2 * Copyright (c) 2007 Bobby Bingham
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
32 #include "libavutil/eval.h"
33 #include "libavutil/avstring.h"
34 #include "libavutil/internal.h"
35 #include "libavutil/libm.h"
36 #include "libavutil/imgutils.h"
37 #include "libavutil/mathematics.h"
38 #include "libavutil/opt.h"
40 static const char *const var_names[] = {
41 "in_w", "iw", ///< width of the input video
42 "in_h", "ih", ///< height of the input video
43 "out_w", "ow", ///< width of the cropped video
44 "out_h", "oh", ///< height of the cropped video
52 "n", ///< number of frame
53 "pos", ///< position in the file
54 "t", ///< timestamp expressed in seconds
76 typedef struct CropContext {
78 int x; ///< x offset of the non-cropped area with respect to the input area
79 int y; ///< y offset of the non-cropped area with respect to the input area
80 int w; ///< width of the cropped area
81 int h; ///< height of the cropped area
83 AVRational out_sar; ///< output sample aspect ratio
84 int keep_aspect; ///< keep display aspect ratio when cropping
86 int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
87 int hsub, vsub; ///< chroma subsampling
88 char *x_expr, *y_expr, *w_expr, *h_expr;
89 AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */
90 double var_values[VAR_VARS_NB];
93 static int query_formats(AVFilterContext *ctx)
95 AVFilterFormats *formats = NULL;
98 for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
99 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
100 if (!(desc->flags & (AV_PIX_FMT_FLAG_HWACCEL | AV_PIX_FMT_FLAG_BITSTREAM)) &&
101 !((desc->log2_chroma_w || desc->log2_chroma_h) && !(desc->flags & AV_PIX_FMT_FLAG_PLANAR)))
102 ff_add_format(&formats, fmt);
105 return ff_set_common_formats(ctx, formats);
108 static av_cold void uninit(AVFilterContext *ctx)
110 CropContext *s = ctx->priv;
112 av_expr_free(s->x_pexpr);
114 av_expr_free(s->y_pexpr);
118 static inline int normalize_double(int *n, double d)
123 ret = AVERROR(EINVAL);
124 } else if (d > INT_MAX || d < INT_MIN) {
125 *n = d > INT_MAX ? INT_MAX : INT_MIN;
126 ret = AVERROR(EINVAL);
133 static int config_input(AVFilterLink *link)
135 AVFilterContext *ctx = link->dst;
136 CropContext *s = ctx->priv;
137 const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
142 s->var_values[VAR_IN_W] = s->var_values[VAR_IW] = ctx->inputs[0]->w;
143 s->var_values[VAR_IN_H] = s->var_values[VAR_IH] = ctx->inputs[0]->h;
144 s->var_values[VAR_A] = (float) link->w / link->h;
145 s->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
146 s->var_values[VAR_DAR] = s->var_values[VAR_A] * s->var_values[VAR_SAR];
147 s->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
148 s->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
149 s->var_values[VAR_X] = NAN;
150 s->var_values[VAR_Y] = NAN;
151 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = NAN;
152 s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = NAN;
153 s->var_values[VAR_N] = 0;
154 s->var_values[VAR_T] = NAN;
155 s->var_values[VAR_POS] = NAN;
157 av_image_fill_max_pixsteps(s->max_step, NULL, pix_desc);
158 s->hsub = pix_desc->log2_chroma_w;
159 s->vsub = pix_desc->log2_chroma_h;
161 if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
162 var_names, s->var_values,
163 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
165 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
166 if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
167 var_names, s->var_values,
168 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
170 s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = res;
171 /* evaluate again ow as it may depend on oh */
172 if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
173 var_names, s->var_values,
174 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
177 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
178 if (normalize_double(&s->w, s->var_values[VAR_OUT_W]) < 0 ||
179 normalize_double(&s->h, s->var_values[VAR_OUT_H]) < 0) {
180 av_log(ctx, AV_LOG_ERROR,
181 "Too big value or invalid expression for out_w/ow or out_h/oh. "
182 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
183 s->w_expr, s->h_expr);
184 return AVERROR(EINVAL);
186 s->w &= ~((1 << s->hsub) - 1);
187 s->h &= ~((1 << s->vsub) - 1);
189 av_expr_free(s->x_pexpr);
190 av_expr_free(s->y_pexpr);
191 s->x_pexpr = s->y_pexpr = NULL;
192 if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
193 NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
194 (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
195 NULL, NULL, NULL, NULL, 0, ctx)) < 0)
196 return AVERROR(EINVAL);
198 if (s->keep_aspect) {
199 AVRational dar = av_mul_q(link->sample_aspect_ratio,
200 (AVRational){ link->w, link->h });
201 av_reduce(&s->out_sar.num, &s->out_sar.den,
202 dar.num * s->h, dar.den * s->w, INT_MAX);
204 s->out_sar = link->sample_aspect_ratio;
206 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
207 link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
208 s->w, s->h, s->out_sar.num, s->out_sar.den);
210 if (s->w <= 0 || s->h <= 0 ||
211 s->w > link->w || s->h > link->h) {
212 av_log(ctx, AV_LOG_ERROR,
213 "Invalid too big or non positive size for width '%d' or height '%d'\n",
215 return AVERROR(EINVAL);
218 /* set default, required in the case the first computed value for x/y is NAN */
219 s->x = (link->w - s->w) / 2;
220 s->y = (link->h - s->h) / 2;
221 s->x &= ~((1 << s->hsub) - 1);
222 s->y &= ~((1 << s->vsub) - 1);
226 av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
230 static int config_output(AVFilterLink *link)
232 CropContext *s = link->src->priv;
236 link->sample_aspect_ratio = s->out_sar;
241 static int filter_frame(AVFilterLink *link, AVFrame *frame)
243 AVFilterContext *ctx = link->dst;
244 CropContext *s = ctx->priv;
245 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
249 frame->height = s->h;
251 s->var_values[VAR_N] = link->frame_count;
252 s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
253 NAN : frame->pts * av_q2d(link->time_base);
254 s->var_values[VAR_POS] = av_frame_get_pkt_pos(frame) == -1 ?
255 NAN : av_frame_get_pkt_pos(frame);
256 s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
257 s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, NULL);
258 s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
260 normalize_double(&s->x, s->var_values[VAR_X]);
261 normalize_double(&s->y, s->var_values[VAR_Y]);
267 if ((unsigned)s->x + (unsigned)s->w > link->w)
268 s->x = link->w - s->w;
269 if ((unsigned)s->y + (unsigned)s->h > link->h)
270 s->y = link->h - s->h;
271 s->x &= ~((1 << s->hsub) - 1);
272 s->y &= ~((1 << s->vsub) - 1);
274 av_log(ctx, AV_LOG_TRACE, "n:%d t:%f pos:%f x:%d y:%d x+w:%d y+h:%d\n",
275 (int)s->var_values[VAR_N], s->var_values[VAR_T], s->var_values[VAR_POS],
276 s->x, s->y, s->x+s->w, s->y+s->h);
278 frame->data[0] += s->y * frame->linesize[0];
279 frame->data[0] += s->x * s->max_step[0];
281 if (!(desc->flags & AV_PIX_FMT_FLAG_PAL || desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL)) {
282 for (i = 1; i < 3; i ++) {
283 if (frame->data[i]) {
284 frame->data[i] += (s->y >> s->vsub) * frame->linesize[i];
285 frame->data[i] += (s->x * s->max_step[i]) >> s->hsub;
291 if (frame->data[3]) {
292 frame->data[3] += s->y * frame->linesize[3];
293 frame->data[3] += s->x * s->max_step[3];
296 return ff_filter_frame(link->dst->outputs[0], frame);
299 #define OFFSET(x) offsetof(CropContext, x)
300 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
302 static const AVOption crop_options[] = {
303 { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
304 { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
305 { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
306 { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
307 { "x", "set the x crop area expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "(in_w-out_w)/2"}, CHAR_MIN, CHAR_MAX, FLAGS },
308 { "y", "set the y crop area expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "(in_h-out_h)/2"}, CHAR_MIN, CHAR_MAX, FLAGS },
309 { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
313 AVFILTER_DEFINE_CLASS(crop);
315 static const AVFilterPad avfilter_vf_crop_inputs[] = {
318 .type = AVMEDIA_TYPE_VIDEO,
319 .filter_frame = filter_frame,
320 .config_props = config_input,
325 static const AVFilterPad avfilter_vf_crop_outputs[] = {
328 .type = AVMEDIA_TYPE_VIDEO,
329 .config_props = config_output,
334 AVFilter ff_vf_crop = {
336 .description = NULL_IF_CONFIG_SMALL("Crop the input video."),
337 .priv_size = sizeof(CropContext),
338 .priv_class = &crop_class,
339 .query_formats = query_formats,
341 .inputs = avfilter_vf_crop_inputs,
342 .outputs = avfilter_vf_crop_outputs,