/*
  * Copyright (c) 2018 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 MaskFunContext {
     const AVClass *class;
 
     int low, high;
     int planes;
     int fill;
     int sum;
 
     int linesize[4];
     int width[4], height[4];
     int nb_planes;
     int depth;
     int max;
     uint64_t max_sum;
 
     AVFrame *empty;
     int (*getsum)(AVFilterContext *ctx, AVFrame *out);
     int (*maskfun)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
 } MaskFunContext;
 
 #define OFFSET(x) offsetof(MaskFunContext, x)
 #define VF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption maskfun_options[] = {
     { "low",    "set low threshold",  OFFSET(low),    AV_OPT_TYPE_INT, {.i64=10},  0, UINT16_MAX, VF },
     { "high",   "set high threshold", OFFSET(high),   AV_OPT_TYPE_INT, {.i64=10},  0, UINT16_MAX, VF },
     { "planes", "set planes",         OFFSET(planes), AV_OPT_TYPE_INT, {.i64=0xF}, 0, 0xF,        VF },
     { "fill",   "set fill value",     OFFSET(fill),   AV_OPT_TYPE_INT, {.i64=0},   0, UINT16_MAX, VF },
     { "sum",    "set sum value",      OFFSET(sum),    AV_OPT_TYPE_INT, {.i64=10},  0, UINT16_MAX, VF },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(maskfun);
 
 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 filter_frame(AVFilterLink *inlink, AVFrame *frame)
 {
     AVFilterContext *ctx = inlink->dst;
     MaskFunContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
 
     if (s->getsum(ctx, frame)) {
         AVFrame *out = av_frame_clone(s->empty);
 
         if (!out) {
             av_frame_free(&frame);
             return AVERROR(ENOMEM);
         }
         out->pts = frame->pts;
         av_frame_free(&frame);
 
         return ff_filter_frame(outlink, out);
     }
 
     ctx->internal->execute(ctx, s->maskfun, frame, NULL,
                            FFMIN(s->height[1], ff_filter_get_nb_threads(ctx)));
 
     return ff_filter_frame(outlink, frame);
 }
 
 #define GETSUM(name, type, div)                              \
 static int getsum##name(AVFilterContext *ctx, AVFrame *out)  \
 {                                                            \
     MaskFunContext *s = ctx->priv;                           \
     uint64_t sum = 0;                                        \
     int p;                                                   \
                                                              \
     for (p = 0; p < s->nb_planes; p++) {                     \
         const int linesize = out->linesize[p] / div;         \
         const int w = s->width[p];                           \
         const int h = s->height[p];                          \
         type *dst = (type *)out->data[p];                    \
                                                              \
         if (!((1 << p) & s->planes))                         \
             continue;                                        \
                                                              \
         for (int y = 0; y < h; y++) {                        \
             for (int x = 0; x < w; x++)                      \
                 sum += dst[x];                               \
             if (sum >= s->max_sum)                           \
                 return 1;                                    \
             dst += linesize;                                 \
         }                                                    \
     }                                                        \
                                                              \
     return 0;                                                \
 }
 
 GETSUM(8, uint8_t, 1)
 GETSUM(16, uint16_t, 2)
 
 #define MASKFUN(name, type, div)                             \
 static int maskfun##name(AVFilterContext *ctx, void *arg,    \
                          int jobnr, int nb_jobs)             \
 {                                                            \
     MaskFunContext *s = ctx->priv;                           \
     AVFrame *out = arg;                                      \
     const int low = s->low;                                  \
     const int high = s->high;                                \
     const int max = s->max;                                  \
     int p;                                                   \
                                                              \
     for (p = 0; p < s->nb_planes; p++) {                     \
         const int linesize = out->linesize[p] / div;         \
         const int w = s->width[p];                           \
         const int h = s->height[p];                          \
         const int slice_start = (h * jobnr) / nb_jobs;       \
         const int slice_end = (h * (jobnr+1)) / nb_jobs;     \
         type *dst = (type *)out->data[p] + slice_start * linesize; \
                                                              \
         if (!((1 << p) & s->planes))                         \
             continue;                                        \
                                                              \
         for (int y = slice_start; y < slice_end; y++) {      \
             for (int x = 0; x < w; x++) {                    \
                 if (dst[x] <= low)                           \
                     dst[x] = 0;                              \
                 else if (dst[x] > high)                      \
                     dst[x] = max;                            \
             }                                                \
                                                              \
             dst += linesize;                                 \
         }                                                    \
     }                                                        \
                                                              \
     return 0;                                                \
 }
 
 MASKFUN(8, uint8_t, 1)
 MASKFUN(16, uint16_t, 2)
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     MaskFunContext *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     int vsub, hsub, ret;
 
     s->nb_planes = av_pix_fmt_count_planes(inlink->format);
 
     if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
         return ret;
 
     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;
     s->max = (1 << s->depth) - 1;
     s->fill = FFMIN(s->fill, s->max);
 
     if (s->depth == 8) {
         s->maskfun = maskfun8;
         s->getsum = getsum8;
     } else {
         s->maskfun = maskfun16;
         s->getsum = getsum16;
     }
 
     s->empty = ff_get_video_buffer(inlink, inlink->w, inlink->h);
     if (!s->empty)
         return AVERROR(ENOMEM);
 
     if (s->depth == 8) {
         for (int p = 0; p < s->nb_planes; p++) {
             uint8_t *dst = s->empty->data[p];
 
             for (int y = 0; y < s->height[p]; y++) {
                 memset(dst, s->fill, s->width[p]);
                 dst += s->empty->linesize[p];
             }
         }
     } else {
         for (int p = 0; p < s->nb_planes; p++) {
             uint16_t *dst = (uint16_t *)s->empty->data[p];
 
             for (int y = 0; y < s->height[p]; y++) {
                 for (int x = 0; x < s->width[p]; x++)
                     dst[x] = s->fill;
                 dst += s->empty->linesize[p] / 2;
             }
         }
     }
 
     s->max_sum = 0;
     for (int p = 0; p < s->nb_planes; p++) {
         if (!((1 << p) & s->planes))
             continue;
         s->max_sum += (uint64_t)s->sum * s->width[p] * s->height[p];
     }
 
     return 0;
 }
 

 static av_cold void uninit(AVFilterContext *ctx)
 {
     MaskFunContext *s = ctx->priv;
 
     av_frame_free(&s->empty);
 }
 

 static const AVFilterPad maskfun_inputs[] = {
     {
         .name           = "default",
         .type           = AVMEDIA_TYPE_VIDEO,
         .filter_frame   = filter_frame,
         .config_props   = config_input,
         .needs_writable = 1,
     },
     { NULL }
 };
 
 static const AVFilterPad maskfun_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 
 AVFilter ff_vf_maskfun = {
     .name          = "maskfun",
     .description   = NULL_IF_CONFIG_SMALL("Create Mask."),
     .priv_size     = sizeof(MaskFunContext),
     .query_formats = query_formats,

     .uninit        = uninit,

     .inputs        = maskfun_inputs,
     .outputs       = maskfun_outputs,
     .priv_class    = &maskfun_class,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
 };