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"
43 int buf_prev_row_idx, buf_row_idx;
47 char *rate; ///< video frame rate
48 double random_fill_ratio;
50 int stitch, scroll, start_full;
51 int64_t generation; ///< the generation number, starting from 0
56 #define OFFSET(x) offsetof(CellAutoContext, x)
58 static const AVOption cellauto_options[] = {
59 { "filename", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
60 { "f", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
61 { "pattern", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
62 { "p", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
63 { "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 },
64 { "r", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 },
65 { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0 },
66 { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0 },
67 { "rule", "set rule", OFFSET(rule), AV_OPT_TYPE_INT, {.dbl = 110}, 0, 255 },
68 { "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 },
69 { "ratio", "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl = 1/M_PHI}, 0, 1 },
70 { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX },
71 { "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX },
72 { "scroll", "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
73 { "start_full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 0}, 0, 1 },
74 { "full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
75 { "stitch", "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
79 static const AVClass cellauto_class = {
81 avfilter_default_filter_name,
86 static void show_cellauto_row(AVFilterContext *ctx)
88 CellAutoContext *cellauto = ctx->priv;
90 uint8_t *row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
91 char *line = av_malloc(cellauto->w + 1);
95 for (i = 0; i < cellauto->w; i++)
96 line[i] = row[i] ? '@' : ' ';
98 av_log(ctx, AV_LOG_DEBUG, "generation:%"PRId64" row:%s|\n", cellauto->generation, line);
103 static int init_pattern_from_string(AVFilterContext *ctx)
105 CellAutoContext *cellauto = ctx->priv;
109 w = strlen(cellauto->pattern);
110 av_log(ctx, AV_LOG_DEBUG, "w:%d\n", w);
113 if (w > cellauto->w) {
114 av_log(ctx, AV_LOG_ERROR,
115 "The specified width is %d which cannot contain the provided string width of %d\n",
117 return AVERROR(EINVAL);
120 /* width was not specified, set it to width of the provided row */
122 cellauto->h = (double)cellauto->w * M_PHI;
125 cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
127 return AVERROR(ENOMEM);
130 p = cellauto->pattern;
131 for (i = (cellauto->w - w)/2;; i++) {
132 av_log(ctx, AV_LOG_DEBUG, "%d %c\n", i, *p == '\n' ? 'N' : *p);
133 if (*p == '\n' || !*p)
136 cellauto->buf[i] = !!isgraph(*(p++));
142 static int init_pattern_from_file(AVFilterContext *ctx)
144 CellAutoContext *cellauto = ctx->priv;
147 ret = av_file_map(cellauto->filename,
148 &cellauto->file_buf, &cellauto->file_bufsize, 0, ctx);
152 /* create a string based on the read file */
153 cellauto->pattern = av_malloc(cellauto->file_bufsize + 1);
154 if (!cellauto->pattern)
155 return AVERROR(ENOMEM);
156 memcpy(cellauto->pattern, cellauto->file_buf, cellauto->file_bufsize);
157 cellauto->pattern[cellauto->file_bufsize] = 0;
159 return init_pattern_from_string(ctx);
162 static int init(AVFilterContext *ctx, const char *args, void *opaque)
164 CellAutoContext *cellauto = ctx->priv;
165 AVRational frame_rate;
168 cellauto->class = &cellauto_class;
169 av_opt_set_defaults(cellauto);
171 if ((ret = av_set_options_string(cellauto, args, "=", ":")) < 0) {
172 av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
176 if ((ret = av_parse_video_rate(&frame_rate, cellauto->rate)) < 0) {
177 av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", cellauto->rate);
178 return AVERROR(EINVAL);
181 if (!cellauto->w && !cellauto->filename && !cellauto->pattern)
182 av_opt_set(cellauto, "size", "320x518", 0);
184 cellauto->time_base.num = frame_rate.den;
185 cellauto->time_base.den = frame_rate.num;
187 if (cellauto->filename && cellauto->pattern) {
188 av_log(ctx, AV_LOG_ERROR, "Only one of the filename or pattern options can be used\n");
189 return AVERROR(EINVAL);
192 if (cellauto->filename) {
193 if ((ret = init_pattern_from_file(ctx)) < 0)
195 } else if (cellauto->pattern) {
196 if ((ret = init_pattern_from_string(ctx)) < 0)
199 /* fill the first row randomly */
202 cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
204 return AVERROR(ENOMEM);
205 if (cellauto->random_seed == -1)
206 cellauto->random_seed = av_get_random_seed();
208 av_lfg_init(&cellauto->lfg, cellauto->random_seed);
210 for (i = 0; i < cellauto->w; i++) {
211 double r = (double)av_lfg_get(&cellauto->lfg) / UINT32_MAX;
212 if (r <= cellauto->random_fill_ratio)
213 cellauto->buf[i] = 1;
217 av_log(ctx, AV_LOG_INFO,
218 "s:%dx%d r:%d/%d rule:%d stitch:%d scroll:%d full:%d seed:%u\n",
219 cellauto->w, cellauto->h, frame_rate.num, frame_rate.den,
220 cellauto->rule, cellauto->stitch, cellauto->scroll, cellauto->start_full,
221 cellauto->random_seed);
225 static av_cold void uninit(AVFilterContext *ctx)
227 CellAutoContext *cellauto = ctx->priv;
229 av_file_unmap(cellauto->file_buf, cellauto->file_bufsize);
230 av_freep(&cellauto->buf);
231 av_freep(&cellauto->pattern);
234 static int config_props(AVFilterLink *outlink)
236 CellAutoContext *cellauto = outlink->src->priv;
238 outlink->w = cellauto->w;
239 outlink->h = cellauto->h;
240 outlink->time_base = cellauto->time_base;
245 static void evolve(AVFilterContext *ctx)
247 CellAutoContext *cellauto = ctx->priv;
249 uint8_t *row, *prev_row = cellauto->buf + cellauto->buf_row_idx * cellauto->w;
252 cellauto->buf_prev_row_idx = cellauto->buf_row_idx;
253 cellauto->buf_row_idx = cellauto->buf_row_idx == cellauto->h-1 ? 0 : cellauto->buf_row_idx+1;
254 row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
256 for (i = 0; i < cellauto->w; i++) {
257 if (cellauto->stitch) {
258 pos[NW] = i-1 < 0 ? cellauto->w-1 : i-1;
260 pos[NE] = i+1 == cellauto->w ? 0 : i+1;
261 v = prev_row[pos[NW]]<<2 | prev_row[pos[N]]<<1 | prev_row[pos[NE]];
264 v|= i-1 >= 0 ? prev_row[i-1]<<2 : 0;
265 v|= prev_row[i ]<<1 ;
266 v|= i+1 < cellauto->w ? prev_row[i+1] : 0;
268 row[i] = !!(cellauto->rule & (1<<v));
269 av_dlog(ctx, "i:%d context:%c%c%c -> cell:%d\n", i,
270 v&4?'@':' ', v&2?'@':' ', v&1?'@':' ', row[i]);
273 cellauto->generation++;
276 static void fill_picture(AVFilterContext *ctx, AVFilterBufferRef *picref)
278 CellAutoContext *cellauto = ctx->priv;
279 int i, j, k, row_idx = 0;
280 uint8_t *p0 = picref->data[0];
282 if (cellauto->scroll && cellauto->generation >= cellauto->h)
283 /* show on top the oldest row */
284 row_idx = (cellauto->buf_row_idx + 1) % cellauto->h;
286 /* fill the output picture with the whole buffer */
287 for (i = 0; i < cellauto->h; i++) {
289 uint8_t *row = cellauto->buf + row_idx*cellauto->w;
291 for (k = 0, j = 0; j < cellauto->w; j++) {
292 byte |= row[j]<<(7-k++);
293 if (k==8 || j == cellauto->w-1) {
299 row_idx = (row_idx + 1) % cellauto->h;
300 p0 += picref->linesize[0];
304 static int request_frame(AVFilterLink *outlink)
306 CellAutoContext *cellauto = outlink->src->priv;
307 AVFilterBufferRef *picref =
308 avfilter_get_video_buffer(outlink, AV_PERM_WRITE, cellauto->w, cellauto->h);
309 picref->video->sample_aspect_ratio = (AVRational) {1, 1};
310 if (cellauto->generation == 0 && cellauto->start_full) {
312 for (i = 0; i < cellauto->h-1; i++)
313 evolve(outlink->src);
315 fill_picture(outlink->src, picref);
316 evolve(outlink->src);
318 picref->pts = cellauto->pts++;
322 show_cellauto_row(outlink->src);
325 avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
326 avfilter_draw_slice(outlink, 0, cellauto->h, 1);
327 avfilter_end_frame(outlink);
328 avfilter_unref_buffer(picref);
333 static int query_formats(AVFilterContext *ctx)
335 static const enum PixelFormat pix_fmts[] = { PIX_FMT_MONOBLACK, PIX_FMT_NONE };
336 avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
340 AVFilter avfilter_vsrc_cellauto = {
342 .description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."),
343 .priv_size = sizeof(CellAutoContext),
346 .query_formats = query_formats,
348 .inputs = (const AVFilterPad[]) {
351 .outputs = (const AVFilterPad[]) {
353 .type = AVMEDIA_TYPE_VIDEO,
354 .request_frame = request_frame,
355 .config_props = config_props },