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vf_pad.c
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1 /*
2  * Copyright (c) 2008 vmrsss
3  * Copyright (c) 2009 Stefano Sabatini
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * video padding filter
25  */
26 
27 #include "avfilter.h"
28 #include "formats.h"
29 #include "internal.h"
30 #include "video.h"
31 #include "libavutil/avstring.h"
32 #include "libavutil/common.h"
33 #include "libavutil/eval.h"
34 #include "libavutil/pixdesc.h"
35 #include "libavutil/colorspace.h"
36 #include "libavutil/avassert.h"
37 #include "libavutil/imgutils.h"
38 #include "libavutil/parseutils.h"
39 #include "libavutil/mathematics.h"
40 #include "libavutil/opt.h"
41 
42 #include "drawutils.h"
43 
44 static const char *const var_names[] = {
45  "in_w", "iw",
46  "in_h", "ih",
47  "out_w", "ow",
48  "out_h", "oh",
49  "x",
50  "y",
51  "a",
52  "sar",
53  "dar",
54  "hsub",
55  "vsub",
56  NULL
57 };
58 
59 enum var_name {
72 };
73 
75 {
77 }
78 
79 typedef struct PadContext {
80  const AVClass *class;
81  int w, h; ///< output dimensions, a value of 0 will result in the input size
82  int x, y; ///< offsets of the input area with respect to the padded area
83  int in_w, in_h; ///< width and height for the padded input video, which has to be aligned to the chroma values in order to avoid chroma issues
84 
85  char *w_expr; ///< width expression string
86  char *h_expr; ///< height expression string
87  char *x_expr; ///< width expression string
88  char *y_expr; ///< height expression string
89  uint8_t rgba_color[4]; ///< color for the padding area
92 } PadContext;
93 
94 static int config_input(AVFilterLink *inlink)
95 {
96  AVFilterContext *ctx = inlink->dst;
97  PadContext *s = ctx->priv;
98  int ret;
99  double var_values[VARS_NB], res;
100  char *expr;
101 
102  ff_draw_init(&s->draw, inlink->format, 0);
103  ff_draw_color(&s->draw, &s->color, s->rgba_color);
104 
105  var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
106  var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
107  var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
108  var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
109  var_values[VAR_A] = (double) inlink->w / inlink->h;
110  var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
111  (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
112  var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
113  var_values[VAR_HSUB] = 1 << s->draw.hsub_max;
114  var_values[VAR_VSUB] = 1 << s->draw.vsub_max;
115 
116  /* evaluate width and height */
117  av_expr_parse_and_eval(&res, (expr = s->w_expr),
118  var_names, var_values,
119  NULL, NULL, NULL, NULL, NULL, 0, ctx);
120  s->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
121  if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
122  var_names, var_values,
123  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
124  goto eval_fail;
125  s->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
126  /* evaluate the width again, as it may depend on the evaluated output height */
127  if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
128  var_names, var_values,
129  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
130  goto eval_fail;
131  s->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
132 
133  /* evaluate x and y */
134  av_expr_parse_and_eval(&res, (expr = s->x_expr),
135  var_names, var_values,
136  NULL, NULL, NULL, NULL, NULL, 0, ctx);
137  s->x = var_values[VAR_X] = res;
138  if ((ret = av_expr_parse_and_eval(&res, (expr = s->y_expr),
139  var_names, var_values,
140  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
141  goto eval_fail;
142  s->y = var_values[VAR_Y] = res;
143  /* evaluate x again, as it may depend on the evaluated y value */
144  if ((ret = av_expr_parse_and_eval(&res, (expr = s->x_expr),
145  var_names, var_values,
146  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
147  goto eval_fail;
148  s->x = var_values[VAR_X] = res;
149 
150  /* sanity check params */
151  if (s->w < 0 || s->h < 0 || s->x < 0 || s->y < 0) {
152  av_log(ctx, AV_LOG_ERROR, "Negative values are not acceptable.\n");
153  return AVERROR(EINVAL);
154  }
155 
156  if (!s->w)
157  s->w = inlink->w;
158  if (!s->h)
159  s->h = inlink->h;
160 
161  s->w = ff_draw_round_to_sub(&s->draw, 0, -1, s->w);
162  s->h = ff_draw_round_to_sub(&s->draw, 1, -1, s->h);
163  s->x = ff_draw_round_to_sub(&s->draw, 0, -1, s->x);
164  s->y = ff_draw_round_to_sub(&s->draw, 1, -1, s->y);
165  s->in_w = ff_draw_round_to_sub(&s->draw, 0, -1, inlink->w);
166  s->in_h = ff_draw_round_to_sub(&s->draw, 1, -1, inlink->h);
167 
168  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d -> w:%d h:%d x:%d y:%d color:0x%02X%02X%02X%02X\n",
169  inlink->w, inlink->h, s->w, s->h, s->x, s->y,
170  s->rgba_color[0], s->rgba_color[1], s->rgba_color[2], s->rgba_color[3]);
171 
172  if (s->x < 0 || s->y < 0 ||
173  s->w <= 0 || s->h <= 0 ||
174  (unsigned)s->x + (unsigned)inlink->w > s->w ||
175  (unsigned)s->y + (unsigned)inlink->h > s->h) {
176  av_log(ctx, AV_LOG_ERROR,
177  "Input area %d:%d:%d:%d not within the padded area 0:0:%d:%d or zero-sized\n",
178  s->x, s->y, s->x + inlink->w, s->y + inlink->h, s->w, s->h);
179  return AVERROR(EINVAL);
180  }
181 
182  return 0;
183 
184 eval_fail:
186  "Error when evaluating the expression '%s'\n", expr);
187  return ret;
188 
189 }
190 
191 static int config_output(AVFilterLink *outlink)
192 {
193  PadContext *s = outlink->src->priv;
194 
195  outlink->w = s->w;
196  outlink->h = s->h;
197  return 0;
198 }
199 
200 static AVFrame *get_video_buffer(AVFilterLink *inlink, int w, int h)
201 {
202  PadContext *s = inlink->dst->priv;
203 
205  w + (s->w - s->in_w),
206  h + (s->h - s->in_h));
207  int plane;
208 
209  if (!frame)
210  return NULL;
211 
212  frame->width = w;
213  frame->height = h;
214 
215  for (plane = 0; plane < 4 && frame->data[plane] && frame->linesize[plane]; plane++) {
216  int hsub = s->draw.hsub[plane];
217  int vsub = s->draw.vsub[plane];
218  frame->data[plane] += (s->x >> hsub) * s->draw.pixelstep[plane] +
219  (s->y >> vsub) * frame->linesize[plane];
220  }
221 
222  return frame;
223 }
224 
225 /* check whether each plane in this buffer can be padded without copying */
227 {
228  int planes[4] = { -1, -1, -1, -1}, *p = planes;
229  int i, j;
230 
231  /* get all planes in this buffer */
232  for (i = 0; i < FF_ARRAY_ELEMS(planes) && frame->data[i]; i++) {
233  if (av_frame_get_plane_buffer(frame, i) == buf)
234  *p++ = i;
235  }
236 
237  /* for each plane in this buffer, check that it can be padded without
238  * going over buffer bounds or other planes */
239  for (i = 0; i < FF_ARRAY_ELEMS(planes) && planes[i] >= 0; i++) {
240  int hsub = s->draw.hsub[planes[i]];
241  int vsub = s->draw.vsub[planes[i]];
242 
243  uint8_t *start = frame->data[planes[i]];
244  uint8_t *end = start + (frame->height >> vsub) *
245  frame->linesize[planes[i]];
246 
247  /* amount of free space needed before the start and after the end
248  * of the plane */
249  ptrdiff_t req_start = (s->x >> hsub) * s->draw.pixelstep[planes[i]] +
250  (s->y >> vsub) * frame->linesize[planes[i]];
251  ptrdiff_t req_end = ((s->w - s->x - frame->width) >> hsub) *
252  s->draw.pixelstep[planes[i]] +
253  ((s->h - s->y - frame->height) >> vsub) * frame->linesize[planes[i]];
254 
255  if (frame->linesize[planes[i]] < (s->w >> hsub) * s->draw.pixelstep[planes[i]])
256  return 1;
257  if (start - buf->data < req_start ||
258  (buf->data + buf->size) - end < req_end)
259  return 1;
260 
261  for (j = 0; j < FF_ARRAY_ELEMS(planes) && planes[j] >= 0; j++) {
262  int vsub1 = s->draw.vsub[planes[j]];
263  uint8_t *start1 = frame->data[planes[j]];
264  uint8_t *end1 = start1 + (frame->height >> vsub1) *
265  frame->linesize[planes[j]];
266  if (i == j)
267  continue;
268 
269  if (FFSIGN(start - end1) != FFSIGN(start - end1 - req_start) ||
270  FFSIGN(end - start1) != FFSIGN(end - start1 + req_end))
271  return 1;
272  }
273  }
274 
275  return 0;
276 }
277 
279 {
280  int i;
281 
282  if (!av_frame_is_writable(frame))
283  return 1;
284 
285  for (i = 0; i < 4 && frame->buf[i]; i++)
286  if (buffer_needs_copy(s, frame, frame->buf[i]))
287  return 1;
288  return 0;
289 }
290 
291 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
292 {
293  PadContext *s = inlink->dst->priv;
294  AVFrame *out;
295  int needs_copy = frame_needs_copy(s, in);
296 
297  if (needs_copy) {
298  av_log(inlink->dst, AV_LOG_DEBUG, "Direct padding impossible allocating new frame\n");
299  out = ff_get_video_buffer(inlink->dst->outputs[0],
300  FFMAX(inlink->w, s->w),
301  FFMAX(inlink->h, s->h));
302  if (!out) {
303  av_frame_free(&in);
304  return AVERROR(ENOMEM);
305  }
306 
307  av_frame_copy_props(out, in);
308  } else {
309  int i;
310 
311  out = in;
312  for (i = 0; i < 4 && out->data[i] && out->linesize[i]; i++) {
313  int hsub = s->draw.hsub[i];
314  int vsub = s->draw.vsub[i];
315  out->data[i] -= (s->x >> hsub) * s->draw.pixelstep[i] +
316  (s->y >> vsub) * out->linesize[i];
317  }
318  }
319 
320  /* top bar */
321  if (s->y) {
322  ff_fill_rectangle(&s->draw, &s->color,
323  out->data, out->linesize,
324  0, 0, s->w, s->y);
325  }
326 
327  /* bottom bar */
328  if (s->h > s->y + s->in_h) {
329  ff_fill_rectangle(&s->draw, &s->color,
330  out->data, out->linesize,
331  0, s->y + s->in_h, s->w, s->h - s->y - s->in_h);
332  }
333 
334  /* left border */
335  ff_fill_rectangle(&s->draw, &s->color, out->data, out->linesize,
336  0, s->y, s->x, in->height);
337 
338  if (needs_copy) {
340  out->data, out->linesize, in->data, in->linesize,
341  s->x, s->y, 0, 0, in->width, in->height);
342  }
343 
344  /* right border */
345  ff_fill_rectangle(&s->draw, &s->color, out->data, out->linesize,
346  s->x + s->in_w, s->y, s->w - s->x - s->in_w,
347  in->height);
348 
349  out->width = s->w;
350  out->height = s->h;
351 
352  if (in != out)
353  av_frame_free(&in);
354  return ff_filter_frame(inlink->dst->outputs[0], out);
355 }
356 
357 #define OFFSET(x) offsetof(PadContext, x)
358 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
359 
360 static const AVOption pad_options[] = {
361  { "width", "set the pad area width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
362  { "w", "set the pad area width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
363  { "height", "set the pad area height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
364  { "h", "set the pad area height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
365  { "x", "set the x offset expression for the input image position", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX, FLAGS },
366  { "y", "set the y offset expression for the input image position", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX, FLAGS },
367  { "color", "set the color of the padded area border", OFFSET(rgba_color), AV_OPT_TYPE_COLOR, {.str = "black"}, .flags = FLAGS },
368  { NULL }
369 };
370 
372 
374  {
375  .name = "default",
376  .type = AVMEDIA_TYPE_VIDEO,
377  .config_props = config_input,
378  .get_video_buffer = get_video_buffer,
379  .filter_frame = filter_frame,
380  },
381  { NULL }
382 };
383 
385  {
386  .name = "default",
387  .type = AVMEDIA_TYPE_VIDEO,
388  .config_props = config_output,
389  },
390  { NULL }
391 };
392 
394  .name = "pad",
395  .description = NULL_IF_CONFIG_SMALL("Pad the input video."),
396  .priv_size = sizeof(PadContext),
397  .priv_class = &pad_class,
399  .inputs = avfilter_vf_pad_inputs,
400  .outputs = avfilter_vf_pad_outputs,
401 };