[deb_ffmpeg.git] / ffmpeg / libavfilter / vsrc_cellauto.c

/*
 * 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_array(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_array(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 ff_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,
};
Commit	Line	Data
2ba45a60 DM	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_idxcellauto->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	};