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vsrc_life.c
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1 /*
2  * Copyright (c) Stefano Sabatini 2010
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  * life video source, based on John Conways' Life Game
24  */
25 
26 /* #define DEBUG */
27 
28 #include "libavutil/file.h"
29 #include "libavutil/intreadwrite.h"
30 #include "libavutil/lfg.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/parseutils.h"
33 #include "libavutil/random_seed.h"
34 #include "libavutil/avstring.h"
35 #include "avfilter.h"
36 #include "internal.h"
37 #include "formats.h"
38 #include "video.h"
39 
40 typedef struct {
41  const AVClass *class;
42  int w, h;
43  char *filename;
44  char *rule_str;
45  uint8_t *file_buf;
46  size_t file_bufsize;
47 
48  /**
49  * The two grid state buffers.
50  *
51  * A 0xFF (ALIVE_CELL) value means the cell is alive (or new born), while
52  * the decreasing values from 0xFE to 0 means the cell is dead; the range
53  * of values is used for the slow death effect, or mold (0xFE means dead,
54  * 0xFD means very dead, 0xFC means very very dead... and 0x00 means
55  * definitely dead/mold).
56  */
57  uint8_t *buf[2];
58 
59  uint8_t buf_idx;
60  uint16_t stay_rule; ///< encode the behavior for filled cells
61  uint16_t born_rule; ///< encode the behavior for empty cells
62  uint64_t pts;
63  AVRational time_base;
64  char *rate; ///< video frame rate
65  double random_fill_ratio;
66  uint32_t random_seed;
67  int stitch;
68  int mold;
69  char *life_color_str;
70  char *death_color_str;
71  char *mold_color_str;
72  uint8_t life_color[4];
73  uint8_t death_color[4];
74  uint8_t mold_color[4];
75  AVLFG lfg;
76  void (*draw)(AVFilterContext*, AVFilterBufferRef*);
77 } LifeContext;
78 
79 #define ALIVE_CELL 0xFF
80 #define OFFSET(x) offsetof(LifeContext, x)
81 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
82 
83 static const AVOption life_options[] = {
84  { "filename", "set source file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
85  { "f", "set source file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
86  { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
87  { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
88  { "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, FLAGS },
89  { "r", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, FLAGS },
90  { "rule", "set rule", OFFSET(rule_str), AV_OPT_TYPE_STRING, {.str = "B3/S23"}, CHAR_MIN, CHAR_MAX, FLAGS },
91  { "random_fill_ratio", "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl=1/M_PHI}, 0, 1, FLAGS },
92  { "ratio", "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl=1/M_PHI}, 0, 1, FLAGS },
93  { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.i64=-1}, -1, UINT32_MAX, FLAGS },
94  { "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.i64=-1}, -1, UINT32_MAX, FLAGS },
95  { "stitch", "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS },
96  { "mold", "set mold speed for dead cells", OFFSET(mold), AV_OPT_TYPE_INT, {.i64=0}, 0, 0xFF, FLAGS },
97  { "life_color", "set life color", OFFSET( life_color_str), AV_OPT_TYPE_STRING, {.str="white"}, CHAR_MIN, CHAR_MAX, FLAGS },
98  { "death_color", "set death color", OFFSET(death_color_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS },
99  { "mold_color", "set mold color", OFFSET( mold_color_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS },
100  { NULL },
101 };
102 
103 AVFILTER_DEFINE_CLASS(life);
104 
105 static int parse_rule(uint16_t *born_rule, uint16_t *stay_rule,
106  const char *rule_str, void *log_ctx)
107 {
108  char *tail;
109  const char *p = rule_str;
110  *born_rule = 0;
111  *stay_rule = 0;
112 
113  if (strchr("bBsS", *p)) {
114  /* parse rule as a Born / Stay Alive code, see
115  * http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life */
116  do {
117  uint16_t *rule = (*p == 'b' || *p == 'B') ? born_rule : stay_rule;
118  p++;
119  while (*p >= '0' && *p <= '8') {
120  *rule += 1<<(*p - '0');
121  p++;
122  }
123  if (*p != '/')
124  break;
125  p++;
126  } while (strchr("bBsS", *p));
127 
128  if (*p)
129  goto error;
130  } else {
131  /* parse rule as a number, expressed in the form STAY|(BORN<<9),
132  * where STAY and BORN encode the corresponding 9-bits rule */
133  long int rule = strtol(rule_str, &tail, 10);
134  if (*tail)
135  goto error;
136  *born_rule = ((1<<9)-1) & rule;
137  *stay_rule = rule >> 9;
138  }
139 
140  return 0;
141 
142 error:
143  av_log(log_ctx, AV_LOG_ERROR, "Invalid rule code '%s' provided\n", rule_str);
144  return AVERROR(EINVAL);
145 }
146 
147 #ifdef DEBUG
148 static void show_life_grid(AVFilterContext *ctx)
149 {
150  LifeContext *life = ctx->priv;
151  int i, j;
152 
153  char *line = av_malloc(life->w + 1);
154  if (!line)
155  return;
156  for (i = 0; i < life->h; i++) {
157  for (j = 0; j < life->w; j++)
158  line[j] = life->buf[life->buf_idx][i*life->w + j] == ALIVE_CELL ? '@' : ' ';
159  line[j] = 0;
160  av_log(ctx, AV_LOG_DEBUG, "%3d: %s\n", i, line);
161  }
162  av_free(line);
163 }
164 #endif
165 
166 static int init_pattern_from_file(AVFilterContext *ctx)
167 {
168  LifeContext *life = ctx->priv;
169  char *p;
170  int ret, i, i0, j, h = 0, w, max_w = 0;
171 
172  if ((ret = av_file_map(life->filename, &life->file_buf, &life->file_bufsize,
173  0, ctx)) < 0)
174  return ret;
175  av_freep(&life->filename);
176 
177  /* prescan file to get the number of lines and the maximum width */
178  w = 0;
179  for (i = 0; i < life->file_bufsize; i++) {
180  if (life->file_buf[i] == '\n') {
181  h++; max_w = FFMAX(w, max_w); w = 0;
182  } else {
183  w++;
184  }
185  }
186  av_log(ctx, AV_LOG_DEBUG, "h:%d max_w:%d\n", h, max_w);
187 
188  if (life->w) {
189  if (max_w > life->w || h > life->h) {
190  av_log(ctx, AV_LOG_ERROR,
191  "The specified size is %dx%d which cannot contain the provided file size of %dx%d\n",
192  life->w, life->h, max_w, h);
193  return AVERROR(EINVAL);
194  }
195  } else {
196  /* size was not specified, set it to size of the grid */
197  life->w = max_w;
198  life->h = h;
199  }
200 
201  if (!(life->buf[0] = av_mallocz(sizeof(char) * life->h * life->w)) ||
202  !(life->buf[1] = av_mallocz(sizeof(char) * life->h * life->w))) {
203  av_free(life->buf[0]);
204  av_free(life->buf[1]);
205  return AVERROR(ENOMEM);
206  }
207 
208  /* fill buf[0] */
209  p = life->file_buf;
210  for (i0 = 0, i = (life->h - h)/2; i0 < h; i0++, i++) {
211  for (j = (life->w - max_w)/2;; j++) {
212  av_log(ctx, AV_LOG_DEBUG, "%d:%d %c\n", i, j, *p == '\n' ? 'N' : *p);
213  if (*p == '\n') {
214  p++; break;
215  } else
216  life->buf[0][i*life->w + j] = av_isgraph(*(p++)) ? ALIVE_CELL : 0;
217  }
218  }
219  life->buf_idx = 0;
220 
221  return 0;
222 }
223 
224 static int init(AVFilterContext *ctx, const char *args)
225 {
226  LifeContext *life = ctx->priv;
227  AVRational frame_rate;
228  int ret;
229 
230  life->class = &life_class;
231  av_opt_set_defaults(life);
232 
233  if ((ret = av_set_options_string(life, args, "=", ":")) < 0)
234  return ret;
235 
236  if ((ret = av_parse_video_rate(&frame_rate, life->rate)) < 0) {
237  av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", life->rate);
238  return AVERROR(EINVAL);
239  }
240  av_freep(&life->rate);
241 
242  if (!life->w && !life->filename)
243  av_opt_set(life, "size", "320x240", 0);
244 
245  if ((ret = parse_rule(&life->born_rule, &life->stay_rule, life->rule_str, ctx)) < 0)
246  return ret;
247 
248 #define PARSE_COLOR(name) do { \
249  if ((ret = av_parse_color(life->name ## _color, life->name ## _color_str, -1, ctx))) { \
250  av_log(ctx, AV_LOG_ERROR, "Invalid " #name " color '%s'\n", \
251  life->name ## _color_str); \
252  return ret; \
253  } \
254  av_freep(&life->name ## _color_str); \
255 } while (0)
256 
257  PARSE_COLOR(life);
258  PARSE_COLOR(death);
259  PARSE_COLOR(mold);
260 
261  if (!life->mold && memcmp(life->mold_color, "\x00\x00\x00", 3))
262  av_log(ctx, AV_LOG_WARNING,
263  "Mold color is set while mold isn't, ignoring the color.\n");
264 
265  life->time_base.num = frame_rate.den;
266  life->time_base.den = frame_rate.num;
267 
268  if (!life->filename) {
269  /* fill the grid randomly */
270  int i;
271 
272  if (!(life->buf[0] = av_mallocz(sizeof(char) * life->h * life->w)) ||
273  !(life->buf[1] = av_mallocz(sizeof(char) * life->h * life->w))) {
274  av_free(life->buf[0]);
275  av_free(life->buf[1]);
276  return AVERROR(ENOMEM);
277  }
278  if (life->random_seed == -1)
279  life->random_seed = av_get_random_seed();
280 
281  av_lfg_init(&life->lfg, life->random_seed);
282 
283  for (i = 0; i < life->w * life->h; i++) {
284  double r = (double)av_lfg_get(&life->lfg) / UINT32_MAX;
285  if (r <= life->random_fill_ratio)
286  life->buf[0][i] = ALIVE_CELL;
287  }
288  life->buf_idx = 0;
289  } else {
290  if ((ret = init_pattern_from_file(ctx)) < 0)
291  return ret;
292  }
293 
294  av_log(ctx, AV_LOG_VERBOSE,
295  "s:%dx%d r:%d/%d rule:%s stay_rule:%d born_rule:%d stitch:%d seed:%u\n",
296  life->w, life->h, frame_rate.num, frame_rate.den,
297  life->rule_str, life->stay_rule, life->born_rule, life->stitch,
298  life->random_seed);
299  return 0;
300 }
301 
302 static av_cold void uninit(AVFilterContext *ctx)
303 {
304  LifeContext *life = ctx->priv;
305 
306  av_file_unmap(life->file_buf, life->file_bufsize);
307  av_freep(&life->rule_str);
308  av_freep(&life->buf[0]);
309  av_freep(&life->buf[1]);
310 }
311 
312 static int config_props(AVFilterLink *outlink)
313 {
314  LifeContext *life = outlink->src->priv;
315 
316  outlink->w = life->w;
317  outlink->h = life->h;
318  outlink->time_base = life->time_base;
319 
320  return 0;
321 }
322 
323 static void evolve(AVFilterContext *ctx)
324 {
325  LifeContext *life = ctx->priv;
326  int i, j;
327  uint8_t *oldbuf = life->buf[ life->buf_idx];
328  uint8_t *newbuf = life->buf[!life->buf_idx];
329 
330  enum { NW, N, NE, W, E, SW, S, SE };
331 
332  /* evolve the grid */
333  for (i = 0; i < life->h; i++) {
334  for (j = 0; j < life->w; j++) {
335  int pos[8][2], n, alive, cell;
336  if (life->stitch) {
337  pos[NW][0] = (i-1) < 0 ? life->h-1 : i-1; pos[NW][1] = (j-1) < 0 ? life->w-1 : j-1;
338  pos[N ][0] = (i-1) < 0 ? life->h-1 : i-1; pos[N ][1] = j ;
339  pos[NE][0] = (i-1) < 0 ? life->h-1 : i-1; pos[NE][1] = (j+1) == life->w ? 0 : j+1;
340  pos[W ][0] = i ; pos[W ][1] = (j-1) < 0 ? life->w-1 : j-1;
341  pos[E ][0] = i ; pos[E ][1] = (j+1) == life->w ? 0 : j+1;
342  pos[SW][0] = (i+1) == life->h ? 0 : i+1; pos[SW][1] = (j-1) < 0 ? life->w-1 : j-1;
343  pos[S ][0] = (i+1) == life->h ? 0 : i+1; pos[S ][1] = j ;
344  pos[SE][0] = (i+1) == life->h ? 0 : i+1; pos[SE][1] = (j+1) == life->w ? 0 : j+1;
345  } else {
346  pos[NW][0] = (i-1) < 0 ? -1 : i-1; pos[NW][1] = (j-1) < 0 ? -1 : j-1;
347  pos[N ][0] = (i-1) < 0 ? -1 : i-1; pos[N ][1] = j ;
348  pos[NE][0] = (i-1) < 0 ? -1 : i-1; pos[NE][1] = (j+1) == life->w ? -1 : j+1;
349  pos[W ][0] = i ; pos[W ][1] = (j-1) < 0 ? -1 : j-1;
350  pos[E ][0] = i ; pos[E ][1] = (j+1) == life->w ? -1 : j+1;
351  pos[SW][0] = (i+1) == life->h ? -1 : i+1; pos[SW][1] = (j-1) < 0 ? -1 : j-1;
352  pos[S ][0] = (i+1) == life->h ? -1 : i+1; pos[S ][1] = j ;
353  pos[SE][0] = (i+1) == life->h ? -1 : i+1; pos[SE][1] = (j+1) == life->w ? -1 : j+1;
354  }
355 
356  /* compute the number of live neighbor cells */
357  n = (pos[NW][0] == -1 || pos[NW][1] == -1 ? 0 : oldbuf[pos[NW][0]*life->w + pos[NW][1]] == ALIVE_CELL) +
358  (pos[N ][0] == -1 || pos[N ][1] == -1 ? 0 : oldbuf[pos[N ][0]*life->w + pos[N ][1]] == ALIVE_CELL) +
359  (pos[NE][0] == -1 || pos[NE][1] == -1 ? 0 : oldbuf[pos[NE][0]*life->w + pos[NE][1]] == ALIVE_CELL) +
360  (pos[W ][0] == -1 || pos[W ][1] == -1 ? 0 : oldbuf[pos[W ][0]*life->w + pos[W ][1]] == ALIVE_CELL) +
361  (pos[E ][0] == -1 || pos[E ][1] == -1 ? 0 : oldbuf[pos[E ][0]*life->w + pos[E ][1]] == ALIVE_CELL) +
362  (pos[SW][0] == -1 || pos[SW][1] == -1 ? 0 : oldbuf[pos[SW][0]*life->w + pos[SW][1]] == ALIVE_CELL) +
363  (pos[S ][0] == -1 || pos[S ][1] == -1 ? 0 : oldbuf[pos[S ][0]*life->w + pos[S ][1]] == ALIVE_CELL) +
364  (pos[SE][0] == -1 || pos[SE][1] == -1 ? 0 : oldbuf[pos[SE][0]*life->w + pos[SE][1]] == ALIVE_CELL);
365  cell = oldbuf[i*life->w + j];
366  alive = 1<<n & (cell == ALIVE_CELL ? life->stay_rule : life->born_rule);
367  if (alive) *newbuf = ALIVE_CELL; // new cell is alive
368  else if (cell) *newbuf = cell - 1; // new cell is dead and in the process of mold
369  else *newbuf = 0; // new cell is definitely dead
370  av_dlog(ctx, "i:%d j:%d live_neighbors:%d cell:%d -> cell:%d\n", i, j, n, cell, *newbuf);
371  newbuf++;
372  }
373  }
374 
375  life->buf_idx = !life->buf_idx;
376 }
377 
378 static void fill_picture_monoblack(AVFilterContext *ctx, AVFilterBufferRef *picref)
379 {
380  LifeContext *life = ctx->priv;
381  uint8_t *buf = life->buf[life->buf_idx];
382  int i, j, k;
383 
384  /* fill the output picture with the old grid buffer */
385  for (i = 0; i < life->h; i++) {
386  uint8_t byte = 0;
387  uint8_t *p = picref->data[0] + i * picref->linesize[0];
388  for (k = 0, j = 0; j < life->w; j++) {
389  byte |= (buf[i*life->w+j] == ALIVE_CELL)<<(7-k++);
390  if (k==8 || j == life->w-1) {
391  k = 0;
392  *p++ = byte;
393  byte = 0;
394  }
395  }
396  }
397 }
398 
399 // divide by 255 and round to nearest
400 // apply a fast variant: (X+127)/255 = ((X+127)*257+257)>>16 = ((X+128)*257)>>16
401 #define FAST_DIV255(x) ((((x) + 128) * 257) >> 16)
402 
403 static void fill_picture_rgb(AVFilterContext *ctx, AVFilterBufferRef *picref)
404 {
405  LifeContext *life = ctx->priv;
406  uint8_t *buf = life->buf[life->buf_idx];
407  int i, j;
408 
409  /* fill the output picture with the old grid buffer */
410  for (i = 0; i < life->h; i++) {
411  uint8_t *p = picref->data[0] + i * picref->linesize[0];
412  for (j = 0; j < life->w; j++) {
413  uint8_t v = buf[i*life->w + j];
414  if (life->mold && v != ALIVE_CELL) {
415  const uint8_t *c1 = life-> mold_color;
416  const uint8_t *c2 = life->death_color;
417  int death_age = FFMIN((0xff - v) * life->mold, 0xff);
418  *p++ = FAST_DIV255((c2[0] << 8) + ((int)c1[0] - (int)c2[0]) * death_age);
419  *p++ = FAST_DIV255((c2[1] << 8) + ((int)c1[1] - (int)c2[1]) * death_age);
420  *p++ = FAST_DIV255((c2[2] << 8) + ((int)c1[2] - (int)c2[2]) * death_age);
421  } else {
422  const uint8_t *c = v == ALIVE_CELL ? life->life_color : life->death_color;
423  AV_WB24(p, c[0]<<16 | c[1]<<8 | c[2]);
424  p += 3;
425  }
426  }
427  }
428 }
429 
430 static int request_frame(AVFilterLink *outlink)
431 {
432  LifeContext *life = outlink->src->priv;
433  AVFilterBufferRef *picref = ff_get_video_buffer(outlink, AV_PERM_WRITE, life->w, life->h);
434  picref->video->sample_aspect_ratio = (AVRational) {1, 1};
435  picref->pts = life->pts++;
436  picref->pos = -1;
437 
438  life->draw(outlink->src, picref);
439  evolve(outlink->src);
440 #ifdef DEBUG
441  show_life_grid(outlink->src);
442 #endif
443  ff_filter_frame(outlink, picref);
444 
445  return 0;
446 }
447 
448 static int query_formats(AVFilterContext *ctx)
449 {
450  LifeContext *life = ctx->priv;
451  enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_NONE, AV_PIX_FMT_NONE };
452  if (life->mold || memcmp(life-> life_color, "\xff\xff\xff", 3)
453  || memcmp(life->death_color, "\x00\x00\x00", 3)) {
454  pix_fmts[0] = AV_PIX_FMT_RGB24;
455  life->draw = fill_picture_rgb;
456  } else {
457  pix_fmts[0] = AV_PIX_FMT_MONOBLACK;
458  life->draw = fill_picture_monoblack;
459  }
460  ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
461  return 0;
462 }
463 
464 static const AVFilterPad life_outputs[] = {
465  {
466  .name = "default",
467  .type = AVMEDIA_TYPE_VIDEO,
468  .request_frame = request_frame,
469  .config_props = config_props,
470  },
471  { NULL}
472 };
473 
474 AVFilter avfilter_vsrc_life = {
475  .name = "life",
476  .description = NULL_IF_CONFIG_SMALL("Create life."),
477  .priv_size = sizeof(LifeContext),
478  .init = init,
479  .uninit = uninit,
480  .query_formats = query_formats,
481  .inputs = NULL,
482  .outputs = life_outputs,
483  .priv_class = &life_class,
484 };
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