libavfilter/vf_hysteresis.c - manifest_repos/ffmpeg - Git at Google

 /*
  * Copyright (c) 2013 Oka Motofumi (chikuzen.mo at gmail dot com)
  * Copyright (c) 2016 Paul B Mahol
  *
  * 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
  */

 #include "libavutil/imgutils.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/opt.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 #include "framesync.h"

 #define OFFSET(x) offsetof(HysteresisContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

 typedef struct HysteresisContext {
     const AVClass *class;
     FFFrameSync fs;

     int planes;
     int threshold;

     int width[4], height[4];
     int nb_planes;
     int depth;

     uint8_t *map;
     uint32_t *xy;
     int index;

     void (*hysteresis)(struct HysteresisContext *s, const uint8_t *bsrc, const uint8_t *osrc, uint8_t *dst,
                        ptrdiff_t blinesize, ptrdiff_t olinesize,
                        ptrdiff_t destlinesize,
                        int w, int h);
 } HysteresisContext;

 static const AVOption hysteresis_options[] = {
     { "planes",    "set planes",    OFFSET(planes),    AV_OPT_TYPE_INT, {.i64=0xF}, 0, 0xF, FLAGS },
     { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_INT, {.i64=0},   0, UINT16_MAX, FLAGS },
     { NULL }
 };

 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
         AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
         AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
         AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
         AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV440P12,
         AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
         AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
         AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
         AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
         AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
         AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
         AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
         AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16,
         AV_PIX_FMT_NONE
     };

     return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
 }

 static int process_frame(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     HysteresisContext *s = fs->opaque;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *out, *base, *alt;
     int ret;

     if ((ret = ff_framesync_get_frame(&s->fs, 0, &base, 0)) < 0 ||
         (ret = ff_framesync_get_frame(&s->fs, 1, &alt,  0)) < 0)
         return ret;

     if (ctx->is_disabled) {
         out = av_frame_clone(base);
         if (!out)
             return AVERROR(ENOMEM);
     } else {
         int p;

         out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!out)
             return AVERROR(ENOMEM);
         av_frame_copy_props(out, base);

         for (p = 0; p < s->nb_planes; p++) {
             if (!((1 << p) & s->planes)) {
                 av_image_copy_plane(out->data[p], out->linesize[p], base->data[p], base->linesize[p],
                                     s->width[p], s->height[p]);
                 continue;
             } else {
                 int y;

                 for (y = 0; y < s->height[p]; y++) {
                     memset(out->data[p] + y * out->linesize[p], 0, s->width[p]);
                 }
             }

             s->index = -1;
             memset(s->map, 0, s->width[0] * s->height[0]);
             memset(s->xy, 0, s->width[0] * s->height[0] * 4);

             s->hysteresis(s, base->data[p], alt->data[p],
                           out->data[p],
                           base->linesize[p], alt->linesize[p],
                           out->linesize[p],
                           s->width[p], s->height[p]);
         }
     }
     out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);

     return ff_filter_frame(outlink, out);
 }

 static int passed(HysteresisContext *s, int x, int y, int w)
 {
     return s->map[x + y * w];
 }

 static void push(HysteresisContext *s, int x, int y, int w)
 {
     s->map[x + y * w] = 0xff;
     s->xy[++s->index] = (uint16_t)(x) << 16 | (uint16_t)y;
 }

 static void pop(HysteresisContext *s, int *x, int *y)
 {
     uint32_t val = s->xy[s->index--];

     *x = val >> 16;
     *y = val & 0x0000FFFF;
 }

 static int is_empty(HysteresisContext *s)
 {
     return s->index < 0;
 }

 static void hysteresis8(HysteresisContext *s, const uint8_t *bsrc, const uint8_t *asrc,
                         uint8_t *dst,
                         ptrdiff_t blinesize, ptrdiff_t alinesize,
                         ptrdiff_t dlinesize,
                         int w, int h)
 {
     const int t = s->threshold;
     int x, y;

     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if ((bsrc[x + y * blinesize] > t) && (asrc[x + y * alinesize] > t) && !passed(s, x, y, w)) {
                 int posx, posy;

                 dst[x + y * dlinesize] = asrc[x + y * alinesize];

                 push(s, x, y, w);

                 while (!is_empty(s)) {
                     int x_min, x_max, y_min, y_max, yy, xx;

                     pop(s, &posx, &posy);

                     x_min = posx > 0 ? posx - 1 : 0;
                     x_max = posx < w - 1 ? posx + 1 : posx;
                     y_min = posy > 0 ? posy - 1 : 0;
                     y_max = posy < h - 1 ? posy + 1 : posy;

                     for (yy = y_min; yy <= y_max; yy++) {
                         for (xx = x_min; xx <= x_max; xx++) {
                             if ((asrc[xx + yy * alinesize] > t) && !passed(s, xx, yy, w)) {
                                 dst[xx + yy * dlinesize] = asrc[xx + yy * alinesize];
                                 push(s, xx, yy, w);
                             }
                         }
                     }
                 }
             }
         }
     }
 }

 static void hysteresis16(HysteresisContext *s, const uint8_t *bbsrc, const uint8_t *aasrc,
                         uint8_t *ddst,
                         ptrdiff_t blinesize, ptrdiff_t alinesize,
                         ptrdiff_t dlinesize,
                         int w, int h)
 {
     const uint16_t *bsrc = (const uint16_t *)bbsrc;
     const uint16_t *asrc = (const uint16_t *)aasrc;
     uint16_t *dst = (uint16_t *)ddst;
     const int t = s->threshold;
     int x, y;

     blinesize /= 2;
     alinesize /= 2;
     dlinesize /= 2;

     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if ((bsrc[x + y * blinesize] > t) && (asrc[x + y * alinesize] > t) && !passed(s, x, y, w)) {
                 int posx, posy;

                 dst[x + y * dlinesize] = asrc[x + y * alinesize];

                 push(s, x, y, w);

                 while (!is_empty(s)) {
                     int x_min, x_max, y_min, y_max, yy, xx;

                     pop(s, &posx, &posy);

                     x_min = posx > 0 ? posx - 1 : 0;
                     x_max = posx < w - 1 ? posx + 1 : posx;
                     y_min = posy > 0 ? posy - 1 : 0;
                     y_max = posy < h - 1 ? posy + 1 : posy;

                     for (yy = y_min; yy <= y_max; yy++) {
                         for (xx = x_min; xx <= x_max; xx++) {
                             if ((asrc[xx + yy * alinesize] > t) && !passed(s, xx, yy, w)) {
                                 dst[xx + yy * dlinesize] = asrc[xx + yy * alinesize];
                                 push(s, xx, yy, w);
                             }
                         }
                     }
                 }
             }
         }
     }
 }

 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     HysteresisContext *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     int vsub, hsub;

     s->nb_planes = av_pix_fmt_count_planes(inlink->format);

     hsub = desc->log2_chroma_w;
     vsub = desc->log2_chroma_h;
     s->height[1] = s->height[2] = AV_CEIL_RSHIFT(inlink->h, vsub);
     s->height[0] = s->height[3] = inlink->h;
     s->width[1]  = s->width[2]  = AV_CEIL_RSHIFT(inlink->w, hsub);
     s->width[0]  = s->width[3]  = inlink->w;

     s->depth = desc->comp[0].depth;

     if (desc->comp[0].depth == 8)
         s->hysteresis = hysteresis8;
     else
         s->hysteresis = hysteresis16;

     s->map = av_calloc(inlink->w, inlink->h * sizeof (*s->map));
     if (!s->map)
         return AVERROR(ENOMEM);

     s->xy = av_calloc(inlink->w, inlink->h * sizeof(*s->xy));
     if (!s->xy)
         return AVERROR(ENOMEM);

     return 0;
 }

 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     HysteresisContext *s = ctx->priv;
     AVFilterLink *base = ctx->inputs[0];
     AVFilterLink *alt = ctx->inputs[1];
     FFFrameSyncIn *in;
     int ret;

     if (base->format != alt->format) {
         av_log(ctx, AV_LOG_ERROR, "inputs must be of same pixel format\n");
         return AVERROR(EINVAL);
     }
     if (base->w != alt->w || base->h != alt->h) {
         av_log(ctx, AV_LOG_ERROR, "First input link %s parameters "
                "(size %dx%d) do not match the corresponding "
                "second input link %s parameters (size %dx%d)\n",
                ctx->input_pads[0].name, base->w, base->h,
                ctx->input_pads[1].name,
                alt->w, alt->h);
         return AVERROR(EINVAL);
     }

     outlink->w = base->w;
     outlink->h = base->h;
     outlink->sample_aspect_ratio = base->sample_aspect_ratio;
     outlink->frame_rate = base->frame_rate;

     if ((ret = ff_framesync_init(&s->fs, ctx, 2)) < 0)
         return ret;

     in = s->fs.in;
     in[0].time_base = base->time_base;
     in[1].time_base = alt->time_base;
     in[0].sync   = 1;
     in[0].before = EXT_STOP;
     in[0].after  = EXT_INFINITY;
     in[1].sync   = 1;
     in[1].before = EXT_STOP;
     in[1].after  = EXT_INFINITY;
     s->fs.opaque   = s;
     s->fs.on_event = process_frame;

     ret = ff_framesync_configure(&s->fs);
     outlink->time_base = s->fs.time_base;

     return ret;
 }

 static int activate(AVFilterContext *ctx)
 {
     HysteresisContext *s = ctx->priv;
     return ff_framesync_activate(&s->fs);
 }

 static av_cold void uninit(AVFilterContext *ctx)
 {
     HysteresisContext *s = ctx->priv;

     ff_framesync_uninit(&s->fs);
     av_freep(&s->map);
     av_freep(&s->xy);
 }

 FRAMESYNC_DEFINE_CLASS(hysteresis, HysteresisContext, fs);

 static const AVFilterPad hysteresis_inputs[] = {
     {
         .name         = "base",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_input,
     },
     {
         .name         = "alt",
         .type         = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };

 static const AVFilterPad hysteresis_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_output,
     },
     { NULL }
 };

 AVFilter ff_vf_hysteresis = {
     .name          = "hysteresis",
     .description   = NULL_IF_CONFIG_SMALL("Grow first stream into second stream by connecting components."),
     .preinit       = hysteresis_framesync_preinit,
     .priv_size     = sizeof(HysteresisContext),
     .uninit        = uninit,
     .query_formats = query_formats,
     .activate      = activate,
     .inputs        = hysteresis_inputs,
     .outputs       = hysteresis_outputs,
     .priv_class    = &hysteresis_class,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
 };
	/*
	* Copyright (c) 2013 Oka Motofumi (chikuzen.mo at gmail dot com)
	* Copyright (c) 2016 Paul B Mahol
	*
	* 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
	*/

	#include "libavutil/imgutils.h"
	#include "libavutil/pixdesc.h"
	#include "libavutil/opt.h"
	#include "avfilter.h"
	#include "formats.h"
	#include "internal.h"
	#include "video.h"
	#include "framesync.h"

	#define OFFSET(x) offsetof(HysteresisContext, x)
	#define FLAGS AV_OPT_FLAG_FILTERING_PARAM\|AV_OPT_FLAG_VIDEO_PARAM

	typedef struct HysteresisContext {
	const AVClass *class;
	FFFrameSync fs;

	int planes;
	int threshold;

	int width[4], height[4];
	int nb_planes;
	int depth;

	uint8_t *map;
	uint32_t *xy;
	int index;

	void (hysteresis)(struct HysteresisContext s, const uint8_t bsrc, const uint8_t osrc, uint8_t *dst,
	ptrdiff_t blinesize, ptrdiff_t olinesize,
	ptrdiff_t destlinesize,
	int w, int h);
	} HysteresisContext;

	static const AVOption hysteresis_options[] = {
	{ "planes", "set planes", OFFSET(planes), AV_OPT_TYPE_INT, {.i64=0xF}, 0, 0xF, FLAGS },
	{ "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_INT, {.i64=0}, 0, UINT16_MAX, FLAGS },
	{ NULL }
	};

	static int query_formats(AVFilterContext *ctx)
	{
	static const enum AVPixelFormat pix_fmts[] = {
	AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P,
	AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
	AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P,
	AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
	AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
	AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
	AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
	AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV440P12,
	AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
	AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
	AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
	AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
	AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
	AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
	AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
	AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
	AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16,
	AV_PIX_FMT_NONE
	};

	return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
	}

	static int process_frame(FFFrameSync *fs)
	{
	AVFilterContext *ctx = fs->parent;
	HysteresisContext *s = fs->opaque;
	AVFilterLink *outlink = ctx->outputs[0];
	AVFrame out, base, *alt;
	int ret;

	if ((ret = ff_framesync_get_frame(&s->fs, 0, &base, 0)) < 0 \|\|
	(ret = ff_framesync_get_frame(&s->fs, 1, &alt, 0)) < 0)
	return ret;

	if (ctx->is_disabled) {
	out = av_frame_clone(base);
	if (!out)
	return AVERROR(ENOMEM);
	} else {
	int p;

	out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
	if (!out)
	return AVERROR(ENOMEM);
	av_frame_copy_props(out, base);

	for (p = 0; p < s->nb_planes; p++) {
	if (!((1 << p) & s->planes)) {
	av_image_copy_plane(out->data[p], out->linesize[p], base->data[p], base->linesize[p],
	s->width[p], s->height[p]);
	continue;
	} else {
	int y;

	for (y = 0; y < s->height[p]; y++) {
	memset(out->data[p] + y * out->linesize[p], 0, s->width[p]);
	}
	}

	s->index = -1;
	memset(s->map, 0, s->width[0] * s->height[0]);
	memset(s->xy, 0, s->width[0] * s->height[0] * 4);

	s->hysteresis(s, base->data[p], alt->data[p],
	out->data[p],
	base->linesize[p], alt->linesize[p],
	out->linesize[p],
	s->width[p], s->height[p]);
	}
	}
	out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);

	return ff_filter_frame(outlink, out);
	}

	static int passed(HysteresisContext *s, int x, int y, int w)
	{
	return s->map[x + y * w];
	}

	static void push(HysteresisContext *s, int x, int y, int w)
	{
	s->map[x + y * w] = 0xff;
	s->xy[++s->index] = (uint16_t)(x) << 16 \| (uint16_t)y;
	}

	static void pop(HysteresisContext s, int x, int *y)
	{
	uint32_t val = s->xy[s->index--];

	*x = val >> 16;
	*y = val & 0x0000FFFF;
	}

	static int is_empty(HysteresisContext *s)
	{
	return s->index < 0;
	}

	static void hysteresis8(HysteresisContext s, const uint8_t bsrc, const uint8_t *asrc,
	uint8_t *dst,
	ptrdiff_t blinesize, ptrdiff_t alinesize,
	ptrdiff_t dlinesize,
	int w, int h)
	{
	const int t = s->threshold;
	int x, y;

	for (y = 0; y < h; y++) {
	for (x = 0; x < w; x++) {
	if ((bsrc[x + y * blinesize] > t) && (asrc[x + y * alinesize] > t) && !passed(s, x, y, w)) {
	int posx, posy;

	dst[x + y * dlinesize] = asrc[x + y * alinesize];

	push(s, x, y, w);

	while (!is_empty(s)) {
	int x_min, x_max, y_min, y_max, yy, xx;

	pop(s, &posx, &posy);

	x_min = posx > 0 ? posx - 1 : 0;
	x_max = posx < w - 1 ? posx + 1 : posx;
	y_min = posy > 0 ? posy - 1 : 0;
	y_max = posy < h - 1 ? posy + 1 : posy;

	for (yy = y_min; yy <= y_max; yy++) {
	for (xx = x_min; xx <= x_max; xx++) {
	if ((asrc[xx + yy * alinesize] > t) && !passed(s, xx, yy, w)) {
	dst[xx + yy * dlinesize] = asrc[xx + yy * alinesize];
	push(s, xx, yy, w);
	}
	}
	}
	}
	}
	}
	}
	}

	static void hysteresis16(HysteresisContext s, const uint8_t bbsrc, const uint8_t *aasrc,
	uint8_t *ddst,
	ptrdiff_t blinesize, ptrdiff_t alinesize,
	ptrdiff_t dlinesize,
	int w, int h)
	{
	const uint16_t bsrc = (const uint16_t )bbsrc;
	const uint16_t asrc = (const uint16_t )aasrc;
	uint16_t dst = (uint16_t )ddst;
	const int t = s->threshold;
	int x, y;

	blinesize /= 2;
	alinesize /= 2;
	dlinesize /= 2;

	for (y = 0; y < h; y++) {
	for (x = 0; x < w; x++) {
	if ((bsrc[x + y * blinesize] > t) && (asrc[x + y * alinesize] > t) && !passed(s, x, y, w)) {
	int posx, posy;

	dst[x + y * dlinesize] = asrc[x + y * alinesize];

	push(s, x, y, w);

	while (!is_empty(s)) {
	int x_min, x_max, y_min, y_max, yy, xx;

	pop(s, &posx, &posy);

	x_min = posx > 0 ? posx - 1 : 0;
	x_max = posx < w - 1 ? posx + 1 : posx;
	y_min = posy > 0 ? posy - 1 : 0;
	y_max = posy < h - 1 ? posy + 1 : posy;

	for (yy = y_min; yy <= y_max; yy++) {
	for (xx = x_min; xx <= x_max; xx++) {
	if ((asrc[xx + yy * alinesize] > t) && !passed(s, xx, yy, w)) {
	dst[xx + yy * dlinesize] = asrc[xx + yy * alinesize];
	push(s, xx, yy, w);
	}
	}
	}
	}
	}
	}
	}
	}

	static int config_input(AVFilterLink *inlink)
	{
	AVFilterContext *ctx = inlink->dst;
	HysteresisContext *s = ctx->priv;
	const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
	int vsub, hsub;

	s->nb_planes = av_pix_fmt_count_planes(inlink->format);

	hsub = desc->log2_chroma_w;
	vsub = desc->log2_chroma_h;
	s->height[1] = s->height[2] = AV_CEIL_RSHIFT(inlink->h, vsub);
	s->height[0] = s->height[3] = inlink->h;
	s->width[1] = s->width[2] = AV_CEIL_RSHIFT(inlink->w, hsub);
	s->width[0] = s->width[3] = inlink->w;

	s->depth = desc->comp[0].depth;

	if (desc->comp[0].depth == 8)
	s->hysteresis = hysteresis8;
	else
	s->hysteresis = hysteresis16;

	s->map = av_calloc(inlink->w, inlink->h * sizeof (*s->map));
	if (!s->map)
	return AVERROR(ENOMEM);

	s->xy = av_calloc(inlink->w, inlink->h * sizeof(*s->xy));
	if (!s->xy)
	return AVERROR(ENOMEM);

	return 0;
	}

	static int config_output(AVFilterLink *outlink)
	{
	AVFilterContext *ctx = outlink->src;
	HysteresisContext *s = ctx->priv;
	AVFilterLink *base = ctx->inputs[0];
	AVFilterLink *alt = ctx->inputs[1];
	FFFrameSyncIn *in;
	int ret;

	if (base->format != alt->format) {
	av_log(ctx, AV_LOG_ERROR, "inputs must be of same pixel format\n");
	return AVERROR(EINVAL);
	}
	if (base->w != alt->w \|\| base->h != alt->h) {
	av_log(ctx, AV_LOG_ERROR, "First input link %s parameters "
	"(size %dx%d) do not match the corresponding "
	"second input link %s parameters (size %dx%d)\n",
	ctx->input_pads[0].name, base->w, base->h,
	ctx->input_pads[1].name,
	alt->w, alt->h);
	return AVERROR(EINVAL);
	}

	outlink->w = base->w;
	outlink->h = base->h;
	outlink->sample_aspect_ratio = base->sample_aspect_ratio;
	outlink->frame_rate = base->frame_rate;

	if ((ret = ff_framesync_init(&s->fs, ctx, 2)) < 0)
	return ret;

	in = s->fs.in;
	in[0].time_base = base->time_base;
	in[1].time_base = alt->time_base;
	in[0].sync = 1;
	in[0].before = EXT_STOP;
	in[0].after = EXT_INFINITY;
	in[1].sync = 1;
	in[1].before = EXT_STOP;
	in[1].after = EXT_INFINITY;
	s->fs.opaque = s;
	s->fs.on_event = process_frame;

	ret = ff_framesync_configure(&s->fs);
	outlink->time_base = s->fs.time_base;

	return ret;
	}

	static int activate(AVFilterContext *ctx)
	{
	HysteresisContext *s = ctx->priv;
	return ff_framesync_activate(&s->fs);
	}

	static av_cold void uninit(AVFilterContext *ctx)
	{
	HysteresisContext *s = ctx->priv;

	ff_framesync_uninit(&s->fs);
	av_freep(&s->map);
	av_freep(&s->xy);
	}

	FRAMESYNC_DEFINE_CLASS(hysteresis, HysteresisContext, fs);

	static const AVFilterPad hysteresis_inputs[] = {
	{
	.name = "base",
	.type = AVMEDIA_TYPE_VIDEO,
	.config_props = config_input,
	},
	{
	.name = "alt",
	.type = AVMEDIA_TYPE_VIDEO,
	},
	{ NULL }
	};

	static const AVFilterPad hysteresis_outputs[] = {
	{
	.name = "default",
	.type = AVMEDIA_TYPE_VIDEO,
	.config_props = config_output,
	},
	{ NULL }
	};

	AVFilter ff_vf_hysteresis = {
	.name = "hysteresis",
	.description = NULL_IF_CONFIG_SMALL("Grow first stream into second stream by connecting components."),
	.preinit = hysteresis_framesync_preinit,
	.priv_size = sizeof(HysteresisContext),
	.uninit = uninit,
	.query_formats = query_formats,
	.activate = activate,
	.inputs = hysteresis_inputs,
	.outputs = hysteresis_outputs,
	.priv_class = &hysteresis_class,
	.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
	};