/*
  * Copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at>

  * Copyright (c) 2013 Clément Bœsch <u pkh me>

  *
  * 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.
  */
 
 /**
  * @todo try to change to int
  * @todo try lifting based implementation
  * @todo optimize optimize optimize
  * @todo hard thresholding
  * @todo use QP to decide filter strength
  * @todo wavelet normalization / least squares optimal signal vs. noise thresholds
  */
 
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 #include "internal.h"
 

 typedef struct OWDenoiseContext {

     const AVClass *class;
     double luma_strength;
     double chroma_strength;
     int depth;
     float *plane[16+1][4];
     int linesize;
     int hsub, vsub;

     int pixel_depth;

 } OWDenoiseContext;
 
 #define OFFSET(x) offsetof(OWDenoiseContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 static const AVOption owdenoise_options[] = {
     { "depth",           "set depth",           OFFSET(depth),           AV_OPT_TYPE_INT,    {.i64 =   8}, 8,   16, FLAGS },
     { "luma_strength",   "set luma strength",   OFFSET(luma_strength),   AV_OPT_TYPE_DOUBLE, {.dbl = 1.0}, 0, 1000, FLAGS },
     { "ls",              "set luma strength",   OFFSET(luma_strength),   AV_OPT_TYPE_DOUBLE, {.dbl = 1.0}, 0, 1000, FLAGS },
     { "chroma_strength", "set chroma strength", OFFSET(chroma_strength), AV_OPT_TYPE_DOUBLE, {.dbl = 1.0}, 0, 1000, FLAGS },
     { "cs",              "set chroma strength", OFFSET(chroma_strength), AV_OPT_TYPE_DOUBLE, {.dbl = 1.0}, 0, 1000, FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(owdenoise);
 
 DECLARE_ALIGNED(8, static const uint8_t, dither)[8][8] = {
     {  0,  48,  12,  60,   3,  51,  15,  63 },
     { 32,  16,  44,  28,  35,  19,  47,  31 },
     {  8,  56,   4,  52,  11,  59,   7,  55 },
     { 40,  24,  36,  20,  43,  27,  39,  23 },
     {  2,  50,  14,  62,   1,  49,  13,  61 },
     { 34,  18,  46,  30,  33,  17,  45,  29 },
     { 10,  58,   6,  54,   9,  57,   5,  53 },
     { 42,  26,  38,  22,  41,  25,  37,  21 },
 };
 
 static const double coeff[2][5] = {
     {
          0.6029490182363579  * M_SQRT2,
          0.2668641184428723  * M_SQRT2,
         -0.07822326652898785 * M_SQRT2,
         -0.01686411844287495 * M_SQRT2,
          0.02674875741080976 * M_SQRT2,
     },{
          1.115087052456994   / M_SQRT2,
         -0.5912717631142470  / M_SQRT2,
         -0.05754352622849957 / M_SQRT2,
          0.09127176311424948 / M_SQRT2,
     }
 };
 
 static const double icoeff[2][5] = {
     {
          1.115087052456994   / M_SQRT2,
          0.5912717631142470  / M_SQRT2,
         -0.05754352622849957 / M_SQRT2,
         -0.09127176311424948 / M_SQRT2,
     },{
          0.6029490182363579  * M_SQRT2,
         -0.2668641184428723  * M_SQRT2,
         -0.07822326652898785 * M_SQRT2,
          0.01686411844287495 * M_SQRT2,
          0.02674875741080976 * M_SQRT2,
     }
 };
 
 
 static inline void decompose(float *dst_l, float *dst_h, const float *src,
                              int linesize, int w)
 {
     int x, i;
     for (x = 0; x < w; x++) {
         double sum_l = src[x * linesize] * coeff[0][0];
         double sum_h = src[x * linesize] * coeff[1][0];
         for (i = 1; i <= 4; i++) {

             const double s = src[avpriv_mirror(x - i, w - 1) * linesize]
                            + src[avpriv_mirror(x + i, w - 1) * linesize];

 
             sum_l += coeff[0][i] * s;
             sum_h += coeff[1][i] * s;
         }
         dst_l[x * linesize] = sum_l;
         dst_h[x * linesize] = sum_h;
     }
 }
 
 static inline void compose(float *dst, const float *src_l, const float *src_h,
                            int linesize, int w)
 {
     int x, i;
     for (x = 0; x < w; x++) {
         double sum_l = src_l[x * linesize] * icoeff[0][0];
         double sum_h = src_h[x * linesize] * icoeff[1][0];
         for (i = 1; i <= 4; i++) {

             const int x0 = avpriv_mirror(x - i, w - 1) * linesize;
             const int x1 = avpriv_mirror(x + i, w - 1) * linesize;

 
             sum_l += icoeff[0][i] * (src_l[x0] + src_l[x1]);
             sum_h += icoeff[1][i] * (src_h[x0] + src_h[x1]);
         }
         dst[x * linesize] = (sum_l + sum_h) * 0.5;
     }
 }
 
 static inline void decompose2D(float *dst_l, float *dst_h, const float *src,
                                int xlinesize, int ylinesize,
                                int step, int w, int h)
 {
     int y, x;
     for (y = 0; y < h; y++)
         for (x = 0; x < step; x++)
             decompose(dst_l + ylinesize*y + xlinesize*x,
                       dst_h + ylinesize*y + xlinesize*x,
                       src   + ylinesize*y + xlinesize*x,
                       step * xlinesize, (w - x + step - 1) / step);
 }
 
 static inline void compose2D(float *dst, const float *src_l, const float *src_h,
                              int xlinesize, int ylinesize,
                              int step, int w, int h)
 {
     int y, x;
     for (y = 0; y < h; y++)
         for (x = 0; x < step; x++)
             compose(dst   + ylinesize*y + xlinesize*x,
                     src_l + ylinesize*y + xlinesize*x,
                     src_h + ylinesize*y + xlinesize*x,
                     step * xlinesize, (w - x + step - 1) / step);
 }
 
 static void decompose2D2(float *dst[4], float *src, float *temp[2],
                          int linesize, int step, int w, int h)
 {
     decompose2D(temp[0], temp[1], src,     1, linesize, step, w, h);
     decompose2D( dst[0],  dst[1], temp[0], linesize, 1, step, h, w);
     decompose2D( dst[2],  dst[3], temp[1], linesize, 1, step, h, w);
 }
 
 static void compose2D2(float *dst, float *src[4], float *temp[2],
                        int linesize, int step, int w, int h)
 {
     compose2D(temp[0],  src[0],  src[1], linesize, 1, step, h, w);
     compose2D(temp[1],  src[2],  src[3], linesize, 1, step, h, w);
     compose2D(dst,     temp[0], temp[1], 1, linesize, step, w, h);
 }
 
 static void filter(OWDenoiseContext *s,
                    uint8_t       *dst, int dst_linesize,
                    const uint8_t *src, int src_linesize,
                    int width, int height, double strength)
 {
     int x, y, i, j, depth = s->depth;
 
     while (1<<depth > width || 1<<depth > height)
         depth--;
 

     if (s->pixel_depth <= 8) {
         for (y = 0; y < height; y++)
             for(x = 0; x < width; x++)
                 s->plane[0][0][y*s->linesize + x] = src[y*src_linesize + x];
     } else {
         const uint16_t *src16 = (const uint16_t *)src;
 
         src_linesize /= 2;
         for (y = 0; y < height; y++)
             for(x = 0; x < width; x++)
                 s->plane[0][0][y*s->linesize + x] = src16[y*src_linesize + x];
     }

 
     for (i = 0; i < depth; i++)
         decompose2D2(s->plane[i + 1], s->plane[i][0], s->plane[0] + 1, s->linesize, 1<<i, width, height);
 
     for (i = 0; i < depth; i++) {
         for (j = 1; j < 4; j++) {
             for (y = 0; y < height; y++) {
                 for (x = 0; x < width; x++) {
                     double v = s->plane[i + 1][j][y*s->linesize + x];
                     if      (v >  strength) v -= strength;
                     else if (v < -strength) v += strength;
                     else                    v  = 0;
                     s->plane[i + 1][j][x + y*s->linesize] = v;
                 }
             }
         }
     }
     for (i = depth-1; i >= 0; i--)
         compose2D2(s->plane[i][0], s->plane[i + 1], s->plane[0] + 1, s->linesize, 1<<i, width, height);
 

     if (s->pixel_depth <= 8) {
         for (y = 0; y < height; y++) {
             for (x = 0; x < width; x++) {
                 i = s->plane[0][0][y*s->linesize + x] + dither[x&7][y&7]*(1.0/64) + 1.0/128; // yes the rounding is insane but optimal :)
                 if ((unsigned)i > 255U) i = ~(i >> 31);
                 dst[y*dst_linesize + x] = i;
             }
         }
     } else {
         uint16_t *dst16 = (uint16_t *)dst;
 
         dst_linesize /= 2;
         for (y = 0; y < height; y++) {
             for (x = 0; x < width; x++) {
                 i = s->plane[0][0][y*s->linesize + x];
                 dst16[y*dst_linesize + x] = i;
             }

         }
     }
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;
     OWDenoiseContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *out;

     const int cw = AV_CEIL_RSHIFT(inlink->w, s->hsub);
     const int ch = AV_CEIL_RSHIFT(inlink->h, s->vsub);

 
     if (av_frame_is_writable(in)) {
         out = in;

 
         if (s->luma_strength > 0)
             filter(s, out->data[0], out->linesize[0], in->data[0], in->linesize[0], inlink->w, inlink->h, s->luma_strength);
         if (s->chroma_strength > 0) {
             filter(s, out->data[1], out->linesize[1], in->data[1], in->linesize[1], cw,        ch,        s->chroma_strength);
             filter(s, out->data[2], out->linesize[2], in->data[2], in->linesize[2], cw,        ch,        s->chroma_strength);
         }

     } else {
         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);
 

         if (s->luma_strength > 0) {
             filter(s, out->data[0], out->linesize[0], in->data[0], in->linesize[0], inlink->w, inlink->h, s->luma_strength);
         } else {
             av_image_copy_plane(out->data[0], out->linesize[0], in ->data[0], in ->linesize[0], inlink->w, inlink->h);
         }
         if (s->chroma_strength > 0) {
             filter(s, out->data[1], out->linesize[1], in->data[1], in->linesize[1], cw, ch, s->chroma_strength);
             filter(s, out->data[2], out->linesize[2], in->data[2], in->linesize[2], cw, ch, s->chroma_strength);
         } else {
             av_image_copy_plane(out->data[1], out->linesize[1], in ->data[1], in ->linesize[1], inlink->w, inlink->h);
             av_image_copy_plane(out->data[2], out->linesize[2], in ->data[2], in ->linesize[2], inlink->w, inlink->h);
         }

 
         if (in->data[3])
             av_image_copy_plane(out->data[3], out->linesize[3],
                                 in ->data[3], in ->linesize[3],
                                 inlink->w, inlink->h);
         av_frame_free(&in);
     }
 
     return ff_filter_frame(outlink, out);
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUV444P,      AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV420P,      AV_PIX_FMT_YUV411P,
         AV_PIX_FMT_YUV410P,      AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVA444P,     AV_PIX_FMT_YUVA422P,
         AV_PIX_FMT_YUVA420P,

         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_YUV440P10,
         AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12,
         AV_PIX_FMT_YUV440P12,
         AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14,
         AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,

         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_input(AVFilterLink *inlink)
 {
     int i, j;
     OWDenoiseContext *s = inlink->dst->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     const int h = FFALIGN(inlink->h, 16);
 
     s->hsub = desc->log2_chroma_w;
     s->vsub = desc->log2_chroma_h;

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

 
     s->linesize = FFALIGN(inlink->w, 16);
     for (j = 0; j < 4; j++) {
         for (i = 0; i <= s->depth; i++) {

             s->plane[i][j] = av_malloc_array(s->linesize, h * sizeof(s->plane[0][0][0]));

             if (!s->plane[i][j])
                 return AVERROR(ENOMEM);
         }
     }
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     int i, j;
     OWDenoiseContext *s = ctx->priv;
 
     for (j = 0; j < 4; j++)
         for (i = 0; i <= s->depth; i++)
             av_freep(&s->plane[i][j]);
 }
 
 static const AVFilterPad owdenoise_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_input,
     },
     { NULL }
 };
 
 static const AVFilterPad owdenoise_outputs[] = {

     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }

 };
 

 AVFilter ff_vf_owdenoise = {

     .name          = "owdenoise",
     .description   = NULL_IF_CONFIG_SMALL("Denoise using wavelets."),
     .priv_size     = sizeof(OWDenoiseContext),
     .uninit        = uninit,
     .query_formats = query_formats,
     .inputs        = owdenoise_inputs,
     .outputs       = owdenoise_outputs,
     .priv_class    = &owdenoise_class,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
 };