h264_metadata: Add option to delete filler data
[libav.git] / libavfilter / vf_cropdetect.c
1 /*
2 * Copyright (c) 2002 A'rpi
3 * This file is part of Libav.
4 *
5 * Libav 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 * Libav 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 Libav; 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 <stdio.h>
27
28 #include "libavutil/imgutils.h"
29 #include "libavutil/internal.h"
30 #include "libavutil/opt.h"
31
32 #include "avfilter.h"
33 #include "formats.h"
34 #include "internal.h"
35 #include "video.h"
36
37 typedef struct CropDetectContext {
38 const AVClass *class;
39 int x1, y1, x2, y2;
40 int limit;
41 int round;
42 int reset_count;
43 int frame_nb;
44 int max_pixsteps[4];
45 } CropDetectContext;
46
47 static int query_formats(AVFilterContext *ctx)
48 {
49 static const enum AVPixelFormat pix_fmts[] = {
50 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
51 AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
52 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
53 AV_PIX_FMT_YUV411P, AV_PIX_FMT_GRAY8,
54 AV_PIX_FMT_NV12, AV_PIX_FMT_NV21,
55 AV_PIX_FMT_NONE
56 };
57
58 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
59 return 0;
60 }
61
62 static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp)
63 {
64 int total = 0;
65 int div = len;
66
67 switch (bpp) {
68 case 1:
69 while (--len >= 0) {
70 total += src[0];
71 src += stride;
72 }
73 break;
74 case 3:
75 case 4:
76 while (--len >= 0) {
77 total += src[0] + src[1] + src[2];
78 src += stride;
79 }
80 div *= 3;
81 break;
82 }
83 total /= div;
84
85 av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total);
86 return total;
87 }
88
89 static av_cold int init(AVFilterContext *ctx)
90 {
91 CropDetectContext *s = ctx->priv;
92
93 s->frame_nb = -2;
94
95 av_log(ctx, AV_LOG_VERBOSE, "limit:%d round:%d reset_count:%d\n",
96 s->limit, s->round, s->reset_count);
97
98 return 0;
99 }
100
101 static int config_input(AVFilterLink *inlink)
102 {
103 AVFilterContext *ctx = inlink->dst;
104 CropDetectContext *s = ctx->priv;
105
106 av_image_fill_max_pixsteps(s->max_pixsteps, NULL,
107 av_pix_fmt_desc_get(inlink->format));
108
109 s->x1 = inlink->w - 1;
110 s->y1 = inlink->h - 1;
111 s->x2 = 0;
112 s->y2 = 0;
113
114 return 0;
115 }
116
117 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
118 {
119 AVFilterContext *ctx = inlink->dst;
120 CropDetectContext *s = ctx->priv;
121 int bpp = s->max_pixsteps[0];
122 int w, h, x, y, shrink_by;
123
124 // ignore first 2 frames - they may be empty
125 if (++s->frame_nb > 0) {
126 // Reset the crop area every reset_count frames, if reset_count is > 0
127 if (s->reset_count > 0 && s->frame_nb > s->reset_count) {
128 s->x1 = frame->width - 1;
129 s->y1 = frame->height - 1;
130 s->x2 = 0;
131 s->y2 = 0;
132 s->frame_nb = 1;
133 }
134
135 for (y = 0; y < s->y1; y++) {
136 if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > s->limit) {
137 s->y1 = y;
138 break;
139 }
140 }
141
142 for (y = frame->height - 1; y > s->y2; y--) {
143 if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > s->limit) {
144 s->y2 = y;
145 break;
146 }
147 }
148
149 for (y = 0; y < s->x1; y++) {
150 if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > s->limit) {
151 s->x1 = y;
152 break;
153 }
154 }
155
156 for (y = frame->width - 1; y > s->x2; y--) {
157 if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > s->limit) {
158 s->x2 = y;
159 break;
160 }
161 }
162
163 // round x and y (up), important for yuv colorspaces
164 // make sure they stay rounded!
165 x = (s->x1+1) & ~1;
166 y = (s->y1+1) & ~1;
167
168 w = s->x2 - x + 1;
169 h = s->y2 - y + 1;
170
171 // w and h must be divisible by 2 as well because of yuv
172 // colorspace problems.
173 if (s->round <= 1)
174 s->round = 16;
175 if (s->round % 2)
176 s->round *= 2;
177
178 shrink_by = w % s->round;
179 w -= shrink_by;
180 x += (shrink_by/2 + 1) & ~1;
181
182 shrink_by = h % s->round;
183 h -= shrink_by;
184 y += (shrink_by/2 + 1) & ~1;
185
186 av_log(ctx, AV_LOG_INFO,
187 "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",
188 s->x1, s->x2, s->y1, s->y2, w, h, x, y, frame->pts,
189 frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base),
190 w, h, x, y);
191 }
192
193 return ff_filter_frame(inlink->dst->outputs[0], frame);
194 }
195
196 #define OFFSET(x) offsetof(CropDetectContext, x)
197 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
198 static const AVOption options[] = {
199 { "limit", "Threshold below which the pixel is considered black", OFFSET(limit), AV_OPT_TYPE_INT, { .i64 = 24 }, 0, INT_MAX, FLAGS },
200 { "round", "Value by which the width/height should be divisible", OFFSET(round), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
201 { "reset", "Recalculate the crop area after this many frames", OFFSET(reset_count), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
202 { NULL },
203 };
204
205 static const AVClass cropdetect_class = {
206 .class_name = "cropdetect",
207 .item_name = av_default_item_name,
208 .option = options,
209 .version = LIBAVUTIL_VERSION_INT,
210 };
211
212 static const AVFilterPad avfilter_vf_cropdetect_inputs[] = {
213 {
214 .name = "default",
215 .type = AVMEDIA_TYPE_VIDEO,
216 .config_props = config_input,
217 .get_video_buffer = ff_null_get_video_buffer,
218 .filter_frame = filter_frame,
219 },
220 { NULL }
221 };
222
223 static const AVFilterPad avfilter_vf_cropdetect_outputs[] = {
224 {
225 .name = "default",
226 .type = AVMEDIA_TYPE_VIDEO
227 },
228 { NULL }
229 };
230
231 AVFilter ff_vf_cropdetect = {
232 .name = "cropdetect",
233 .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."),
234
235 .priv_size = sizeof(CropDetectContext),
236 .priv_class = &cropdetect_class,
237 .init = init,
238
239 .query_formats = query_formats,
240
241 .inputs = avfilter_vf_cropdetect_inputs,
242
243 .outputs = avfilter_vf_cropdetect_outputs,
244 };