mirror of https://github.com/nothings/stb.git
Merge branch 'DanielGibson-write-jpg' into dev
Fabian Giesen
commit
3870b2fe3b
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@ -1,5 +1,5 @@
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/* stb_image_write - v1.05 - public domain - http://nothings.org/stb/stb_image_write.h
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writes out PNG/BMP/TGA images to C stdio - Sean Barrett 2010-2015
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writes out PNG/BMP/TGA/JPEG/HDR images to C stdio - Sean Barrett 2010-2015
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no warranty implied; use at your own risk
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Before #including,
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@ -35,6 +35,7 @@ USAGE:
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int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
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int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
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int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
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int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality)
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There are also four equivalent functions that use an arbitrary write function. You are
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expected to open/close your file-equivalent before and after calling these:
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@ -43,6 +44,7 @@ USAGE:
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int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
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int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality);
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where the callback is:
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void stbi_write_func(void *context, void *data, int size);
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@ -79,6 +81,10 @@ USAGE:
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TGA supports RLE or non-RLE compressed data. To use non-RLE-compressed
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data, set the global variable 'stbi_write_tga_with_rle' to 0.
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JPEG does ignore alpha channels in input data; quality is between 1 and 100.
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Higher quality looks better but results in a bigger image.
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JPEG baseline (no JPEG progressive).
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CREDITS:
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@ -94,6 +100,9 @@ CREDITS:
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Alan Hickman
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initial file IO callback implementation
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Emmanuel Julien
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JPEG
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Jon Olick (original jo_jpeg.cpp code)
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Daniel Gibson
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bugfixes:
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github:Chribba
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Guillaume Chereau
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@ -131,6 +140,7 @@ STBIWDEF int stbi_write_png(char const *filename, int w, int h, int comp, const
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STBIWDEF int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
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STBIWDEF int stbi_write_jpg(char const *filename, int x, int y, int comp, const void *data, int quality);
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#endif
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typedef void stbi_write_func(void *context, void *data, int size);
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@ -139,6 +149,7 @@ STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int w,
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STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
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STBIWDEF int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality);
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#ifdef __cplusplus
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}
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@ -277,6 +288,11 @@ static void stbiw__writef(stbi__write_context *s, const char *fmt, ...)
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va_end(v);
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}
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static void stbiw__putc(stbi__write_context *s, unsigned char c)
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{
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s->func(s->context, &c, 1);
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}
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static void stbiw__write3(stbi__write_context *s, unsigned char a, unsigned char b, unsigned char c)
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{
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unsigned char arr[3];
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@ -450,7 +466,7 @@ static int stbi_write_tga_core(stbi__write_context *s, int x, int y, int comp, v
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return 1;
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}
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int stbi_write_tga_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data)
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STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data)
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{
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stbi__write_context s;
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stbi__start_write_callbacks(&s, func, context);
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@ -458,7 +474,7 @@ int stbi_write_tga_to_func(stbi_write_func *func, void *context, int x, int y, i
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}
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#ifndef STBI_WRITE_NO_STDIO
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int stbi_write_tga(char const *filename, int x, int y, int comp, const void *data)
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STBIWDEF int stbi_write_tga(char const *filename, int x, int y, int comp, const void *data)
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{
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stbi__write_context s;
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if (stbi__start_write_file(&s,filename)) {
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@ -620,7 +636,7 @@ static int stbi_write_hdr_core(stbi__write_context *s, int x, int y, int comp, f
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}
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}
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int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const float *data)
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STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const float *data)
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{
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stbi__write_context s;
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stbi__start_write_callbacks(&s, func, context);
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@ -628,7 +644,7 @@ int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int x, int y, i
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}
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#ifndef STBI_WRITE_NO_STDIO
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int stbi_write_hdr(char const *filename, int x, int y, int comp, const float *data)
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STBIWDEF int stbi_write_hdr(char const *filename, int x, int y, int comp, const float *data)
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{
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stbi__write_context s;
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if (stbi__start_write_file(&s,filename)) {
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@ -1013,6 +1029,351 @@ STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int x,
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return 1;
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}
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/* ***************************************************************************
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*
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* JPEG writer
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*
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* This is based on Jon Olick's jo_jpeg.cpp:
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* public domain Simple, Minimalistic JPEG writer - http://www.jonolick.com/code.html
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*/
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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,
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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 };
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static void stbiw__jpg_writeBits(stbi__write_context *s, int *bitBufP, int *bitCntP, const unsigned short *bs) {
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int bitBuf = *bitBufP, bitCnt = *bitCntP;
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bitCnt += bs[1];
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bitBuf |= bs[0] << (24 - bitCnt);
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while(bitCnt >= 8) {
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unsigned char c = (bitBuf >> 16) & 255;
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stbiw__putc(s, c);
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if(c == 255) {
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stbiw__putc(s, 0);
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}
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bitBuf <<= 8;
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bitCnt -= 8;
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}
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*bitBufP = bitBuf;
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*bitCntP = bitCnt;
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}
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static void stbiw__jpg_DCT(float *d0p, float *d1p, float *d2p, float *d3p, float *d4p, float *d5p, float *d6p, float *d7p) {
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float d0 = *d0p, d1 = *d1p, d2 = *d2p, d3 = *d3p, d4 = *d4p, d5 = *d5p, d6 = *d6p, d7 = *d7p;
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float z1, z2, z3, z4, z5, z11, z13;
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float tmp0 = d0 + d7;
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float tmp7 = d0 - d7;
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float tmp1 = d1 + d6;
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float tmp6 = d1 - d6;
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float tmp2 = d2 + d5;
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float tmp5 = d2 - d5;
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float tmp3 = d3 + d4;
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float tmp4 = d3 - d4;
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// Even part
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float tmp10 = tmp0 + tmp3; // phase 2
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float tmp13 = tmp0 - tmp3;
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float tmp11 = tmp1 + tmp2;
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float tmp12 = tmp1 - tmp2;
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d0 = tmp10 + tmp11; // phase 3
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d4 = tmp10 - tmp11;
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z1 = (tmp12 + tmp13) * 0.707106781f; // c4
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d2 = tmp13 + z1; // phase 5
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d6 = tmp13 - z1;
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// Odd part
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tmp10 = tmp4 + tmp5; // phase 2
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tmp11 = tmp5 + tmp6;
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tmp12 = tmp6 + tmp7;
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// The rotator is modified from fig 4-8 to avoid extra negations.
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z5 = (tmp10 - tmp12) * 0.382683433f; // c6
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z2 = tmp10 * 0.541196100f + z5; // c2-c6
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z4 = tmp12 * 1.306562965f + z5; // c2+c6
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z3 = tmp11 * 0.707106781f; // c4
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z11 = tmp7 + z3; // phase 5
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z13 = tmp7 - z3;
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*d5p = z13 + z2; // phase 6
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*d3p = z13 - z2;
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*d1p = z11 + z4;
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*d7p = z11 - z4;
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*d0p = d0; *d2p = d2; *d4p = d4; *d6p = d6;
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}
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static void stbiw__jpg_calcBits(int val, unsigned short bits[2]) {
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int tmp1 = val < 0 ? -val : val;
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val = val < 0 ? val-1 : val;
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bits[1] = 1;
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while(tmp1 >>= 1) {
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++bits[1];
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}
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bits[0] = val & ((1<<bits[1])-1);
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}
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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]) {
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const unsigned short EOB[2] = { HTAC[0x00][0], HTAC[0x00][1] };
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const unsigned short M16zeroes[2] = { HTAC[0xF0][0], HTAC[0xF0][1] };
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int dataOff, i, diff, end0pos;
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int DU[64];
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// DCT rows
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for(dataOff=0; dataOff<64; dataOff+=8) {
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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]);
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}
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// DCT columns
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for(dataOff=0; dataOff<8; ++dataOff) {
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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]);
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}
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// Quantize/descale/zigzag the coefficients
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for(i=0; i<64; ++i) {
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float v = CDU[i]*fdtbl[i];
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// DU[stbiw__jpg_ZigZag[i]] = (int)(v < 0 ? ceilf(v - 0.5f) : floorf(v + 0.5f));
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// ceilf() and floorf() are C99, not C89, but I /think/ they're not needed here anyway?
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DU[stbiw__jpg_ZigZag[i]] = (int)(v < 0 ? v - 0.5f : v + 0.5f);
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}
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// Encode DC
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diff = DU[0] - DC;
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if (diff == 0) {
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTDC[0]);
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} else {
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unsigned short bits[2];
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stbiw__jpg_calcBits(diff, bits);
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTDC[bits[1]]);
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, bits);
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}
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// Encode ACs
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end0pos = 63;
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for(; (end0pos>0)&&(DU[end0pos]==0); --end0pos) {
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}
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// end0pos = first element in reverse order !=0
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if(end0pos == 0) {
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, EOB);
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return DU[0];
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}
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for(i = 1; i <= end0pos; ++i) {
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int startpos = i;
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int nrzeroes;
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unsigned short bits[2];
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for (; DU[i]==0 && i<=end0pos; ++i) {
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}
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nrzeroes = i-startpos;
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if ( nrzeroes >= 16 ) {
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int lng = nrzeroes>>4;
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int nrmarker;
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for (nrmarker=1; nrmarker <= lng; ++nrmarker)
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, M16zeroes);
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nrzeroes &= 15;
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}
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stbiw__jpg_calcBits(DU[i], bits);
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTAC[(nrzeroes<<4)+bits[1]]);
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, bits);
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}
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if(end0pos != 63) {
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stbiw__jpg_writeBits(s, bitBuf, bitCnt, EOB);
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}
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return DU[0];
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}
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static int stbi_write_jpg_core(stbi__write_context *s, int width, int height, int comp, const void* data, int quality) {
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// Constants that don't pollute global namespace
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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};
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static const unsigned char std_dc_luminance_values[] = {0,1,2,3,4,5,6,7,8,9,10,11};
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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};
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static const unsigned char std_ac_luminance_values[] = {
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0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,0x21,0x31,0x41,0x06,0x13,0x51,0x61,0x07,0x22,0x71,0x14,0x32,0x81,0x91,0xa1,0x08,
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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,
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||||
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
|
||||
|
||||
/* Revision history
|
||||
|
|
|
|||
Loading…
Reference in New Issue