nengel@0: /*
nengel@0:  * Small jpeg decoder library (Internal header)
nengel@0:  *
nengel@0:  * Copyright (c) 2006, Luc Saillard <luc@saillard.org>
nengel@0:  * All rights reserved.
nengel@0:  * Redistribution and use in source and binary forms, with or without
nengel@0:  * modification, are permitted provided that the following conditions are met:
nengel@0:  * 
nengel@0:  * - Redistributions of source code must retain the above copyright notice,
nengel@0:  *  this list of conditions and the following disclaimer.
nengel@0:  *
nengel@0:  * - Redistributions in binary form must reproduce the above copyright notice,
nengel@0:  *  this list of conditions and the following disclaimer in the documentation
nengel@0:  *  and/or other materials provided with the distribution.
nengel@0:  *
nengel@0:  * - Neither the name of the author nor the names of its contributors may be
nengel@0:  *  used to endorse or promote products derived from this software without
nengel@0:  *  specific prior written permission.
nengel@0:  * 
nengel@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
nengel@0:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
nengel@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
nengel@0:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
nengel@0:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
nengel@0:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
nengel@0:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
nengel@0:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
nengel@0:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
nengel@0:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
nengel@0:  * POSSIBILITY OF SUCH DAMAGE.
nengel@0:  *
nengel@0:  */
nengel@0: 
nengel@0: #ifndef __TINYJPEG_INTERNAL_H_
nengel@0: #define __TINYJPEG_INTERNAL_H_
nengel@0: 
nengel@0: #define SANITY_CHECK 1
nengel@0: 
nengel@0: struct jdec_private;
nengel@0: 
nengel@0: #define HUFFMAN_BITS_SIZE  256
nengel@0: #define HUFFMAN_HASH_NBITS 9
nengel@0: #define HUFFMAN_HASH_SIZE  (1UL<<HUFFMAN_HASH_NBITS)
nengel@0: #define HUFFMAN_HASH_MASK  (HUFFMAN_HASH_SIZE-1)
nengel@0: 
nengel@0: #define HUFFMAN_TABLES	   4
nengel@0: #define COMPONENTS	   3
nengel@0: 
nengel@0: #define cY  0
nengel@0: #define cCb 1
nengel@0: #define cCr 2
nengel@0: 
nengel@0: #define BLACK_Y 0
nengel@0: #define BLACK_U 127
nengel@0: #define BLACK_V 127
nengel@0: 
nengel@0: #if DEBUG
nengel@0: #define trace(fmt, args...) do { \
nengel@0:    fprintf(stderr, fmt, ## args); \
nengel@0:    fflush(stderr); \
nengel@0: } while(0)
nengel@0: #else
nengel@0: #define trace(fmt, args...) do { } while (0)
nengel@0: #endif
nengel@0: #define error(fmt, args...) do { \
nengel@0:    snprintf(error_string, sizeof(error_string), fmt, ## args); \
nengel@0:    return -1; \
nengel@0: } while(0)
nengel@0: 
nengel@0: #define be16_to_cpu(x) (((x)[0]<<8)|(x)[1])
nengel@0: 
nengel@0: enum std_markers {
nengel@0:    DQT  = 0xDB, /* Define Quantization Table */
nengel@0:    SOF  = 0xC0, /* Start of Frame (size information) */
nengel@0:    DHT  = 0xC4, /* Huffman Table */
nengel@0:    SOI  = 0xD8, /* Start of Image */
nengel@0:    SOS  = 0xDA, /* Start of Scan */
nengel@0:    RST  = 0xD0, /* Reset Marker d0 -> .. */
nengel@0:    RST7 = 0xD7, /* Reset Marker .. -> d7 */
nengel@0:    EOI  = 0xD9, /* End of Image */
nengel@0:    DRI  = 0xDD, /* Define Restart Interval */
nengel@0:    APP0 = 0xE0,
nengel@0: };
nengel@0: 
nengel@0: struct huffman_table
nengel@0: {
nengel@0:   /* Fast look up table, using HUFFMAN_HASH_NBITS bits we can have directly the symbol,
nengel@0:    * if the symbol is <0, then we need to look into the tree table */
nengel@0:   short int lookup[HUFFMAN_HASH_SIZE];
nengel@0:   /* code size: give the number of bits of a symbol is encoded */
nengel@0:   unsigned char code_size[HUFFMAN_HASH_SIZE];
nengel@0:   /* some place to store value that is not encoded in the lookup table */
nengel@0:   uint16_t slowtable[16-HUFFMAN_HASH_NBITS][256];
nengel@0: };
nengel@0: 
nengel@0: struct component 
nengel@0: {
nengel@0:   unsigned int Hfactor;
nengel@0:   unsigned int Vfactor;
nengel@0:   float *Q_table;		/* Pointer to the quantisation table to use */
nengel@0:   struct huffman_table *AC_table;
nengel@0:   struct huffman_table *DC_table;
nengel@0:   short int previous_DC;	/* Previous DC coefficient */
nengel@0:   short int DCT[64];		/* DCT coef */
nengel@0: #if SANITY_CHECK
nengel@0:   unsigned int cid;
nengel@0: #endif
nengel@0: };
nengel@0: 
nengel@0: typedef int (*decode_MCU_fct) (struct jdec_private *priv);
nengel@0: typedef void (*convert_colorspace_fct) (struct jdec_private *priv);
nengel@0: 
nengel@0: struct jdec_private
nengel@0: {
nengel@0:   /* Public variables */
nengel@0:   uint8_t *components[COMPONENTS];
nengel@0:   unsigned int width, height;	/* Size of the image */
nengel@0:   unsigned int mcus_in_width, mcus_in_height;
nengel@0: 	unsigned int mcus_posx, mcus_posy;
nengel@0:   unsigned int flags;
nengel@0: 
nengel@0:   /* Private variables */
nengel@0:   const unsigned char *stream_begin, *stream_end;
nengel@0:   unsigned int stream_length;
nengel@0: 
nengel@0:   const unsigned char *stream;	/* Pointer to the current stream */
nengel@0:   unsigned int reservoir, nbits_in_reservoir;
nengel@0: 
nengel@0:   struct component component_infos[COMPONENTS];
nengel@0:   float Q_tables[COMPONENTS][64];		/* quantization tables */
nengel@0:   struct huffman_table HTDC[HUFFMAN_TABLES];	/* DC huffman tables   */
nengel@0:   struct huffman_table HTAC[HUFFMAN_TABLES];	/* AC huffman tables   */
nengel@0:   int default_huffman_table_initialized;
nengel@0:   unsigned int restart_interval;
nengel@0: //   int restarts_to_go;			/* MCUs left in this restart interval */
nengel@0:   int last_rst_marker_seen;			/* Rst marker is incremented each time */
nengel@0: 
nengel@0:   /* Temp space used after the IDCT to store each components */
nengel@0:   uint8_t Y[64*4], Cr[64], Cb[64];
nengel@0: 
nengel@0:   /* Internal Pointer use for colorspace conversion, do not modify it !!! */
nengel@0:   uint8_t *plane;
nengel@0: 
nengel@0: };
nengel@0: 
nengel@0: #if defined(__GNUC__) && (__GNUC__ > 3) && defined(__OPTIMIZE__)
nengel@0: #define __likely(x)       __builtin_expect(!!(x), 1)
nengel@0: #define __unlikely(x)     __builtin_expect(!!(x), 0)
nengel@0: #else
nengel@0: #define __likely(x)       (x)
nengel@0: #define __unlikely(x)     (x)
nengel@0: #endif
nengel@0: 
nengel@0: #define IDCT tinyjpeg_idct_float
nengel@0: void tinyjpeg_idct_float (struct component *compptr, uint8_t *output_buf, int stride);
nengel@0: int parse_JFIF(struct jdec_private *priv, const unsigned char *stream);
nengel@0: 
nengel@0: #endif
nengel@0: