/*

  * Original copyright (c) 2002 Remi Guyomarch <rguyom@pobox.com>
  * Port copyright (c) 2010 Daniel G. Taylor <dan@programmer-art.org>

  * Relicensed to the LGPL with permission from Remi Guyomarch.
  *
  * 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
  */
 
 /**

  * @file

  * blur / sharpen filter, ported to FFmpeg from MPlayer
  * libmpcodecs/unsharp.c.

  *
  * This code is based on:
  *
  * An Efficient algorithm for Gaussian blur using finite-state machines
  * Frederick M. Waltz and John W. V. Miller
  *
  * SPIE Conf. on Machine Vision Systems for Inspection and Metrology VII
  * Originally published Boston, Nov 98
  *
  * http://www.engin.umd.umich.edu/~jwvm/ece581/21_GBlur.pdf
  */
 
 #include "avfilter.h"
 #include "libavutil/common.h"
 #include "libavutil/mem.h"
 #include "libavutil/pixdesc.h"
 
 #define MIN_SIZE 3
 #define MAX_SIZE 13
 

 /* right-shift and round-up */
 #define SHIFTUP(x,shift) (-((-(x))>>(shift)))

 
 typedef struct FilterParam {
     int msize_x;                             ///< matrix width
     int msize_y;                             ///< matrix height
     int amount;                              ///< effect amount
     int steps_x;                             ///< horizontal step count
     int steps_y;                             ///< vertical step count
     int scalebits;                           ///< bits to shift pixel
     int32_t halfscale;                       ///< amount to add to pixel
     uint32_t *sc[(MAX_SIZE * MAX_SIZE) - 1]; ///< finite state machine storage
 } FilterParam;
 
 typedef struct {
     FilterParam luma;   ///< luma parameters (width, height, amount)
     FilterParam chroma; ///< chroma parameters (width, height, amount)

     int hsub, vsub;

 } UnsharpContext;
 

 static void apply_unsharp(      uint8_t *dst, int dst_stride,
                           const uint8_t *src, int src_stride,

                           int width, int height, FilterParam *fp)

 {
     uint32_t **sc = fp->sc;
     uint32_t sr[(MAX_SIZE * MAX_SIZE) - 1], tmp1, tmp2;
 
     int32_t res;
     int x, y, z;

     const uint8_t *src2 = NULL;  //silence a warning

 
     if (!fp->amount) {
         if (dst_stride == src_stride)
             memcpy(dst, src, src_stride * height);
         else
             for (y = 0; y < height; y++, dst += dst_stride, src += src_stride)
                 memcpy(dst, src, width);
         return;
     }
 
     for (y = 0; y < 2 * fp->steps_y; y++)
         memset(sc[y], 0, sizeof(sc[y][0]) * (width + 2 * fp->steps_x));
 

     for (y = -fp->steps_y; y < height + fp->steps_y; y++) {

         if (y < height)
             src2 = src;
 

         memset(sr, 0, sizeof(sr[0]) * (2 * fp->steps_x - 1));

         for (x = -fp->steps_x; x < width + fp->steps_x; x++) {

             tmp1 = x <= 0 ? src2[0] : x >= width ? src2[width-1] : src2[x];

             for (z = 0; z < fp->steps_x * 2; z += 2) {
                 tmp2 = sr[z + 0] + tmp1; sr[z + 0] = tmp1;
                 tmp1 = sr[z + 1] + tmp2; sr[z + 1] = tmp2;
             }
             for (z = 0; z < fp->steps_y * 2; z += 2) {
                 tmp2 = sc[z + 0][x + fp->steps_x] + tmp1; sc[z + 0][x + fp->steps_x] = tmp1;
                 tmp1 = sc[z + 1][x + fp->steps_x] + tmp2; sc[z + 1][x + fp->steps_x] = tmp2;
             }
             if (x >= fp->steps_x && y >= fp->steps_y) {

                 const uint8_t *srx = src - fp->steps_y * src_stride + x - fp->steps_x;
                 uint8_t       *dsx = dst - fp->steps_y * dst_stride + x - fp->steps_x;

 
                 res = (int32_t)*srx + ((((int32_t) * srx - (int32_t)((tmp1 + fp->halfscale) >> fp->scalebits)) * fp->amount) >> 16);
                 *dsx = av_clip_uint8(res);
             }
         }
         if (y >= 0) {
             dst += dst_stride;
             src += src_stride;
         }
     }
 }
 
 static void set_filter_param(FilterParam *fp, int msize_x, int msize_y, double amount)
 {
     fp->msize_x = msize_x;
     fp->msize_y = msize_y;
     fp->amount = amount * 65536.0;
 
     fp->steps_x = msize_x / 2;
     fp->steps_y = msize_y / 2;
     fp->scalebits = (fp->steps_x + fp->steps_y) * 2;
     fp->halfscale = 1 << (fp->scalebits - 1);
 }
 
 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     UnsharpContext *unsharp = ctx->priv;

     int lmsize_x = 5, cmsize_x = 5;
     int lmsize_y = 5, cmsize_y = 5;

     double lamount = 1.0f, camount = 0.0f;
 
     if (args)
         sscanf(args, "%d:%d:%lf:%d:%d:%lf", &lmsize_x, &lmsize_y, &lamount,
                                             &cmsize_x, &cmsize_y, &camount);
 

     if ((lamount && (lmsize_x < 2 || lmsize_y < 2)) ||
         (camount && (cmsize_x < 2 || cmsize_y < 2))) {

         av_log(ctx, AV_LOG_ERROR,
                "Invalid value <2 for lmsize_x:%d or lmsize_y:%d or cmsize_x:%d or cmsize_y:%d\n",
                lmsize_x, lmsize_y, cmsize_x, cmsize_y);
         return AVERROR(EINVAL);
     }
 

     set_filter_param(&unsharp->luma,   lmsize_x, lmsize_y, lamount);
     set_filter_param(&unsharp->chroma, cmsize_x, cmsize_y, camount);
 
     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     enum PixelFormat pix_fmts[] = {
         PIX_FMT_YUV420P,  PIX_FMT_YUV422P,  PIX_FMT_YUV444P,  PIX_FMT_YUV410P,
         PIX_FMT_YUV411P,  PIX_FMT_YUV440P,  PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P,
         PIX_FMT_YUVJ444P, PIX_FMT_YUVJ440P, PIX_FMT_NONE
     };
 

     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));

 
     return 0;
 }
 
 static void init_filter_param(AVFilterContext *ctx, FilterParam *fp, const char *effect_type, int width)
 {
     int z;
     const char *effect;
 
     effect = fp->amount == 0 ? "none" : fp->amount < 0 ? "blur" : "sharpen";
 
     av_log(ctx, AV_LOG_INFO, "effect:%s type:%s msize_x:%d msize_y:%d amount:%0.2f\n",
            effect, effect_type, fp->msize_x, fp->msize_y, fp->amount / 65535.0);
 
     for (z = 0; z < 2 * fp->steps_y; z++)
         fp->sc[z] = av_malloc(sizeof(*(fp->sc[z])) * (width + 2 * fp->steps_x));
 }
 
 static int config_props(AVFilterLink *link)
 {
     UnsharpContext *unsharp = link->dst->priv;
 

     unsharp->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
     unsharp->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
 

     init_filter_param(link->dst, &unsharp->luma,   "luma",   link->w);

     init_filter_param(link->dst, &unsharp->chroma, "chroma", SHIFTUP(link->w, unsharp->hsub));

 
     return 0;
 }
 
 static void free_filter_param(FilterParam *fp)
 {
     int z;
 
     for (z = 0; z < 2 * fp->steps_y; z++)
         av_free(fp->sc[z]);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     UnsharpContext *unsharp = ctx->priv;
 
     free_filter_param(&unsharp->luma);
     free_filter_param(&unsharp->chroma);
 }
 
 static void end_frame(AVFilterLink *link)
 {
     UnsharpContext *unsharp = link->dst->priv;

     AVFilterBufferRef *in  = link->cur_buf;
     AVFilterBufferRef *out = link->dst->outputs[0]->out_buf;

     int cw = SHIFTUP(link->w, unsharp->hsub);
     int ch = SHIFTUP(link->h, unsharp->vsub);

     apply_unsharp(out->data[0], out->linesize[0], in->data[0], in->linesize[0], link->w, link->h, &unsharp->luma);
     apply_unsharp(out->data[1], out->linesize[1], in->data[1], in->linesize[1], cw,      ch,      &unsharp->chroma);
     apply_unsharp(out->data[2], out->linesize[2], in->data[2], in->linesize[2], cw,      ch,      &unsharp->chroma);

     avfilter_unref_buffer(in);

     avfilter_draw_slice(link->dst->outputs[0], 0, link->h, 1);
     avfilter_end_frame(link->dst->outputs[0]);

     avfilter_unref_buffer(out);

 }
 
 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
 {
 }
 
 AVFilter avfilter_vf_unsharp = {
     .name      = "unsharp",
     .description = NULL_IF_CONFIG_SMALL("Sharpen or blur the input video."),
 
     .priv_size = sizeof(UnsharpContext),
 
     .init = init,
     .uninit = uninit,
     .query_formats = query_formats,
 

     .inputs    = (const AVFilterPad[]) {{ .name       = "default",

                                     .type             = AVMEDIA_TYPE_VIDEO,
                                     .draw_slice       = draw_slice,
                                     .end_frame        = end_frame,
                                     .config_props     = config_props,
                                     .min_perms        = AV_PERM_READ, },
                                   { .name = NULL}},
 

     .outputs   = (const AVFilterPad[]) {{ .name       = "default",

                                     .type             = AVMEDIA_TYPE_VIDEO, },
                                   { .name = NULL}},
 };