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path: root/libavfilter/vf_cropdetect.c (plain)
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1/*
2 * Copyright (c) 2002 A'rpi
3 * This file is part of FFmpeg.
4 *
5 * FFmpeg is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * FFmpeg is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20/**
21 * @file
22 * border detection filter
23 * Ported from MPlayer libmpcodecs/vf_cropdetect.c.
24 */
25
26#include "libavutil/imgutils.h"
27#include "libavutil/internal.h"
28#include "libavutil/opt.h"
29
30#include "avfilter.h"
31#include "formats.h"
32#include "internal.h"
33#include "video.h"
34
35typedef struct CropDetectContext {
36 const AVClass *class;
37 int x1, y1, x2, y2;
38 float limit;
39 int round;
40 int reset_count;
41 int frame_nb;
42 int max_pixsteps[4];
43 int max_outliers;
44} CropDetectContext;
45
46static int query_formats(AVFilterContext *ctx)
47{
48 static const enum AVPixelFormat pix_fmts[] = {
49 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
50 AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
51 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
52 AV_PIX_FMT_YUV411P, AV_PIX_FMT_GRAY8,
53 AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV410P,
54 AV_PIX_FMT_YUV420P9 , AV_PIX_FMT_YUV422P9 , AV_PIX_FMT_YUV444P9,
55 AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
56 AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12,
57 AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
58 AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
59 AV_PIX_FMT_NV12, AV_PIX_FMT_NV21,
60 AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
61 AV_PIX_FMT_RGBA, AV_PIX_FMT_BGRA,
62 AV_PIX_FMT_NONE
63 };
64
65 AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
66 if (!fmts_list)
67 return AVERROR(ENOMEM);
68 return ff_set_common_formats(ctx, fmts_list);
69}
70
71static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp)
72{
73 int total = 0;
74 int div = len;
75 const uint16_t *src16 = (const uint16_t *)src;
76
77 switch (bpp) {
78 case 1:
79 while (len >= 8) {
80 total += src[ 0] + src[ stride] + src[2*stride] + src[3*stride]
81 + src[4*stride] + src[5*stride] + src[6*stride] + src[7*stride];
82 src += 8*stride;
83 len -= 8;
84 }
85 while (--len >= 0) {
86 total += src[0];
87 src += stride;
88 }
89 break;
90 case 2:
91 stride >>= 1;
92 while (len >= 8) {
93 total += src16[ 0] + src16[ stride] + src16[2*stride] + src16[3*stride]
94 + src16[4*stride] + src16[5*stride] + src16[6*stride] + src16[7*stride];
95 src16 += 8*stride;
96 len -= 8;
97 }
98 while (--len >= 0) {
99 total += src16[0];
100 src16 += stride;
101 }
102 break;
103 case 3:
104 case 4:
105 while (len >= 4) {
106 total += src[0] + src[1 ] + src[2 ]
107 + src[ stride] + src[1+ stride] + src[2+ stride]
108 + src[2*stride] + src[1+2*stride] + src[2+2*stride]
109 + src[3*stride] + src[1+3*stride] + src[2+3*stride];
110 src += 4*stride;
111 len -= 4;
112 }
113 while (--len >= 0) {
114 total += src[0] + src[1] + src[2];
115 src += stride;
116 }
117 div *= 3;
118 break;
119 }
120 total /= div;
121
122 av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total);
123 return total;
124}
125
126static av_cold int init(AVFilterContext *ctx)
127{
128 CropDetectContext *s = ctx->priv;
129
130 s->frame_nb = -2;
131
132 av_log(ctx, AV_LOG_VERBOSE, "limit:%f round:%d reset_count:%d\n",
133 s->limit, s->round, s->reset_count);
134
135 return 0;
136}
137
138static int config_input(AVFilterLink *inlink)
139{
140 AVFilterContext *ctx = inlink->dst;
141 CropDetectContext *s = ctx->priv;
142 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
143
144 av_image_fill_max_pixsteps(s->max_pixsteps, NULL, desc);
145
146 if (s->limit < 1.0)
147 s->limit *= (1 << desc->comp[0].depth) - 1;
148
149 s->x1 = inlink->w - 1;
150 s->y1 = inlink->h - 1;
151 s->x2 = 0;
152 s->y2 = 0;
153
154 return 0;
155}
156
157#define SET_META(key, value) \
158 av_dict_set_int(metadata, key, value, 0)
159
160static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
161{
162 AVFilterContext *ctx = inlink->dst;
163 CropDetectContext *s = ctx->priv;
164 int bpp = s->max_pixsteps[0];
165 int w, h, x, y, shrink_by;
166 AVDictionary **metadata;
167 int outliers, last_y;
168 int limit = lrint(s->limit);
169
170 // ignore first 2 frames - they may be empty
171 if (++s->frame_nb > 0) {
172 metadata = avpriv_frame_get_metadatap(frame);
173
174 // Reset the crop area every reset_count frames, if reset_count is > 0
175 if (s->reset_count > 0 && s->frame_nb > s->reset_count) {
176 s->x1 = frame->width - 1;
177 s->y1 = frame->height - 1;
178 s->x2 = 0;
179 s->y2 = 0;
180 s->frame_nb = 1;
181 }
182
183#define FIND(DST, FROM, NOEND, INC, STEP0, STEP1, LEN) \
184 outliers = 0;\
185 for (last_y = y = FROM; NOEND; y = y INC) {\
186 if (checkline(ctx, frame->data[0] + STEP0 * y, STEP1, LEN, bpp) > limit) {\
187 if (++outliers > s->max_outliers) { \
188 DST = last_y;\
189 break;\
190 }\
191 } else\
192 last_y = y INC;\
193 }
194
195 FIND(s->y1, 0, y < s->y1, +1, frame->linesize[0], bpp, frame->width);
196 FIND(s->y2, frame->height - 1, y > FFMAX(s->y2, s->y1), -1, frame->linesize[0], bpp, frame->width);
197 FIND(s->x1, 0, y < s->x1, +1, bpp, frame->linesize[0], frame->height);
198 FIND(s->x2, frame->width - 1, y > FFMAX(s->x2, s->x1), -1, bpp, frame->linesize[0], frame->height);
199
200
201 // round x and y (up), important for yuv colorspaces
202 // make sure they stay rounded!
203 x = (s->x1+1) & ~1;
204 y = (s->y1+1) & ~1;
205
206 w = s->x2 - x + 1;
207 h = s->y2 - y + 1;
208
209 // w and h must be divisible by 2 as well because of yuv
210 // colorspace problems.
211 if (s->round <= 1)
212 s->round = 16;
213 if (s->round % 2)
214 s->round *= 2;
215
216 shrink_by = w % s->round;
217 w -= shrink_by;
218 x += (shrink_by/2 + 1) & ~1;
219
220 shrink_by = h % s->round;
221 h -= shrink_by;
222 y += (shrink_by/2 + 1) & ~1;
223
224 SET_META("lavfi.cropdetect.x1", s->x1);
225 SET_META("lavfi.cropdetect.x2", s->x2);
226 SET_META("lavfi.cropdetect.y1", s->y1);
227 SET_META("lavfi.cropdetect.y2", s->y2);
228 SET_META("lavfi.cropdetect.w", w);
229 SET_META("lavfi.cropdetect.h", h);
230 SET_META("lavfi.cropdetect.x", x);
231 SET_META("lavfi.cropdetect.y", y);
232
233 av_log(ctx, AV_LOG_INFO,
234 "x1:%d x2:%d y1:%d y2:%d w:%d h:%d x:%d y:%d pts:%"PRId64" t:%f crop=%d:%d:%d:%d\n",
235 s->x1, s->x2, s->y1, s->y2, w, h, x, y, frame->pts,
236 frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base),
237 w, h, x, y);
238 }
239
240 return ff_filter_frame(inlink->dst->outputs[0], frame);
241}
242
243#define OFFSET(x) offsetof(CropDetectContext, x)
244#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
245
246static const AVOption cropdetect_options[] = {
247 { "limit", "Threshold below which the pixel is considered black", OFFSET(limit), AV_OPT_TYPE_FLOAT, { .dbl = 24.0/255 }, 0, 65535, FLAGS },
248 { "round", "Value by which the width/height should be divisible", OFFSET(round), AV_OPT_TYPE_INT, { .i64 = 16 }, 0, INT_MAX, FLAGS },
249 { "reset", "Recalculate the crop area after this many frames", OFFSET(reset_count), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
250 { "reset_count", "Recalculate the crop area after this many frames",OFFSET(reset_count),AV_OPT_TYPE_INT,{ .i64 = 0 }, 0, INT_MAX, FLAGS },
251 { "max_outliers", "Threshold count of outliers", OFFSET(max_outliers),AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
252 { NULL }
253};
254
255AVFILTER_DEFINE_CLASS(cropdetect);
256
257static const AVFilterPad avfilter_vf_cropdetect_inputs[] = {
258 {
259 .name = "default",
260 .type = AVMEDIA_TYPE_VIDEO,
261 .config_props = config_input,
262 .filter_frame = filter_frame,
263 },
264 { NULL }
265};
266
267static const AVFilterPad avfilter_vf_cropdetect_outputs[] = {
268 {
269 .name = "default",
270 .type = AVMEDIA_TYPE_VIDEO
271 },
272 { NULL }
273};
274
275AVFilter ff_vf_cropdetect = {
276 .name = "cropdetect",
277 .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."),
278 .priv_size = sizeof(CropDetectContext),
279 .priv_class = &cropdetect_class,
280 .init = init,
281 .query_formats = query_formats,
282 .inputs = avfilter_vf_cropdetect_inputs,
283 .outputs = avfilter_vf_cropdetect_outputs,
284 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
285};
286
generated by cgit at 2024-05-17 05:03:57 (GMT)