/*
 * Small jpeg decoder library (Internal header)
 *
 * Copyright (c) 2006, Luc Saillard <luc@saillard.org>
 * All rights reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * - Redistributions of source code must retain the above copyright notice,
 *  this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 *
 * - Neither the name of the author nor the names of its contributors may be
 *  used to endorse or promote products derived from this software without
 *  specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef __TINYJPEG_INTERNAL_H_
#define __TINYJPEG_INTERNAL_H_

#define SANITY_CHECK 1

struct jdec_private;

#define HUFFMAN_BITS_SIZE  256
#define HUFFMAN_HASH_NBITS 9
#define HUFFMAN_HASH_SIZE  (1UL<<HUFFMAN_HASH_NBITS)
#define HUFFMAN_HASH_MASK  (HUFFMAN_HASH_SIZE-1)

#define HUFFMAN_TABLES	   4
#define COMPONENTS	   3

#define cY  0
#define cCb 1
#define cCr 2

#define BLACK_Y 0
#define BLACK_U 127
#define BLACK_V 127

#if DEBUG
#define trace(fmt, args...) do { \
   fprintf(stderr, fmt, ## args); \
   fflush(stderr); \
} while(0)
#else
#define trace(fmt, args...) do { } while (0)
#endif
#define error(fmt, args...) do { \
   snprintf(error_string, sizeof(error_string), fmt, ## args); \
   return -1; \
} while(0)

#define be16_to_cpu(x) (((x)[0]<<8)|(x)[1])

enum std_markers {
   DQT  = 0xDB, /* Define Quantization Table */
   SOF  = 0xC0, /* Start of Frame (size information) */
   DHT  = 0xC4, /* Huffman Table */
   SOI  = 0xD8, /* Start of Image */
   SOS  = 0xDA, /* Start of Scan */
   RST  = 0xD0, /* Reset Marker d0 -> .. */
   RST7 = 0xD7, /* Reset Marker .. -> d7 */
   EOI  = 0xD9, /* End of Image */
   DRI  = 0xDD, /* Define Restart Interval */
   APP0 = 0xE0,
};

struct huffman_table
{
  /* Fast look up table, using HUFFMAN_HASH_NBITS bits we can have directly the symbol,
   * if the symbol is <0, then we need to look into the tree table */
  short int lookup[HUFFMAN_HASH_SIZE];
  /* code size: give the number of bits of a symbol is encoded */
  unsigned char code_size[HUFFMAN_HASH_SIZE];
  /* some place to store value that is not encoded in the lookup table */
  uint16_t slowtable[16-HUFFMAN_HASH_NBITS][256];
};

struct component 
{
  unsigned int Hfactor;
  unsigned int Vfactor;
  float *Q_table;		/* Pointer to the quantisation table to use */
  struct huffman_table *AC_table;
  struct huffman_table *DC_table;
  short int previous_DC;	/* Previous DC coefficient */
  short int DCT[64];		/* DCT coef */
#if SANITY_CHECK
  unsigned int cid;
#endif
};

typedef int (*decode_MCU_fct) (struct jdec_private *priv);
typedef void (*convert_colorspace_fct) (struct jdec_private *priv);

struct jdec_private
{
  /* Public variables */
  uint8_t *components[COMPONENTS];
  unsigned int width, height;	/* Size of the image */
  unsigned int mcus_in_width, mcus_in_height;
	unsigned int mcus_posx, mcus_posy;
  unsigned int flags;

  /* Private variables */
  const unsigned char *stream_begin, *stream_end;
  unsigned int stream_length;

  const unsigned char *stream;	/* Pointer to the current stream */
  unsigned int reservoir, nbits_in_reservoir;

  struct component component_infos[COMPONENTS];
  float Q_tables[COMPONENTS][64];		/* quantization tables */
  struct huffman_table HTDC[HUFFMAN_TABLES];	/* DC huffman tables   */
  struct huffman_table HTAC[HUFFMAN_TABLES];	/* AC huffman tables   */
  int default_huffman_table_initialized;
  unsigned int restart_interval;
//   int restarts_to_go;			/* MCUs left in this restart interval */
  int last_rst_marker_seen;			/* Rst marker is incremented each time */

  /* Temp space used after the IDCT to store each components */
  uint8_t Y[64*4], Cr[64], Cb[64];

  /* Internal Pointer use for colorspace conversion, do not modify it !!! */
  uint8_t *plane;

};

#if defined(__GNUC__) && (__GNUC__ > 3) && defined(__OPTIMIZE__)
#define __likely(x)       __builtin_expect(!!(x), 1)
#define __unlikely(x)     __builtin_expect(!!(x), 0)
#else
#define __likely(x)       (x)
#define __unlikely(x)     (x)
#endif

#define IDCT tinyjpeg_idct_float
void tinyjpeg_idct_float (struct component *compptr, uint8_t *output_buf, int stride);
int parse_JFIF(struct jdec_private *priv, const unsigned char *stream);

#endif