return 0;
96
}
97
98
2
static int query_formats(AVFilterContext *ctx)
99
{
100
2
    const EdgeDetectContext *edgedetect = ctx->priv;
101
    static const enum AVPixelFormat wires_pix_fmts[] = {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE};
102
    static const enum AVPixelFormat canny_pix_fmts[] = {AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_GBRP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE};
103
    static const enum AVPixelFormat colormix_pix_fmts[] = {AV_PIX_FMT_GBRP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE};
104
    AVFilterFormats *fmts_list;
105
2
    const enum AVPixelFormat *pix_fmts = NULL;
106
107
2
    if (edgedetect->mode == MODE_WIRES) {
108
1
        pix_fmts = wires_pix_fmts;
109
1
    } else if (edgedetect->mode == MODE_COLORMIX) {
110
1
        pix_fmts = colormix_pix_fmts;
111
    } else if (edgedetect->mode == MODE_CANNY) {
112
        pix_fmts = canny_pix_fmts;
113
    } else {
114
        av_assert0(0);
115
    }
116
2
    fmts_list = ff_make_format_list(pix_fmts);
117
2
    if (!fmts_list)
118
        return AVERROR(ENOMEM);
119
2
    return ff_set_common_formats(ctx, fmts_list);
120
}
121
122
2
static int config_props(AVFilterLink *inlink)
123
{
124
    int p;
125
2
    AVFilterContext *ctx = inlink->dst;
126
2
    EdgeDetectContext *edgedetect = ctx->priv;
127
2
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
128
129
2
    edgedetect->nb_planes = inlink->format == AV_PIX_FMT_GRAY8 ? 1 : 3;
130
6
    for (p = 0; p < edgedetect->nb_planes; p++) {
131
4
        struct plane_info *plane = &edgedetect->planes[p];
132
4
        int vsub = p ? desc->log2_chroma_h : 0;
133
4
        int hsub = p ? desc->log2_chroma_w : 0;
134
135
4
        plane->width      = AV_CEIL_RSHIFT(inlink->w, hsub);
136
4
        plane->height     = AV_CEIL_RSHIFT(inlink->h, vsub);
137
4
        plane->tmpbuf     = av_malloc(plane->width * plane->height);
138
4
        plane->gradients  = av_calloc(plane->width * plane->height, sizeof(*plane->gradients));
139
4
        plane->directions = av_malloc(plane->width * plane->height);
140

4
        if (!plane->tmpbuf || !plane->gradients || !plane->directions)
141
            return AVERROR(ENOMEM);
142
    }
143
2
    return 0;
144
}
145
146
80
static void gaussian_blur(AVFilterContext *ctx, int w, int h,
147
                                uint8_t *dst, int dst_linesize,
148
                          const uint8_t *src, int src_linesize)
149
{
150
    int i, j;
151
152
80
    memcpy(dst, src, w); dst += dst_linesize; src += src_linesize;
153
80
    if (h > 1) {
154
80
        memcpy(dst, src, w); dst += dst_linesize; src += src_linesize;
155
    }
156
22800
    for (j = 2; j < h - 2; j++) {
157
22720
        dst[0] = src[0];
158
22720
        if (w > 1)
159
22720
            dst[1] = src[1];
160
7929280
        for (i = 2; i < w - 2; i++) {
161
            /* Gaussian mask of size 5x5 with sigma = 1.4 */
162
7906560
            dst[i] = ((src[-2*src_linesize + i-2] + src[2*src_linesize + i-2]) * 2
163
7906560
                    + (src[-2*src_linesize + i-1] + src[2*src_linesize + i-1]) * 4
164
7906560
                    + (src[-2*src_linesize + i  ] + src[2*src_linesize + i  ]) * 5
165
7906560
                    + (src[-2*src_linesize + i+1] + src[2*src_linesize + i+1]) * 4
166
7906560
                    + (src[-2*src_linesize + i+2] + src[2*src_linesize + i+2]) * 2
167
168
7906560
                    + (src[  -src_linesize + i-2] + src[  src_linesize + i-2]) *  4
169
7906560
                    + (src[  -src_linesize + i-1] + src[  src_linesize + i-1]) *  9
170
7906560
                    + (src[  -src_linesize + i  ] + src[  src_linesize + i  ]) * 12
171
7906560
                    + (src[  -src_linesize + i+1] + src[  src_linesize + i+1]) *  9
172
7906560
                    + (src[  -src_linesize + i+2] + src[  src_linesize + i+2]) *  4
173
174
7906560
                    + src[i-2] *  5
175
7906560
                    + src[i-1] * 12
176
7906560
                    + src[i  ] * 15
177
7906560
                    + src[i+1] * 12
178
7906560
                    + src[i+2] *  5) / 159;
179
        }
180
22720
        if (w > 2)
181
22720
            dst[i    ] = src[i    ];
182
22720
        if (w > 3)
183
22720
            dst[i + 1] = src[i + 1];
184
185
22720
        dst += dst_linesize;
186
22720
        src += src_linesize;
187
    }
188
80
    if (h > 2) {
189
80
        memcpy(dst, src, w); dst += dst_linesize; src += src_linesize;
190
    }
191
80
    if (h > 3)
192
80
        memcpy(dst, src, w);
193
80
}
194
195
enum {
196
    DIRECTION_45UP,
197
    DIRECTION_45DOWN,
198
    DIRECTION_HORIZONTAL,
199
    DIRECTION_VERTICAL,
200
};
201
202
8008000
static int get_rounded_direction(int gx, int gy)
203
{
204
    /* reference angles:
205
     *   tan( pi/8) = sqrt(2)-1
206
     *   tan(3pi/8) = sqrt(2)+1
207
     * Gy/Gx is the tangent of the angle (theta), so Gy/Gx is compared against
208
     * <ref-angle>, or more simply Gy against <ref-angle>*Gx
209
     *
210
     * Gx and Gy bounds = [-1020;1020], using 16-bit arithmetic:
211
     *   round((sqrt(2)-1) * (1<<16)) =  27146
212
     *   round((sqrt(2)+1) * (1<<16)) = 158218
213
     */
214
8008000
    if (gx) {
215
        int tanpi8gx, tan3pi8gx;
216
217
7585320
        if (gx < 0)
218
2361364
            gx = -gx, gy = -gy;
219
7585320
        gy *= (1 << 16);
220
7585320
        tanpi8gx  =  27146 * gx;
221
7585320
        tan3pi8gx = 158218 * gx;
222

7585320
        if (gy > -tan3pi8gx && gy < -tanpi8gx)  return DIRECTION_45UP;
223

6819244
        if (gy > -tanpi8gx  && gy <  tanpi8gx)  return DIRECTION_HORIZONTAL;
224

5019981
        if (gy >  tanpi8gx  && gy <  tan3pi8gx) return DIRECTION_45DOWN;
225
    }
226
2229043
    return DIRECTION_VERTICAL;
227
}
228
229
80
static void sobel(int w, int h,
230
                       uint16_t *dst, int dst_linesize,
231
                         int8_t *dir, int dir_linesize,
232
                  const uint8_t *src, int src_linesize)
233
{
234
    int i, j;
235
236
22960
    for (j = 1; j < h - 1; j++) {
237
22880
        dst += dst_linesize;
238
22880
        dir += dir_linesize;
239
22880
        src += src_linesize;
240
8030880
        for (i = 1; i < w - 1; i++) {
241
8008000
            const int gx =
242
8008000
                -1*src[-src_linesize + i-1] + 1*src[-src_linesize + i+1]
243
8008000
                -2*src[                i-1] + 2*src[                i+1]
244
8008000
                -1*src[ src_linesize + i-1] + 1*src[ src_linesize + i+1];
245
8008000
            const int gy =
246
8008000
                -1*src[-src_linesize + i-1] + 1*src[ src_linesize + i-1]
247
8008000
                -2*src[-src_linesize + i  ] + 2*src[ src_linesize + i  ]
248
8008000
                -1*src[-src_linesize + i+1] + 1*src[ src_linesize + i+1];
249
250
8008000
            dst[i] = FFABS(gx) + FFABS(gy);
251
8008000
            dir[i] = get_rounded_direction(gx, gy);
252
        }
253
    }
254
80
}
255
256
80
static void non_maximum_suppression(int w, int h,
257
                                          uint8_t  *dst, int dst_linesize,
258
                                    const  int8_t  *dir, int dir_linesize,
259
                                    const uint16_t *src, int src_linesize)
260
{
261
    int i, j;
262
263
#define COPY_MAXIMA(ay, ax, by, bx) do {                \
264
    if (src[i] > src[(ay)*src_linesize + i+(ax)] &&     \
265
        src[i] > src[(by)*src_linesize + i+(bx)])       \
266
        dst[i] = av_clip_uint8(src[i]);                 \
267
} while (0)
268
269
22960
    for (j = 1; j < h - 1; j++) {
270
22880
        dst += dst_linesize;
271
22880
        dir += dir_linesize;
272
22880
        src += src_linesize;
273
8030880
        for (i = 1; i < w - 1; i++) {
274

8008000
            switch (dir[i]) {
275

766076
            case DIRECTION_45UP:        COPY_MAXIMA( 1, -1, -1,  1); break;
276

3213618
            case DIRECTION_45DOWN:      COPY_MAXIMA(-1, -1,  1,  1); break;
277

1799263
            case DIRECTION_HORIZONTAL:  COPY_MAXIMA( 0, -1,  0,  1); break;
278

2229043
            case DIRECTION_VERTICAL:    COPY_MAXIMA(-1,  0,  1,  0); break;
279
            }
280
8008000
        }
281
    }
282
80
}
283
284
80
static void double_threshold(int low, int high, int w, int h,
285
                                   uint8_t *dst, int dst_linesize,
286
                             const uint8_t *src, int src_linesize)
287
{
288
    int i, j;
289
290
23120
    for (j = 0; j < h; j++) {
291
8133120
        for (i = 0; i < w; i++) {
292
8110080
            if (src[i] > high) {
293
1254839
                dst[i] = src[i];
294
1254839
                continue;
295
            }
296
297


6855241
            if (!(!i || i == w - 1 || !j || j == h - 1) &&
298
6753161
                src[i] > low &&
299
284516
                (src[-src_linesize + i-1] > high ||
300
277202
                 src[-src_linesize + i  ] > high ||
301
270538
                 src[-src_linesize + i+1] > high ||
302
266122
                 src[                i-1] > high ||
303
261152
                 src[                i+1] > high ||
304
257280
                 src[ src_linesize + i-1] > high ||
305
253625
                 src[ src_linesize + i  ] > high ||
306
248785
                 src[ src_linesize + i+1] > high))
307
40463
                dst[i] = src[i];
308
            else
309
6814778
                dst[i] = 0;
310
        }
311
23040
        dst += dst_linesize;
312
23040
        src += src_linesize;
313
    }
314
80
}
315
316
60
static void color_mix(int w, int h,
317
                            uint8_t *dst, int dst_linesize,
318
                      const uint8_t *src, int src_linesize)
319
{
320
    int i, j;
321
322
17340
    for (j = 0; j < h; j++) {
323
6099840
        for (i = 0; i < w; i++)
324
6082560
            dst[i] = (dst[i] + src[i]) >> 1;
325
17280
        dst += dst_linesize;
326
17280
        src += src_linesize;
327
    }
328
60
}
329
330
40
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
331
{
332
40
    AVFilterContext *ctx = inlink->dst;
333
40
    EdgeDetectContext *edgedetect = ctx->priv;
334
40
    AVFilterLink *outlink = ctx->outputs[0];
335
40
    int p, direct = 0;
336
    AVFrame *out;
337
338

40
    if (edgedetect->mode != MODE_COLORMIX && av_frame_is_writable(in)) {
339
20
        direct = 1;
340
20
        out = in;
341
    } else {
342
20
        out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
343
20
        if (!out) {
344
            av_frame_free(&in);
345
            return AVERROR(ENOMEM);
346
        }
347
20
        av_frame_copy_props(out, in);
348
    }
349
350
120
    for (p = 0; p < edgedetect->nb_planes; p++) {
351
80
        struct plane_info *plane = &edgedetect->planes[p];
352
80
        uint8_t  *tmpbuf     = plane->tmpbuf;
353
80
        uint16_t *gradients  = plane->gradients;
354
80
        int8_t   *directions = plane->directions;
355
80
        const int width      = plane->width;
356
80
        const int height     = plane->height;
357
358
80
        if (!((1 << p) & edgedetect->filter_planes)) {
359
            if (!direct)
360
                av_image_copy_plane(out->data[p], out->linesize[p],
361
                                    in->data[p], in->linesize[p],
362
                                    width, height);
363
            continue;
364
        }
365
366
        /* gaussian filter to reduce noise  */
367
80
        gaussian_blur(ctx, width, height,
368
                      tmpbuf,      width,
369
80
                      in->data[p], in->linesize[p]);
370
371
        /* compute the 16-bits gradients and directions for the next step */
372
80
        sobel(width, height,
373
              gradients, width,
374
              directions,width,
375
              tmpbuf,    width);
376
377
        /* non_maximum_suppression() will actually keep & clip what's necessary and
378
         * ignore the rest, so we need a clean output buffer */
379
80
        memset(tmpbuf, 0, width * height);
380
80
        non_maximum_suppression(width, height,
381
                                tmpbuf,    width,
382
                                directions,width,
383
                                gradients, width);
384
385
        /* keep high values, or low values surrounded by high values */
386
80
        double_threshold(edgedetect->low_u8, edgedetect->high_u8,
387
                         width, height,
388
                         out->data[p], out->linesize[p],
389
                         tmpbuf,       width);
390
391
80
        if (edgedetect->mode == MODE_COLORMIX) {
392
60
            color_mix(width, height,
393
                      out->data[p], out->linesize[p],
394
60
                      in->data[p], in->linesize[p]);
395
        }
396
    }
397
398
40
    if (!direct)
399
20
        av_frame_free(&in);
400
40
    return ff_filter_frame(outlink, out);
401
}
402
403
2
static av_cold void uninit(AVFilterContext *ctx)
404
{
405
    int p;
406
2
    EdgeDetectContext *edgedetect = ctx->priv;
407
408
6
    for (p = 0; p < edgedetect->nb_planes; p++) {
409
4
        struct plane_info *plane = &edgedetect->planes[p];
410
4
        av_freep(&plane->tmpbuf);
411
4
        av_freep(&plane->gradients);
412
4
        av_freep(&plane->directions);
413
    }
414
2
}
415
416
static const AVFilterPad edgedetect_inputs[] = {
417
    {
418
        .name         = "default",
419
        .type         = AVMEDIA_TYPE_VIDEO,
420
        .config_props = config_props,
421
        .filter_frame = filter_frame,
422
    },
423
    { NULL }
424
};
425
426
static const AVFilterPad edgedetect_outputs[] = {
427
    {
428
        .name = "default",
429
        .type = AVMEDIA_TYPE_VIDEO,
430
    },
431
    { NULL }
432
};
433
434
AVFilter ff_vf_edgedetect = {
435
    .name          = "edgedetect",
436
    .description   = NULL_IF_CONFIG_SMALL("Detect and draw edge."),
437
    .priv_size     = sizeof(EdgeDetectContext),
438
    .init          = init,
439
    .uninit        = uninit,
440
    .query_formats = query_formats,
441
    .inputs        = edgedetect_inputs,
442
    .outputs       = edgedetect_outputs,
443
    .priv_class    = &edgedetect_class,
444
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
445
};