FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/vsrc_cellauto.c
Date: 2026-09-25 07:50:45
Exec Total Coverage
Lines: 0 123 0.0%
Functions: 0 8 0.0%
Branches: 0 76 0.0%

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1 /*
2 * Copyright (c) Stefano Sabatini 2011
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 * cellular automaton video source, based on Stephen Wolfram "experimentus crucis"
24 */
25
26 /* #define DEBUG */
27
28 #include "libavutil/file.h"
29 #include "libavutil/internal.h"
30 #include "libavutil/lfg.h"
31 #include "libavutil/mem.h"
32 #include "libavutil/opt.h"
33 #include "libavutil/random_seed.h"
34 #include "libavutil/avstring.h"
35 #include "avfilter.h"
36 #include "filters.h"
37 #include "video.h"
38
39 typedef struct CellAutoContext {
40 const AVClass *class;
41 int w, h;
42 char *filename;
43 char *rule_str;
44 uint8_t *file_buf;
45 size_t file_bufsize;
46 uint8_t *buf;
47 int buf_prev_row_idx, buf_row_idx;
48 uint8_t rule;
49 uint64_t pts;
50 AVRational frame_rate;
51 double random_fill_ratio;
52 int64_t random_seed;
53 int stitch, scroll, start_full;
54 int64_t generation; ///< the generation number, starting from 0
55 AVLFG lfg;
56 char *pattern;
57 } CellAutoContext;
58
59 #define OFFSET(x) offsetof(CellAutoContext, x)
60 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
61
62 static const AVOption cellauto_options[] = {
63 { "filename", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
64 { "f", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
65 { "pattern", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
66 { "p", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
67 { "rate", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, FLAGS },
68 { "r", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, FLAGS },
69 { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
70 { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
71 { "rule", "set rule", OFFSET(rule), AV_OPT_TYPE_INT, {.i64 = 110}, 0, 255, FLAGS },
72 { "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 },
73 { "ratio", "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl = 1/M_PHI}, 0, 1, FLAGS },
74 { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
75 { "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
76 { "scroll", "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, FLAGS },
77 { "start_full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS },
78 { "full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, FLAGS },
79 { "stitch", "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, FLAGS },
80 { NULL }
81 };
82
83 AVFILTER_DEFINE_CLASS(cellauto);
84
85 #ifdef DEBUG
86 static void show_cellauto_row(AVFilterContext *ctx)
87 {
88 CellAutoContext *s = ctx->priv;
89 int i;
90 uint8_t *row = s->buf + s->w * s->buf_row_idx;
91 char *line = av_malloc(s->w + 1);
92 if (!line)
93 return;
94
95 for (i = 0; i < s->w; i++)
96 line[i] = row[i] ? '@' : ' ';
97 line[i] = 0;
98 av_log(ctx, AV_LOG_DEBUG, "generation:%"PRId64" row:%s|\n", s->generation, line);
99 av_free(line);
100 }
101 #endif
102
103 ✗ static int init_pattern_from_string(AVFilterContext *ctx)
104 {
105 ✗ CellAutoContext *s = ctx->priv;
106 char *p;
107 ✗ int i, w = 0;
108
109 ✗ w = strlen(s->pattern);
110 ✗ av_log(ctx, AV_LOG_DEBUG, "w:%d\n", w);
111
112 ✗ if (s->w) {
113 ✗ if (w > s->w) {
114 ✗ av_log(ctx, AV_LOG_ERROR,
115 "The specified width is %d which cannot contain the provided string width of %d\n",
116 s->w, w);
117 ✗ return AVERROR(EINVAL);
118 }
119 } else {
120 /* width was not specified, set it to width of the provided row */
121 ✗ s->w = w;
122 ✗ s->h = (double)s->w * M_PHI;
123 }
124
125 ✗ s->buf = av_calloc(s->w, s->h * sizeof(*s->buf));
126 ✗ if (!s->buf)
127 ✗ return AVERROR(ENOMEM);
128
129 /* fill buf */
130 ✗ p = s->pattern;
131 ✗ for (i = (s->w - w)/2;; i++) {
132 ✗ av_log(ctx, AV_LOG_DEBUG, "%d %c\n", i, *p == '\n' ? 'N' : *p);
133 ✗ if (*p == '\n' || !*p)
134 break;
135 else
136 ✗ s->buf[i] = !!av_isgraph(*(p++));
137 }
138
139 ✗ return 0;
140 }
141
142 ✗ static int init_pattern_from_file(AVFilterContext *ctx)
143 {
144 ✗ CellAutoContext *s = ctx->priv;
145 int ret;
146
147 ✗ ret = av_file_map(s->filename,
148 &s->file_buf, &s->file_bufsize, 0, ctx);
149 ✗ if (ret < 0)
150 ✗ return ret;
151
152 /* create a string based on the read file */
153 ✗ s->pattern = av_malloc(s->file_bufsize + 1);
154 ✗ if (!s->pattern)
155 ✗ return AVERROR(ENOMEM);
156 ✗ memcpy(s->pattern, s->file_buf, s->file_bufsize);
157 ✗ s->pattern[s->file_bufsize] = 0;
158
159 ✗ return init_pattern_from_string(ctx);
160 }
161
162 ✗ static av_cold int init(AVFilterContext *ctx)
163 {
164 ✗ CellAutoContext *s = ctx->priv;
165 int ret;
166
167 ✗ if (!s->w && !s->filename && !s->pattern)
168 ✗ av_opt_set(s, "size", "320x518", 0);
169
170 ✗ if (s->filename && s->pattern) {
171 ✗ av_log(ctx, AV_LOG_ERROR, "Only one of the filename or pattern options can be used\n");
172 ✗ return AVERROR(EINVAL);
173 }
174
175 ✗ if (s->filename) {
176 ✗ if ((ret = init_pattern_from_file(ctx)) < 0)
177 ✗ return ret;
178 ✗ } else if (s->pattern) {
179 ✗ if ((ret = init_pattern_from_string(ctx)) < 0)
180 ✗ return ret;
181 } else {
182 /* fill the first row randomly */
183 int i;
184
185 ✗ s->buf = av_calloc(s->w, s->h * sizeof(*s->buf));
186 ✗ if (!s->buf)
187 ✗ return AVERROR(ENOMEM);
188 ✗ if (s->random_seed == -1)
189 ✗ s->random_seed = av_get_random_seed();
190
191 ✗ av_lfg_init(&s->lfg, s->random_seed);
192
193 ✗ for (i = 0; i < s->w; i++) {
194 ✗ double r = (double)av_lfg_get(&s->lfg) / UINT32_MAX;
195 ✗ if (r <= s->random_fill_ratio)
196 ✗ s->buf[i] = 1;
197 }
198 }
199
200 ✗ av_log(ctx, AV_LOG_VERBOSE,
201 "s:%dx%d r:%d/%d rule:%d stitch:%d scroll:%d full:%d seed:%"PRId64"\n",
202 s->w, s->h, s->frame_rate.num, s->frame_rate.den,
203 ✗ s->rule, s->stitch, s->scroll, s->start_full,
204 s->random_seed);
205 ✗ return 0;
206 }
207
208 ✗ static av_cold void uninit(AVFilterContext *ctx)
209 {
210 ✗ CellAutoContext *s = ctx->priv;
211
212 ✗ av_file_unmap(s->file_buf, s->file_bufsize);
213 ✗ av_freep(&s->buf);
214 ✗ av_freep(&s->pattern);
215 ✗ }
216
217 ✗ static int config_props(AVFilterLink *outlink)
218 {
219 ✗ CellAutoContext *s = outlink->src->priv;
220 ✗ FilterLink *l = ff_filter_link(outlink);
221
222 ✗ outlink->w = s->w;
223 ✗ outlink->h = s->h;
224 ✗ outlink->time_base = av_inv_q(s->frame_rate);
225 ✗ l->frame_rate = s->frame_rate;
226
227 ✗ return 0;
228 }
229
230 ✗ static void evolve(AVFilterContext *ctx)
231 {
232 ✗ CellAutoContext *s = ctx->priv;
233 int i, v, pos[3];
234 ✗ uint8_t *row, *prev_row = s->buf + s->buf_row_idx * s->w;
235 enum { NW, N, NE };
236
237 ✗ s->buf_prev_row_idx = s->buf_row_idx;
238 ✗ s->buf_row_idx = s->buf_row_idx == s->h-1 ? 0 : s->buf_row_idx+1;
239 ✗ row = s->buf + s->w * s->buf_row_idx;
240
241 ✗ for (i = 0; i < s->w; i++) {
242 ✗ if (s->stitch) {
243 ✗ pos[NW] = i-1 < 0 ? s->w-1 : i-1;
244 ✗ pos[N] = i;
245 ✗ pos[NE] = i+1 == s->w ? 0 : i+1;
246 ✗ v = prev_row[pos[NW]]<<2 | prev_row[pos[N]]<<1 | prev_row[pos[NE]];
247 } else {
248 ✗ v = 0;
249 ✗ v|= i-1 >= 0 ? prev_row[i-1]<<2 : 0;
250 ✗ v|= prev_row[i ]<<1 ;
251 ✗ v|= i+1 < s->w ? prev_row[i+1] : 0;
252 }
253 ✗ row[i] = !!(s->rule & (1<<v));
254 ff_dlog(ctx, "i:%d context:%c%c%c -> cell:%d\n", i,
255 v&4?'@':' ', v&2?'@':' ', v&1?'@':' ', row[i]);
256 }
257
258 ✗ s->generation++;
259 ✗ }
260
261 ✗ static void fill_picture(AVFilterContext *ctx, AVFrame *picref)
262 {
263 ✗ CellAutoContext *s = ctx->priv;
264 ✗ int i, j, k, row_idx = 0;
265 ✗ uint8_t *p0 = picref->data[0];
266
267 ✗ if (s->scroll && s->generation >= s->h)
268 /* show on top the oldest row */
269 ✗ row_idx = (s->buf_row_idx + 1) % s->h;
270
271 /* fill the output picture with the whole buffer */
272 ✗ for (i = 0; i < s->h; i++) {
273 ✗ uint8_t byte = 0;
274 ✗ uint8_t *row = s->buf + row_idx*s->w;
275 ✗ uint8_t *p = p0;
276 ✗ for (k = 0, j = 0; j < s->w; j++) {
277 ✗ byte |= row[j]<<(7-k++);
278 ✗ if (k==8 || j == s->w-1) {
279 ✗ k = 0;
280 ✗ *p++ = byte;
281 ✗ byte = 0;
282 }
283 }
284 ✗ row_idx = (row_idx + 1) % s->h;
285 ✗ p0 += picref->linesize[0];
286 }
287 ✗ }
288
289 ✗ static int request_frame(AVFilterLink *outlink)
290 {
291 ✗ CellAutoContext *s = outlink->src->priv;
292 ✗ AVFrame *picref = ff_get_video_buffer(outlink, s->w, s->h);
293 ✗ if (!picref)
294 ✗ return AVERROR(ENOMEM);
295 ✗ picref->sample_aspect_ratio = (AVRational) {1, 1};
296 ✗ if (s->generation == 0 && s->start_full) {
297 int i;
298 ✗ for (i = 0; i < s->h-1; i++)
299 ✗ evolve(outlink->src);
300 }
301 ✗ fill_picture(outlink->src, picref);
302 ✗ evolve(outlink->src);
303
304 ✗ picref->pts = s->pts++;
305 ✗ picref->duration = 1;
306
307 #ifdef DEBUG
308 show_cellauto_row(outlink->src);
309 #endif
310 ✗ return ff_filter_frame(outlink, picref);
311 }
312
313 static const AVFilterPad cellauto_outputs[] = {
314 {
315 .name = "default",
316 .type = AVMEDIA_TYPE_VIDEO,
317 .request_frame = request_frame,
318 .config_props = config_props,
319 },
320 };
321
322 const FFFilter ff_vsrc_cellauto = {
323 .p.name = "cellauto",
324 .p.description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."),
325 .p.priv_class = &cellauto_class,
326 .p.inputs = NULL,
327 .priv_size = sizeof(CellAutoContext),
328 .init = init,
329 .uninit = uninit,
330 FILTER_OUTPUTS(cellauto_outputs),
331 FILTER_SINGLE_PIXFMT(AV_PIX_FMT_MONOBLACK),
332 };
333