/*
  * Copyright (c) 2013 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/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 #include "drawutils.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 
 #define R 0
 #define G 1
 #define B 2
 #define A 3
 

 typedef struct Range {

     double in_min, in_max;
     double out_min, out_max;
 } Range;
 

 typedef struct ColorLevelsContext {

     const AVClass *class;
     Range range[4];
     int nb_comp;
     int bpp;
     int step;
     uint8_t rgba_map[4];
     int linesize;
 } ColorLevelsContext;
 
 #define OFFSET(x) offsetof(ColorLevelsContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 static const AVOption colorlevels_options[] = {
     { "rimin", "set input red black point",    OFFSET(range[R].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
     { "gimin", "set input green black point",  OFFSET(range[G].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
     { "bimin", "set input blue black point",   OFFSET(range[B].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
     { "aimin", "set input alpha black point",  OFFSET(range[A].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
     { "rimax", "set input red white point",    OFFSET(range[R].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
     { "gimax", "set input green white point",  OFFSET(range[G].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
     { "bimax", "set input blue white point",   OFFSET(range[B].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
     { "aimax", "set input alpha white point",  OFFSET(range[A].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
     { "romin", "set output red black point",   OFFSET(range[R].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
     { "gomin", "set output green black point", OFFSET(range[G].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
     { "bomin", "set output blue black point",  OFFSET(range[B].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
     { "aomin", "set output alpha black point", OFFSET(range[A].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
     { "romax", "set output red white point",   OFFSET(range[R].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
     { "gomax", "set output green white point", OFFSET(range[G].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
     { "bomax", "set output blue white point",  OFFSET(range[B].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
     { "aomax", "set output alpha white point", OFFSET(range[A].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(colorlevels);
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_0RGB,  AV_PIX_FMT_0BGR,
         AV_PIX_FMT_ARGB,  AV_PIX_FMT_ABGR,
         AV_PIX_FMT_RGB0,  AV_PIX_FMT_BGR0,
         AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
         AV_PIX_FMT_RGB48, AV_PIX_FMT_BGR48,
         AV_PIX_FMT_RGBA64, AV_PIX_FMT_BGRA64,
         AV_PIX_FMT_RGBA,  AV_PIX_FMT_BGRA,
         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)
 {
     AVFilterContext *ctx = inlink->dst;
     ColorLevelsContext *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
 
     s->nb_comp = desc->nb_components;

     s->bpp = desc->comp[0].depth >> 3;

     s->step = (av_get_padded_bits_per_pixel(desc) >> 3) / s->bpp;
     s->linesize = inlink->w * s->step;
     ff_fill_rgba_map(s->rgba_map, inlink->format);
 
     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;
     ColorLevelsContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     const int step = s->step;
     AVFrame *out;
     int x, y, i;
 
     if (av_frame_is_writable(in)) {
         out = in;
     } 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);
     }
 
     switch (s->bpp) {
     case 1:
         for (i = 0; i < s->nb_comp; i++) {
             Range *r = &s->range[i];
             const uint8_t offset = s->rgba_map[i];
             const uint8_t *srcrow = in->data[0];
             uint8_t *dstrow = out->data[0];

             int imin = lrint(r->in_min  * UINT8_MAX);
             int imax = lrint(r->in_max  * UINT8_MAX);
             int omin = lrint(r->out_min * UINT8_MAX);
             int omax = lrint(r->out_max * UINT8_MAX);

             double coeff;
 
             if (imin < 0) {
                 imin = UINT8_MAX;
                 for (y = 0; y < inlink->h; y++) {
                     const uint8_t *src = srcrow;
 
                     for (x = 0; x < s->linesize; x += step)
                         imin = FFMIN(imin, src[x + offset]);
                     srcrow += in->linesize[0];
                 }
             }
             if (imax < 0) {
                 srcrow = in->data[0];
                 imax = 0;
                 for (y = 0; y < inlink->h; y++) {
                     const uint8_t *src = srcrow;
 
                     for (x = 0; x < s->linesize; x += step)
                         imax = FFMAX(imax, src[x + offset]);
                     srcrow += in->linesize[0];
                 }
             }
 
             srcrow = in->data[0];
             coeff = (omax - omin) / (double)(imax - imin);
             for (y = 0; y < inlink->h; y++) {
                 const uint8_t *src = srcrow;
                 uint8_t *dst = dstrow;
 
                 for (x = 0; x < s->linesize; x += step)
                     dst[x + offset] = av_clip_uint8((src[x + offset] - imin) * coeff + omin);
                 dstrow += out->linesize[0];
                 srcrow += in->linesize[0];
             }
         }
         break;
     case 2:
         for (i = 0; i < s->nb_comp; i++) {
             Range *r = &s->range[i];
             const uint8_t offset = s->rgba_map[i];
             const uint8_t *srcrow = in->data[0];
             uint8_t *dstrow = out->data[0];

             int imin = lrint(r->in_min  * UINT16_MAX);
             int imax = lrint(r->in_max  * UINT16_MAX);
             int omin = lrint(r->out_min * UINT16_MAX);
             int omax = lrint(r->out_max * UINT16_MAX);

             double coeff;
 
             if (imin < 0) {
                 imin = UINT16_MAX;
                 for (y = 0; y < inlink->h; y++) {
                     const uint16_t *src = (const uint16_t *)srcrow;
 
                     for (x = 0; x < s->linesize; x += step)
                         imin = FFMIN(imin, src[x + offset]);
                     srcrow += in->linesize[0];
                 }
             }
             if (imax < 0) {
                 srcrow = in->data[0];
                 imax = 0;
                 for (y = 0; y < inlink->h; y++) {
                     const uint16_t *src = (const uint16_t *)srcrow;
 
                     for (x = 0; x < s->linesize; x += step)
                         imax = FFMAX(imax, src[x + offset]);
                     srcrow += in->linesize[0];
                 }
             }
 
             srcrow = in->data[0];
             coeff = (omax - omin) / (double)(imax - imin);
             for (y = 0; y < inlink->h; y++) {
                 const uint16_t *src = (const uint16_t*)srcrow;
                 uint16_t *dst = (uint16_t *)dstrow;
 
                 for (x = 0; x < s->linesize; x += step)
                     dst[x + offset] = av_clip_uint16((src[x + offset] - imin) * coeff + omin);
                 dstrow += out->linesize[0];
                 srcrow += in->linesize[0];
             }
         }
     }
 
     if (in != out)
         av_frame_free(&in);
     return ff_filter_frame(outlink, out);
 }
 
 static const AVFilterPad colorlevels_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_input,
     },
     { NULL }
 };
 
 static const AVFilterPad colorlevels_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 
 AVFilter ff_vf_colorlevels = {
     .name          = "colorlevels",
     .description   = NULL_IF_CONFIG_SMALL("Adjust the color levels."),
     .priv_size     = sizeof(ColorLevelsContext),
     .priv_class    = &colorlevels_class,
     .query_formats = query_formats,
     .inputs        = colorlevels_inputs,
     .outputs       = colorlevels_outputs,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
 };