/* * Copyright (c) Stefano Sabatini 2011 * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * cellular automaton video source, based on Stephen Wolfram "experimentus crucis" */ /* #define DEBUG */ #include "libavutil/file.h" #include "libavutil/lfg.h" #include "libavutil/opt.h" #include "libavutil/parseutils.h" #include "libavutil/random_seed.h" #include "avfilter.h" typedef struct { const AVClass *class; int w, h; char *filename; char *rule_str; uint8_t *file_buf; size_t file_bufsize; uint8_t *buf; int buf_prev_row_idx, buf_row_idx; uint8_t rule; uint64_t pts; AVRational time_base; char *size; ///< video frame size char *rate; ///< video frame rate double random_fill_ratio; uint32_t random_seed; int stitch, scroll, start_full; int64_t generation; ///< the generation number, starting from 0 AVLFG lfg; char *pattern; } CellAutoContext; #define OFFSET(x) offsetof(CellAutoContext, x) static const AVOption cellauto_options[] = { { "filename", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 }, { "f", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 }, { "pattern", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 }, { "p", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 }, { "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 }, { "r", "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 }, { "size", "set video size", OFFSET(size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 }, { "s", "set video size", OFFSET(size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 }, { "rule", "set rule", OFFSET(rule), AV_OPT_TYPE_INT, {.dbl = 110}, 0, 255 }, { "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 }, { "ratio", "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl = 1/M_PHI}, 0, 1 }, { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX }, { "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX }, { "scroll", "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 }, { "start_full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 0}, 0, 1 }, { "full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 }, { "stitch", "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 }, { NULL }, }; static const char *cellauto_get_name(void *ctx) { return "cellauto"; } static const AVClass cellauto_class = { "CellAutoContext", cellauto_get_name, cellauto_options }; #ifdef DEBUG static void show_cellauto_row(AVFilterContext *ctx) { CellAutoContext *cellauto = ctx->priv; int i; uint8_t *row = cellauto->buf + cellauto->w * cellauto->buf_row_idx; char *line = av_malloc(cellauto->w + 1); if (!line) return; for (i = 0; i < cellauto->w; i++) line[i] = row[i] ? '@' : ' '; line[i] = 0; av_log(ctx, AV_LOG_DEBUG, "generation:%"PRId64" row:%s|\n", cellauto->generation, line); av_free(line); } #endif static int init_pattern_from_string(AVFilterContext *ctx) { CellAutoContext *cellauto = ctx->priv; char *p; int i, w = 0; w = strlen(cellauto->pattern); av_log(ctx, AV_LOG_DEBUG, "w:%d\n", w); if (cellauto->size) { if (w > cellauto->w) { av_log(ctx, AV_LOG_ERROR, "The specified width is %d which cannot contain the provided string width of %d\n", cellauto->w, w); return AVERROR(EINVAL); } } else { /* width was not specified, set it to width of the provided row */ cellauto->w = w; cellauto->h = (double)cellauto->w * M_PHI; } cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h); if (!cellauto->buf) return AVERROR(ENOMEM); /* fill buf */ p = cellauto->pattern; for (i = (cellauto->w - w)/2;; i++) { av_log(ctx, AV_LOG_DEBUG, "%d %c\n", i, *p == '\n' ? 'N' : *p); if (*p == '\n' || !*p) break; else cellauto->buf[i] = !!isgraph(*(p++)); } return 0; } static int init_pattern_from_file(AVFilterContext *ctx) { CellAutoContext *cellauto = ctx->priv; int ret; ret = av_file_map(cellauto->filename, &cellauto->file_buf, &cellauto->file_bufsize, 0, ctx); if (ret < 0) return ret; /* create a string based on the read file */ cellauto->pattern = av_malloc(cellauto->file_bufsize + 1); if (!cellauto->pattern) return AVERROR(ENOMEM); memcpy(cellauto->pattern, cellauto->file_buf, cellauto->file_bufsize); cellauto->pattern[cellauto->file_bufsize] = 0; return init_pattern_from_string(ctx); } static int init(AVFilterContext *ctx, const char *args, void *opaque) { CellAutoContext *cellauto = ctx->priv; AVRational frame_rate; int ret; cellauto->class = &cellauto_class; av_opt_set_defaults(cellauto); if ((ret = av_set_options_string(cellauto, args, "=", ":")) < 0) { av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args); return ret; } if ((ret = av_parse_video_rate(&frame_rate, cellauto->rate)) < 0) { av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", cellauto->rate); return AVERROR(EINVAL); } if (!cellauto->size && !cellauto->filename && !cellauto->pattern) av_opt_set(cellauto, "size", "320x518", 0); if (cellauto->size && (ret = av_parse_video_size(&cellauto->w, &cellauto->h, cellauto->size)) < 0) { av_log(ctx, AV_LOG_ERROR, "Invalid frame size: %s\n", cellauto->size); return ret; } cellauto->time_base.num = frame_rate.den; cellauto->time_base.den = frame_rate.num; if (cellauto->filename && cellauto->pattern) { av_log(ctx, AV_LOG_ERROR, "Only one of the filename or pattern options can be used\n"); return AVERROR(EINVAL); } if (cellauto->filename) { if ((ret = init_pattern_from_file(ctx)) < 0) return ret; } else if (cellauto->pattern) { if ((ret = init_pattern_from_string(ctx)) < 0) return ret; } else { /* fill the first row randomly */ int i; cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h); if (!cellauto->buf) return AVERROR(ENOMEM); if (cellauto->random_seed == -1) cellauto->random_seed = av_get_random_seed(); av_lfg_init(&cellauto->lfg, cellauto->random_seed); for (i = 0; i < cellauto->w; i++) { double r = (double)av_lfg_get(&cellauto->lfg) / UINT32_MAX; if (r <= cellauto->random_fill_ratio) cellauto->buf[i] = 1; } } av_log(ctx, AV_LOG_INFO, "s:%dx%d r:%d/%d rule:%d stitch:%d scroll:%d full:%d seed:%u\n", cellauto->w, cellauto->h, frame_rate.num, frame_rate.den, cellauto->rule, cellauto->stitch, cellauto->scroll, cellauto->start_full, cellauto->random_seed); return 0; } static av_cold void uninit(AVFilterContext *ctx) { CellAutoContext *cellauto = ctx->priv; av_file_unmap(cellauto->file_buf, cellauto->file_bufsize); av_freep(&cellauto->buf); av_freep(&cellauto->pattern); } static int config_props(AVFilterLink *outlink) { CellAutoContext *cellauto = outlink->src->priv; outlink->w = cellauto->w; outlink->h = cellauto->h; outlink->time_base = cellauto->time_base; return 0; } static void evolve(AVFilterContext *ctx) { CellAutoContext *cellauto = ctx->priv; int i, v, pos[3]; uint8_t *row, *prev_row = cellauto->buf + cellauto->buf_row_idx * cellauto->w; enum { NW, N, NE }; cellauto->buf_prev_row_idx = cellauto->buf_row_idx; cellauto->buf_row_idx = cellauto->buf_row_idx == cellauto->h-1 ? 0 : cellauto->buf_row_idx+1; row = cellauto->buf + cellauto->w * cellauto->buf_row_idx; for (i = 0; i < cellauto->w; i++) { if (cellauto->stitch) { pos[NW] = i-1 < 0 ? cellauto->w-1 : i-1; pos[N] = i; pos[NE] = i+1 == cellauto->w ? 0 : i+1; v = prev_row[pos[NW]]<<2 | prev_row[pos[N]]<<1 | prev_row[pos[NE]]; } else { v = 0; v|= i-1 >= 0 ? prev_row[i-1]<<2 : 0; v|= prev_row[i ]<<1 ; v|= i+1 < cellauto->w ? prev_row[i+1] : 0; } row[i] = !!(cellauto->rule & (1<<v)); av_dlog(ctx, "i:%d context:%c%c%c -> cell:%d\n", i, v&4?'@':' ', v&2?'@':' ', v&1?'@':' ', row[i]); } cellauto->generation++; } static void fill_picture(AVFilterContext *ctx, AVFilterBufferRef *picref) { CellAutoContext *cellauto = ctx->priv; int i, j, k, row_idx = 0; uint8_t *p0 = picref->data[0]; if (cellauto->scroll && cellauto->generation >= cellauto->h) /* show on top the oldest row */ row_idx = (cellauto->buf_row_idx + 1) % cellauto->h; /* fill the output picture with the whole buffer */ for (i = 0; i < cellauto->h; i++) { uint8_t byte = 0; uint8_t *row = cellauto->buf + row_idx*cellauto->w; uint8_t *p = p0; for (k = 0, j = 0; j < cellauto->w; j++) { byte |= row[j]<<(7-k++); if (k==8 || j == cellauto->w-1) { k = 0; *p++ = byte; byte = 0; } } row_idx = (row_idx + 1) % cellauto->h; p0 += picref->linesize[0]; } } static int request_frame(AVFilterLink *outlink) { CellAutoContext *cellauto = outlink->src->priv; AVFilterBufferRef *picref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, cellauto->w, cellauto->h); picref->video->sample_aspect_ratio = (AVRational) {1, 1}; if (cellauto->generation == 0 && cellauto->start_full) { int i; for (i = 0; i < cellauto->h-1; i++) evolve(outlink->src); } fill_picture(outlink->src, picref); evolve(outlink->src); picref->pts = cellauto->pts++; picref->pos = -1; #ifdef DEBUG show_cellauto_row(outlink->src); #endif avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0)); avfilter_draw_slice(outlink, 0, cellauto->h, 1); avfilter_end_frame(outlink); avfilter_unref_buffer(picref); return 0; } static int query_formats(AVFilterContext *ctx) { static const enum PixelFormat pix_fmts[] = { PIX_FMT_MONOBLACK, PIX_FMT_NONE }; avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts)); return 0; } AVFilter avfilter_vsrc_cellauto = { .name = "cellauto", .description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."), .priv_size = sizeof(CellAutoContext), .init = init, .uninit = uninit, .query_formats = query_formats, .inputs = (const AVFilterPad[]) { { .name = NULL} }, .outputs = (const AVFilterPad[]) { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .request_frame = request_frame, .config_props = config_props }, { .name = NULL} }, };