/*
  * Copyright (c) 2012-2013 Oka Motofumi (chikuzen.mo at gmail dot com)
  * Copyright (c) 2015 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"
 
 typedef struct NContext {
     const AVClass *class;
     int planeheight[4];
     int planewidth[4];
     int nb_planes;
     int threshold[4];
     int coordinates;
     uint8_t *buffer;
 
     void (*filter)(uint8_t *dst, const uint8_t *p1, int width,
                    int threshold, const uint8_t *coordinates[], int coord);
 } NContext;
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
         AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
     };
 

     return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));

 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     NContext *s = ctx->priv;
 
     av_freep(&s->buffer);
 }
 
 static inline void line_copy8(uint8_t *line, const uint8_t *srcp, int width, int mergin)
 {
     int i;
 
     memcpy(line, srcp, width);
 
     for (i = mergin; i > 0; i--) {
         line[-i] = line[i];
         line[width - 1 + i] = line[width - 1 - i];
     }
 }
 
 static void erosion(uint8_t *dst, const uint8_t *p1, int width,
                     int threshold, const uint8_t *coordinates[], int coord)
 {
     int x, i;
 
     for (x = 0; x < width; x++) {
         int min = p1[x];
         int limit = FFMAX(min - threshold, 0);
 
         for (i = 0; i < 8; i++) {
             if (coord & (1 << i)) {
                 min = FFMIN(min, *(coordinates[i] + x));
             }
             min = FFMAX(min, limit);
         }
 
         dst[x] = min;
     }
 }
 
 static void dilation(uint8_t *dst, const uint8_t *p1, int width,
                      int threshold, const uint8_t *coordinates[], int coord)
 {
     int x, i;
 
     for (x = 0; x < width; x++) {
         int max = p1[x];
         int limit = FFMIN(max + threshold, 255);
 
         for (i = 0; i < 8; i++) {
             if (coord & (1 << i)) {
                 max = FFMAX(max, *(coordinates[i] + x));
             }
             max = FFMIN(max, limit);
         }
 
         dst[x] = max;
     }
 }
 
 static void deflate(uint8_t *dst, const uint8_t *p1, int width,
                     int threshold, const uint8_t *coordinates[], int coord)
 {
     int x, i;
 
     for (x = 0; x < width; x++) {
         int sum = 0;
         int limit = FFMAX(p1[x] - threshold, 0);
 
         for (i = 0; i < 8; sum += *(coordinates[i++] + x));
 
         dst[x] = FFMAX(FFMIN(sum / 8, p1[x]), limit);
     }
 }
 
 static void inflate(uint8_t *dst, const uint8_t *p1, int width,
                     int threshold, const uint8_t *coordinates[], int coord)
 {
     int x, i;
 
     for (x = 0; x < width; x++) {
         int sum = 0;
         int limit = FFMIN(p1[x] + threshold, 255);
 
         for (i = 0; i < 8; sum += *(coordinates[i++] + x));
 
         dst[x] = FFMIN(FFMAX(sum / 8, p1[x]), limit);
     }
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     NContext *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     int ret;
 
     if ((ret = av_image_fill_linesizes(s->planewidth, inlink->format, inlink->w)) < 0)
         return ret;
 

     s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);

     s->planeheight[0] = s->planeheight[3] = inlink->h;
 
     s->nb_planes = av_pix_fmt_count_planes(inlink->format);
     s->buffer = av_malloc(3 * (s->planewidth[0] + 32));
     if (!s->buffer)
         return AVERROR(ENOMEM);
 
     if (!strcmp(ctx->filter->name, "erosion"))
         s->filter = erosion;
     else if (!strcmp(ctx->filter->name, "dilation"))
         s->filter = dilation;
     else if (!strcmp(ctx->filter->name, "deflate"))
         s->filter = deflate;
     else if (!strcmp(ctx->filter->name, "inflate"))
         s->filter = inflate;
 
     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;
     AVFilterLink *outlink = ctx->outputs[0];
     NContext *s = ctx->priv;
     AVFrame *out;
     int plane, y;
 
     out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
     if (!out) {
         av_frame_free(&in);
         return AVERROR(ENOMEM);
     }
     av_frame_copy_props(out, in);
 
     for (plane = 0; plane < s->nb_planes; plane++) {
         const int threshold = s->threshold[plane];
 
         if (threshold) {
             const uint8_t *src = in->data[plane];
             uint8_t *dst = out->data[plane];
             int stride = in->linesize[plane];
             int height = s->planeheight[plane];
             int width  = s->planewidth[plane];
             uint8_t *p0 = s->buffer + 16;
             uint8_t *p1 = p0 + s->planewidth[0];
             uint8_t *p2 = p1 + s->planewidth[0];
             uint8_t *orig = p0, *end = p2;
 
             line_copy8(p0, src + stride, width, 1);
             line_copy8(p1, src, width, 1);
 
             for (y = 0; y < height; y++) {
                 const uint8_t *coordinates[] = { p0 - 1, p0, p0 + 1,
                                                  p1 - 1,     p1 + 1,
                                                  p2 - 1, p2, p2 + 1};
                 src += stride * (y < height - 1 ? 1 : -1);
                 line_copy8(p2, src, width, 1);
 
                 s->filter(dst, p1, width, threshold, coordinates, s->coordinates);
 
                 p0 = p1;
                 p1 = p2;
                 p2 = (p2 == end) ? orig: p2 + s->planewidth[0];
                 dst += out->linesize[plane];
             }
         } else {
             av_image_copy_plane(out->data[plane], out->linesize[plane],
                                 in->data[plane], in->linesize[plane],
                                 s->planewidth[plane], s->planeheight[plane]);
         }
     }
 
     av_frame_free(&in);
     return ff_filter_frame(outlink, out);
 }
 
 static const AVFilterPad neighbor_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_input,
     },
     { NULL }
 };
 
 static const AVFilterPad neighbor_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 
 #define OFFSET(x) offsetof(NContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 #define DEFINE_NEIGHBOR_FILTER(name_, description_)          \
 AVFILTER_DEFINE_CLASS(name_);                                \
                                                              \
 AVFilter ff_vf_##name_ = {                                   \
     .name          = #name_,                                 \
     .description   = NULL_IF_CONFIG_SMALL(description_),     \
     .priv_size     = sizeof(NContext),                       \
     .priv_class    = &name_##_class,                         \
     .uninit        = uninit,                                 \
     .query_formats = query_formats,                          \
     .inputs        = neighbor_inputs,                        \
     .outputs       = neighbor_outputs,                       \
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, \
 }
 
 #if CONFIG_EROSION_FILTER
 
 static const AVOption erosion_options[] = {
     { "threshold0",  "set threshold for 1st plane",   OFFSET(threshold[0]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold1",  "set threshold for 2nd plane",   OFFSET(threshold[1]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold2",  "set threshold for 3rd plane",   OFFSET(threshold[2]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold3",  "set threshold for 4th plane",   OFFSET(threshold[3]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "coordinates", "set coordinates",               OFFSET(coordinates),    AV_OPT_TYPE_INT, {.i64=255},   0, 255,   FLAGS },
     { NULL }
 };
 

 DEFINE_NEIGHBOR_FILTER(erosion, "Apply erosion effect.");

 
 #endif /* CONFIG_EROSION_FILTER */
 
 #if CONFIG_DILATION_FILTER
 
 static const AVOption dilation_options[] = {
     { "threshold0",  "set threshold for 1st plane",   OFFSET(threshold[0]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold1",  "set threshold for 2nd plane",   OFFSET(threshold[1]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold2",  "set threshold for 3rd plane",   OFFSET(threshold[2]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold3",  "set threshold for 4th plane",   OFFSET(threshold[3]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "coordinates", "set coordinates",               OFFSET(coordinates),    AV_OPT_TYPE_INT, {.i64=255},   0, 255,   FLAGS },
     { NULL }
 };
 

 DEFINE_NEIGHBOR_FILTER(dilation, "Apply dilation effect.");

 
 #endif /* CONFIG_DILATION_FILTER */
 
 #if CONFIG_DEFLATE_FILTER
 
 static const AVOption deflate_options[] = {
     { "threshold0", "set threshold for 1st plane",   OFFSET(threshold[0]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold1", "set threshold for 2nd plane",   OFFSET(threshold[1]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold2", "set threshold for 3rd plane",   OFFSET(threshold[2]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold3", "set threshold for 4th plane",   OFFSET(threshold[3]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { NULL }
 };
 

 DEFINE_NEIGHBOR_FILTER(deflate, "Apply deflate effect.");

 
 #endif /* CONFIG_DEFLATE_FILTER */
 
 #if CONFIG_INFLATE_FILTER
 
 static const AVOption inflate_options[] = {
     { "threshold0", "set threshold for 1st plane",   OFFSET(threshold[0]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold1", "set threshold for 2nd plane",   OFFSET(threshold[1]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold2", "set threshold for 3rd plane",   OFFSET(threshold[2]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { "threshold3", "set threshold for 4th plane",   OFFSET(threshold[3]),   AV_OPT_TYPE_INT, {.i64=65535}, 0, 65535, FLAGS },
     { NULL }
 };
 

 DEFINE_NEIGHBOR_FILTER(inflate, "Apply inflate effect.");

 
 #endif /* CONFIG_INFLATE_FILTER */