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Merge branch 'DanielGibson-write-jpg' into dev

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master
Fabian Giesen ago%!(EXTRA string=8 years)
parent 423298e071 526ed469e2
commit 3870b2fe3b
1 changed files with 366 additions and 5 deletions
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  1. 371
      stb_image_write.h

371
stb_image_write.h
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@ -1,5 +1,5 @@
/* stb_image_write - v1.05 - public domain - http://nothings.org/stb/stb_image_write.h /* stb_image_write - v1.05 - public domain - http://nothings.org/stb/stb_image_write.h
writes out PNG/BMP/TGA images to C stdio - Sean Barrett 2010-2015 writes out PNG/BMP/TGA/JPEG/HDR images to C stdio - Sean Barrett 2010-2015
no warranty implied; use at your own risk no warranty implied; use at your own risk
Before #including, Before #including,
@ -35,6 +35,7 @@ USAGE:
int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data); int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data); int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data); int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality)
There are also four equivalent functions that use an arbitrary write function. You are There are also four equivalent functions that use an arbitrary write function. You are
expected to open/close your file-equivalent before and after calling these: expected to open/close your file-equivalent before and after calling these:
@ -43,6 +44,7 @@ USAGE:
int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data); int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data); int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data); int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality);
where the callback is: where the callback is:
void stbi_write_func(void *context, void *data, int size); void stbi_write_func(void *context, void *data, int size);
@ -80,6 +82,10 @@ USAGE:
TGA supports RLE or non-RLE compressed data. To use non-RLE-compressed TGA supports RLE or non-RLE compressed data. To use non-RLE-compressed
data, set the global variable 'stbi_write_tga_with_rle' to 0. data, set the global variable 'stbi_write_tga_with_rle' to 0.
JPEG does ignore alpha channels in input data; quality is between 1 and 100.
Higher quality looks better but results in a bigger image.
JPEG baseline (no JPEG progressive).
CREDITS: CREDITS:
PNG/BMP/TGA PNG/BMP/TGA
@ -94,6 +100,9 @@ CREDITS:
Alan Hickman Alan Hickman
initial file IO callback implementation initial file IO callback implementation
Emmanuel Julien Emmanuel Julien
JPEG
Jon Olick (original jo_jpeg.cpp code)
Daniel Gibson
bugfixes: bugfixes:
github:Chribba github:Chribba
Guillaume Chereau Guillaume Chereau
@ -131,6 +140,7 @@ STBIWDEF int stbi_write_png(char const *filename, int w, int h, int comp, const
STBIWDEF int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data); STBIWDEF int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data); STBIWDEF int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data); STBIWDEF int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
STBIWDEF int stbi_write_jpg(char const *filename, int x, int y, int comp, const void *data, int quality);
#endif #endif
typedef void stbi_write_func(void *context, void *data, int size); typedef void stbi_write_func(void *context, void *data, int size);
@ -139,6 +149,7 @@ STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int w,
STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data); STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data); STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data); STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
STBIWDEF int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality);
#ifdef __cplusplus #ifdef __cplusplus
} }
@ -277,6 +288,11 @@ static void stbiw__writef(stbi__write_context *s, const char *fmt, ...)
va_end(v); va_end(v);
} }
static void stbiw__putc(stbi__write_context *s, unsigned char c)
{
s->func(s->context, &c, 1);
}
static void stbiw__write3(stbi__write_context *s, unsigned char a, unsigned char b, unsigned char c) static void stbiw__write3(stbi__write_context *s, unsigned char a, unsigned char b, unsigned char c)
{ {
unsigned char arr[3]; unsigned char arr[3];
@ -450,7 +466,7 @@ static int stbi_write_tga_core(stbi__write_context *s, int x, int y, int comp, v
return 1; return 1;
} }
int stbi_write_tga_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data) STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data)
{ {
stbi__write_context s; stbi__write_context s;
stbi__start_write_callbacks(&s, func, context); stbi__start_write_callbacks(&s, func, context);
@ -458,7 +474,7 @@ int stbi_write_tga_to_func(stbi_write_func *func, void *context, int x, int y, i
} }
#ifndef STBI_WRITE_NO_STDIO #ifndef STBI_WRITE_NO_STDIO
int stbi_write_tga(char const *filename, int x, int y, int comp, const void *data) STBIWDEF int stbi_write_tga(char const *filename, int x, int y, int comp, const void *data)
{ {
stbi__write_context s; stbi__write_context s;
if (stbi__start_write_file(&s,filename)) { if (stbi__start_write_file(&s,filename)) {
@ -620,7 +636,7 @@ static int stbi_write_hdr_core(stbi__write_context *s, int x, int y, int comp, f
} }
} }
int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const float *data) STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const float *data)
{ {
stbi__write_context s; stbi__write_context s;
stbi__start_write_callbacks(&s, func, context); stbi__start_write_callbacks(&s, func, context);
@ -628,7 +644,7 @@ int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int x, int y, i
} }
#ifndef STBI_WRITE_NO_STDIO #ifndef STBI_WRITE_NO_STDIO
int stbi_write_hdr(char const *filename, int x, int y, int comp, const float *data) STBIWDEF int stbi_write_hdr(char const *filename, int x, int y, int comp, const float *data)
{ {
stbi__write_context s; stbi__write_context s;
if (stbi__start_write_file(&s,filename)) { if (stbi__start_write_file(&s,filename)) {
@ -1013,6 +1029,351 @@ STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int x,
return 1; return 1;
} }
/* ***************************************************************************
*
* JPEG writer
*
* This is based on Jon Olick's jo_jpeg.cpp:
* public domain Simple, Minimalistic JPEG writer - http://www.jonolick.com/code.html
*/
static const unsigned char stbiw__jpg_ZigZag[] = { 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 };
static void stbiw__jpg_writeBits(stbi__write_context *s, int *bitBufP, int *bitCntP, const unsigned short *bs) {
int bitBuf = *bitBufP, bitCnt = *bitCntP;
bitCnt += bs[1];
bitBuf |= bs[0] << (24 - bitCnt);
while(bitCnt >= 8) {
unsigned char c = (bitBuf >> 16) & 255;
stbiw__putc(s, c);
if(c == 255) {
stbiw__putc(s, 0);
}
bitBuf <<= 8;
bitCnt -= 8;
}
*bitBufP = bitBuf;
*bitCntP = bitCnt;
}
static void stbiw__jpg_DCT(float *d0p, float *d1p, float *d2p, float *d3p, float *d4p, float *d5p, float *d6p, float *d7p) {
float d0 = *d0p, d1 = *d1p, d2 = *d2p, d3 = *d3p, d4 = *d4p, d5 = *d5p, d6 = *d6p, d7 = *d7p;
float z1, z2, z3, z4, z5, z11, z13;
float tmp0 = d0 + d7;
float tmp7 = d0 - d7;
float tmp1 = d1 + d6;
float tmp6 = d1 - d6;
float tmp2 = d2 + d5;
float tmp5 = d2 - d5;
float tmp3 = d3 + d4;
float tmp4 = d3 - d4;
// Even part
float tmp10 = tmp0 + tmp3; // phase 2
float tmp13 = tmp0 - tmp3;
float tmp11 = tmp1 + tmp2;
float tmp12 = tmp1 - tmp2;
d0 = tmp10 + tmp11; // phase 3
d4 = tmp10 - tmp11;
z1 = (tmp12 + tmp13) * 0.707106781f; // c4
d2 = tmp13 + z1; // phase 5
d6 = tmp13 - z1;
// Odd part
tmp10 = tmp4 + tmp5; // phase 2
tmp11 = tmp5 + tmp6;
tmp12 = tmp6 + tmp7;
// The rotator is modified from fig 4-8 to avoid extra negations.
z5 = (tmp10 - tmp12) * 0.382683433f; // c6
z2 = tmp10 * 0.541196100f + z5; // c2-c6
z4 = tmp12 * 1.306562965f + z5; // c2+c6
z3 = tmp11 * 0.707106781f; // c4
z11 = tmp7 + z3; // phase 5
z13 = tmp7 - z3;
*d5p = z13 + z2; // phase 6
*d3p = z13 - z2;
*d1p = z11 + z4;
*d7p = z11 - z4;
*d0p = d0; *d2p = d2; *d4p = d4; *d6p = d6;
}
static void stbiw__jpg_calcBits(int val, unsigned short bits[2]) {
int tmp1 = val < 0 ? -val : val;
val = val < 0 ? val-1 : val;
bits[1] = 1;
while(tmp1 >>= 1) {
++bits[1];
}
bits[0] = val & ((1<<bits[1])-1);
}
static int stbiw__jpg_processDU(stbi__write_context *s, int *bitBuf, int *bitCnt, float *CDU, float *fdtbl, int DC, const unsigned short HTDC[256][2], const unsigned short HTAC[256][2]) {
const unsigned short EOB[2] = { HTAC[0x00][0], HTAC[0x00][1] };
const unsigned short M16zeroes[2] = { HTAC[0xF0][0], HTAC[0xF0][1] };
int dataOff, i, diff, end0pos;
int DU[64];
// DCT rows
for(dataOff=0; dataOff<64; dataOff+=8) {
stbiw__jpg_DCT(&CDU[dataOff], &CDU[dataOff+1], &CDU[dataOff+2], &CDU[dataOff+3], &CDU[dataOff+4], &CDU[dataOff+5], &CDU[dataOff+6], &CDU[dataOff+7]);
}
// DCT columns
for(dataOff=0; dataOff<8; ++dataOff) {
stbiw__jpg_DCT(&CDU[dataOff], &CDU[dataOff+8], &CDU[dataOff+16], &CDU[dataOff+24], &CDU[dataOff+32], &CDU[dataOff+40], &CDU[dataOff+48], &CDU[dataOff+56]);
}
// Quantize/descale/zigzag the coefficients
for(i=0; i<64; ++i) {
float v = CDU[i]*fdtbl[i];
// DU[stbiw__jpg_ZigZag[i]] = (int)(v < 0 ? ceilf(v - 0.5f) : floorf(v + 0.5f));
// ceilf() and floorf() are C99, not C89, but I /think/ they're not needed here anyway?
DU[stbiw__jpg_ZigZag[i]] = (int)(v < 0 ? v - 0.5f : v + 0.5f);
}
// Encode DC
diff = DU[0] - DC;
if (diff == 0) {
stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTDC[0]);
} else {
unsigned short bits[2];
stbiw__jpg_calcBits(diff, bits);
stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTDC[bits[1]]);
stbiw__jpg_writeBits(s, bitBuf, bitCnt, bits);
}
// Encode ACs
end0pos = 63;
for(; (end0pos>0)&&(DU[end0pos]==0); --end0pos) {
}
// end0pos = first element in reverse order !=0
if(end0pos == 0) {
stbiw__jpg_writeBits(s, bitBuf, bitCnt, EOB);
return DU[0];
}
for(i = 1; i <= end0pos; ++i) {
int startpos = i;
int nrzeroes;
unsigned short bits[2];
for (; DU[i]==0 && i<=end0pos; ++i) {
}
nrzeroes = i-startpos;
if ( nrzeroes >= 16 ) {
int lng = nrzeroes>>4;
int nrmarker;
for (nrmarker=1; nrmarker <= lng; ++nrmarker)
stbiw__jpg_writeBits(s, bitBuf, bitCnt, M16zeroes);
nrzeroes &= 15;
}
stbiw__jpg_calcBits(DU[i], bits);
stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTAC[(nrzeroes<<4)+bits[1]]);
stbiw__jpg_writeBits(s, bitBuf, bitCnt, bits);
}
if(end0pos != 63) {
stbiw__jpg_writeBits(s, bitBuf, bitCnt, EOB);
}
return DU[0];
}
static int stbi_write_jpg_core(stbi__write_context *s, int width, int height, int comp, const void* data, int quality) {
// Constants that don't pollute global namespace
static const unsigned char std_dc_luminance_nrcodes[] = {0,0,1,5,1,1,1,1,1,1,0,0,0,0,0,0,0};
static const unsigned char std_dc_luminance_values[] = {0,1,2,3,4,5,6,7,8,9,10,11};
static const unsigned char std_ac_luminance_nrcodes[] = {0,0,2,1,3,3,2,4,3,5,5,4,4,0,0,1,0x7d};
static const unsigned char std_ac_luminance_values[] = {
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 std_dc_chrominance_nrcodes[] = {0,0,3,1,1,1,1,1,1,1,1,1,0,0,0,0,0};
static const unsigned char std_dc_chrominance_values[] = {0,1,2,3,4,5,6,7,8,9,10,11};
static const unsigned char std_ac_chrominance_nrcodes[] = {0,0,2,1,2,4,4,3,4,7,5,4,4,0,1,2,0x77};
static const unsigned char std_ac_chrominance_values[] = {
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
};
// Huffman tables
static const unsigned short YDC_HT[256][2] = { {0,2},{2,3},{3,3},{4,3},{5,3},{6,3},{14,4},{30,5},{62,6},{126,7},{254,8},{510,9}};
static const unsigned short UVDC_HT[256][2] = { {0,2},{1,2},{2,2},{6,3},{14,4},{30,5},{62,6},{126,7},{254,8},{510,9},{1022,10},{2046,11}};
static const unsigned short YAC_HT[256][2] = {
{10,4},{0,2},{1,2},{4,3},{11,4},{26,5},{120,7},{248,8},{1014,10},{65410,16},{65411,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{12,4},{27,5},{121,7},{502,9},{2038,11},{65412,16},{65413,16},{65414,16},{65415,16},{65416,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{28,5},{249,8},{1015,10},{4084,12},{65417,16},{65418,16},{65419,16},{65420,16},{65421,16},{65422,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{58,6},{503,9},{4085,12},{65423,16},{65424,16},{65425,16},{65426,16},{65427,16},{65428,16},{65429,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{59,6},{1016,10},{65430,16},{65431,16},{65432,16},{65433,16},{65434,16},{65435,16},{65436,16},{65437,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{122,7},{2039,11},{65438,16},{65439,16},{65440,16},{65441,16},{65442,16},{65443,16},{65444,16},{65445,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{123,7},{4086,12},{65446,16},{65447,16},{65448,16},{65449,16},{65450,16},{65451,16},{65452,16},{65453,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{250,8},{4087,12},{65454,16},{65455,16},{65456,16},{65457,16},{65458,16},{65459,16},{65460,16},{65461,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{504,9},{32704,15},{65462,16},{65463,16},{65464,16},{65465,16},{65466,16},{65467,16},{65468,16},{65469,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{505,9},{65470,16},{65471,16},{65472,16},{65473,16},{65474,16},{65475,16},{65476,16},{65477,16},{65478,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{506,9},{65479,16},{65480,16},{65481,16},{65482,16},{65483,16},{65484,16},{65485,16},{65486,16},{65487,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{1017,10},{65488,16},{65489,16},{65490,16},{65491,16},{65492,16},{65493,16},{65494,16},{65495,16},{65496,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{1018,10},{65497,16},{65498,16},{65499,16},{65500,16},{65501,16},{65502,16},{65503,16},{65504,16},{65505,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{2040,11},{65506,16},{65507,16},{65508,16},{65509,16},{65510,16},{65511,16},{65512,16},{65513,16},{65514,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{65515,16},{65516,16},{65517,16},{65518,16},{65519,16},{65520,16},{65521,16},{65522,16},{65523,16},{65524,16},{0,0},{0,0},{0,0},{0,0},{0,0},
{2041,11},{65525,16},{65526,16},{65527,16},{65528,16},{65529,16},{65530,16},{65531,16},{65532,16},{65533,16},{65534,16},{0,0},{0,0},{0,0},{0,0},{0,0}
};
static const unsigned short UVAC_HT[256][2] = {
{0,2},{1,2},{4,3},{10,4},{24,5},{25,5},{56,6},{120,7},{500,9},{1014,10},{4084,12},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{11,4},{57,6},{246,8},{501,9},{2038,11},{4085,12},{65416,16},{65417,16},{65418,16},{65419,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{26,5},{247,8},{1015,10},{4086,12},{32706,15},{65420,16},{65421,16},{65422,16},{65423,16},{65424,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{27,5},{248,8},{1016,10},{4087,12},{65425,16},{65426,16},{65427,16},{65428,16},{65429,16},{65430,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{58,6},{502,9},{65431,16},{65432,16},{65433,16},{65434,16},{65435,16},{65436,16},{65437,16},{65438,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{59,6},{1017,10},{65439,16},{65440,16},{65441,16},{65442,16},{65443,16},{65444,16},{65445,16},{65446,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{121,7},{2039,11},{65447,16},{65448,16},{65449,16},{65450,16},{65451,16},{65452,16},{65453,16},{65454,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{122,7},{2040,11},{65455,16},{65456,16},{65457,16},{65458,16},{65459,16},{65460,16},{65461,16},{65462,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{249,8},{65463,16},{65464,16},{65465,16},{65466,16},{65467,16},{65468,16},{65469,16},{65470,16},{65471,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{503,9},{65472,16},{65473,16},{65474,16},{65475,16},{65476,16},{65477,16},{65478,16},{65479,16},{65480,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{504,9},{65481,16},{65482,16},{65483,16},{65484,16},{65485,16},{65486,16},{65487,16},{65488,16},{65489,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{505,9},{65490,16},{65491,16},{65492,16},{65493,16},{65494,16},{65495,16},{65496,16},{65497,16},{65498,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{506,9},{65499,16},{65500,16},{65501,16},{65502,16},{65503,16},{65504,16},{65505,16},{65506,16},{65507,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{2041,11},{65508,16},{65509,16},{65510,16},{65511,16},{65512,16},{65513,16},{65514,16},{65515,16},{65516,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
{16352,14},{65517,16},{65518,16},{65519,16},{65520,16},{65521,16},{65522,16},{65523,16},{65524,16},{65525,16},{0,0},{0,0},{0,0},{0,0},{0,0},
{1018,10},{32707,15},{65526,16},{65527,16},{65528,16},{65529,16},{65530,16},{65531,16},{65532,16},{65533,16},{65534,16},{0,0},{0,0},{0,0},{0,0},{0,0}
};
static const int YQT[] = {16,11,10,16,24,40,51,61,12,12,14,19,26,58,60,55,14,13,16,24,40,57,69,56,14,17,22,29,51,87,80,62,18,22,
37,56,68,109,103,77,24,35,55,64,81,104,113,92,49,64,78,87,103,121,120,101,72,92,95,98,112,100,103,99};
static const int UVQT[] = {17,18,24,47,99,99,99,99,18,21,26,66,99,99,99,99,24,26,56,99,99,99,99,99,47,66,99,99,99,99,99,99,
99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99};
static const float aasf[] = { 1.0f * 2.828427125f, 1.387039845f * 2.828427125f, 1.306562965f * 2.828427125f, 1.175875602f * 2.828427125f,
1.0f * 2.828427125f, 0.785694958f * 2.828427125f, 0.541196100f * 2.828427125f, 0.275899379f * 2.828427125f };
int row, col, i, k;
float fdtbl_Y[64], fdtbl_UV[64];
unsigned char YTable[64], UVTable[64];
if(!data || !width || !height || comp > 4 || comp < 1) {
return 0;
}
quality = quality ? quality : 90;
quality = quality < 1 ? 1 : quality > 100 ? 100 : quality;
quality = quality < 50 ? 5000 / quality : 200 - quality * 2;
for(i = 0; i < 64; ++i) {
int uvti, yti = (YQT[i]*quality+50)/100;
YTable[stbiw__jpg_ZigZag[i]] = yti < 1 ? 1 : yti > 255 ? 255 : yti;
uvti = (UVQT[i]*quality+50)/100;
UVTable[stbiw__jpg_ZigZag[i]] = uvti < 1 ? 1 : uvti > 255 ? 255 : uvti;
}
for(row = 0, k = 0; row < 8; ++row) {
for(col = 0; col < 8; ++col, ++k) {
fdtbl_Y[k] = 1 / (YTable [stbiw__jpg_ZigZag[k]] * aasf[row] * aasf[col]);
fdtbl_UV[k] = 1 / (UVTable[stbiw__jpg_ZigZag[k]] * aasf[row] * aasf[col]);
}
}
// Write Headers
{
static const unsigned char head0[] = { 0xFF,0xD8,0xFF,0xE0,0,0x10,'J','F','I','F',0,1,1,0,0,1,0,1,0,0,0xFF,0xDB,0,0x84,0 };
static const unsigned char head2[] = { 0xFF,0xDA,0,0xC,3,1,0,2,0x11,3,0x11,0,0x3F,0 };
const unsigned char head1[] = { 0xFF,0xC0,0,0x11,8,(unsigned char)(height>>8),STBIW_UCHAR(height),(unsigned char)(width>>8),STBIW_UCHAR(width),
3,1,0x11,0,2,0x11,1,3,0x11,1,0xFF,0xC4,0x01,0xA2,0 };
s->func(s->context, (void*)head0, sizeof(head0));
s->func(s->context, (void*)YTable, sizeof(YTable));
stbiw__putc(s, 1);
s->func(s->context, UVTable, sizeof(UVTable));
s->func(s->context, (void*)head1, sizeof(head1));
s->func(s->context, (void*)(std_dc_luminance_nrcodes+1), sizeof(std_dc_luminance_nrcodes)-1);
s->func(s->context, (void*)std_dc_luminance_values, sizeof(std_dc_luminance_values));
stbiw__putc(s, 0x10); // HTYACinfo
s->func(s->context, (void*)(std_ac_luminance_nrcodes+1), sizeof(std_ac_luminance_nrcodes)-1);
s->func(s->context, (void*)std_ac_luminance_values, sizeof(std_ac_luminance_values));
stbiw__putc(s, 1); // HTUDCinfo
s->func(s->context, (void*)(std_dc_chrominance_nrcodes+1), sizeof(std_dc_chrominance_nrcodes)-1);
s->func(s->context, (void*)std_dc_chrominance_values, sizeof(std_dc_chrominance_values));
stbiw__putc(s, 0x11); // HTUACinfo
s->func(s->context, (void*)(std_ac_chrominance_nrcodes+1), sizeof(std_ac_chrominance_nrcodes)-1);
s->func(s->context, (void*)std_ac_chrominance_values, sizeof(std_ac_chrominance_values));
s->func(s->context, (void*)head2, sizeof(head2));
}
// Encode 8x8 macroblocks
{
static const unsigned short fillBits[] = {0x7F, 7};
const unsigned char *imageData = (const unsigned char *)data;
int DCY=0, DCU=0, DCV=0;
int bitBuf=0, bitCnt=0;
// comp == 2 is grey+alpha (alpha is ignored)
int ofsG = comp > 2 ? 1 : 0, ofsB = comp > 2 ? 2 : 0;
int x, y, pos;
for(y = 0; y < height; y += 8) {
for(x = 0; x < width; x += 8) {
float YDU[64], UDU[64], VDU[64];
for(row = y, pos = 0; row < y+8; ++row) {
for(col = x; col < x+8; ++col, ++pos) {
int p = row*width*comp + col*comp;
float r, g, b;
if(row >= height) {
p -= width*comp*(row+1 - height);
}
if(col >= width) {
p -= comp*(col+1 - width);
}
r = imageData[p+0];
g = imageData[p+ofsG];
b = imageData[p+ofsB];
YDU[pos]=+0.29900f*r+0.58700f*g+0.11400f*b-128;
UDU[pos]=-0.16874f*r-0.33126f*g+0.50000f*b;
VDU[pos]=+0.50000f*r-0.41869f*g-0.08131f*b;
}
}
DCY = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, YDU, fdtbl_Y, DCY, YDC_HT, YAC_HT);
DCU = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, UDU, fdtbl_UV, DCU, UVDC_HT, UVAC_HT);
DCV = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, VDU, fdtbl_UV, DCV, UVDC_HT, UVAC_HT);
}
}
// Do the bit alignment of the EOI marker
stbiw__jpg_writeBits(s, &bitBuf, &bitCnt, fillBits);
}
// EOI
stbiw__putc(s, 0xFF);
stbiw__putc(s, 0xD9);
return 1;
}
STBIWDEF int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality)
{
stbi__write_context s;
stbi__start_write_callbacks(&s, func, context);
return stbi_write_jpg_core(&s, x, y, comp, (void *) data, quality);
}
#ifndef STBI_WRITE_NO_STDIO
STBIWDEF int stbi_write_jpg(char const *filename, int x, int y, int comp, const void *data, int quality)
{
stbi__write_context s;
if (stbi__start_write_file(&s,filename)) {
int r = stbi_write_jpg_core(&s, x, y, comp, data, quality);
stbi__end_write_file(&s);
return r;
} else
return 0;
}
#endif
#endif // STB_IMAGE_WRITE_IMPLEMENTATION #endif // STB_IMAGE_WRITE_IMPLEMENTATION
/* Revision history /* Revision history

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