/*
  * Copyright (c) 2012 Jeremy Tran
  * Copyright (c) 2004 Tobias Diedrich
  * Copyright (c) 2003 Donald A. Graft
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 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 General Public License for more details.
  *
  * You should have received a copy of the GNU 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
  * Kernel Deinterlacer
  * Ported from MPlayer libmpcodecs/vf_kerndeint.c.
  */
 
 #include "libavutil/imgutils.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 
 typedef struct {
     const AVClass *class;
     int           frame; ///< frame count, starting from 0
     int           thresh, map, order, sharp, twoway;
     int           vsub;

     int           is_packed_rgb;

     uint8_t       *tmp_data    [4];  ///< temporary plane data buffer
     int            tmp_linesize[4];  ///< temporary plane byte linesize
     int            tmp_bwidth  [4];  ///< temporary plane byte width

 } KerndeintContext;
 
 #define OFFSET(x) offsetof(KerndeintContext, x)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 static const AVOption kerndeint_options[] = {
     { "thresh", "set the threshold", OFFSET(thresh), AV_OPT_TYPE_INT, {.i64=10}, 0, 255, FLAGS },
     { "map",    "set the map", OFFSET(map), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
     { "order",  "set the order", OFFSET(order), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
     { "sharp",  "enable sharpening", OFFSET(sharp), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
     { "twoway", "enable twoway", OFFSET(twoway), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(kerndeint);
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     KerndeintContext *kerndeint = ctx->priv;
 

     av_freep(&kerndeint->tmp_data[0]);

 }
 
 static int query_formats(AVFilterContext *ctx)
 {

     static const enum AVPixelFormat pix_fmts[] = {

         AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUYV422,

         AV_PIX_FMT_ARGB, AV_PIX_FMT_0RGB,
         AV_PIX_FMT_ABGR, AV_PIX_FMT_0BGR,
         AV_PIX_FMT_RGBA, AV_PIX_FMT_RGB0,
         AV_PIX_FMT_BGRA, AV_PIX_FMT_BGR0,

         AV_PIX_FMT_NONE
     };
 

     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
     if (!fmts_list)
         return AVERROR(ENOMEM);
     return ff_set_common_formats(ctx, fmts_list);

 }
 
 static int config_props(AVFilterLink *inlink)
 {
     KerndeintContext *kerndeint = inlink->dst->priv;

     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

     int ret;

     kerndeint->is_packed_rgb = av_pix_fmt_desc_get(inlink->format)->flags & AV_PIX_FMT_FLAG_RGB;

     kerndeint->vsub = desc->log2_chroma_h;
 

     ret = av_image_alloc(kerndeint->tmp_data, kerndeint->tmp_linesize,
                          inlink->w, inlink->h, inlink->format, 16);

     if (ret < 0)
         return ret;
     memset(kerndeint->tmp_data[0], 0, ret);

 
     if ((ret = av_image_fill_linesizes(kerndeint->tmp_bwidth, inlink->format, inlink->w)) < 0)
         return ret;
 

     return 0;

 }
 

 static int filter_frame(AVFilterLink *inlink, AVFrame *inpic)

 {
     KerndeintContext *kerndeint = inlink->dst->priv;
     AVFilterLink *outlink = inlink->dst->outputs[0];

     AVFrame *outpic;

     const uint8_t *prvp;   ///< Previous field's pixel line number n
     const uint8_t *prvpp;  ///< Previous field's pixel line number (n - 1)
     const uint8_t *prvpn;  ///< Previous field's pixel line number (n + 1)
     const uint8_t *prvppp; ///< Previous field's pixel line number (n - 2)
     const uint8_t *prvpnn; ///< Previous field's pixel line number (n + 2)
     const uint8_t *prvp4p; ///< Previous field's pixel line number (n - 4)
     const uint8_t *prvp4n; ///< Previous field's pixel line number (n + 4)
 
     const uint8_t *srcp;   ///< Current field's pixel line number n
     const uint8_t *srcpp;  ///< Current field's pixel line number (n - 1)
     const uint8_t *srcpn;  ///< Current field's pixel line number (n + 1)
     const uint8_t *srcppp; ///< Current field's pixel line number (n - 2)
     const uint8_t *srcpnn; ///< Current field's pixel line number (n + 2)
     const uint8_t *srcp3p; ///< Current field's pixel line number (n - 3)
     const uint8_t *srcp3n; ///< Current field's pixel line number (n + 3)
     const uint8_t *srcp4p; ///< Current field's pixel line number (n - 4)
     const uint8_t *srcp4n; ///< Current field's pixel line number (n + 4)
 
     uint8_t *dstp, *dstp_saved;
     const uint8_t *srcp_saved;
 
     int src_linesize, psrc_linesize, dst_linesize, bwidth;
     int x, y, plane, val, hi, lo, g, h, n = kerndeint->frame++;
     double valf;
 
     const int thresh = kerndeint->thresh;
     const int order  = kerndeint->order;
     const int map    = kerndeint->map;
     const int sharp  = kerndeint->sharp;
     const int twoway = kerndeint->twoway;
 

     const int is_packed_rgb = kerndeint->is_packed_rgb;

     outpic = ff_get_video_buffer(outlink, outlink->w, outlink->h);

     if (!outpic) {

         av_frame_free(&inpic);

         return AVERROR(ENOMEM);
     }

     av_frame_copy_props(outpic, inpic);
     outpic->interlaced_frame = 0;

     for (plane = 0; plane < 4 && inpic->data[plane] && inpic->linesize[plane]; plane++) {

         h = plane == 0 ? inlink->h : FF_CEIL_RSHIFT(inlink->h, kerndeint->vsub);

         bwidth = kerndeint->tmp_bwidth[plane];
 

         srcp_saved        = inpic->data[plane];

         src_linesize      = inpic->linesize[plane];

         psrc_linesize     = kerndeint->tmp_linesize[plane];

         dstp_saved        = outpic->data[plane];

         dst_linesize      = outpic->linesize[plane];
         srcp              = srcp_saved + (1 - order) * src_linesize;
         dstp              = dstp_saved + (1 - order) * dst_linesize;
 
         for (y = 0; y < h; y += 2) {
             memcpy(dstp, srcp, bwidth);
             srcp += 2 * src_linesize;
             dstp += 2 * dst_linesize;
         }
 
         // Copy through the lines that will be missed below.
         memcpy(dstp_saved + order            * dst_linesize, srcp_saved + (1 -     order) * src_linesize, bwidth);
         memcpy(dstp_saved + (2 + order    )  * dst_linesize, srcp_saved + (3 -     order) * src_linesize, bwidth);
         memcpy(dstp_saved + (h - 2 + order)  * dst_linesize, srcp_saved + (h - 1 - order) * src_linesize, bwidth);
         memcpy(dstp_saved + (h - 4 + order)  * dst_linesize, srcp_saved + (h - 3 - order) * src_linesize, bwidth);
 
         /* For the other field choose adaptively between using the previous field
            or the interpolant from the current field. */
         prvp   = kerndeint->tmp_data[plane] + 5 * psrc_linesize - (1 - order) * psrc_linesize;
         prvpp  = prvp - psrc_linesize;
         prvppp = prvp - 2 * psrc_linesize;
         prvp4p = prvp - 4 * psrc_linesize;
         prvpn  = prvp + psrc_linesize;
         prvpnn = prvp + 2 * psrc_linesize;
         prvp4n = prvp + 4 * psrc_linesize;
 
         srcp   = srcp_saved + 5 * src_linesize - (1 - order) * src_linesize;
         srcpp  = srcp - src_linesize;
         srcppp = srcp - 2 * src_linesize;
         srcp3p = srcp - 3 * src_linesize;
         srcp4p = srcp - 4 * src_linesize;
 
         srcpn  = srcp + src_linesize;
         srcpnn = srcp + 2 * src_linesize;
         srcp3n = srcp + 3 * src_linesize;
         srcp4n = srcp + 4 * src_linesize;
 
         dstp   = dstp_saved + 5 * dst_linesize - (1 - order) * dst_linesize;
 
         for (y = 5 - (1 - order); y <= h - 5 - (1 - order); y += 2) {
             for (x = 0; x < bwidth; x++) {
                 if (thresh == 0 || n == 0 ||
                     (abs((int)prvp[x]  - (int)srcp[x])  > thresh) ||
                     (abs((int)prvpp[x] - (int)srcpp[x]) > thresh) ||
                     (abs((int)prvpn[x] - (int)srcpn[x]) > thresh)) {
                     if (map) {
                         g = x & ~3;
 

                         if (is_packed_rgb) {

                             AV_WB32(dstp + g, 0xffffffff);
                             x = g + 3;
                         } else if (inlink->format == AV_PIX_FMT_YUYV422) {
                             // y <- 235, u <- 128, y <- 235, v <- 128
                             AV_WB32(dstp + g, 0xeb80eb80);
                             x = g + 3;
                         } else {
                             dstp[x] = plane == 0 ? 235 : 128;
                         }
                     } else {

                         if (is_packed_rgb) {

                             hi = 255;
                             lo = 0;
                         } else if (inlink->format == AV_PIX_FMT_YUYV422) {
                             hi = x & 1 ? 240 : 235;
                             lo = 16;
                         } else {
                             hi = plane == 0 ? 235 : 240;
                             lo = 16;
                         }
 
                         if (sharp) {
                             if (twoway) {
                                 valf = + 0.526 * ((int)srcpp[x] + (int)srcpn[x])
                                     + 0.170 * ((int)srcp[x] + (int)prvp[x])
                                     - 0.116 * ((int)srcppp[x] + (int)srcpnn[x] + (int)prvppp[x] + (int)prvpnn[x])
                                     - 0.026 * ((int)srcp3p[x] + (int)srcp3n[x])
                                     + 0.031 * ((int)srcp4p[x] + (int)srcp4n[x] + (int)prvp4p[x] + (int)prvp4n[x]);
                             } else {
                                 valf = + 0.526 * ((int)srcpp[x] + (int)srcpn[x])
                                     + 0.170 * ((int)prvp[x])
                                     - 0.116 * ((int)prvppp[x] + (int)prvpnn[x])
                                     - 0.026 * ((int)srcp3p[x] + (int)srcp3n[x])
                                     + 0.031 * ((int)prvp4p[x] + (int)prvp4p[x]);
                             }
                             dstp[x] = av_clip(valf, lo, hi);
                         } else {
                             if (twoway) {
                                 val = (8 * ((int)srcpp[x] + (int)srcpn[x]) + 2 * ((int)srcp[x] + (int)prvp[x])
                                        - (int)(srcppp[x]) - (int)(srcpnn[x])
                                        - (int)(prvppp[x]) - (int)(prvpnn[x])) >> 4;
                             } else {
                                 val = (8 * ((int)srcpp[x] + (int)srcpn[x]) + 2 * ((int)prvp[x])
                                        - (int)(prvppp[x]) - (int)(prvpnn[x])) >> 4;
                             }
                             dstp[x] = av_clip(val, lo, hi);
                         }
                     }
                 } else {
                     dstp[x] = srcp[x];
                 }
             }
             prvp   += 2 * psrc_linesize;
             prvpp  += 2 * psrc_linesize;
             prvppp += 2 * psrc_linesize;
             prvpn  += 2 * psrc_linesize;
             prvpnn += 2 * psrc_linesize;
             prvp4p += 2 * psrc_linesize;
             prvp4n += 2 * psrc_linesize;
             srcp   += 2 * src_linesize;
             srcpp  += 2 * src_linesize;
             srcppp += 2 * src_linesize;
             srcp3p += 2 * src_linesize;
             srcp4p += 2 * src_linesize;
             srcpn  += 2 * src_linesize;
             srcpnn += 2 * src_linesize;
             srcp3n += 2 * src_linesize;
             srcp4n += 2 * src_linesize;
             dstp   += 2 * dst_linesize;
         }
 
         srcp = inpic->data[plane];
         dstp = kerndeint->tmp_data[plane];
         av_image_copy_plane(dstp, psrc_linesize, srcp, src_linesize, bwidth, h);
     }
 

     av_frame_free(&inpic);

     return ff_filter_frame(outlink, outpic);
 }
 
 static const AVFilterPad kerndeint_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_props,
     },
     { NULL }
 };
 
 static const AVFilterPad kerndeint_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter ff_vf_kerndeint = {

     .name          = "kerndeint",
     .description   = NULL_IF_CONFIG_SMALL("Apply kernel deinterlacing to the input."),
     .priv_size     = sizeof(KerndeintContext),

     .priv_class    = &kerndeint_class,

     .uninit        = uninit,
     .query_formats = query_formats,
     .inputs        = kerndeint_inputs,
     .outputs       = kerndeint_outputs,
 };