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
85 int exact; ///< exact cropping, for subsampled formats
87 int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
88 int hsub, vsub; ///< chroma subsampling
89 char *x_expr, *y_expr, *w_expr, *h_expr;
90 AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */
91 double var_values[VAR_VARS_NB];
94 static int query_formats(AVFilterContext *ctx)
96 AVFilterFormats *formats = NULL;
99 for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
100 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
101 if (!(desc->flags & (AV_PIX_FMT_FLAG_HWACCEL | AV_PIX_FMT_FLAG_BITSTREAM)) &&
102 !((desc->log2_chroma_w || desc->log2_chroma_h) && !(desc->flags & AV_PIX_FMT_FLAG_PLANAR)) &&
103 (ret = ff_add_format(&formats, fmt)) < 0)
107 return ff_set_common_formats(ctx, formats);
110 static av_cold void uninit(AVFilterContext *ctx)
112 CropContext *s = ctx->priv;
114 av_expr_free(s->x_pexpr);
116 av_expr_free(s->y_pexpr);
120 static inline int normalize_double(int *n, double d)
125 ret = AVERROR(EINVAL);
126 } else if (d > INT_MAX || d < INT_MIN) {
127 *n = d > INT_MAX ? INT_MAX : INT_MIN;
128 ret = AVERROR(EINVAL);
135 static int config_input(AVFilterLink *link)
137 AVFilterContext *ctx = link->dst;
138 CropContext *s = ctx->priv;
139 const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
144 s->var_values[VAR_IN_W] = s->var_values[VAR_IW] = ctx->inputs[0]->w;
145 s->var_values[VAR_IN_H] = s->var_values[VAR_IH] = ctx->inputs[0]->h;
146 s->var_values[VAR_A] = (float) link->w / link->h;
147 s->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
148 s->var_values[VAR_DAR] = s->var_values[VAR_A] * s->var_values[VAR_SAR];
149 s->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
150 s->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
151 s->var_values[VAR_X] = NAN;
152 s->var_values[VAR_Y] = NAN;
153 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = NAN;
154 s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = NAN;
155 s->var_values[VAR_N] = 0;
156 s->var_values[VAR_T] = NAN;
157 s->var_values[VAR_POS] = NAN;
159 av_image_fill_max_pixsteps(s->max_step, NULL, pix_desc);
160 s->hsub = pix_desc->log2_chroma_w;
161 s->vsub = pix_desc->log2_chroma_h;
163 if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
164 var_names, s->var_values,
165 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
167 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
168 if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
169 var_names, s->var_values,
170 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
172 s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = res;
173 /* evaluate again ow as it may depend on oh */
174 if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
175 var_names, s->var_values,
176 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
179 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
180 if (normalize_double(&s->w, s->var_values[VAR_OUT_W]) < 0 ||
181 normalize_double(&s->h, s->var_values[VAR_OUT_H]) < 0) {
182 av_log(ctx, AV_LOG_ERROR,
183 "Too big value or invalid expression for out_w/ow or out_h/oh. "
184 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
185 s->w_expr, s->h_expr);
186 return AVERROR(EINVAL);
190 s->w &= ~((1 << s->hsub) - 1);
191 s->h &= ~((1 << s->vsub) - 1);
194 av_expr_free(s->x_pexpr);
195 av_expr_free(s->y_pexpr);
196 s->x_pexpr = s->y_pexpr = NULL;
197 if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
198 NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
199 (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
200 NULL, NULL, NULL, NULL, 0, ctx)) < 0)
201 return AVERROR(EINVAL);
203 if (s->keep_aspect) {
204 AVRational dar = av_mul_q(link->sample_aspect_ratio,
205 (AVRational){ link->w, link->h });
206 av_reduce(&s->out_sar.num, &s->out_sar.den,
207 dar.num * s->h, dar.den * s->w, INT_MAX);
209 s->out_sar = link->sample_aspect_ratio;
211 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
212 link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
213 s->w, s->h, s->out_sar.num, s->out_sar.den);
215 if (s->w <= 0 || s->h <= 0 ||
216 s->w > link->w || s->h > link->h) {
217 av_log(ctx, AV_LOG_ERROR,
218 "Invalid too big or non positive size for width '%d' or height '%d'\n",
220 return AVERROR(EINVAL);
223 /* set default, required in the case the first computed value for x/y is NAN */
224 s->x = (link->w - s->w) / 2;
225 s->y = (link->h - s->h) / 2;
227 s->x &= ~((1 << s->hsub) - 1);
228 s->y &= ~((1 << s->vsub) - 1);
233 av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
237 static int config_output(AVFilterLink *link)
239 CropContext *s = link->src->priv;
243 link->sample_aspect_ratio = s->out_sar;
248 static int filter_frame(AVFilterLink *link, AVFrame *frame)
250 AVFilterContext *ctx = link->dst;
251 CropContext *s = ctx->priv;
252 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
256 frame->height = s->h;
258 s->var_values[VAR_N] = link->frame_count_out;
259 s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
260 NAN : frame->pts * av_q2d(link->time_base);
261 s->var_values[VAR_POS] = frame->pkt_pos == -1 ?
262 NAN : frame->pkt_pos;
263 s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
264 s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, NULL);
265 /* It is necessary if x is expressed from y */
266 s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
268 normalize_double(&s->x, s->var_values[VAR_X]);
269 normalize_double(&s->y, s->var_values[VAR_Y]);
275 if ((unsigned)s->x + (unsigned)s->w > link->w)
276 s->x = link->w - s->w;
277 if ((unsigned)s->y + (unsigned)s->h > link->h)
278 s->y = link->h - s->h;
280 s->x &= ~((1 << s->hsub) - 1);
281 s->y &= ~((1 << s->vsub) - 1);
284 av_log(ctx, AV_LOG_TRACE, "n:%d t:%f pos:%f x:%d y:%d x+w:%d y+h:%d\n",
285 (int)s->var_values[VAR_N], s->var_values[VAR_T], s->var_values[VAR_POS],
286 s->x, s->y, s->x+s->w, s->y+s->h);
288 frame->data[0] += s->y * frame->linesize[0];
289 frame->data[0] += s->x * s->max_step[0];
291 if (!(desc->flags & AV_PIX_FMT_FLAG_PAL || desc->flags & FF_PSEUDOPAL)) {
292 for (i = 1; i < 3; i ++) {
293 if (frame->data[i]) {
294 frame->data[i] += (s->y >> s->vsub) * frame->linesize[i];
295 frame->data[i] += (s->x * s->max_step[i]) >> s->hsub;
301 if (frame->data[3]) {
302 frame->data[3] += s->y * frame->linesize[3];
303 frame->data[3] += s->x * s->max_step[3];
306 return ff_filter_frame(link->dst->outputs[0], frame);
309 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
310 char *res, int res_len, int flags)
312 CropContext *s = ctx->priv;
315 if ( !strcmp(cmd, "out_w") || !strcmp(cmd, "w")
316 || !strcmp(cmd, "out_h") || !strcmp(cmd, "h")
317 || !strcmp(cmd, "x") || !strcmp(cmd, "y")) {
324 AVFilterLink *outlink = ctx->outputs[0];
325 AVFilterLink *inlink = ctx->inputs[0];
327 av_opt_set(s, cmd, args, 0);
329 if ((ret = config_input(inlink)) < 0) {
337 ret = config_output(outlink);
340 ret = AVERROR(ENOSYS);
345 #define OFFSET(x) offsetof(CropContext, x)
346 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
348 static const AVOption crop_options[] = {
349 { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
350 { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
351 { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
352 { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
353 { "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 },
354 { "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 },
355 { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
356 { "exact", "do exact cropping", OFFSET(exact), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
360 AVFILTER_DEFINE_CLASS(crop);
362 static const AVFilterPad avfilter_vf_crop_inputs[] = {
365 .type = AVMEDIA_TYPE_VIDEO,
366 .filter_frame = filter_frame,
367 .config_props = config_input,
372 static const AVFilterPad avfilter_vf_crop_outputs[] = {
375 .type = AVMEDIA_TYPE_VIDEO,
376 .config_props = config_output,
381 AVFilter ff_vf_crop = {
383 .description = NULL_IF_CONFIG_SMALL("Crop the input video."),
384 .priv_size = sizeof(CropContext),
385 .priv_class = &crop_class,
386 .query_formats = query_formats,
388 .inputs = avfilter_vf_crop_inputs,
389 .outputs = avfilter_vf_crop_outputs,
390 .process_command = process_command,