/*
  * 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
  * Display frame palette (AV_PIX_FMT_PAL8)
  */
 
 #include "libavutil/avassert.h"
 #include "libavutil/opt.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 

 typedef struct ShowPaletteContext {

     const AVClass *class;
     int size;
 } ShowPaletteContext;
 
 #define OFFSET(x) offsetof(ShowPaletteContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 static const AVOption showpalette_options[] = {
     { "s", "set pixel box size", OFFSET(size), AV_OPT_TYPE_INT, {.i64=30}, 1, 100, FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(showpalette);
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat in_fmts[]  = {AV_PIX_FMT_PAL8,  AV_PIX_FMT_NONE};
     static const enum AVPixelFormat out_fmts[] = {AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE};

     int ret;

     AVFilterFormats *in  = ff_make_format_list(in_fmts);
     AVFilterFormats *out = ff_make_format_list(out_fmts);

     if (!in || !out) {

         ret = AVERROR(ENOMEM);
         goto fail;

     }

     if ((ret = ff_formats_ref(in , &ctx->inputs[0]->out_formats)) < 0 ||
         (ret = ff_formats_ref(out, &ctx->outputs[0]->in_formats)) < 0)

         goto fail;

     return 0;

 fail:
     if (in)
         av_freep(&in->formats);
     av_freep(&in);
     if (out)
         av_freep(&out->formats);
     av_freep(&out);
     return ret;

 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     const ShowPaletteContext *s = ctx->priv;
     outlink->w = outlink->h = 16 * s->size;
     return 0;
 }
 
 static int disp_palette(AVFrame *out, const AVFrame *in, int size)
 {
     int x, y, i, j;
     uint32_t *dst = (uint32_t *)out->data[0];
     const int dst_linesize = out->linesize[0] >> 2;
     const uint32_t *pal = (uint32_t *)in->data[1];
 
     for (y = 0; y < 16; y++)
         for (x = 0; x < 16; x++)
             for (j = 0; j < size; j++)
                 for (i = 0; i < size; i++)
                     dst[(y*dst_linesize + x) * size + j*dst_linesize + i] = pal[y*16 + x];
     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     int ret;
     AVFrame *out;
     AVFilterContext *ctx = inlink->dst;
     const ShowPaletteContext *s= ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
 
     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);
     ret = disp_palette(out, in, s->size);
     av_frame_free(&in);
     return ret < 0 ? ret : ff_filter_frame(outlink, out);
 }
 
 static const AVFilterPad showpalette_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad showpalette_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_output,
     },
     { NULL }
 };
 
 AVFilter ff_vf_showpalette = {
     .name          = "showpalette",

     .description   = NULL_IF_CONFIG_SMALL("Display frame palette."),

     .priv_size     = sizeof(ShowPaletteContext),
     .query_formats = query_formats,
     .inputs        = showpalette_inputs,
     .outputs       = showpalette_outputs,
     .priv_class    = &showpalette_class,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
 };