/*
  * QuickTime palette handling
  * Copyright (c) 2001 Fabrice Bellard
  * Copyright (c) 2009 Baptiste Coudurier <baptiste dot coudurier at gmail dot com>
  * Copyright (c) 2015 Mats Peterson
  *
  * 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 <stdio.h>
 #include <stdint.h>
 
 #include "avformat.h"
 #include "libavutil/intreadwrite.h"
 #include "qtpalette.h"
 
 int ff_get_qtpalette(int codec_id, AVIOContext *pb, uint32_t *palette)
 {
     int tmp, bit_depth, color_table_id, greyscale, i;
 
     avio_seek(pb, 82, SEEK_CUR);
 
     /* Get the bit depth and greyscale state */
     tmp = avio_rb16(pb);
     bit_depth = tmp & 0x1F;
     greyscale = tmp & 0x20;
 
     /* Get the color table ID */
     color_table_id = avio_rb16(pb);
 
     /* Do not create a greyscale palette for Cinepak */
     if (greyscale && codec_id == AV_CODEC_ID_CINEPAK)
         return 0;
 

     /* If the depth is 1, 2, 4, or 8 bpp, file is palettized. */
     if ((bit_depth == 1 || bit_depth == 2 || bit_depth == 4 || bit_depth == 8)) {

         uint32_t color_count, color_start, color_end;

         uint32_t a, r, g, b;
 

         /* Ignore the greyscale bit for 1-bit video and sample
          * descriptions containing a color table. */
         if (greyscale && bit_depth > 1 && color_table_id) {

             int color_index, color_dec;
             /* compute the greyscale palette */
             color_count = 1 << bit_depth;
             color_index = 255;
             color_dec   = 256 / (color_count - 1);
             for (i = 0; i < color_count; i++) {
                 r = g = b = color_index;
                 palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);
                 color_index -= color_dec;
                 if (color_index < 0)
                     color_index = 0;
             }
         } else if (color_table_id) {
             /* The color table ID is non-zero. Interpret this as
              * being -1, which means use the default Macintosh
              * color table */
             const uint8_t *color_table;
             color_count = 1 << bit_depth;

             if (bit_depth == 1)
                 color_table = ff_qt_default_palette_2;
             else if (bit_depth == 2)

                 color_table = ff_qt_default_palette_4;
             else if (bit_depth == 4)
                 color_table = ff_qt_default_palette_16;
             else
                 color_table = ff_qt_default_palette_256;
             for (i = 0; i < color_count; i++) {
                 r = color_table[i * 3 + 0];
                 g = color_table[i * 3 + 1];
                 b = color_table[i * 3 + 2];
                 palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);
             }
         } else {
             /* The color table ID is 0; the color table is in the sample
              * description */
             color_start = avio_rb32(pb);
             avio_rb16(pb); /* color table flags */
             color_end = avio_rb16(pb);
             if ((color_start <= 255) && (color_end <= 255)) {
                 for (i = color_start; i <= color_end; i++) {
                     /* each A, R, G, or B component is 16 bits;
                      * only use the top 8 bits */
                     a = avio_r8(pb);
                     avio_r8(pb);
                     r = avio_r8(pb);
                     avio_r8(pb);
                     g = avio_r8(pb);
                     avio_r8(pb);
                     b = avio_r8(pb);
                     avio_r8(pb);
                     palette[i] = (a << 24 ) | (r << 16) | (g << 8) | (b);
                 }
             }
         }
 
         return 1;
     }
 
     return 0;
 }