tinyjpeg.c

M8手机图片查看器

/*
 * Small jpeg decoder library
 *
 * Copyright (c) 2006, Luc Saillard <[e-mail]>
 * 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.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "stdint.h"
#include <errno.h>

#include "tinyjpeg.h"
#include "tinyjpeg-internal.h"

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,
};

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


#if 0
static char *print_bits(unsigned int value, char *bitstr)
{
  int i, j;
  i=31;
  while (i>0)
   {
     if (value & (1UL<<i))
       break;
     i--;
   }
  j=0;
  while (i>=0)
   {
     bitstr[j++] = (value & (1UL<<i))?'1':'0';
     i--;
   }
  bitstr[j] = 0;
  return bitstr;
}

static void print_next_16bytes(int offset, const unsigned char *stream)
{
  trace("%4.4x: %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x %2.2x\n",
	offset,
	stream[0], stream[1], stream[2], stream[3], 
	stream[4], stream[5], stream[6], stream[7],
	stream[8], stream[9], stream[10], stream[11], 
	stream[12], stream[13], stream[14], stream[15]);
}

#endif

/* Global variable to return the last error found while deconding */
static char error_string[256];

static const unsigned char zigzag[64] = 
{
   0,  1,  5,  6, 14, 15, 27, 28,
   2,  4,  7, 13, 16, 26, 29, 42,
   3,  8, 12, 17, 25, 30, 41, 43,
   9, 11, 18, 24, 31, 40, 44, 53,
  10, 19, 23, 32, 39, 45, 52, 54,
  20, 22, 33, 38, 46, 51, 55, 60,
  21, 34, 37, 47, 50, 56, 59, 61,
  35, 36, 48, 49, 57, 58, 62, 63
};

/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
/* IMPORTANT: these are only valid for 8-bit data precision! */
static const unsigned char bits_dc_luminance[17] =
{ 
  0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 
};
static const unsigned char val_dc_luminance[] =
{
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 
};
  
static const unsigned char bits_dc_chrominance[17] =
{
  0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 
};
static const unsigned char val_dc_chrominance[] = 
{
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 
};
  
static const unsigned char bits_ac_luminance[17] =
{
  0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d 
};
static const unsigned char val_ac_luminance[] =
{
  0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
  0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
  0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
  0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
  0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
  0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
  0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
  0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
  0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
  0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
  0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
  0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
  0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
  0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
  0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
  0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
  0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
  0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
  0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
  0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  0xf9, 0xfa
};

static const unsigned char bits_ac_chrominance[17] =
{ 
  0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 
};

static const unsigned char val_ac_chrominance[] =
{
  0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
  0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
  0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
  0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
  0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
  0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
  0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
  0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
  0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
  0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
  0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
  0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
  0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
  0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
  0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
  0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
  0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
  0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
  0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
  0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  0xf9, 0xfa
};


/*
 * 4 functions to manage the stream
 *
 *  fill_nbits: put at least nbits in the reservoir of bits.
 *              But convert any 0xff,0x00 into 0xff
 *  get_nbits: read nbits from the stream, and put it in result,
 *             bits is removed from the stream and the reservoir is filled
 *             automaticaly. The result is signed according to the number of
 *             bits.
 *  look_nbits: read nbits from the stream without marking as read.
 *  skip_nbits: read nbits from the stream but do not return the result.
 * 
 * stream: current pointer in the jpeg data (read bytes per bytes)
 * nbits_in_reservoir: number of bits filled into the reservoir
 * reservoir: register that contains bits information. Only nbits_in_reservoir
 *            is valid.
 *                          nbits_in_reservoir
 *                        <--    17 bits    -->
 *            Ex: 0000 0000 1010 0000 1111 0000   <== reservoir
 *                        ^
 *                        bit 1
 *            To get two bits from this example
 *                 result = (reservoir >> 15) & 3
 *
 */
#define fill_nbits(reservoir,nbits_in_reservoir,stream,nbits_wanted) do { \
   while (nbits_in_reservoir<nbits_wanted) \
    { \
      unsigned char c; \
      if (stream >= priv->stream_end) \
        longjmp(priv->jump_state, -EIO); \
      c = *stream++; \
      reservoir <<= 8; \
      if (c == 0xff && *stream == 0x00) \
        stream++; \
      reservoir |= c; \
      nbits_in_reservoir+=8; \
    } \
}  while(0);

/* Signed version !!!! */
#define get_nbits(reservoir,nbits_in_reservoir,stream,nbits_wanted,result) do { \
   fill_nbits(reservoir,nbits_in_reservoir,stream,(nbits_wanted)); \
   result = ((reservoir)>>(nbits_in_reservoir-(nbits_wanted))); \
   nbits_in_reservoir -= (nbits_wanted);  \
   reservoir &= ((1U<<nbits_in_reservoir)-1); \
   if ((unsigned int)result < (1UL<<((nbits_wanted)-1))) \
       result += (0xFFFFFFFFUL<<(nbits_wanted))+1; \
}  while(0);

#define look_nbits(reservoir,nbits_in_reservoir,stream,nbits_wanted,result) do { \
   fill_nbits(reservoir,nbits_in_reservoir,stream,(nbits_wanted)); \
   result = ((reservoir)>>(nbits_in_reservoir-(nbits_wanted))); \
}  while(0);

/* To speed up the decoding, we assume that the reservoir have enough bit 
 * slow version:
 * #define skip_nbits(reservoir,nbits_in_reservoir,stream,nbits_wanted) do { \
 *   fill_nbits(reservoir,nbits_in_reservoir,stream,(nbits_wanted)); \
 *   nbits_in_reservoir -= (nbits_wanted); \
 *   reservoir &= ((1U<<nbits_in_reservoir)-1); \
 * }  while(0);
 */
#define skip_nbits(reservoir,nbits_in_reservoir,stream,nbits_wanted) do { \
   nbits_in_reservoir -= (nbits_wanted); \
   reservoir &= ((1U<<nbits_in_reservoir)-1); \
}  while(0);


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

static void resync(struct jdec_private *priv);

/**
 * Get the next (valid) huffman code in the stream.
 *
 * To speedup the procedure, we look HUFFMAN_HASH_NBITS bits and the code is
 * lower than HUFFMAN_HASH_NBITS we have automaticaly the length of the code
 * and the value by using two lookup table.
 * Else if the value is not found, just search (linear) into an array for each
 * bits is the code is present.
 *
 * If the code is not present for any reason, -1 is return.
 */
static int get_next_huffman_code(struct jdec_private *priv, struct huffman_table *huffman_table)
{
  int value, hcode;
  unsigned int extra_nbits, nbits;
  uint16_t *slowtable;

  look_nbits(priv->reservoir, priv->nbits_in_reservoir, priv->stream, HUFFMAN_HASH_NBITS, hcode);
  value = huffman_table->lookup[hcode];
  if (__likely(value >= 0))
  { 
     unsigned int code_size = huffman_table->code_size[value];
     skip_nbits(priv->reservoir, priv->nbits_in_reservoir, priv->stream, code_size);
     return value;
  }

  /* Decode more bits each time ... */
  for (extra_nbits=0; extra_nbits<16-HUFFMAN_HASH_NBITS; extra_nbits++)
   {
     nbits = HUFFMAN_HASH_NBITS + 1 + extra_nbits;

     look_nbits(priv->reservoir, priv->nbits_in_reservoir, priv->stream, nbits, hcode);
     slowtable = huffman_table->slowtable[extra_nbits];
     /* Search if the code is in this array */
     while (slowtable[0]) {
	if (slowtable[0] == hcode) {
	   skip_nbits(priv->reservoir, priv->nbits_in_reservoir, priv->stream, nbits);
	   return slowtable[1];
	}
	slowtable+=2;
     }
   }
  return 0;
}




/**
 *
 * Decode a single block that contains the DCT coefficients.
 * The table coefficients is already dezigzaged at the end of the operation.
 *
 */
static void process_Huffman_data_unit(struct jdec_private *priv, int component)
{
  unsigned char j;
  unsigned int huff_code;
  unsigned char size_val, count_0;

  struct component *c = &priv->component_infos[component];
  short int DCT[64];


  /* Initialize the DCT coef table */
  memset(DCT, 0, sizeof(DCT));

  /* DC coefficient decoding */
  huff_code = get_next_huffman_code(priv, c->DC_table);
  //trace("+ %x\n", huff_code);
  if (huff_code) {
     get_nbits(priv->reservoir, priv->nbits_in_reservoir, priv->stream, huff_code, DCT[0]);
     DCT[0] += c->previous_DC;
     c->previous_DC = DCT[0];
  } else {
     DCT[0] = c->previous_DC;
  }

  /* AC coefficient decoding */
  j = 1;
  while (j<64)
   {
     huff_code = get_next_huffman_code(priv, c->AC_table);
     //trace("- %x\n", huff_code);

     size_val = huff_code & 0xF;
     count_0 = huff_code >> 4;

     if (size_val == 0)
      { /* RLE */
	if (count_0 == 0)
	  break;	/* EOB found, go out */
	else if (count_0 == 0xF)
	  j += 16;	/* skip 16 zeros */
      }
     else
      {
	j += count_0;	/* skip count_0 zeroes */
	if (__unlikely(j >= 64))
	 {
	   _snprintf(error_string, sizeof(error_string), "Bad huffman data (buffer overflow)");
	   break;
	 }
	get_nbits(priv->reservoir, priv->nbits_in_reservoir, priv->stream, size_val, DCT[j]);
	j++;
      }
   }

  for (j = 0; j < 64; j++)
    c->DCT[j] = DCT[zigzag[j]];
}

/*
 * Takes two array of bits, and build the huffman table for size, and code
 * 
 * lookup will return the symbol if the code is less or equal than HUFFMAN_HASH_NBITS.
 * code_size will be used to known how many bits this symbol is encoded.
 * slowtable will be used when the first lookup didn't give the result.
 */
static void build_huffman_table(const unsigned char *bits, const unsigned char *vals, struct huffman_table *table)
{
  unsigned int i, j, code, code_size, val, nbits;
  unsigned char huffsize[HUFFMAN_BITS_SIZE+1], *hz;
  unsigned int huffcode[HUFFMAN_BITS_SIZE+1], *hc;
  int next_free_entry;

  /*
   * Build a temp array 
   *   huffsize[X] => numbers of bits to write vals[X]
   */
  hz = huffsize;
  for (i=1; i<=16; i++)
   {
     for (j=1; j<=bits[i]; j++)
       *hz++ = i;
   }
  *hz = 0;

  memset(table->lookup, 0xff, sizeof(table->lookup));
  for (i=0; i<(16-HUFFMAN_HASH_NBITS); i++)
    table->slowtable[i][0] = 0;

  /* Build a temp array
   *   huffcode[X] => code used to write vals[X]
   */
  code = 0;
  hc = huffcode;
  hz = huffsize;
  nbits = *hz;
  while (*hz)
   {
     while (*hz == nbits)
      {
	*hc++ = code++;
	hz++;
      }
     code <<= 1;
     nbits++;
   }

  /*
   * Build the lookup table, and the slowtable if needed.
   */
  next_free_entry = -1;
  for (i=0; huffsize[i]; i++)
   {
     val = vals[i];
     code = huffcode[i];
     code_size = huffsize[i];

     trace("val=%2.2x code=%8.8x codesize=%2.2d\n", val, code, code_size);

     table->code_size[val] = code_size;
     if (code_size <= HUFFMAN_HASH_NBITS)
      {
	/*
	 * Good: val can be put in the lookup table, so fill all value of this
	 * column with value val 
	 */
	int repeat = 1UL<<(HUFFMAN_HASH_NBITS - code_size);
	code <<= HUFFMAN_HASH_NBITS - code_size;
	while ( repeat-- )
	  table->lookup[code++] = val;

      }
     else
      {
	/* Perhaps sorting the array will be an optimization */
	uint16_t *slowtable = table->slowtable[code_size-HUFFMAN_HASH_NBITS-1];
	while(slowtable[0])
	  slowtable+=2;
	slowtable[0] = code;
	slowtable[1] = val;
	slowtable[2] = 0;
	/* TODO: NEED TO CHECK FOR AN OVERFLOW OF THE TABLE */
      }

   }
}

static void build_default_huffman_tables(struct jdec_private *priv)
{
  if (   (priv->flags & TINYJPEG_FLAGS_MJPEG_TABLE) 
      && priv->default_huffman_table_initialized)
    return;

  build_huffman_table(bits_dc_luminance, val_dc_luminance, &priv->HTDC[0]);
  build_huffman_table(bits_ac_luminance, val_ac_luminance, &priv->HTAC[0]);

  build_huffman_table(bits_dc_chrominance, val_dc_chrominance, &priv->HTDC[1]);
  build_huffman_table(bits_ac_chrominance, val_ac_chrominance, &priv->HTAC[1]);

  priv->default_huffman_table_initialized = 1;
}



/*******************************************************************************
 *
 * Colorspace conversion routine
 *
 *
 * Note:
 * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
 * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
 * The conversion equations to be implemented are therefore
 *      R = Y                + 1.40200 * Cr
 *      G = Y - 0.34414 * Cb - 0.71414 * Cr
 *      B = Y + 1.77200 * Cb
 * 
 ******************************************************************************/

static unsigned char clamp(int i)
{
  if (i<0)
    return 0;
  else if (i>255)
    return 255;
  else
    return i;
}   


/**
 *  YCrCb -> YUV420P (1x1)
 *  .---.
 *  | 1 |
 *  `---'
 */
static void YCrCB_to_YUV420P_1x1(struct jdec_private *priv)
{
  const unsigned char *s, *y;
  unsigned char *p;
  int i,j;

  p = priv->plane[0];
  y = priv->Y;
  for (i=0; i<8; i++)
   {
     memcpy(p, y, 8);
     p+=priv->width;
     y+=8;
   }