/*
* 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 "libavutil/avstring.h"
#include "avfilter.h"
#include "internal.h"
#include "formats.h"
#include "video.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 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)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption cellauto_options[] = {
{ "filename", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "f", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "pattern", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "p", "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "rate", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
{ "r", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
{ "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
{ "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, FLAGS },
{ "rule", "set rule", OFFSET(rule), AV_OPT_TYPE_INT, {.i64 = 110}, 0, 255, FLAGS },
{ "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 },
{ "ratio", "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl = 1/M_PHI}, 0, 1, FLAGS },
{ "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
{ "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
{ "scroll", "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS },
{ "start_full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
{ "full", "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS },
{ "stitch", "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(cellauto);
#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->w) {
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] = !!av_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 av_cold int init(AVFilterContext *ctx)
{
CellAutoContext *cellauto = ctx->priv;
int ret;
if (!cellauto->w && !cellauto->filename && !cellauto->pattern)
av_opt_set(cellauto, "size", "320x518", 0);
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_VERBOSE,
"s:%dx%d r:%d/%d rule:%d stitch:%d scroll:%d full:%d seed:%u\n",
cellauto->w, cellauto->h, cellauto->frame_rate.num, cellauto->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 = av_inv_q(cellauto->frame_rate);
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, AVFrame *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;
AVFrame *picref = ff_get_video_buffer(outlink, cellauto->w, cellauto->h);
if (!picref)
return AVERROR(ENOMEM);
picref->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++;
#ifdef DEBUG
show_cellauto_row(outlink->src);
#endif
return ff_filter_frame(outlink, picref);
}
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE };
ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
return 0;
}
static const AVFilterPad cellauto_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame,
.config_props = config_props,
},
{ NULL }
};
AVFilter avfilter_vsrc_cellauto = {
.name = "cellauto",
.description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."),
.priv_size = sizeof(CellAutoContext),
.priv_class = &cellauto_class,
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = NULL,
.outputs = cellauto_outputs,
};