1/* 2 * Copyright (c) 2007 Bobby Bingham 3 * 4 * This file is part of FFmpeg. 5 * 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. 10 * 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. 15 * 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 19 */ 20 21/** 22 * @file 23 * video crop filter 24 */ 25 26#include <stdio.h> 27 28#include "avfilter.h" 29#include "formats.h" 30#include "internal.h" 31#include "video.h" 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" 39 40static 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 45 "a", 46 "sar", 47 "dar", 48 "hsub", 49 "vsub", 50 "x", 51 "y", 52 "n", ///< number of frame 53 "pos", ///< position in the file 54 "t", ///< timestamp expressed in seconds 55 NULL 56}; 57 58enum var_name { 59 VAR_IN_W, VAR_IW, 60 VAR_IN_H, VAR_IH, 61 VAR_OUT_W, VAR_OW, 62 VAR_OUT_H, VAR_OH, 63 VAR_A, 64 VAR_SAR, 65 VAR_DAR, 66 VAR_HSUB, 67 VAR_VSUB, 68 VAR_X, 69 VAR_Y, 70 VAR_N, 71 VAR_POS, 72 VAR_T, 73 VAR_VARS_NB 74}; 75 76typedef struct CropContext { 77 const AVClass *class; 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 82 83 AVRational out_sar; ///< output sample aspect ratio 84 int keep_aspect; ///< keep display aspect ratio when cropping 85 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]; 91} CropContext; 92 93static int query_formats(AVFilterContext *ctx) 94{ 95 AVFilterFormats *formats = NULL; 96 int fmt; 97 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); 103 } 104 105 ff_set_common_formats(ctx, formats); 106 return 0; 107} 108 109static av_cold void uninit(AVFilterContext *ctx) 110{ 111 CropContext *s = ctx->priv; 112 113 av_expr_free(s->x_pexpr); 114 s->x_pexpr = NULL; 115 av_expr_free(s->y_pexpr); 116 s->y_pexpr = NULL; 117} 118 119static inline int normalize_double(int *n, double d) 120{ 121 int ret = 0; 122 123 if (isnan(d)) { 124 ret = AVERROR(EINVAL); 125 } else if (d > INT_MAX || d < INT_MIN) { 126 *n = d > INT_MAX ? INT_MAX : INT_MIN; 127 ret = AVERROR(EINVAL); 128 } else 129 *n = round(d); 130 131 return ret; 132} 133 134static int config_input(AVFilterLink *link) 135{ 136 AVFilterContext *ctx = link->dst; 137 CropContext *s = ctx->priv; 138 const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format); 139 int ret; 140 const char *expr; 141 double res; 142 143 s->var_values[VAR_IN_W] = s->var_values[VAR_IW] = ctx->inputs[0]->w; 144 s->var_values[VAR_IN_H] = s->var_values[VAR_IH] = ctx->inputs[0]->h; 145 s->var_values[VAR_A] = (float) link->w / link->h; 146 s->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1; 147 s->var_values[VAR_DAR] = s->var_values[VAR_A] * s->var_values[VAR_SAR]; 148 s->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w; 149 s->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h; 150 s->var_values[VAR_X] = NAN; 151 s->var_values[VAR_Y] = NAN; 152 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = NAN; 153 s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = NAN; 154 s->var_values[VAR_N] = 0; 155 s->var_values[VAR_T] = NAN; 156 s->var_values[VAR_POS] = NAN; 157 158 av_image_fill_max_pixsteps(s->max_step, NULL, pix_desc); 159 s->hsub = pix_desc->log2_chroma_w; 160 s->vsub = pix_desc->log2_chroma_h; 161 162 if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr), 163 var_names, s->var_values, 164 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) 165 goto fail_expr; 166 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res; 167 if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr), 168 var_names, s->var_values, 169 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) 170 goto fail_expr; 171 s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = res; 172 /* evaluate again ow as it may depend on oh */ 173 if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr), 174 var_names, s->var_values, 175 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) 176 goto fail_expr; 177 178 s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res; 179 if (normalize_double(&s->w, s->var_values[VAR_OUT_W]) < 0 || 180 normalize_double(&s->h, s->var_values[VAR_OUT_H]) < 0) { 181 av_log(ctx, AV_LOG_ERROR, 182 "Too big value or invalid expression for out_w/ow or out_h/oh. " 183 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n", 184 s->w_expr, s->h_expr); 185 return AVERROR(EINVAL); 186 } 187 s->w &= ~((1 << s->hsub) - 1); 188 s->h &= ~((1 << s->vsub) - 1); 189 190 av_expr_free(s->x_pexpr); 191 av_expr_free(s->y_pexpr); 192 s->x_pexpr = s->y_pexpr = NULL; 193 if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names, 194 NULL, NULL, NULL, NULL, 0, ctx)) < 0 || 195 (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names, 196 NULL, NULL, NULL, NULL, 0, ctx)) < 0) 197 return AVERROR(EINVAL); 198 199 if (s->keep_aspect) { 200 AVRational dar = av_mul_q(link->sample_aspect_ratio, 201 (AVRational){ link->w, link->h }); 202 av_reduce(&s->out_sar.num, &s->out_sar.den, 203 dar.num * s->h, dar.den * s->w, INT_MAX); 204 } else 205 s->out_sar = link->sample_aspect_ratio; 206 207 av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n", 208 link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den, 209 s->w, s->h, s->out_sar.num, s->out_sar.den); 210 211 if (s->w <= 0 || s->h <= 0 || 212 s->w > link->w || s->h > link->h) { 213 av_log(ctx, AV_LOG_ERROR, 214 "Invalid too big or non positive size for width '%d' or height '%d'\n", 215 s->w, s->h); 216 return AVERROR(EINVAL); 217 } 218 219 /* set default, required in the case the first computed value for x/y is NAN */ 220 s->x = (link->w - s->w) / 2; 221 s->y = (link->h - s->h) / 2; 222 s->x &= ~((1 << s->hsub) - 1); 223 s->y &= ~((1 << s->vsub) - 1); 224 return 0; 225 226fail_expr: 227 av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr); 228 return ret; 229} 230 231static int config_output(AVFilterLink *link) 232{ 233 CropContext *s = link->src->priv; 234 235 link->w = s->w; 236 link->h = s->h; 237 link->sample_aspect_ratio = s->out_sar; 238 239 return 0; 240} 241 242static int filter_frame(AVFilterLink *link, AVFrame *frame) 243{ 244 AVFilterContext *ctx = link->dst; 245 CropContext *s = ctx->priv; 246 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format); 247 int i; 248 249 frame->width = s->w; 250 frame->height = s->h; 251 252 s->var_values[VAR_N] = link->frame_count; 253 s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ? 254 NAN : frame->pts * av_q2d(link->time_base); 255 s->var_values[VAR_POS] = av_frame_get_pkt_pos(frame) == -1 ? 256 NAN : av_frame_get_pkt_pos(frame); 257 s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL); 258 s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, NULL); 259 s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL); 260 261 normalize_double(&s->x, s->var_values[VAR_X]); 262 normalize_double(&s->y, s->var_values[VAR_Y]); 263 264 if (s->x < 0) 265 s->x = 0; 266 if (s->y < 0) 267 s->y = 0; 268 if ((unsigned)s->x + (unsigned)s->w > link->w) 269 s->x = link->w - s->w; 270 if ((unsigned)s->y + (unsigned)s->h > link->h) 271 s->y = link->h - s->h; 272 s->x &= ~((1 << s->hsub) - 1); 273 s->y &= ~((1 << s->vsub) - 1); 274 275 av_dlog(ctx, "n:%d t:%f pos:%f x:%d y:%d x+w:%d y+h:%d\n", 276 (int)s->var_values[VAR_N], s->var_values[VAR_T], s->var_values[VAR_POS], 277 s->x, s->y, s->x+s->w, s->y+s->h); 278 279 frame->data[0] += s->y * frame->linesize[0]; 280 frame->data[0] += s->x * s->max_step[0]; 281 282 if (!(desc->flags & AV_PIX_FMT_FLAG_PAL || desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL)) { 283 for (i = 1; i < 3; i ++) { 284 if (frame->data[i]) { 285 frame->data[i] += (s->y >> s->vsub) * frame->linesize[i]; 286 frame->data[i] += (s->x * s->max_step[i]) >> s->hsub; 287 } 288 } 289 } 290 291 /* alpha plane */ 292 if (frame->data[3]) { 293 frame->data[3] += s->y * frame->linesize[3]; 294 frame->data[3] += s->x * s->max_step[3]; 295 } 296 297 return ff_filter_frame(link->dst->outputs[0], frame); 298} 299 300#define OFFSET(x) offsetof(CropContext, x) 301#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM 302 303static const AVOption crop_options[] = { 304 { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS }, 305 { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS }, 306 { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS }, 307 { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS }, 308 { "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 }, 309 { "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 }, 310 { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS }, 311 { NULL } 312}; 313 314AVFILTER_DEFINE_CLASS(crop); 315 316static const AVFilterPad avfilter_vf_crop_inputs[] = { 317 { 318 .name = "default", 319 .type = AVMEDIA_TYPE_VIDEO, 320 .filter_frame = filter_frame, 321 .config_props = config_input, 322 }, 323 { NULL } 324}; 325 326static const AVFilterPad avfilter_vf_crop_outputs[] = { 327 { 328 .name = "default", 329 .type = AVMEDIA_TYPE_VIDEO, 330 .config_props = config_output, 331 }, 332 { NULL } 333}; 334 335AVFilter ff_vf_crop = { 336 .name = "crop", 337 .description = NULL_IF_CONFIG_SMALL("Crop the input video."), 338 .priv_size = sizeof(CropContext), 339 .priv_class = &crop_class, 340 .query_formats = query_formats, 341 .uninit = uninit, 342 .inputs = avfilter_vf_crop_inputs, 343 .outputs = avfilter_vf_crop_outputs, 344}; 345