libavfilter/vsrc_cellauto.c
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00001 /*
00002  * Copyright (c) Stefano Sabatini 2011
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00026 /* #define DEBUG */
00027 
00028 #include "libavutil/file.h"
00029 #include "libavutil/lfg.h"
00030 #include "libavutil/opt.h"
00031 #include "libavutil/parseutils.h"
00032 #include "libavutil/random_seed.h"
00033 #include "avfilter.h"
00034 
00035 typedef struct {
00036     const AVClass *class;
00037     int w, h;
00038     char *filename;
00039     char *rule_str;
00040     uint8_t *file_buf;
00041     size_t file_bufsize;
00042     uint8_t *buf;
00043     int buf_prev_row_idx, buf_row_idx;
00044     uint8_t rule;
00045     uint64_t pts;
00046     AVRational time_base;
00047     char *size;                 
00048     char *rate;                 
00049     double   random_fill_ratio;
00050     uint32_t random_seed;
00051     int stitch, scroll, start_full;
00052     int64_t generation;         
00053     AVLFG lfg;
00054     char *pattern;
00055 } CellAutoContext;
00056 
00057 #define OFFSET(x) offsetof(CellAutoContext, x)
00058 
00059 static const AVOption cellauto_options[] = {
00060     { "filename", "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
00061     { "f",        "read initial pattern from file", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
00062     { "pattern",  "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
00063     { "p",        "set initial pattern", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
00064     { "rate",     "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 },
00065     { "r",        "set video rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0 },
00066     { "size",     "set video size", OFFSET(size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
00067     { "s",        "set video size", OFFSET(size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
00068     { "rule",     "set rule",       OFFSET(rule), AV_OPT_TYPE_INT,    {.dbl = 110},  0, 255 },
00069     { "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 },
00070     { "ratio",             "set fill ratio for filling initial grid randomly", OFFSET(random_fill_ratio), AV_OPT_TYPE_DOUBLE, {.dbl = 1/M_PHI}, 0, 1 },
00071     { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX },
00072     { "seed",        "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_INT, {.dbl = -1}, -1, UINT32_MAX },
00073     { "scroll",      "scroll pattern downward", OFFSET(scroll), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
00074     { "start_full",  "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 0}, 0, 1 },
00075     { "full",        "start filling the whole video", OFFSET(start_full), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1 },
00076     { "stitch",      "stitch boundaries", OFFSET(stitch), AV_OPT_TYPE_INT,    {.dbl = 1},   0, 1 },
00077     { NULL },
00078 };
00079 
00080 static const char *cellauto_get_name(void *ctx)
00081 {
00082     return "cellauto";
00083 }
00084 
00085 static const AVClass cellauto_class = {
00086     "CellAutoContext",
00087     cellauto_get_name,
00088     cellauto_options
00089 };
00090 
00091 #ifdef DEBUG
00092 static void show_cellauto_row(AVFilterContext *ctx)
00093 {
00094     CellAutoContext *cellauto = ctx->priv;
00095     int i;
00096     uint8_t *row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
00097     char *line = av_malloc(cellauto->w + 1);
00098     if (!line)
00099         return;
00100 
00101     for (i = 0; i < cellauto->w; i++)
00102         line[i] = row[i] ? '@' : ' ';
00103     line[i] = 0;
00104     av_log(ctx, AV_LOG_DEBUG, "generation:%"PRId64" row:%s|\n", cellauto->generation, line);
00105     av_free(line);
00106 }
00107 #endif
00108 
00109 static int init_pattern_from_string(AVFilterContext *ctx)
00110 {
00111     CellAutoContext *cellauto = ctx->priv;
00112     char *p;
00113     int i, w = 0;
00114 
00115     w = strlen(cellauto->pattern);
00116     av_log(ctx, AV_LOG_DEBUG, "w:%d\n", w);
00117 
00118     if (cellauto->size) {
00119         if (w > cellauto->w) {
00120             av_log(ctx, AV_LOG_ERROR,
00121                    "The specified width is %d which cannot contain the provided string width of %d\n",
00122                    cellauto->w, w);
00123             return AVERROR(EINVAL);
00124         }
00125     } else {
00126         /* width was not specified, set it to width of the provided row */
00127         cellauto->w = w;
00128         cellauto->h = (double)cellauto->w * M_PHI;
00129     }
00130 
00131     cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
00132     if (!cellauto->buf)
00133         return AVERROR(ENOMEM);
00134 
00135     /* fill buf */
00136     p = cellauto->pattern;
00137     for (i = (cellauto->w - w)/2;; i++) {
00138         av_log(ctx, AV_LOG_DEBUG, "%d %c\n", i, *p == '\n' ? 'N' : *p);
00139         if (*p == '\n' || !*p)
00140             break;
00141         else
00142             cellauto->buf[i] = !!isgraph(*(p++));
00143     }
00144 
00145     return 0;
00146 }
00147 
00148 static int init_pattern_from_file(AVFilterContext *ctx)
00149 {
00150     CellAutoContext *cellauto = ctx->priv;
00151     int ret;
00152 
00153     ret = av_file_map(cellauto->filename,
00154                       &cellauto->file_buf, &cellauto->file_bufsize, 0, ctx);
00155     if (ret < 0)
00156         return ret;
00157 
00158     /* create a string based on the read file */
00159     cellauto->pattern = av_malloc(cellauto->file_bufsize + 1);
00160     if (!cellauto->pattern)
00161         return AVERROR(ENOMEM);
00162     memcpy(cellauto->pattern, cellauto->file_buf, cellauto->file_bufsize);
00163     cellauto->pattern[cellauto->file_bufsize] = 0;
00164 
00165     return init_pattern_from_string(ctx);
00166 }
00167 
00168 static int init(AVFilterContext *ctx, const char *args, void *opaque)
00169 {
00170     CellAutoContext *cellauto = ctx->priv;
00171     AVRational frame_rate;
00172     int ret;
00173 
00174     cellauto->class = &cellauto_class;
00175     av_opt_set_defaults(cellauto);
00176 
00177     if ((ret = av_set_options_string(cellauto, args, "=", ":")) < 0) {
00178         av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
00179         return ret;
00180     }
00181 
00182     if ((ret = av_parse_video_rate(&frame_rate, cellauto->rate)) < 0) {
00183         av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", cellauto->rate);
00184         return AVERROR(EINVAL);
00185     }
00186 
00187     if (!cellauto->size && !cellauto->filename && !cellauto->pattern)
00188         av_opt_set(cellauto, "size", "320x518", 0);
00189 
00190     if (cellauto->size &&
00191         (ret = av_parse_video_size(&cellauto->w, &cellauto->h, cellauto->size)) < 0) {
00192         av_log(ctx, AV_LOG_ERROR, "Invalid frame size: %s\n", cellauto->size);
00193         return ret;
00194     }
00195 
00196     cellauto->time_base.num = frame_rate.den;
00197     cellauto->time_base.den = frame_rate.num;
00198 
00199     if (cellauto->filename && cellauto->pattern) {
00200         av_log(ctx, AV_LOG_ERROR, "Only one of the filename or pattern options can be used\n");
00201         return AVERROR(EINVAL);
00202     }
00203 
00204     if (cellauto->filename) {
00205         if ((ret = init_pattern_from_file(ctx)) < 0)
00206             return ret;
00207     } else if (cellauto->pattern) {
00208         if ((ret = init_pattern_from_string(ctx)) < 0)
00209             return ret;
00210     } else {
00211         /* fill the first row randomly */
00212         int i;
00213 
00214         cellauto->buf = av_mallocz(sizeof(uint8_t) * cellauto->w * cellauto->h);
00215         if (!cellauto->buf)
00216             return AVERROR(ENOMEM);
00217         if (cellauto->random_seed == -1)
00218             cellauto->random_seed = av_get_random_seed();
00219 
00220         av_lfg_init(&cellauto->lfg, cellauto->random_seed);
00221 
00222         for (i = 0; i < cellauto->w; i++) {
00223             double r = (double)av_lfg_get(&cellauto->lfg) / UINT32_MAX;
00224             if (r <= cellauto->random_fill_ratio)
00225                 cellauto->buf[i] = 1;
00226         }
00227     }
00228 
00229     av_log(ctx, AV_LOG_INFO,
00230            "s:%dx%d r:%d/%d rule:%d stitch:%d scroll:%d full:%d seed:%u\n",
00231            cellauto->w, cellauto->h, frame_rate.num, frame_rate.den,
00232            cellauto->rule, cellauto->stitch, cellauto->scroll, cellauto->start_full,
00233            cellauto->random_seed);
00234     return 0;
00235 }
00236 
00237 static av_cold void uninit(AVFilterContext *ctx)
00238 {
00239     CellAutoContext *cellauto = ctx->priv;
00240 
00241     av_file_unmap(cellauto->file_buf, cellauto->file_bufsize);
00242     av_freep(&cellauto->buf);
00243     av_freep(&cellauto->pattern);
00244 }
00245 
00246 static int config_props(AVFilterLink *outlink)
00247 {
00248     CellAutoContext *cellauto = outlink->src->priv;
00249 
00250     outlink->w = cellauto->w;
00251     outlink->h = cellauto->h;
00252     outlink->time_base = cellauto->time_base;
00253 
00254     return 0;
00255 }
00256 
00257 static void evolve(AVFilterContext *ctx)
00258 {
00259     CellAutoContext *cellauto = ctx->priv;
00260     int i, v, pos[3];
00261     uint8_t *row, *prev_row = cellauto->buf + cellauto->buf_row_idx * cellauto->w;
00262     enum { NW, N, NE };
00263 
00264     cellauto->buf_prev_row_idx = cellauto->buf_row_idx;
00265     cellauto->buf_row_idx      = cellauto->buf_row_idx == cellauto->h-1 ? 0 : cellauto->buf_row_idx+1;
00266     row = cellauto->buf + cellauto->w * cellauto->buf_row_idx;
00267 
00268     for (i = 0; i < cellauto->w; i++) {
00269         if (cellauto->stitch) {
00270             pos[NW] = i-1 < 0 ? cellauto->w-1 : i-1;
00271             pos[N]  = i;
00272             pos[NE] = i+1 == cellauto->w ? 0  : i+1;
00273             v = prev_row[pos[NW]]<<2 | prev_row[pos[N]]<<1 | prev_row[pos[NE]];
00274         } else {
00275             v = 0;
00276             v|= i-1 >= 0          ? prev_row[i-1]<<2 : 0;
00277             v|=                     prev_row[i  ]<<1    ;
00278             v|= i+1 < cellauto->w ? prev_row[i+1]    : 0;
00279         }
00280         row[i] = !!(cellauto->rule & (1<<v));
00281         av_dlog(ctx, "i:%d context:%c%c%c -> cell:%d\n", i,
00282                 v&4?'@':' ', v&2?'@':' ', v&1?'@':' ', row[i]);
00283     }
00284 
00285     cellauto->generation++;
00286 }
00287 
00288 static void fill_picture(AVFilterContext *ctx, AVFilterBufferRef *picref)
00289 {
00290     CellAutoContext *cellauto = ctx->priv;
00291     int i, j, k, row_idx = 0;
00292     uint8_t *p0 = picref->data[0];
00293 
00294     if (cellauto->scroll && cellauto->generation >= cellauto->h)
00295         /* show on top the oldest row */
00296         row_idx = (cellauto->buf_row_idx + 1) % cellauto->h;
00297 
00298     /* fill the output picture with the whole buffer */
00299     for (i = 0; i < cellauto->h; i++) {
00300         uint8_t byte = 0;
00301         uint8_t *row = cellauto->buf + row_idx*cellauto->w;
00302         uint8_t *p = p0;
00303         for (k = 0, j = 0; j < cellauto->w; j++) {
00304             byte |= row[j]<<(7-k++);
00305             if (k==8 || j == cellauto->w-1) {
00306                 k = 0;
00307                 *p++ = byte;
00308                 byte = 0;
00309             }
00310         }
00311         row_idx = (row_idx + 1) % cellauto->h;
00312         p0 += picref->linesize[0];
00313     }
00314 }
00315 
00316 static int request_frame(AVFilterLink *outlink)
00317 {
00318     CellAutoContext *cellauto = outlink->src->priv;
00319     AVFilterBufferRef *picref =
00320         avfilter_get_video_buffer(outlink, AV_PERM_WRITE, cellauto->w, cellauto->h);
00321     picref->video->sample_aspect_ratio = (AVRational) {1, 1};
00322     if (cellauto->generation == 0 && cellauto->start_full) {
00323         int i;
00324         for (i = 0; i < cellauto->h-1; i++)
00325             evolve(outlink->src);
00326     }
00327     fill_picture(outlink->src, picref);
00328     evolve(outlink->src);
00329 
00330     picref->pts = cellauto->pts++;
00331     picref->pos = -1;
00332 
00333 #ifdef DEBUG
00334     show_cellauto_row(outlink->src);
00335 #endif
00336 
00337     avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
00338     avfilter_draw_slice(outlink, 0, cellauto->h, 1);
00339     avfilter_end_frame(outlink);
00340     avfilter_unref_buffer(picref);
00341 
00342     return 0;
00343 }
00344 
00345 static int query_formats(AVFilterContext *ctx)
00346 {
00347     static const enum PixelFormat pix_fmts[] = { PIX_FMT_MONOBLACK, PIX_FMT_NONE };
00348     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
00349     return 0;
00350 }
00351 
00352 AVFilter avfilter_vsrc_cellauto = {
00353     .name        = "cellauto",
00354     .description = NULL_IF_CONFIG_SMALL("Create pattern generated by an elementary cellular automaton."),
00355     .priv_size = sizeof(CellAutoContext),
00356     .init      = init,
00357     .uninit    = uninit,
00358     .query_formats = query_formats,
00359 
00360     .inputs    = (const AVFilterPad[]) {
00361         { .name = NULL}
00362     },
00363     .outputs   = (const AVFilterPad[]) {
00364         { .name            = "default",
00365           .type            = AVMEDIA_TYPE_VIDEO,
00366           .request_frame   = request_frame,
00367           .config_props    = config_props },
00368         { .name = NULL}
00369     },
00370 };