Add core JPEG reader, adapted from the JPEG plugin's decoder, with some changes to prevent include conflicts between the two decoders.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20836 a1c6a512-1295-4272-9138-f99709370657

apps/recorder/jpeg_common.h

@@ -0,0 +1,97 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* JPEG image viewer
+* Common structs and defines for plugin and core JPEG decoders
+*
+* File scrolling addition (C) 2005 Alexander Spyridakis
+* Copyright (C) 2004 Jörg Hohensohn aka [IDC]Dragon
+* Heavily borrowed from the IJG implementation (C) Thomas G. Lane
+* Small & fast downscaling IDCT (C) 2002 by Guido Vollbeding  JPEGclub.org
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+#ifndef _JPEG_COMMON_H
+#define _JPEG_COMMON_H
+
+#define HUFF_LOOKAHEAD 8 /* # of bits of lookahead */
+#define JPEG_READ_BUF_SIZE 16
+struct derived_tbl
+{
+    /* Basic tables: (element [0] of each array is unused) */
+    long mincode[17]; /* smallest code of length k */
+    long maxcode[18]; /* largest code of length k (-1 if none) */
+    /* (maxcode[17] is a sentinel to ensure huff_DECODE terminates) */
+    int valptr[17]; /* huffval[] index of 1st symbol of length k */
+
+    /* Back link to public Huffman table (needed only in slow_DECODE) */
+    int* pub;
+
+    /* Lookahead tables: indexed by the next HUFF_LOOKAHEAD bits of
+    the input data stream.  If the next Huffman code is no more
+    than HUFF_LOOKAHEAD bits long, we can obtain its length and
+    the corresponding symbol directly from these tables. */
+    int look_nbits[1<<HUFF_LOOKAHEAD]; /* # bits, or 0 if too long */
+    unsigned char look_sym[1<<HUFF_LOOKAHEAD]; /* symbol, or unused */
+};
+
+#define QUANT_TABLE_LENGTH  64
+
+/* for type of Huffman table */
+#define DC_LEN 28
+#define AC_LEN 178
+
+struct huffman_table
+{   /* length and code according to JFIF format */
+    int huffmancodes_dc[DC_LEN];
+    int huffmancodes_ac[AC_LEN];
+};
+
+struct frame_component
+{
+    int ID;
+    int horizontal_sampling;
+    int vertical_sampling;
+    int quanttable_select;
+};
+
+struct scan_component
+{
+    int ID;
+    int DC_select;
+    int AC_select;
+};
+
+struct bitstream
+{
+    unsigned long get_buffer; /* current bit-extraction buffer */
+    int bits_left; /* # of unused bits in it */
+    unsigned char* next_input_byte;
+    unsigned char* input_end; /* upper limit +1 */
+};
+
+/* possible return flags for process_markers() */
+#define HUFFTAB   0x0001 /* with huffman table */
+#define QUANTTAB  0x0002 /* with quantization table */
+#define APP0_JFIF 0x0004 /* with APP0 segment following JFIF standard */
+#define FILL_FF   0x0008 /* with 0xFF padding bytes at begin/end */
+#define SOF0      0x0010 /* with SOF0-Segment */
+#define DHT       0x0020 /* with Definition of huffman tables */
+#define SOS       0x0040 /* with Start-of-Scan segment */
+#define DQT       0x0080 /* with definition of quantization table */
+
+#endif /* _JPEG_COMMON_H */

apps/recorder/jpeg_load.h

@@ -0,0 +1,47 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* JPEG image viewer
+* (This is a real mess if it has to be coded in one single C file)
+*
+* File scrolling addition (C) 2005 Alexander Spyridakis
+* Copyright (C) 2004 Jörg Hohensohn aka [IDC]Dragon
+* Heavily borrowed from the IJG implementation (C) Thomas G. Lane
+* Small & fast downscaling IDCT (C) 2002 by Guido Vollbeding  JPEGclub.org
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+#include "resize.h"
+#include "bmp.h"
+#include "jpeg_common.h"
+
+#ifndef _JPEG_LOAD_H
+#define _JPEG_LOAD_H
+
+int read_jpeg_file(const char* filename,
+                   struct bitmap *bm,
+                   int maxsize,
+                   int format,
+                   const struct custom_format *cformat);
+
+int read_jpeg_fd(int fd,
+                 struct bitmap *bm,
+                 int maxsize,
+                 int format,
+                 const struct custom_format *cformat);
+
+#endif /* _JPEG_JPEG_DECODER_H */