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"
44 #define OFFSET(x) offsetof(CropDetectContext, x)
45 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
47 static const AVOption cropdetect_options[] = {
48 { "limit", "set black threshold", OFFSET(limit), AV_OPT_TYPE_INT, {.i64=24}, 0, 255, FLAGS },
49 { "round", "set width/height round value", OFFSET(round), AV_OPT_TYPE_INT, {.i64=16}, 0, INT_MAX, FLAGS },
50 { "reset_count", "set after how many frames to reset detected info", OFFSET(reset_count), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },
54 AVFILTER_DEFINE_CLASS(cropdetect);
56 static int query_formats(AVFilterContext *ctx)
58 static const enum AVPixelFormat pix_fmts[] = {
59 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
60 AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
61 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
62 AV_PIX_FMT_YUV411P, AV_PIX_FMT_GRAY8,
63 AV_PIX_FMT_NV12, AV_PIX_FMT_NV21,
67 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
71 static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp)
86 total += src[0] + src[1] + src[2];
94 av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total);
98 static av_cold int init(AVFilterContext *ctx, const char *args)
100 CropDetectContext *cd = ctx->priv;
103 av_log(ctx, AV_LOG_VERBOSE, "limit:%d round:%d reset_count:%d\n",
104 cd->limit, cd->round, cd->reset_count);
109 static int config_input(AVFilterLink *inlink)
111 AVFilterContext *ctx = inlink->dst;
112 CropDetectContext *cd = ctx->priv;
114 av_image_fill_max_pixsteps(cd->max_pixsteps, NULL,
115 av_pix_fmt_desc_get(inlink->format));
117 cd->x1 = inlink->w - 1;
118 cd->y1 = inlink->h - 1;
125 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
127 AVFilterContext *ctx = inlink->dst;
128 CropDetectContext *cd = ctx->priv;
129 int bpp = cd->max_pixsteps[0];
130 int w, h, x, y, shrink_by;
132 // ignore first 2 frames - they may be empty
133 if (++cd->frame_nb > 0) {
134 // Reset the crop area every reset_count frames, if reset_count is > 0
135 if (cd->reset_count > 0 && cd->frame_nb > cd->reset_count) {
136 cd->x1 = frame->width - 1;
137 cd->y1 = frame->height - 1;
143 for (y = 0; y < cd->y1; y++) {
144 if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > cd->limit) {
150 for (y = frame->height - 1; y > cd->y2; y--) {
151 if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > cd->limit) {
157 for (y = 0; y < cd->x1; y++) {
158 if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > cd->limit) {
164 for (y = frame->width - 1; y > cd->x2; y--) {
165 if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > cd->limit) {
171 // round x and y (up), important for yuv colorspaces
172 // make sure they stay rounded!
179 // w and h must be divisible by 2 as well because of yuv
180 // colorspace problems.
186 shrink_by = w % cd->round;
188 x += (shrink_by/2 + 1) & ~1;
190 shrink_by = h % cd->round;
192 y += (shrink_by/2 + 1) & ~1;
194 av_log(ctx, AV_LOG_INFO,
195 "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",
196 cd->x1, cd->x2, cd->y1, cd->y2, w, h, x, y, frame->pts,
197 frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base),
201 return ff_filter_frame(inlink->dst->outputs[0], frame);
204 static const AVFilterPad avfilter_vf_cropdetect_inputs[] = {
207 .type = AVMEDIA_TYPE_VIDEO,
208 .config_props = config_input,
209 .get_video_buffer = ff_null_get_video_buffer,
210 .filter_frame = filter_frame,
215 static const AVFilterPad avfilter_vf_cropdetect_outputs[] = {
218 .type = AVMEDIA_TYPE_VIDEO
223 static const char *const shorthand[] = { "limit", "round", "reset_count", NULL };
225 AVFilter avfilter_vf_cropdetect = {
226 .name = "cropdetect",
227 .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."),
229 .priv_size = sizeof(CropDetectContext),
231 .query_formats = query_formats,
232 .inputs = avfilter_vf_cropdetect_inputs,
233 .outputs = avfilter_vf_cropdetect_outputs,
234 .priv_class = &cropdetect_class,
235 .shorthand = shorthand,