apps/plugins/jpeg/jpeg_decoder.h

   1 /***************************************************************************
   2 *             __________               __   ___.
   3 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7 *                     \/            \/     \/    \/            \/
   8 * $Id$
   9 *
  10 * JPEG image viewer
  11 * (This is a real mess if it has to be coded in one single C file)
  12 *
  13 * File scrolling addition (C) 2005 Alexander Spyridakis
  14 * Copyright (C) 2004 Jörg Hohensohn aka [IDC]Dragon
  15 * Heavily borrowed from the IJG implementation (C) Thomas G. Lane
  16 * Small & fast downscaling IDCT (C) 2002 by Guido Vollbeding  JPEGclub.org
  17 *
  18 * This program is free software; you can redistribute it and/or
  19 * modify it under the terms of the GNU General Public License
  20 * as published by the Free Software Foundation; either version 2
  21 * of the License, or (at your option) any later version.
  22 *
  23 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  24 * KIND, either express or implied.
  25 *
  26 ****************************************************************************/
  27
  28 #ifndef _JPEG_JPEG_DECODER_H
  29 #define _JPEG_JPEG_DECODER_H
  30 #include "jpeg_common.h"
  31
  32 struct jpeg
  33 {
  34     int x_size, y_size; /* size of image (can be less than block boundary) */
  35     int x_phys, y_phys; /* physical size, block aligned */
  36     int x_mbl; /* x dimension of MBL */
  37     int y_mbl; /* y dimension of MBL */
  38     int blocks; /* blocks per MB */
  39     int restart_interval; /* number of MCUs between RSTm markers */
  40     int store_pos[4]; /* for Y block ordering */
  41
  42     unsigned char* p_entropy_data;
  43     unsigned char* p_entropy_end;
  44
  45     int quanttable[4][QUANT_TABLE_LENGTH]; /* raw quantization tables 0-3 */
  46     int qt_idct[2][QUANT_TABLE_LENGTH]; /* quantization tables for IDCT */
  47
  48     struct huffman_table hufftable[2]; /* Huffman tables  */
  49     struct derived_tbl dc_derived_tbls[2]; /* Huffman-LUTs */
  50     struct derived_tbl ac_derived_tbls[2];
  51
  52     struct frame_component frameheader[3]; /* Component descriptor */
  53     struct scan_component scanheader[3]; /* currently not used */
  54
  55     int mcu_membership[6]; /* info per block */
  56     int tab_membership[6];
  57     int subsample_x[3]; /* info per component */
  58     int subsample_y[3];
  59 };
  60
  61 /* various helper functions */
  62 void default_huff_tbl(struct jpeg* p_jpeg);
  63 void build_lut(struct jpeg* p_jpeg);
  64 int process_markers(unsigned char* p_src, long size, struct jpeg* p_jpeg);
  65
  66 /* the main decode function */
  67 #ifdef HAVE_LCD_COLOR
  68 int jpeg_decode(struct jpeg* p_jpeg, unsigned char* p_pixel[3],
  69                 int downscale, void (*pf_progress)(int current, int total));
  70 #else
  71 int jpeg_decode(struct jpeg* p_jpeg, unsigned char* p_pixel[1], int downscale,
  72                 void (*pf_progress)(int current, int total));
  73 #endif
  74
  75
  76 #endif /* _JPEG_JPEG_DECODER_H */