yading@11: /*
yading@11:  * Copyright (c) Stefano Sabatini 2011
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * cellular automaton video source, based on Stephen Wolfram "experimentus crucis"
yading@11:  */
yading@11: 
yading@11: /* #define DEBUG */
yading@11: 
yading@11: #include "libavutil/file.h"
yading@11: #include "libavutil/lfg.h"
yading@11: #include "libavutil/opt.h"
yading@11: #include "libavutil/parseutils.h"
yading@11: #include "libavutil/random_seed.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "avfilter.h"
yading@11: #include "internal.h"
yading@11: #include "formats.h"
yading@11: #include "video.h"
yading@11: 
yading@11: typedef struct {
yading@11:     const AVClass *class;
yading@11:     int w, h;
yading@11:     char *filename;
yading@11:     char *rule_str;
yading@11:     uint8_t *file_buf;
yading@11:     size_t file_bufsize;
yading@11:     uint8_t *buf;
yading@11:     int buf_prev_row_idx, buf_row_idx;
yading@11:     uint8_t rule;
yading@11:     uint64_t pts;
yading@11:     AVRational frame_rate;
yading@11:     double   random_fill_ratio;
yading@11:     uint32_t random_seed;
yading@11:     int stitch, scroll, start_full;
yading@11:     int64_t generation;         ///< the generation number, starting from 0
yading@11:     AVLFG lfg;
yading@11:     char *pattern;
yading@11: } CellAutoContext;
yading@11: 
yading@11: #define OFFSET(x) offsetof(CellAutoContext, x)
yading@11: #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
yading@11: 
yading@11: static const AVOption cellauto_options[] = {
yading@11:     { "filename", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
yading@11:     { "f",        "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
yading@11:     { "pattern",  "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
yading@11:     { "p",        "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
yading@11:     { "rate",     "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
yading@11:     { "r",        "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
yading@11:     { "size",     "set video size", OFFSET(w),    AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
yading@11:     { "s",        "set video size", OFFSET(w),    AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
yading@11:     { "rule",     "set rule",       OFFSET(rule), AV_OPT_TYPE_INT,    {.i64 = 110},  0, 255, FLAGS },
yading@11:     { "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 },
yading@11:     { "ratio",             "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl = 1/M_PHI}, 0, 1, FLAGS },
yading@11:     { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
yading@11:     { "seed",        "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
yading@11:     { "scroll",      "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS },
yading@11:     { "start_full",  "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
yading@11:     { "full",        "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS },
yading@11:     { "stitch",      "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT,    {.i64 = 1},   0, 1, FLAGS },
yading@11:     { NULL },
yading@11: };
yading@11: 
yading@11: AVFILTER_DEFINE_CLASS(cellauto);
yading@11: 
yading@11: #ifdef DEBUG
yading@11: static void show_cellauto_row(AVFilterContext *ctx)
yading@11: {
yading@11:     CellAutoContext *cellauto = ctx->priv;
yading@11:     int i;
yading@11:     uint8_t *row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
yading@11:     char *line = av_malloc(cellauto->w + 1);
yading@11:     if (!line)
yading@11:         return;
yading@11: 
yading@11:     for (i = 0; i < cellauto->w; i++)
yading@11:         line[i] = row[i] ? '@' : ' ';
yading@11:     line[i] = 0;
yading@11:     av_log(ctx, AV_LOG_DEBUG, "generation:%"PRId64" row:%s|\n", cellauto->generation, line);
yading@11:     av_free(line);
yading@11: }
yading@11: #endif
yading@11: 
yading@11: static int init_pattern_from_string(AVFilterContext *ctx)
yading@11: {
yading@11:     CellAutoContext *cellauto = ctx->priv;
yading@11:     char *p;
yading@11:     int i, w = 0;
yading@11: 
yading@11:     w = strlen(cellauto->pattern);
yading@11:     av_log(ctx, AV_LOG_DEBUG, "w:%d\n", w);
yading@11: 
yading@11:     if (cellauto->w) {
yading@11:         if (w > cellauto->w) {
yading@11:             av_log(ctx, AV_LOG_ERROR,
yading@11:                    "The specified width is %d which cannot contain the provided string width of %d\n",
yading@11:                    cellauto->w, w);
yading@11:             return AVERROR(EINVAL);
yading@11:         }
yading@11:     } else {
yading@11:         /* width was not specified, set it to width of the provided row */
yading@11:         cellauto->w = w;
yading@11:         cellauto->h = (double)cellauto->w * M_PHI;
yading@11:     }
yading@11: 
yading@11:     cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
yading@11:     if (!cellauto->buf)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     /* fill buf */
yading@11:     p = cellauto->pattern;
yading@11:     for (i = (cellauto->w - w)/2;; i++) {
yading@11:         av_log(ctx, AV_LOG_DEBUG, "%d %c\n", i, *p == '\n' ? 'N' : *p);
yading@11:         if (*p == '\n' || !*p)
yading@11:             break;
yading@11:         else
yading@11:             cellauto->buf[i] = !!av_isgraph(*(p++));
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int init_pattern_from_file(AVFilterContext *ctx)
yading@11: {
yading@11:     CellAutoContext *cellauto = ctx->priv;
yading@11:     int ret;
yading@11: 
yading@11:     ret = av_file_map(cellauto->filename,
yading@11:                       &cellauto->file_buf, &cellauto->file_bufsize, 0, ctx);
yading@11:     if (ret < 0)
yading@11:         return ret;
yading@11: 
yading@11:     /* create a string based on the read file */
yading@11:     cellauto->pattern = av_malloc(cellauto->file_bufsize + 1);
yading@11:     if (!cellauto->pattern)
yading@11:         return AVERROR(ENOMEM);
yading@11:     memcpy(cellauto->pattern, cellauto->file_buf, cellauto->file_bufsize);
yading@11:     cellauto->pattern[cellauto->file_bufsize] = 0;
yading@11: 
yading@11:     return init_pattern_from_string(ctx);
yading@11: }
yading@11: 
yading@11: static int init(AVFilterContext *ctx)
yading@11: {
yading@11:     CellAutoContext *cellauto = ctx->priv;
yading@11:     int ret;
yading@11: 
yading@11:     if (!cellauto->w && !cellauto->filename && !cellauto->pattern)
yading@11:         av_opt_set(cellauto, "size", "320x518", 0);
yading@11: 
yading@11:     if (cellauto->filename && cellauto->pattern) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Only one of the filename or pattern options can be used\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     if (cellauto->filename) {
yading@11:         if ((ret = init_pattern_from_file(ctx)) < 0)
yading@11:             return ret;
yading@11:     } else if (cellauto->pattern) {
yading@11:         if ((ret = init_pattern_from_string(ctx)) < 0)
yading@11:             return ret;
yading@11:     } else {
yading@11:         /* fill the first row randomly */
yading@11:         int i;
yading@11: 
yading@11:         cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
yading@11:         if (!cellauto->buf)
yading@11:             return AVERROR(ENOMEM);
yading@11:         if (cellauto->random_seed == -1)
yading@11:             cellauto->random_seed = av_get_random_seed();
yading@11: 
yading@11:         av_lfg_init(&cellauto->lfg, cellauto->random_seed);
yading@11: 
yading@11:         for (i = 0; i < cellauto->w; i++) {
yading@11:             double r = (double)av_lfg_get(&cellauto->lfg) / UINT32_MAX;
yading@11:             if (r <= cellauto->random_fill_ratio)
yading@11:                 cellauto->buf[i] = 1;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     av_log(ctx, AV_LOG_VERBOSE,
yading@11:            "s:%dx%d r:%d/%d rule:%d stitch:%d scroll:%d full:%d seed:%u\n",
yading@11:            cellauto->w, cellauto->h, cellauto->frame_rate.num, cellauto->frame_rate.den,
yading@11:            cellauto->rule, cellauto->stitch, cellauto->scroll, cellauto->start_full,
yading@11:            cellauto->random_seed);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static av_cold void uninit(AVFilterContext *ctx)
yading@11: {
yading@11:     CellAutoContext *cellauto = ctx->priv;
yading@11: 
yading@11:     av_file_unmap(cellauto->file_buf, cellauto->file_bufsize);
yading@11:     av_freep(&cellauto->buf);
yading@11:     av_freep(&cellauto->pattern);
yading@11: }
yading@11: 
yading@11: static int config_props(AVFilterLink *outlink)
yading@11: {
yading@11:     CellAutoContext *cellauto = outlink->src->priv;
yading@11: 
yading@11:     outlink->w = cellauto->w;
yading@11:     outlink->h = cellauto->h;
yading@11:     outlink->time_base = av_inv_q(cellauto->frame_rate);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static void evolve(AVFilterContext *ctx)
yading@11: {
yading@11:     CellAutoContext *cellauto = ctx->priv;
yading@11:     int i, v, pos[3];
yading@11:     uint8_t *row, *prev_row = cellauto->buf + cellauto->buf_row_idx * cellauto->w;
yading@11:     enum { NW, N, NE };
yading@11: 
yading@11:     cellauto->buf_prev_row_idx = cellauto->buf_row_idx;
yading@11:     cellauto->buf_row_idx      = cellauto->buf_row_idx == cellauto->h-1 ? 0 : cellauto->buf_row_idx+1;
yading@11:     row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
yading@11: 
yading@11:     for (i = 0; i < cellauto->w; i++) {
yading@11:         if (cellauto->stitch) {
yading@11:             pos[NW] = i-1 < 0 ? cellauto->w-1 : i-1;
yading@11:             pos[N]  = i;
yading@11:             pos[NE] = i+1 == cellauto->w ? 0  : i+1;
yading@11:             v = prev_row[pos[NW]]<<2 | prev_row[pos[N]]<<1 | prev_row[pos[NE]];
yading@11:         } else {
yading@11:             v = 0;
yading@11:             v|= i-1 >= 0          ? prev_row[i-1]<<2 : 0;
yading@11:             v|=                     prev_row[i  ]<<1    ;
yading@11:             v|= i+1 < cellauto->w ? prev_row[i+1]    : 0;
yading@11:         }
yading@11:         row[i] = !!(cellauto->rule & (1<<v));
yading@11:         av_dlog(ctx, "i:%d context:%c%c%c -> cell:%d\n", i,
yading@11:                 v&4?'@':' ', v&2?'@':' ', v&1?'@':' ', row[i]);
yading@11:     }
yading@11: 
yading@11:     cellauto->generation++;
yading@11: }
yading@11: 
yading@11: static void fill_picture(AVFilterContext *ctx, AVFrame *picref)
yading@11: {
yading@11:     CellAutoContext *cellauto = ctx->priv;
yading@11:     int i, j, k, row_idx = 0;
yading@11:     uint8_t *p0 = picref->data[0];
yading@11: 
yading@11:     if (cellauto->scroll && cellauto->generation >= cellauto->h)
yading@11:         /* show on top the oldest row */
yading@11:         row_idx = (cellauto->buf_row_idx + 1) % cellauto->h;
yading@11: 
yading@11:     /* fill the output picture with the whole buffer */
yading@11:     for (i = 0; i < cellauto->h; i++) {
yading@11:         uint8_t byte = 0;
yading@11:         uint8_t *row = cellauto->buf + row_idx*cellauto->w;
yading@11:         uint8_t *p = p0;
yading@11:         for (k = 0, j = 0; j < cellauto->w; j++) {
yading@11:             byte |= row[j]<<(7-k++);
yading@11:             if (k==8 || j == cellauto->w-1) {
yading@11:                 k = 0;
yading@11:                 *p++ = byte;
yading@11:                 byte = 0;
yading@11:             }
yading@11:         }
yading@11:         row_idx = (row_idx + 1) % cellauto->h;
yading@11:         p0 += picref->linesize[0];
yading@11:     }
yading@11: }
yading@11: 
yading@11: static int request_frame(AVFilterLink *outlink)
yading@11: {
yading@11:     CellAutoContext *cellauto = outlink->src->priv;
yading@11:     AVFrame *picref = ff_get_video_buffer(outlink, cellauto->w, cellauto->h);
yading@11:     if (!picref)
yading@11:         return AVERROR(ENOMEM);
yading@11:     picref->sample_aspect_ratio = (AVRational) {1, 1};
yading@11:     if (cellauto->generation == 0 && cellauto->start_full) {
yading@11:         int i;
yading@11:         for (i = 0; i < cellauto->h-1; i++)
yading@11:             evolve(outlink->src);
yading@11:     }
yading@11:     fill_picture(outlink->src, picref);
yading@11:     evolve(outlink->src);
yading@11: 
yading@11:     picref->pts = cellauto->pts++;
yading@11: 
yading@11: #ifdef DEBUG
yading@11:     show_cellauto_row(outlink->src);
yading@11: #endif
yading@11:     return ff_filter_frame(outlink, picref);
yading@11: }
yading@11: 
yading@11: static int query_formats(AVFilterContext *ctx)
yading@11: {
yading@11:     static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE };
yading@11:     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static const AVFilterPad cellauto_outputs[] = {
yading@11:     {
yading@11:         .name            = "default",
yading@11:         .type            = AVMEDIA_TYPE_VIDEO,
yading@11:         .request_frame   = request_frame,
yading@11:         .config_props    = config_props,
yading@11:     },
yading@11:     { NULL }
yading@11: };
yading@11: 
yading@11: AVFilter avfilter_vsrc_cellauto = {
yading@11:     .name        = "cellauto",
yading@11:     .description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."),
yading@11:     .priv_size = sizeof(CellAutoContext),
yading@11:     .init      = init,
yading@11:     .uninit    = uninit,
yading@11:     .query_formats = query_formats,
yading@11:     .inputs        = NULL,
yading@11:     .outputs       = cellauto_outputs,
yading@11:     .priv_class    = &cellauto_class,
yading@11: };