| 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/lfg.h" |
| 30 | #include "libavutil/opt.h" |
| 31 | #include "libavutil/parseutils.h" |
| 32 | #include "libavutil/random_seed.h" |
| 33 | #include "libavutil/avstring.h" |
| 34 | #include "avfilter.h" |
| 35 | #include "internal.h" |
| 36 | #include "formats.h" |
| 37 | #include "video.h" |
| 38 | |
| 39 | typedef struct { |
| 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 | uint32_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, 0, FLAGS }, |
| 68 | { "r", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, 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_INT, {.i64 = -1}, -1, UINT32_MAX, FLAGS }, |
| 75 | { "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.i64 = -1}, -1, UINT32_MAX, FLAGS }, |
| 76 | { "scroll", "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS }, |
| 77 | { "start_full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS }, |
| 78 | { "full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS }, |
| 79 | { "stitch", "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT, {.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 *cellauto = ctx->priv; |
| 89 | int i; |
| 90 | uint8_t *row = cellauto->buf + cellauto->w * cellauto->buf_row_idx; |
| 91 | char *line = av_malloc(cellauto->w + 1); |
| 92 | if (!line) |
| 93 | return; |
| 94 | |
| 95 | for (i = 0; i < cellauto->w; i++) |
| 96 | line[i] = row[i] ? '@' : ' '; |
| 97 | line[i] = 0; |
| 98 | av_log(ctx, AV_LOG_DEBUG, "generation:%"PRId64" row:%s|\n", cellauto->generation, line); |
| 99 | av_free(line); |
| 100 | } |
| 101 | #endif |
| 102 | |
| 103 | static int init_pattern_from_string(AVFilterContext *ctx) |
| 104 | { |
| 105 | CellAutoContext *cellauto = ctx->priv; |
| 106 | char *p; |
| 107 | int i, w = 0; |
| 108 | |
| 109 | w = strlen(cellauto->pattern); |
| 110 | av_log(ctx, AV_LOG_DEBUG, "w:%d\n", w); |
| 111 | |
| 112 | if (cellauto->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", |
| 116 | cellauto->w, w); |
| 117 | return AVERROR(EINVAL); |
| 118 | } |
| 119 | } else { |
| 120 | /* width was not specified, set it to width of the provided row */ |
| 121 | cellauto->w = w; |
| 122 | cellauto->h = (double)cellauto->w * M_PHI; |
| 123 | } |
| 124 | |
| 125 | cellauto->buf = av_mallocz_array(sizeof(uint8_t) * cellauto->w, cellauto->h); |
| 126 | if (!cellauto->buf) |
| 127 | return AVERROR(ENOMEM); |
| 128 | |
| 129 | /* fill buf */ |
| 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) |
| 134 | break; |
| 135 | else |
| 136 | cellauto->buf[i] = !!av_isgraph(*(p++)); |
| 137 | } |
| 138 | |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | static int init_pattern_from_file(AVFilterContext *ctx) |
| 143 | { |
| 144 | CellAutoContext *cellauto = ctx->priv; |
| 145 | int ret; |
| 146 | |
| 147 | ret = av_file_map(cellauto->filename, |
| 148 | &cellauto->file_buf, &cellauto->file_bufsize, 0, ctx); |
| 149 | if (ret < 0) |
| 150 | return ret; |
| 151 | |
| 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; |
| 158 | |
| 159 | return init_pattern_from_string(ctx); |
| 160 | } |
| 161 | |
| 162 | static av_cold int init(AVFilterContext *ctx) |
| 163 | { |
| 164 | CellAutoContext *cellauto = ctx->priv; |
| 165 | int ret; |
| 166 | |
| 167 | if (!cellauto->w && !cellauto->filename && !cellauto->pattern) |
| 168 | av_opt_set(cellauto, "size", "320x518", 0); |
| 169 | |
| 170 | if (cellauto->filename && cellauto->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 (cellauto->filename) { |
| 176 | if ((ret = init_pattern_from_file(ctx)) < 0) |
| 177 | return ret; |
| 178 | } else if (cellauto->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 | cellauto->buf = av_mallocz_array(sizeof(uint8_t) * cellauto->w, cellauto->h); |
| 186 | if (!cellauto->buf) |
| 187 | return AVERROR(ENOMEM); |
| 188 | if (cellauto->random_seed == -1) |
| 189 | cellauto->random_seed = av_get_random_seed(); |
| 190 | |
| 191 | av_lfg_init(&cellauto->lfg, cellauto->random_seed); |
| 192 | |
| 193 | for (i = 0; i < cellauto->w; i++) { |
| 194 | double r = (double)av_lfg_get(&cellauto->lfg) / UINT32_MAX; |
| 195 | if (r <= cellauto->random_fill_ratio) |
| 196 | cellauto->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:%u\n", |
| 202 | cellauto->w, cellauto->h, cellauto->frame_rate.num, cellauto->frame_rate.den, |
| 203 | cellauto->rule, cellauto->stitch, cellauto->scroll, cellauto->start_full, |
| 204 | cellauto->random_seed); |
| 205 | return 0; |
| 206 | } |
| 207 | |
| 208 | static av_cold void uninit(AVFilterContext *ctx) |
| 209 | { |
| 210 | CellAutoContext *cellauto = ctx->priv; |
| 211 | |
| 212 | av_file_unmap(cellauto->file_buf, cellauto->file_bufsize); |
| 213 | av_freep(&cellauto->buf); |
| 214 | av_freep(&cellauto->pattern); |
| 215 | } |
| 216 | |
| 217 | static int config_props(AVFilterLink *outlink) |
| 218 | { |
| 219 | CellAutoContext *cellauto = outlink->src->priv; |
| 220 | |
| 221 | outlink->w = cellauto->w; |
| 222 | outlink->h = cellauto->h; |
| 223 | outlink->time_base = av_inv_q(cellauto->frame_rate); |
| 224 | |
| 225 | return 0; |
| 226 | } |
| 227 | |
| 228 | static void evolve(AVFilterContext *ctx) |
| 229 | { |
| 230 | CellAutoContext *cellauto = ctx->priv; |
| 231 | int i, v, pos[3]; |
| 232 | uint8_t *row, *prev_row = cellauto->buf + cellauto->buf_row_idx * cellauto->w; |
| 233 | enum { NW, N, NE }; |
| 234 | |
| 235 | cellauto->buf_prev_row_idx = cellauto->buf_row_idx; |
| 236 | cellauto->buf_row_idx = cellauto->buf_row_idx == cellauto->h-1 ? 0 : cellauto->buf_row_idx+1; |
| 237 | row = cellauto->buf + cellauto->w * cellauto->buf_row_idx; |
| 238 | |
| 239 | for (i = 0; i < cellauto->w; i++) { |
| 240 | if (cellauto->stitch) { |
| 241 | pos[NW] = i-1 < 0 ? cellauto->w-1 : i-1; |
| 242 | pos[N] = i; |
| 243 | pos[NE] = i+1 == cellauto->w ? 0 : i+1; |
| 244 | v = prev_row[pos[NW]]<<2 | prev_row[pos[N]]<<1 | prev_row[pos[NE]]; |
| 245 | } else { |
| 246 | v = 0; |
| 247 | v|= i-1 >= 0 ? prev_row[i-1]<<2 : 0; |
| 248 | v|= prev_row[i ]<<1 ; |
| 249 | v|= i+1 < cellauto->w ? prev_row[i+1] : 0; |
| 250 | } |
| 251 | row[i] = !!(cellauto->rule & (1<<v)); |
| 252 | av_dlog(ctx, "i:%d context:%c%c%c -> cell:%d\n", i, |
| 253 | v&4?'@':' ', v&2?'@':' ', v&1?'@':' ', row[i]); |
| 254 | } |
| 255 | |
| 256 | cellauto->generation++; |
| 257 | } |
| 258 | |
| 259 | static void fill_picture(AVFilterContext *ctx, AVFrame *picref) |
| 260 | { |
| 261 | CellAutoContext *cellauto = ctx->priv; |
| 262 | int i, j, k, row_idx = 0; |
| 263 | uint8_t *p0 = picref->data[0]; |
| 264 | |
| 265 | if (cellauto->scroll && cellauto->generation >= cellauto->h) |
| 266 | /* show on top the oldest row */ |
| 267 | row_idx = (cellauto->buf_row_idx + 1) % cellauto->h; |
| 268 | |
| 269 | /* fill the output picture with the whole buffer */ |
| 270 | for (i = 0; i < cellauto->h; i++) { |
| 271 | uint8_t byte = 0; |
| 272 | uint8_t *row = cellauto->buf + row_idx*cellauto->w; |
| 273 | uint8_t *p = p0; |
| 274 | for (k = 0, j = 0; j < cellauto->w; j++) { |
| 275 | byte |= row[j]<<(7-k++); |
| 276 | if (k==8 || j == cellauto->w-1) { |
| 277 | k = 0; |
| 278 | *p++ = byte; |
| 279 | byte = 0; |
| 280 | } |
| 281 | } |
| 282 | row_idx = (row_idx + 1) % cellauto->h; |
| 283 | p0 += picref->linesize[0]; |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | static int request_frame(AVFilterLink *outlink) |
| 288 | { |
| 289 | CellAutoContext *cellauto = outlink->src->priv; |
| 290 | AVFrame *picref = ff_get_video_buffer(outlink, cellauto->w, cellauto->h); |
| 291 | if (!picref) |
| 292 | return AVERROR(ENOMEM); |
| 293 | picref->sample_aspect_ratio = (AVRational) {1, 1}; |
| 294 | if (cellauto->generation == 0 && cellauto->start_full) { |
| 295 | int i; |
| 296 | for (i = 0; i < cellauto->h-1; i++) |
| 297 | evolve(outlink->src); |
| 298 | } |
| 299 | fill_picture(outlink->src, picref); |
| 300 | evolve(outlink->src); |
| 301 | |
| 302 | picref->pts = cellauto->pts++; |
| 303 | |
| 304 | #ifdef DEBUG |
| 305 | show_cellauto_row(outlink->src); |
| 306 | #endif |
| 307 | return ff_filter_frame(outlink, picref); |
| 308 | } |
| 309 | |
| 310 | static int query_formats(AVFilterContext *ctx) |
| 311 | { |
| 312 | static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE }; |
| 313 | ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); |
| 314 | return 0; |
| 315 | } |
| 316 | |
| 317 | static const AVFilterPad cellauto_outputs[] = { |
| 318 | { |
| 319 | .name = "default", |
| 320 | .type = AVMEDIA_TYPE_VIDEO, |
| 321 | .request_frame = request_frame, |
| 322 | .config_props = config_props, |
| 323 | }, |
| 324 | { NULL } |
| 325 | }; |
| 326 | |
| 327 | AVFilter ff_vsrc_cellauto = { |
| 328 | .name = "cellauto", |
| 329 | .description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."), |
| 330 | .priv_size = sizeof(CellAutoContext), |
| 331 | .priv_class = &cellauto_class, |
| 332 | .init = init, |
| 333 | .uninit = uninit, |
| 334 | .query_formats = query_formats, |
| 335 | .inputs = NULL, |
| 336 | .outputs = cellauto_outputs, |
| 337 | }; |