📄 tinyjpeg.cxx
字号:
/*
* Small jpeg decoder library
*
* 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.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include "tinyjpeg.h"
#include "tinyjpeg-internal.h"
#include "ptbuildopts.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 */
EOI = 0xD9, /* End of Image */
APP0 = 0xE0,
};
#define cY 1
#define cCb 2
#define cCr 3
#define BLACK_Y 0
#define BLACK_U 127
#define BLACK_V 127
#define SANITY_CHECK 1
#ifndef DEBUG
#define DEBUG 0
#define DUMP_TABLE 0
#define LOG2FILE 0
#endif
#if DEBUG
#if LOG2FILE
#define error(fmt, args...) do { \
FILE *f = fopen("/tmp/jpeg.log", "a"); \
fprintf(f, fmt, ## args); \
fflush(f); \
fclose(f); \
return -1; \
} while(0)
#define trace(fmt, args...) do { \
FILE *f = fopen("/tmp/jpeg.log", "a"); \
fprintf(f, fmt, ## args); \
fflush(f); \
fclose(f); \
} while(0)
#else
#define error(fmt, args...) do { \
snprintf(error_string, sizeof(error_string), fmt, ## args); \
return -1; \
} while(0)
#define trace(fmt, args...) do { \
fprintf(stderr, fmt, ## args); \
fflush(stderr); \
} while(0)
#endif
#else
#if defined (P_SOLARIS) && !defined (__GNUC__)
#define error(fmt, args,...) do { return -1; } while(0)
#define trace(fmt, args,...) do { } while (0)
#else
#define error(fmt, args...) do { return -1; } while(0)
#define trace(fmt, args...) do { } while (0)
#endif
#endif
#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);
#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 be16_to_cpu(x) (((x)[0]<<8)|(x)[1])
/**
* 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 (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);
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);
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 */
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[257], *hz;
unsigned int huffcode[257], *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", i, 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
*
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -