2 * Copyright (c) 2002 A'rpi
3 * This file is part of FFmpeg.
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.
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.
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.
22 * border detection filter
23 * Ported from MPlayer libmpcodecs/vf_cropdetect.c.
26 #include "libavutil/imgutils.h"
27 #include "libavutil/internal.h"
28 #include "libavutil/opt.h"
35 typedef struct CropDetectContext {
46 static int query_formats(AVFilterContext *ctx)
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_NV12, AV_PIX_FMT_NV21,
58 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
62 static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp)
77 total += src[0] + src[1] + src[2];
85 av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total);
89 static av_cold int init(AVFilterContext *ctx)
91 CropDetectContext *s = ctx->priv;
95 av_log(ctx, AV_LOG_VERBOSE, "limit:%d round:%d reset_count:%d\n",
96 s->limit, s->round, s->reset_count);
101 static int config_input(AVFilterLink *inlink)
103 AVFilterContext *ctx = inlink->dst;
104 CropDetectContext *s = ctx->priv;
106 av_image_fill_max_pixsteps(s->max_pixsteps, NULL,
107 av_pix_fmt_desc_get(inlink->format));
109 s->x1 = inlink->w - 1;
110 s->y1 = inlink->h - 1;
117 #define SET_META(key, value) \
118 av_dict_set_int(metadata, key, value, 0)
120 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
122 AVFilterContext *ctx = inlink->dst;
123 CropDetectContext *s = ctx->priv;
124 int bpp = s->max_pixsteps[0];
125 int w, h, x, y, shrink_by;
126 AVDictionary **metadata;
127 int outliers, last_y;
129 // ignore first 2 frames - they may be empty
130 if (++s->frame_nb > 0) {
131 metadata = avpriv_frame_get_metadatap(frame);
133 // Reset the crop area every reset_count frames, if reset_count is > 0
134 if (s->reset_count > 0 && s->frame_nb > s->reset_count) {
135 s->x1 = frame->width - 1;
136 s->y1 = frame->height - 1;
142 #define FIND(DST, FROM, NOEND, INC, STEP0, STEP1, LEN) \
144 for (last_y = y = FROM; NOEND; y = y INC) {\
145 if (checkline(ctx, frame->data[0] + STEP0 * y, STEP1, LEN, bpp) > s->limit) {\
146 if (++outliers > s->max_outliers) { \
154 FIND(s->y1, 0, y < s->y1, +1, frame->linesize[0], bpp, frame->width);
155 FIND(s->y2, frame->height - 1, y > FFMAX(s->y2, s->y1), -1, frame->linesize[0], bpp, frame->width);
156 FIND(s->x1, 0, y < s->x1, +1, bpp, frame->linesize[0], frame->height);
157 FIND(s->x2, frame->width - 1, y > FFMAX(s->x2, s->x1), -1, bpp, frame->linesize[0], frame->height);
160 // round x and y (up), important for yuv colorspaces
161 // make sure they stay rounded!
168 // w and h must be divisible by 2 as well because of yuv
169 // colorspace problems.
175 shrink_by = w % s->round;
177 x += (shrink_by/2 + 1) & ~1;
179 shrink_by = h % s->round;
181 y += (shrink_by/2 + 1) & ~1;
183 SET_META("lavfi.cropdetect.x1", s->x1);
184 SET_META("lavfi.cropdetect.x2", s->x2);
185 SET_META("lavfi.cropdetect.y1", s->y1);
186 SET_META("lavfi.cropdetect.y2", s->y2);
187 SET_META("lavfi.cropdetect.w", w);
188 SET_META("lavfi.cropdetect.h", h);
189 SET_META("lavfi.cropdetect.x", x);
190 SET_META("lavfi.cropdetect.y", y);
192 av_log(ctx, AV_LOG_INFO,
193 "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",
194 s->x1, s->x2, s->y1, s->y2, w, h, x, y, frame->pts,
195 frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base),
199 return ff_filter_frame(inlink->dst->outputs[0], frame);
202 #define OFFSET(x) offsetof(CropDetectContext, x)
203 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
205 static const AVOption cropdetect_options[] = {
206 { "limit", "Threshold below which the pixel is considered black", OFFSET(limit), AV_OPT_TYPE_INT, { .i64 = 24 }, 0, 255, FLAGS },
207 { "round", "Value by which the width/height should be divisible", OFFSET(round), AV_OPT_TYPE_INT, { .i64 = 16 }, 0, INT_MAX, FLAGS },
208 { "reset", "Recalculate the crop area after this many frames", OFFSET(reset_count), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
209 { "reset_count", "Recalculate the crop area after this many frames",OFFSET(reset_count),AV_OPT_TYPE_INT,{ .i64 = 0 }, 0, INT_MAX, FLAGS },
210 { "max_outliers", "Threshold count of outliers", OFFSET(max_outliers),AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
214 AVFILTER_DEFINE_CLASS(cropdetect);
216 static const AVFilterPad avfilter_vf_cropdetect_inputs[] = {
219 .type = AVMEDIA_TYPE_VIDEO,
220 .config_props = config_input,
221 .filter_frame = filter_frame,
226 static const AVFilterPad avfilter_vf_cropdetect_outputs[] = {
229 .type = AVMEDIA_TYPE_VIDEO
234 AVFilter ff_vf_cropdetect = {
235 .name = "cropdetect",
236 .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."),
237 .priv_size = sizeof(CropDetectContext),
238 .priv_class = &cropdetect_class,
240 .query_formats = query_formats,
241 .inputs = avfilter_vf_cropdetect_inputs,
242 .outputs = avfilter_vf_cropdetect_outputs,
243 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,