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 int limit; 39 int round; 40 int reset_count; 41 int frame_nb; 42 int max_pixsteps[4]; 43} CropDetectContext; 44 45static int query_formats(AVFilterContext *ctx) 46{ 47 static const enum AVPixelFormat pix_fmts[] = { 48 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P, 49 AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P, 50 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P, 51 AV_PIX_FMT_YUV411P, AV_PIX_FMT_GRAY8, 52 AV_PIX_FMT_NV12, AV_PIX_FMT_NV21, 53 AV_PIX_FMT_NONE 54 }; 55 56 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); 57 return 0; 58} 59 60static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp) 61{ 62 int total = 0; 63 int div = len; 64 65 switch (bpp) { 66 case 1: 67 while (--len >= 0) { 68 total += src[0]; 69 src += stride; 70 } 71 break; 72 case 3: 73 case 4: 74 while (--len >= 0) { 75 total += src[0] + src[1] + src[2]; 76 src += stride; 77 } 78 div *= 3; 79 break; 80 } 81 total /= div; 82 83 av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total); 84 return total; 85} 86 87static av_cold int init(AVFilterContext *ctx) 88{ 89 CropDetectContext *s = ctx->priv; 90 91 s->frame_nb = -2; 92 93 av_log(ctx, AV_LOG_VERBOSE, "limit:%d round:%d reset_count:%d\n", 94 s->limit, s->round, s->reset_count); 95 96 return 0; 97} 98 99static int config_input(AVFilterLink *inlink) 100{ 101 AVFilterContext *ctx = inlink->dst; 102 CropDetectContext *s = ctx->priv; 103 104 av_image_fill_max_pixsteps(s->max_pixsteps, NULL, 105 av_pix_fmt_desc_get(inlink->format)); 106 107 s->x1 = inlink->w - 1; 108 s->y1 = inlink->h - 1; 109 s->x2 = 0; 110 s->y2 = 0; 111 112 return 0; 113} 114 115#define SET_META(key, value) \ 116 snprintf(buf, sizeof(buf), "%d", value); \ 117 av_dict_set(metadata, key, buf, 0) 118 119static int filter_frame(AVFilterLink *inlink, AVFrame *frame) 120{ 121 AVFilterContext *ctx = inlink->dst; 122 CropDetectContext *s = ctx->priv; 123 int bpp = s->max_pixsteps[0]; 124 int w, h, x, y, shrink_by; 125 AVDictionary **metadata; 126 char buf[32]; 127 128 // ignore first 2 frames - they may be empty 129 if (++s->frame_nb > 0) { 130 metadata = avpriv_frame_get_metadatap(frame); 131 132 // Reset the crop area every reset_count frames, if reset_count is > 0 133 if (s->reset_count > 0 && s->frame_nb > s->reset_count) { 134 s->x1 = frame->width - 1; 135 s->y1 = frame->height - 1; 136 s->x2 = 0; 137 s->y2 = 0; 138 s->frame_nb = 1; 139 } 140 141 for (y = 0; y < s->y1; y++) { 142 if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > s->limit) { 143 s->y1 = y; 144 break; 145 } 146 } 147 148 for (y = frame->height - 1; y > s->y2; y--) { 149 if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > s->limit) { 150 s->y2 = y; 151 break; 152 } 153 } 154 155 for (y = 0; y < s->x1; y++) { 156 if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > s->limit) { 157 s->x1 = y; 158 break; 159 } 160 } 161 162 for (y = frame->width - 1; y > s->x2; y--) { 163 if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > s->limit) { 164 s->x2 = y; 165 break; 166 } 167 } 168 169 // round x and y (up), important for yuv colorspaces 170 // make sure they stay rounded! 171 x = (s->x1+1) & ~1; 172 y = (s->y1+1) & ~1; 173 174 w = s->x2 - x + 1; 175 h = s->y2 - y + 1; 176 177 // w and h must be divisible by 2 as well because of yuv 178 // colorspace problems. 179 if (s->round <= 1) 180 s->round = 16; 181 if (s->round % 2) 182 s->round *= 2; 183 184 shrink_by = w % s->round; 185 w -= shrink_by; 186 x += (shrink_by/2 + 1) & ~1; 187 188 shrink_by = h % s->round; 189 h -= shrink_by; 190 y += (shrink_by/2 + 1) & ~1; 191 192 SET_META("lavfi.cropdetect.x1", s->x1); 193 SET_META("lavfi.cropdetect.x2", s->x2); 194 SET_META("lavfi.cropdetect.y1", s->y1); 195 SET_META("lavfi.cropdetect.y2", s->y2); 196 SET_META("lavfi.cropdetect.w", w); 197 SET_META("lavfi.cropdetect.h", h); 198 SET_META("lavfi.cropdetect.x", x); 199 SET_META("lavfi.cropdetect.y", y); 200 201 av_log(ctx, AV_LOG_INFO, 202 "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", 203 s->x1, s->x2, s->y1, s->y2, w, h, x, y, frame->pts, 204 frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base), 205 w, h, x, y); 206 } 207 208 return ff_filter_frame(inlink->dst->outputs[0], frame); 209} 210 211#define OFFSET(x) offsetof(CropDetectContext, x) 212#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM 213 214static const AVOption cropdetect_options[] = { 215 { "limit", "Threshold below which the pixel is considered black", OFFSET(limit), AV_OPT_TYPE_INT, { .i64 = 24 }, 0, 255, FLAGS }, 216 { "round", "Value by which the width/height should be divisible", OFFSET(round), AV_OPT_TYPE_INT, { .i64 = 16 }, 0, INT_MAX, FLAGS }, 217 { "reset", "Recalculate the crop area after this many frames", OFFSET(reset_count), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS }, 218 { "reset_count", "Recalculate the crop area after this many frames",OFFSET(reset_count),AV_OPT_TYPE_INT,{ .i64 = 0 }, 0, INT_MAX, FLAGS }, 219 { NULL } 220}; 221 222AVFILTER_DEFINE_CLASS(cropdetect); 223 224static const AVFilterPad avfilter_vf_cropdetect_inputs[] = { 225 { 226 .name = "default", 227 .type = AVMEDIA_TYPE_VIDEO, 228 .config_props = config_input, 229 .filter_frame = filter_frame, 230 }, 231 { NULL } 232}; 233 234static const AVFilterPad avfilter_vf_cropdetect_outputs[] = { 235 { 236 .name = "default", 237 .type = AVMEDIA_TYPE_VIDEO 238 }, 239 { NULL } 240}; 241 242AVFilter ff_vf_cropdetect = { 243 .name = "cropdetect", 244 .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."), 245 .priv_size = sizeof(CropDetectContext), 246 .priv_class = &cropdetect_class, 247 .init = init, 248 .query_formats = query_formats, 249 .inputs = avfilter_vf_cropdetect_inputs, 250 .outputs = avfilter_vf_cropdetect_outputs, 251 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, 252}; 253