/*
  * Copyright (c) 2011 Stefano Sabatini
  *
  * 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
  * Compute a look-up table for binding the input value to the output
  * value, and apply it to input video.
  */
 
 #include "libavutil/eval.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 
 static const char *var_names[] = {
     "E",
     "PHI",
     "PI",
     "w",        ///< width of the input video
     "h",        ///< height of the input video
     "val",      ///< input value for the pixel
     "maxval",   ///< max value for the pixel
     "minval",   ///< min value for the pixel
     "negval",   ///< negated value
     "clipval",
     NULL
 };
 
 enum var_name {
     VAR_E,
     VAR_PHI,
     VAR_PI,
     VAR_W,
     VAR_H,
     VAR_VAL,
     VAR_MAXVAL,
     VAR_MINVAL,
     VAR_NEGVAL,
     VAR_CLIPVAL,
     VAR_VARS_NB
 };
 
 typedef struct {
     const AVClass *class;
     uint8_t lut[4][256];  ///< lookup table for each component
     char   *comp_expr_str[4];
     AVExpr *comp_expr[4];
     int hsub, vsub;
     double var_values[VAR_VARS_NB];
     int is_rgb, is_yuv;
     int rgba_map[4];
     int step;

     int negate_alpha; /* only used by negate */

 } LutContext;
 
 #define Y 0
 #define U 1
 #define V 2
 #define R 0
 #define G 1
 #define B 2
 #define A 3
 
 #define OFFSET(x) offsetof(LutContext, x)
 
 static const AVOption lut_options[] = {
     {"c0", "set component #0 expression", OFFSET(comp_expr_str[0]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"c1", "set component #1 expression", OFFSET(comp_expr_str[1]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"c2", "set component #2 expression", OFFSET(comp_expr_str[2]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"c3", "set component #3 expression", OFFSET(comp_expr_str[3]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"y",  "set Y expression", OFFSET(comp_expr_str[Y]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"u",  "set U expression", OFFSET(comp_expr_str[U]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"v",  "set V expression", OFFSET(comp_expr_str[V]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"r",  "set R expression", OFFSET(comp_expr_str[R]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"g",  "set G expression", OFFSET(comp_expr_str[G]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"b",  "set B expression", OFFSET(comp_expr_str[B]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {"a",  "set A expression", OFFSET(comp_expr_str[A]),  FF_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
     {NULL},
 };
 
 static const char *lut_get_name(void *ctx)
 {
     return "lut";
 }
 
 static const AVClass lut_class = {
     "LutContext",
     lut_get_name,
     lut_options
 };
 
 static int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     LutContext *lut = ctx->priv;
     int ret;
 
     lut->class = &lut_class;
     av_opt_set_defaults2(lut, 0, 0);
 
     lut->var_values[VAR_PHI] = M_PHI;
     lut->var_values[VAR_PI]  = M_PI;
     lut->var_values[VAR_E ]  = M_E;
 
     lut->is_rgb = !strcmp(ctx->filter->name, "lutrgb");
     lut->is_yuv = !strcmp(ctx->filter->name, "lutyuv");
     if (args && (ret = av_set_options_string(lut, args, "=", ":")) < 0)
         return ret;
 
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     LutContext *lut = ctx->priv;
     int i;
 
     for (i = 0; i < 4; i++) {
         av_expr_free(lut->comp_expr[i]);
         lut->comp_expr[i] = NULL;
         av_freep(&lut->comp_expr_str[i]);
     }
 }
 
 #define YUV_FORMATS                                         \
     PIX_FMT_YUV444P,  PIX_FMT_YUV422P,  PIX_FMT_YUV420P,    \
     PIX_FMT_YUV411P,  PIX_FMT_YUV410P,  PIX_FMT_YUV440P,    \
     PIX_FMT_YUVA420P,                                       \
     PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,   \
     PIX_FMT_YUVJ440P
 
 #define RGB_FORMATS                             \
     PIX_FMT_ARGB,         PIX_FMT_RGBA,         \
     PIX_FMT_ABGR,         PIX_FMT_BGRA,         \
     PIX_FMT_RGB24,        PIX_FMT_BGR24
 
 static enum PixelFormat yuv_pix_fmts[] = { YUV_FORMATS, PIX_FMT_NONE };
 static enum PixelFormat rgb_pix_fmts[] = { RGB_FORMATS, PIX_FMT_NONE };
 static enum PixelFormat all_pix_fmts[] = { RGB_FORMATS, YUV_FORMATS, PIX_FMT_NONE };
 
 static int query_formats(AVFilterContext *ctx)
 {
     LutContext *lut = ctx->priv;
 
     enum PixelFormat *pix_fmts = lut->is_rgb ? rgb_pix_fmts :
                                  lut->is_yuv ? yuv_pix_fmts : all_pix_fmts;
 

     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));

     return 0;
 }
 
 static int pix_fmt_is_in(enum PixelFormat pix_fmt, enum PixelFormat *pix_fmts)
 {
     enum PixelFormat *p;
     for (p = pix_fmts; *p != PIX_FMT_NONE; p++) {
         if (pix_fmt == *p)
             return 1;
     }
     return 0;
 }
 
 /**
  * Clip value val in the minval - maxval range.
  */
 static double clip(void *opaque, double val)
 {
     LutContext *lut = opaque;
     double minval = lut->var_values[VAR_MINVAL];
     double maxval = lut->var_values[VAR_MAXVAL];
 
     return av_clip(val, minval, maxval);
 }
 
 /**
  * Compute gamma correction for value val, assuming the minval-maxval
  * range, val is clipped to a value contained in the same interval.
  */
 static double compute_gammaval(void *opaque, double gamma)
 {
     LutContext *lut = opaque;
     double val    = lut->var_values[VAR_CLIPVAL];
     double minval = lut->var_values[VAR_MINVAL];
     double maxval = lut->var_values[VAR_MAXVAL];
 
     return pow((val-minval)/(maxval-minval), gamma) * (maxval-minval)+minval;
 }
 
 static double (* const funcs1[])(void *, double) = {
     (void *)clip,
     (void *)compute_gammaval,
     NULL
 };
 
 static const char * const funcs1_names[] = {
     "clip",
     "gammaval",
     NULL
 };
 
 static int config_props(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     LutContext *lut = ctx->priv;
     const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[inlink->format];
     int min[4], max[4];
     int val, comp, ret;
 
     lut->hsub = desc->log2_chroma_w;
     lut->vsub = desc->log2_chroma_h;
 
     lut->var_values[VAR_W] = inlink->w;
     lut->var_values[VAR_H] = inlink->h;
 
     switch (inlink->format) {
     case PIX_FMT_YUV410P:
     case PIX_FMT_YUV411P:
     case PIX_FMT_YUV420P:
     case PIX_FMT_YUV422P:
     case PIX_FMT_YUV440P:
     case PIX_FMT_YUV444P:
     case PIX_FMT_YUVA420P:
         min[Y] = min[U] = min[V] = 16;
         max[Y] = 235;
         max[U] = max[V] = 240;
         break;
     default:
         min[0] = min[1] = min[2] = min[3] = 0;
         max[0] = max[1] = max[2] = max[3] = 255;
     }
 
     lut->is_yuv = lut->is_rgb = 0;
     if      (pix_fmt_is_in(inlink->format, yuv_pix_fmts)) lut->is_yuv = 1;
     else if (pix_fmt_is_in(inlink->format, rgb_pix_fmts)) lut->is_rgb = 1;
 
     if (lut->is_rgb) {
         switch (inlink->format) {
         case PIX_FMT_ARGB:  lut->rgba_map[A] = 0; lut->rgba_map[R] = 1; lut->rgba_map[G] = 2; lut->rgba_map[B] = 3; break;
         case PIX_FMT_ABGR:  lut->rgba_map[A] = 0; lut->rgba_map[B] = 1; lut->rgba_map[G] = 2; lut->rgba_map[R] = 3; break;
         case PIX_FMT_RGBA:
         case PIX_FMT_RGB24: lut->rgba_map[R] = 0; lut->rgba_map[G] = 1; lut->rgba_map[B] = 2; lut->rgba_map[A] = 3; break;
         case PIX_FMT_BGRA:
         case PIX_FMT_BGR24: lut->rgba_map[B] = 0; lut->rgba_map[G] = 1; lut->rgba_map[R] = 2; lut->rgba_map[A] = 3; break;
         }
         lut->step = av_get_bits_per_pixel(desc) >> 3;
     }
 
     for (comp = 0; comp < desc->nb_components; comp++) {
         double res;
 
         /* create the parsed expression */
         ret = av_expr_parse(&lut->comp_expr[comp], lut->comp_expr_str[comp],
                             var_names, funcs1_names, funcs1, NULL, NULL, 0, ctx);
         if (ret < 0) {
             av_log(ctx, AV_LOG_ERROR,
                    "Error when parsing the expression '%s' for the component %d.\n",
                    lut->comp_expr_str[comp], comp);
             return AVERROR(EINVAL);
         }
 
         /* compute the lut */
         lut->var_values[VAR_MAXVAL] = max[comp];
         lut->var_values[VAR_MINVAL] = min[comp];
 
         for (val = 0; val < 256; val++) {
             lut->var_values[VAR_VAL] = val;
             lut->var_values[VAR_CLIPVAL] = av_clip(val, min[comp], max[comp]);
             lut->var_values[VAR_NEGVAL] =
                 av_clip(min[comp] + max[comp] - lut->var_values[VAR_VAL],
                         min[comp], max[comp]);
 
             res = av_expr_eval(lut->comp_expr[comp], lut->var_values, lut);
             if (isnan(res)) {
                 av_log(ctx, AV_LOG_ERROR,
                        "Error when evaluating the expression '%s' for the value %d for the component #%d.\n",
                        lut->comp_expr_str[comp], val, comp);
                 return AVERROR(EINVAL);
             }
             lut->lut[comp][val] = av_clip((int)res, min[comp], max[comp]);
             av_log(ctx, AV_LOG_DEBUG, "val[%d][%d] = %d\n", comp, val, lut->lut[comp][val]);
         }
     }
 
     return 0;
 }
 
 static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
 {
     AVFilterContext *ctx = inlink->dst;
     LutContext *lut = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFilterBufferRef *inpic  = inlink ->cur_buf;
     AVFilterBufferRef *outpic = outlink->out_buf;
     uint8_t *inrow, *outrow;
     int i, j, k, plane;
 
     if (lut->is_rgb) {
         /* packed */
         inrow  = inpic ->data[0] + y * inpic ->linesize[0];
         outrow = outpic->data[0] + y * outpic->linesize[0];
 
         for (i = 0; i < h; i ++) {
             for (j = 0; j < inlink->w; j++) {
                 for (k = 0; k < lut->step; k++)
                     outrow[k] = lut->lut[lut->rgba_map[k]][inrow[k]];
                 outrow += lut->step;
                 inrow  += lut->step;
             }
         }
     } else {
         /* planar */
         for (plane = 0; inpic->data[plane]; plane++) {
             int vsub = plane == 1 || plane == 2 ? lut->vsub : 0;
             int hsub = plane == 1 || plane == 2 ? lut->hsub : 0;
 
             inrow  = inpic ->data[plane] + (y>>vsub) * inpic ->linesize[plane];
             outrow = outpic->data[plane] + (y>>vsub) * outpic->linesize[plane];
 
             for (i = 0; i < h>>vsub; i ++) {
                 for (j = 0; j < inlink->w>>hsub; j++)
                     outrow[j] = lut->lut[plane][inrow[j]];
                 inrow  += inpic ->linesize[plane];
                 outrow += outpic->linesize[plane];
             }
         }
     }
 
     avfilter_draw_slice(outlink, y, h, slice_dir);
 }
 
 #define DEFINE_LUT_FILTER(name_, description_, init_)                   \
     AVFilter avfilter_vf_##name_ = {                                    \

         .name          = #name_,                                        \
         .description   = NULL_IF_CONFIG_SMALL(description_),            \

         .priv_size     = sizeof(LutContext),                            \
                                                                         \
         .init          = init_,                                         \
         .uninit        = uninit,                                        \
         .query_formats = query_formats,                                 \
                                                                         \
         .inputs    = (AVFilterPad[]) {{ .name            = "default",   \
                                         .type            = AVMEDIA_TYPE_VIDEO, \
                                         .draw_slice      = draw_slice,  \
                                         .config_props    = config_props, \
                                         .min_perms       = AV_PERM_READ, }, \
                                       { .name = NULL}},                 \
         .outputs   = (AVFilterPad[]) {{ .name            = "default",   \
                                         .type            = AVMEDIA_TYPE_VIDEO, }, \
                                       { .name = NULL}},                 \
     }
 
 DEFINE_LUT_FILTER(lut,    "Compute and apply a lookup table to the RGB/YUV input video.", init);
 DEFINE_LUT_FILTER(lutyuv, "Compute and apply a lookup table to the YUV input video.",     init);
 DEFINE_LUT_FILTER(lutrgb, "Compute and apply a lookup table to the RGB input video.",     init);

 
 #if CONFIG_NEGATE_FILTER
 
 static int negate_init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     LutContext *lut = ctx->priv;
     char lut_params[1024];
 
     if (args)
         sscanf(args, "%d", &lut->negate_alpha);
 
     av_log(ctx, AV_LOG_INFO, "negate_alpha:%d\n", lut->negate_alpha);
 
     snprintf(lut_params, sizeof(lut_params), "c0=negval:c1=negval:c2=negval:a=%s",
              lut->negate_alpha ? "negval" : "val");
 
     return init(ctx, lut_params, opaque);
 }
 
 DEFINE_LUT_FILTER(negate, "Negate input video.", negate_init);
 
 #endif