2 * Copyright (c) Stefano Sabatini 2011
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
23 * cellular automaton video source, based on Stephen Wolfram "experimentus crucis"
28 #include "libavutil/file.h"
29 #include "libavutil/lfg.h"
30 #include "libavutil/opt.h"
31 #include "libavutil/parseutils.h"
32 #include "libavutil/random_seed.h"
46 int buf_prev_row_idx, buf_row_idx;
50 char *rate; ///< video frame rate
51 double random_fill_ratio;
53 int stitch, scroll, start_full;
54 int64_t generation; ///< the generation number, starting from 0
59 #define OFFSET(x) offsetof(CellAutoContext, x)
61 static const AVOption cellauto_options[] = {
62 { "filename", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
63 { "f", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
64 { "pattern", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
65 { "p", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
66 { "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 },
67 { "r", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 },
68 { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0 },
69 { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0 },
70 { "rule", "set rule", OFFSET(rule), AV_OPT_TYPE_INT, {.dbl = 110}, 0, 255 },
71 { "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 },
72 { "ratio", "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl = 1/M_PHI}, 0, 1 },
73 { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX },
74 { "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX },
75 { "scroll", "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
76 { "start_full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 0}, 0, 1 },
77 { "full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
78 { "stitch", "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
82 AVFILTER_DEFINE_CLASS(cellauto);
85 static void show_cellauto_row(AVFilterContext *ctx)
87 CellAutoContext *cellauto = ctx->priv;
89 uint8_t *row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
90 char *line = av_malloc(cellauto->w + 1);
94 for (i = 0; i < cellauto->w; i++)
95 line[i] = row[i] ? '@' : ' ';
97 av_log(ctx, AV_LOG_DEBUG, "generation:%"PRId64" row:%s|\n", cellauto->generation, line);
102 static int init_pattern_from_string(AVFilterContext *ctx)
104 CellAutoContext *cellauto = ctx->priv;
108 w = strlen(cellauto->pattern);
109 av_log(ctx, AV_LOG_DEBUG, "w:%d\n", w);
112 if (w > cellauto->w) {
113 av_log(ctx, AV_LOG_ERROR,
114 "The specified width is %d which cannot contain the provided string width of %d\n",
116 return AVERROR(EINVAL);
119 /* width was not specified, set it to width of the provided row */
121 cellauto->h = (double)cellauto->w * M_PHI;
124 cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
126 return AVERROR(ENOMEM);
129 p = cellauto->pattern;
130 for (i = (cellauto->w - w)/2;; i++) {
131 av_log(ctx, AV_LOG_DEBUG, "%d %c\n", i, *p == '\n' ? 'N' : *p);
132 if (*p == '\n' || !*p)
135 cellauto->buf[i] = !!isgraph(*(p++));
141 static int init_pattern_from_file(AVFilterContext *ctx)
143 CellAutoContext *cellauto = ctx->priv;
146 ret = av_file_map(cellauto->filename,
147 &cellauto->file_buf, &cellauto->file_bufsize, 0, ctx);
151 /* create a string based on the read file */
152 cellauto->pattern = av_malloc(cellauto->file_bufsize + 1);
153 if (!cellauto->pattern)
154 return AVERROR(ENOMEM);
155 memcpy(cellauto->pattern, cellauto->file_buf, cellauto->file_bufsize);
156 cellauto->pattern[cellauto->file_bufsize] = 0;
158 return init_pattern_from_string(ctx);
161 static int init(AVFilterContext *ctx, const char *args)
163 CellAutoContext *cellauto = ctx->priv;
164 AVRational frame_rate;
167 cellauto->class = &cellauto_class;
168 av_opt_set_defaults(cellauto);
170 if ((ret = av_set_options_string(cellauto, args, "=", ":")) < 0) {
171 av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
175 if ((ret = av_parse_video_rate(&frame_rate, cellauto->rate)) < 0) {
176 av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", cellauto->rate);
177 return AVERROR(EINVAL);
180 if (!cellauto->w && !cellauto->filename && !cellauto->pattern)
181 av_opt_set(cellauto, "size", "320x518", 0);
183 cellauto->time_base.num = frame_rate.den;
184 cellauto->time_base.den = frame_rate.num;
186 if (cellauto->filename && cellauto->pattern) {
187 av_log(ctx, AV_LOG_ERROR, "Only one of the filename or pattern options can be used\n");
188 return AVERROR(EINVAL);
191 if (cellauto->filename) {
192 if ((ret = init_pattern_from_file(ctx)) < 0)
194 } else if (cellauto->pattern) {
195 if ((ret = init_pattern_from_string(ctx)) < 0)
198 /* fill the first row randomly */
201 cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
203 return AVERROR(ENOMEM);
204 if (cellauto->random_seed == -1)
205 cellauto->random_seed = av_get_random_seed();
207 av_lfg_init(&cellauto->lfg, cellauto->random_seed);
209 for (i = 0; i < cellauto->w; i++) {
210 double r = (double)av_lfg_get(&cellauto->lfg) / UINT32_MAX;
211 if (r <= cellauto->random_fill_ratio)
212 cellauto->buf[i] = 1;
216 av_log(ctx, AV_LOG_VERBOSE,
217 "s:%dx%d r:%d/%d rule:%d stitch:%d scroll:%d full:%d seed:%u\n",
218 cellauto->w, cellauto->h, frame_rate.num, frame_rate.den,
219 cellauto->rule, cellauto->stitch, cellauto->scroll, cellauto->start_full,
220 cellauto->random_seed);
224 static av_cold void uninit(AVFilterContext *ctx)
226 CellAutoContext *cellauto = ctx->priv;
228 av_file_unmap(cellauto->file_buf, cellauto->file_bufsize);
229 av_freep(&cellauto->buf);
230 av_freep(&cellauto->pattern);
233 static int config_props(AVFilterLink *outlink)
235 CellAutoContext *cellauto = outlink->src->priv;
237 outlink->w = cellauto->w;
238 outlink->h = cellauto->h;
239 outlink->time_base = cellauto->time_base;
244 static void evolve(AVFilterContext *ctx)
246 CellAutoContext *cellauto = ctx->priv;
248 uint8_t *row, *prev_row = cellauto->buf + cellauto->buf_row_idx * cellauto->w;
251 cellauto->buf_prev_row_idx = cellauto->buf_row_idx;
252 cellauto->buf_row_idx = cellauto->buf_row_idx == cellauto->h-1 ? 0 : cellauto->buf_row_idx+1;
253 row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
255 for (i = 0; i < cellauto->w; i++) {
256 if (cellauto->stitch) {
257 pos[NW] = i-1 < 0 ? cellauto->w-1 : i-1;
259 pos[NE] = i+1 == cellauto->w ? 0 : i+1;
260 v = prev_row[pos[NW]]<<2 | prev_row[pos[N]]<<1 | prev_row[pos[NE]];
263 v|= i-1 >= 0 ? prev_row[i-1]<<2 : 0;
264 v|= prev_row[i ]<<1 ;
265 v|= i+1 < cellauto->w ? prev_row[i+1] : 0;
267 row[i] = !!(cellauto->rule & (1<<v));
268 av_dlog(ctx, "i:%d context:%c%c%c -> cell:%d\n", i,
269 v&4?'@':' ', v&2?'@':' ', v&1?'@':' ', row[i]);
272 cellauto->generation++;
275 static void fill_picture(AVFilterContext *ctx, AVFilterBufferRef *picref)
277 CellAutoContext *cellauto = ctx->priv;
278 int i, j, k, row_idx = 0;
279 uint8_t *p0 = picref->data[0];
281 if (cellauto->scroll && cellauto->generation >= cellauto->h)
282 /* show on top the oldest row */
283 row_idx = (cellauto->buf_row_idx + 1) % cellauto->h;
285 /* fill the output picture with the whole buffer */
286 for (i = 0; i < cellauto->h; i++) {
288 uint8_t *row = cellauto->buf + row_idx*cellauto->w;
290 for (k = 0, j = 0; j < cellauto->w; j++) {
291 byte |= row[j]<<(7-k++);
292 if (k==8 || j == cellauto->w-1) {
298 row_idx = (row_idx + 1) % cellauto->h;
299 p0 += picref->linesize[0];
303 static int request_frame(AVFilterLink *outlink)
305 CellAutoContext *cellauto = outlink->src->priv;
306 AVFilterBufferRef *picref =
307 ff_get_video_buffer(outlink, AV_PERM_WRITE, cellauto->w, cellauto->h);
308 picref->video->sample_aspect_ratio = (AVRational) {1, 1};
309 if (cellauto->generation == 0 && cellauto->start_full) {
311 for (i = 0; i < cellauto->h-1; i++)
312 evolve(outlink->src);
314 fill_picture(outlink->src, picref);
315 evolve(outlink->src);
317 picref->pts = cellauto->pts++;
321 show_cellauto_row(outlink->src);
324 ff_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
325 ff_draw_slice(outlink, 0, cellauto->h, 1);
326 ff_end_frame(outlink);
327 avfilter_unref_buffer(picref);
332 static int query_formats(AVFilterContext *ctx)
334 static const enum PixelFormat pix_fmts[] = { PIX_FMT_MONOBLACK, PIX_FMT_NONE };
335 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
339 AVFilter avfilter_vsrc_cellauto = {
341 .description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."),
342 .priv_size = sizeof(CellAutoContext),
345 .query_formats = query_formats,
347 .inputs = (const AVFilterPad[]) {
350 .outputs = (const AVFilterPad[]) {
352 .type = AVMEDIA_TYPE_VIDEO,
353 .request_frame = request_frame,
354 .config_props = config_props },