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
34 #include "libavutil/eval.h"
35 #include "libavutil/avstring.h"
36 #include "libavutil/internal.h"
37 #include "libavutil/libm.h"
38 #include "libavutil/imgutils.h"
39 #include "libavutil/mathematics.h"
40 #include "libavutil/opt.h"
42 static const char *const var_names[] = {
43 "in_w", "iw", ///< width of the input video
44 "in_h", "ih", ///< height of the input video
45 "out_w", "ow", ///< width of the cropped video
46 "out_h", "oh", ///< height of the cropped video
54 "n", ///< number of frame
55 "pos", ///< position in the file
56 "t", ///< timestamp expressed in seconds
80 int x; ///< x offset of the non-cropped area with respect to the input area
81 int y; ///< y offset of the non-cropped area with respect to the input area
82 int w; ///< width of the cropped area
83 int h; ///< height of the cropped area
85 AVRational out_sar; ///< output sample aspect ratio
86 int keep_aspect; ///< keep display aspect ratio when cropping
88 int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
89 int hsub, vsub; ///< chroma subsampling
90 char *x_expr, *y_expr, *w_expr, *h_expr;
91 AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */
92 double var_values[VAR_VARS_NB];
95 #define OFFSET(x) offsetof(CropContext, x)
96 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
98 static const AVOption crop_options[] = {
99 { "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 },
100 { "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 },
101 { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
102 { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
103 { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
104 { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
105 { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
109 AVFILTER_DEFINE_CLASS(crop);
111 static av_cold int init(AVFilterContext *ctx, const char *args)
113 CropContext *crop = ctx->priv;
114 static const char *shorthand[] = { "w", "h", "x", "y", "keep_aspect", NULL };
116 crop->class = &crop_class;
117 av_opt_set_defaults(crop);
119 return av_opt_set_from_string(crop, args, shorthand, "=", ":");
122 static av_cold void uninit(AVFilterContext *ctx)
124 CropContext *crop = ctx->priv;
126 av_expr_free(crop->x_pexpr); crop->x_pexpr = NULL;
127 av_expr_free(crop->y_pexpr); crop->y_pexpr = NULL;
131 static int query_formats(AVFilterContext *ctx)
133 static const enum AVPixelFormat pix_fmts[] = {
134 AV_PIX_FMT_RGB48BE, AV_PIX_FMT_RGB48LE,
135 AV_PIX_FMT_BGR48BE, AV_PIX_FMT_BGR48LE,
136 AV_PIX_FMT_ARGB, AV_PIX_FMT_RGBA,
137 AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA,
138 AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
139 AV_PIX_FMT_RGB565BE, AV_PIX_FMT_RGB565LE,
140 AV_PIX_FMT_RGB555BE, AV_PIX_FMT_RGB555LE,
141 AV_PIX_FMT_BGR565BE, AV_PIX_FMT_BGR565LE,
142 AV_PIX_FMT_BGR555BE, AV_PIX_FMT_BGR555LE,
143 AV_PIX_FMT_GRAY16BE, AV_PIX_FMT_GRAY16LE,
144 AV_PIX_FMT_YUV420P16LE, AV_PIX_FMT_YUV420P16BE,
145 AV_PIX_FMT_YUV422P16LE, AV_PIX_FMT_YUV422P16BE,
146 AV_PIX_FMT_YUV444P16LE, AV_PIX_FMT_YUV444P16BE,
147 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P,
148 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P,
149 AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
150 AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P,
151 AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ440P,
153 AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8,
154 AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE,
155 AV_PIX_FMT_PAL8, AV_PIX_FMT_GRAY8,
159 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
164 static inline int normalize_double(int *n, double d)
169 ret = AVERROR(EINVAL);
170 } else if (d > INT_MAX || d < INT_MIN) {
171 *n = d > INT_MAX ? INT_MAX : INT_MIN;
172 ret = AVERROR(EINVAL);
179 static int config_input(AVFilterLink *link)
181 AVFilterContext *ctx = link->dst;
182 CropContext *crop = ctx->priv;
183 const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
188 crop->var_values[VAR_IN_W] = crop->var_values[VAR_IW] = ctx->inputs[0]->w;
189 crop->var_values[VAR_IN_H] = crop->var_values[VAR_IH] = ctx->inputs[0]->h;
190 crop->var_values[VAR_A] = (float) link->w / link->h;
191 crop->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
192 crop->var_values[VAR_DAR] = crop->var_values[VAR_A] * crop->var_values[VAR_SAR];
193 crop->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
194 crop->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
195 crop->var_values[VAR_X] = NAN;
196 crop->var_values[VAR_Y] = NAN;
197 crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = NAN;
198 crop->var_values[VAR_OUT_H] = crop->var_values[VAR_OH] = NAN;
199 crop->var_values[VAR_N] = 0;
200 crop->var_values[VAR_T] = NAN;
201 crop->var_values[VAR_POS] = NAN;
203 av_image_fill_max_pixsteps(crop->max_step, NULL, pix_desc);
204 crop->hsub = pix_desc->log2_chroma_w;
205 crop->vsub = pix_desc->log2_chroma_h;
207 if ((ret = av_expr_parse_and_eval(&res, (expr = crop->w_expr),
208 var_names, crop->var_values,
209 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
210 crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = res;
211 if ((ret = av_expr_parse_and_eval(&res, (expr = crop->h_expr),
212 var_names, crop->var_values,
213 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
214 crop->var_values[VAR_OUT_H] = crop->var_values[VAR_OH] = res;
215 /* evaluate again ow as it may depend on oh */
216 if ((ret = av_expr_parse_and_eval(&res, (expr = crop->w_expr),
217 var_names, crop->var_values,
218 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
219 crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = res;
220 if (normalize_double(&crop->w, crop->var_values[VAR_OUT_W]) < 0 ||
221 normalize_double(&crop->h, crop->var_values[VAR_OUT_H]) < 0) {
222 av_log(ctx, AV_LOG_ERROR,
223 "Too big value or invalid expression for out_w/ow or out_h/oh. "
224 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
225 crop->w_expr, crop->h_expr);
226 return AVERROR(EINVAL);
228 crop->w &= ~((1 << crop->hsub) - 1);
229 crop->h &= ~((1 << crop->vsub) - 1);
231 if ((ret = av_expr_parse(&crop->x_pexpr, crop->x_expr, var_names,
232 NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
233 (ret = av_expr_parse(&crop->y_pexpr, crop->y_expr, var_names,
234 NULL, NULL, NULL, NULL, 0, ctx)) < 0)
235 return AVERROR(EINVAL);
237 if (crop->keep_aspect) {
238 AVRational dar = av_mul_q(link->sample_aspect_ratio,
239 (AVRational){ link->w, link->h });
240 av_reduce(&crop->out_sar.num, &crop->out_sar.den,
241 dar.num * crop->h, dar.den * crop->w, INT_MAX);
243 crop->out_sar = link->sample_aspect_ratio;
245 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
246 link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
247 crop->w, crop->h, crop->out_sar.num, crop->out_sar.den);
249 if (crop->w <= 0 || crop->h <= 0 ||
250 crop->w > link->w || crop->h > link->h) {
251 av_log(ctx, AV_LOG_ERROR,
252 "Invalid too big or non positive size for width '%d' or height '%d'\n",
254 return AVERROR(EINVAL);
257 /* set default, required in the case the first computed value for x/y is NAN */
258 crop->x = (link->w - crop->w) / 2;
259 crop->y = (link->h - crop->h) / 2;
260 crop->x &= ~((1 << crop->hsub) - 1);
261 crop->y &= ~((1 << crop->vsub) - 1);
265 av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
269 static int config_output(AVFilterLink *link)
271 CropContext *crop = link->src->priv;
275 link->sample_aspect_ratio = crop->out_sar;
280 static int filter_frame(AVFilterLink *link, AVFilterBufferRef *frame)
282 AVFilterContext *ctx = link->dst;
283 CropContext *crop = ctx->priv;
284 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
287 frame->video->w = crop->w;
288 frame->video->h = crop->h;
290 crop->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
291 NAN : frame->pts * av_q2d(link->time_base);
292 crop->var_values[VAR_POS] = frame->pos == -1 ? NAN : frame->pos;
293 crop->var_values[VAR_X] = av_expr_eval(crop->x_pexpr, crop->var_values, NULL);
294 crop->var_values[VAR_Y] = av_expr_eval(crop->y_pexpr, crop->var_values, NULL);
295 crop->var_values[VAR_X] = av_expr_eval(crop->x_pexpr, crop->var_values, NULL);
297 normalize_double(&crop->x, crop->var_values[VAR_X]);
298 normalize_double(&crop->y, crop->var_values[VAR_Y]);
300 if (crop->x < 0) crop->x = 0;
301 if (crop->y < 0) crop->y = 0;
302 if ((unsigned)crop->x + (unsigned)crop->w > link->w) crop->x = link->w - crop->w;
303 if ((unsigned)crop->y + (unsigned)crop->h > link->h) crop->y = link->h - crop->h;
304 crop->x &= ~((1 << crop->hsub) - 1);
305 crop->y &= ~((1 << crop->vsub) - 1);
307 av_dlog(ctx, "n:%d t:%f x:%d y:%d x+w:%d y+h:%d\n",
308 (int)crop->var_values[VAR_N], crop->var_values[VAR_T], crop->x,
309 crop->y, crop->x+crop->w, crop->y+crop->h);
311 frame->data[0] += crop->y * frame->linesize[0];
312 frame->data[0] += crop->x * crop->max_step[0];
314 if (!(desc->flags & PIX_FMT_PAL || desc->flags & PIX_FMT_PSEUDOPAL)) {
315 for (i = 1; i < 3; i ++) {
316 if (frame->data[i]) {
317 frame->data[i] += (crop->y >> crop->vsub) * frame->linesize[i];
318 frame->data[i] += (crop->x * crop->max_step[i]) >> crop->hsub;
324 if (frame->data[3]) {
325 frame->data[3] += crop->y * frame->linesize[3];
326 frame->data[3] += crop->x * crop->max_step[3];
329 crop->var_values[VAR_N] += 1.0;
331 return ff_filter_frame(link->dst->outputs[0], frame);
334 static const AVFilterPad avfilter_vf_crop_inputs[] = {
337 .type = AVMEDIA_TYPE_VIDEO,
338 .filter_frame = filter_frame,
339 .get_video_buffer = ff_null_get_video_buffer,
340 .config_props = config_input,
345 static const AVFilterPad avfilter_vf_crop_outputs[] = {
348 .type = AVMEDIA_TYPE_VIDEO,
349 .config_props = config_output,
354 AVFilter avfilter_vf_crop = {
356 .description = NULL_IF_CONFIG_SMALL("Crop the input video to width:height:x:y."),
358 .priv_size = sizeof(CropContext),
360 .query_formats = query_formats,
364 .inputs = avfilter_vf_crop_inputs,
365 .outputs = avfilter_vf_crop_outputs,
366 .priv_class = &crop_class,