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