提交 47685c5f 编写于 作者: S Sean Barrett

remove deprecated old-precision jpg path from stb_image.h

tweak license reference wording
上级 51a5368d
......@@ -36,7 +36,7 @@
//
// LICENSE
//
// See end of file for licensing information.
// See end of file for license information.
#ifndef STB_C_LEXER_DEFINITIONS
// to change the default parsing rules, copy the following lines
......
......@@ -52,7 +52,7 @@
//
// LICENSE
//
// See end of file for licensing information.
// See end of file for license information.
//
// ALGORITHM
//
......
......@@ -78,7 +78,7 @@
//
// LICENSE
//
// See end of file for licensing information.
// See end of file for license information.
#ifndef INCLUDE_STB_DIVIDE_H
......
......@@ -19,7 +19,7 @@
//
// LICENSE
//
// See end of file for licensing information.
// See end of file for license information.
#ifndef STB_INCLUDE_STB_DXT_H
#define STB_INCLUDE_STB_DXT_H
......
......@@ -67,7 +67,7 @@
//
// LICENSE
//
// See end of file for licensing information.
// See end of file for license information.
//
// VERSION HISTORY
//
......
......@@ -21,7 +21,7 @@
avoid problematic images and only need the trivial interface
JPEG baseline & progressive (12 bpc/arithmetic not supported, same as stock IJG lib)
PNG 1/2/4/8-bit-per-channel (16 bpc not supported)
PNG 1/2/4/8/16-bit-per-channel
TGA (not sure what subset, if a subset)
BMP non-1bpp, non-RLE
......@@ -42,110 +42,13 @@
Full documentation under "DOCUMENTATION" below.
Revision 2.00 release notes:
- Progressive JPEG is now supported.
- PPM and PGM binary formats are now supported, thanks to Ken Miller.
- x86 platforms now make use of SSE2 SIMD instructions for
JPEG decoding, and ARM platforms can use NEON SIMD if requested.
This work was done by Fabian "ryg" Giesen. SSE2 is used by
default, but NEON must be enabled explicitly; see docs.
With other JPEG optimizations included in this version, we see
2x speedup on a JPEG on an x86 machine, and a 1.5x speedup
on a JPEG on an ARM machine, relative to previous versions of this
library. The same results will not obtain for all JPGs and for all
x86/ARM machines. (Note that progressive JPEGs are significantly
slower to decode than regular JPEGs.) This doesn't mean that this
is the fastest JPEG decoder in the land; rather, it brings it
closer to parity with standard libraries. If you want the fastest
decode, look elsewhere. (See "Philosophy" section of docs below.)
See final bullet items below for more info on SIMD.
- Added STBI_MALLOC, STBI_REALLOC, and STBI_FREE macros for replacing
the memory allocator. Unlike other STBI libraries, these macros don't
support a context parameter, so if you need to pass a context in to
the allocator, you'll have to store it in a global or a thread-local
variable.
- Split existing STBI_NO_HDR flag into two flags, STBI_NO_HDR and
STBI_NO_LINEAR.
STBI_NO_HDR: suppress implementation of .hdr reader format
STBI_NO_LINEAR: suppress high-dynamic-range light-linear float API
- You can suppress implementation of any of the decoders to reduce
your code footprint by #defining one or more of the following
symbols before creating the implementation.
STBI_NO_JPEG
STBI_NO_PNG
STBI_NO_BMP
STBI_NO_PSD
STBI_NO_TGA
STBI_NO_GIF
STBI_NO_HDR
STBI_NO_PIC
STBI_NO_PNM (.ppm and .pgm)
- You can request *only* certain decoders and suppress all other ones
(this will be more forward-compatible, as addition of new decoders
doesn't require you to disable them explicitly):
STBI_ONLY_JPEG
STBI_ONLY_PNG
STBI_ONLY_BMP
STBI_ONLY_PSD
STBI_ONLY_TGA
STBI_ONLY_GIF
STBI_ONLY_HDR
STBI_ONLY_PIC
STBI_ONLY_PNM (.ppm and .pgm)
Note that you can define multiples of these, and you will get all
of them ("only x" and "only y" is interpreted to mean "only x&y").
- If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still
want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB
- Compilation of all SIMD code can be suppressed with
#define STBI_NO_SIMD
It should not be necessary to disable SIMD unless you have issues
compiling (e.g. using an x86 compiler which doesn't support SSE
intrinsics or that doesn't support the method used to detect
SSE2 support at run-time), and even those can be reported as
bugs so I can refine the built-in compile-time checking to be
smarter.
- The old STBI_SIMD system which allowed installing a user-defined
IDCT etc. has been removed. If you need this, don't upgrade. My
assumption is that almost nobody was doing this, and those who
were will find the built-in SIMD more satisfactory anyway.
- RGB values computed for JPEG images are slightly different from
previous versions of stb_image. (This is due to using less
integer precision in SIMD.) The C code has been adjusted so
that the same RGB values will be computed regardless of whether
SIMD support is available, so your app should always produce
consistent results. But these results are slightly different from
previous versions. (Specifically, about 3% of available YCbCr values
will compute different RGB results from pre-1.49 versions by +-1;
most of the deviating values are one smaller in the G channel.)
- If you must produce consistent results with previous versions of
stb_image, #define STBI_JPEG_OLD and you will get the same results
you used to; however, you will not get the SIMD speedups for
the YCbCr-to-RGB conversion step (although you should still see
significant JPEG speedup from the other changes).
Please note that STBI_JPEG_OLD is a temporary feature; it will be
removed in future versions of the library. It is only intended for
near-term back-compatibility use.
Latest revision history:
LICENSE
See end of file for license information.
RECENT REVISION HISTORY:
2.14 (2017-03-03) remove deprecated STBI_JPEG_OLD
2.13 (2016-12-04) experimental 16-bit API, only for PNG so far; fixes
2.12 (2016-04-02) fix typo in 2.11 PSD fix that caused crashes
2.11 (2016-04-02) 16-bit PNGS; enable SSE2 in non-gcc x64
......@@ -194,11 +97,6 @@
Philipp Wiesemann Josh Tobin github:rlyeh github:grim210@github
Blazej Dariusz Roszkowski github:sammyhw
LICENSE
See end of file for licensing information.
*/
#ifndef STBI_INCLUDE_STB_IMAGE_H
......@@ -272,13 +170,13 @@ LICENSE
// and for best performance I may provide less-easy-to-use APIs that give higher
// performance, in addition to the easy to use ones. Nevertheless, it's important
// to keep in mind that from the standpoint of you, a client of this library,
// all you care about is #1 and #3, and stb libraries do not emphasize #3 above all.
// all you care about is #1 and #3, and stb libraries DO NOT emphasize #3 above all.
//
// Some secondary priorities arise directly from the first two, some of which
// make more explicit reasons why performance can't be emphasized.
//
// - Portable ("ease of use")
// - Small footprint ("easy to maintain")
// - Small source code footprint ("easy to maintain")
// - No dependencies ("ease of use")
//
// ===========================================================================
......@@ -310,13 +208,6 @@ LICENSE
// (at least this is true for iOS and Android). Therefore, the NEON support is
// toggled by a build flag: define STBI_NEON to get NEON loops.
//
// The output of the JPEG decoder is slightly different from versions where
// SIMD support was introduced (that is, for versions before 1.49). The
// difference is only +-1 in the 8-bit RGB channels, and only on a small
// fraction of pixels. You can force the pre-1.49 behavior by defining
// STBI_JPEG_OLD, but this will disable some of the SIMD decoding path
// and hence cost some performance.
//
// If for some reason you do not want to use any of SIMD code, or if
// you have issues compiling it, you can disable it entirely by
// defining STBI_NO_SIMD.
......@@ -372,6 +263,41 @@ LICENSE
// says there's premultiplied data (currently only happens in iPhone images,
// and only if iPhone convert-to-rgb processing is on).
//
// ===========================================================================
//
// ADDITIONAL CONFIGURATION
//
// - You can suppress implementation of any of the decoders to reduce
// your code footprint by #defining one or more of the following
// symbols before creating the implementation.
//
// STBI_NO_JPEG
// STBI_NO_PNG
// STBI_NO_BMP
// STBI_NO_PSD
// STBI_NO_TGA
// STBI_NO_GIF
// STBI_NO_HDR
// STBI_NO_PIC
// STBI_NO_PNM (.ppm and .pgm)
//
// - You can request *only* certain decoders and suppress all other ones
// (this will be more forward-compatible, as addition of new decoders
// doesn't require you to disable them explicitly):
//
// STBI_ONLY_JPEG
// STBI_ONLY_PNG
// STBI_ONLY_BMP
// STBI_ONLY_PSD
// STBI_ONLY_TGA
// STBI_ONLY_GIF
// STBI_ONLY_HDR
// STBI_ONLY_PIC
// STBI_ONLY_PNM (.ppm and .pgm)
//
// - If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still
// want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB
//
#ifndef STBI_NO_STDIO
......@@ -3345,38 +3271,9 @@ static stbi_uc *stbi__resample_row_generic(stbi_uc *out, stbi_uc *in_near, stbi_
return out;
}
#ifdef STBI_JPEG_OLD
// this is the same YCbCr-to-RGB calculation that stb_image has used
// historically before the algorithm changes in 1.49
#define float2fixed(x) ((int) ((x) * 65536 + 0.5))
static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step)
{
int i;
for (i=0; i < count; ++i) {
int y_fixed = (y[i] << 16) + 32768; // rounding
int r,g,b;
int cr = pcr[i] - 128;
int cb = pcb[i] - 128;
r = y_fixed + cr*float2fixed(1.40200f);
g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f);
b = y_fixed + cb*float2fixed(1.77200f);
r >>= 16;
g >>= 16;
b >>= 16;
if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; }
if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; }
if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; }
out[0] = (stbi_uc)r;
out[1] = (stbi_uc)g;
out[2] = (stbi_uc)b;
out[3] = 255;
out += step;
}
}
#else
// this is a reduced-precision calculation of YCbCr-to-RGB introduced
// to make sure the code produces the same results in both SIMD and scalar
#define float2fixed(x) (((int) ((x) * 4096.0f + 0.5f)) << 8)
#define stbi__float2fixed(x) (((int) ((x) * 4096.0f + 0.5f)) << 8)
static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step)
{
int i;
......@@ -3385,9 +3282,9 @@ static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc
int r,g,b;
int cr = pcr[i] - 128;
int cb = pcb[i] - 128;
r = y_fixed + cr* float2fixed(1.40200f);
g = y_fixed + (cr*-float2fixed(0.71414f)) + ((cb*-float2fixed(0.34414f)) & 0xffff0000);
b = y_fixed + cb* float2fixed(1.77200f);
r = y_fixed + cr* stbi__float2fixed(1.40200f);
g = y_fixed + (cr*-stbi__float2fixed(0.71414f)) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000);
b = y_fixed + cb* stbi__float2fixed(1.77200f);
r >>= 20;
g >>= 20;
b >>= 20;
......@@ -3401,7 +3298,6 @@ static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc
out += step;
}
}
#endif
#if defined(STBI_SSE2) || defined(STBI_NEON)
static void stbi__YCbCr_to_RGB_simd(stbi_uc *out, stbi_uc const *y, stbi_uc const *pcb, stbi_uc const *pcr, int count, int step)
......@@ -3520,9 +3416,9 @@ static void stbi__YCbCr_to_RGB_simd(stbi_uc *out, stbi_uc const *y, stbi_uc cons
int r,g,b;
int cr = pcr[i] - 128;
int cb = pcb[i] - 128;
r = y_fixed + cr* float2fixed(1.40200f);
g = y_fixed + cr*-float2fixed(0.71414f) + ((cb*-float2fixed(0.34414f)) & 0xffff0000);
b = y_fixed + cb* float2fixed(1.77200f);
r = y_fixed + cr* stbi__float2fixed(1.40200f);
g = y_fixed + cr*-stbi__float2fixed(0.71414f) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000);
b = y_fixed + cb* stbi__float2fixed(1.77200f);
r >>= 20;
g >>= 20;
b >>= 20;
......@@ -3548,18 +3444,14 @@ static void stbi__setup_jpeg(stbi__jpeg *j)
#ifdef STBI_SSE2
if (stbi__sse2_available()) {
j->idct_block_kernel = stbi__idct_simd;
#ifndef STBI_JPEG_OLD
j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
#endif
j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
}
#endif
#ifdef STBI_NEON
j->idct_block_kernel = stbi__idct_simd;
#ifndef STBI_JPEG_OLD
j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
#endif
j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
#endif
}
......
/* stb_image_write - v1.03 - 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
no warranty implied; use at your own risk
......@@ -104,12 +104,11 @@ CREDITS:
Filip Wasil
Thatcher Ulrich
github:poppolopoppo
Patrick Boettcher
LICENSE
This software is dual-licensed to the public domain and under the following
license: you are granted a perpetual, irrevocable license to copy, modify,
publish, and distribute this file as you see fit.
See end of file for license information.
*/
......@@ -294,8 +293,8 @@ static void stbiw__write_pixel(stbi__write_context *s, int rgb_dir, int comp, in
s->func(s->context, &d[comp - 1], 1);
switch (comp) {
case 1: /* fall-through wanted */
case 2:
case 2: // 2 pixels = mono + alpha, alpha is written separately, so same as 1-channel case
case 1:
if (expand_mono)
stbiw__write3(s, d[0], d[0], d[0]); // monochrome bmp
else
......@@ -895,6 +894,7 @@ static unsigned char stbiw__paeth(int a, int b, int c)
return STBIW_UCHAR(c);
}
// @OPTIMIZE: provide an option that always forces left-predict or paeth predict
unsigned char *stbi_write_png_to_mem(unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len)
{
int ctype[5] = { -1, 0, 4, 2, 6 };
......@@ -911,10 +911,10 @@ unsigned char *stbi_write_png_to_mem(unsigned char *pixels, int stride_bytes, in
for (j=0; j < y; ++j) {
static int mapping[] = { 0,1,2,3,4 };
static int firstmap[] = { 0,1,0,5,6 };
int *mymap = j ? mapping : firstmap;
int *mymap = (j != 0) ? mapping : firstmap;
int best = 0, bestval = 0x7fffffff;
for (p=0; p < 2; ++p) {
for (k= p?best:0; k < 5; ++k) {
for (k= p?best:0; k < 5; ++k) { // @TODO: clarity: rewrite this to go 0..5, and 'continue' the unwanted ones during 2nd pass
int type = mymap[k],est=0;
unsigned char *z = pixels + stride_bytes*j;
for (i=0; i < n; ++i)
......@@ -1016,6 +1016,9 @@ STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int x,
#endif // STB_IMAGE_WRITE_IMPLEMENTATION
/* Revision history
1.04 (2017-03-03)
monochrome BMP expansion
1.03 ???
1.02 (2016-04-02)
avoid allocating large structures on the stack
1.01 (2016-01-16)
......@@ -1045,3 +1048,45 @@ STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int x,
first public release
0.90 first internal release
*/
/*
------------------------------------------------------------------------------
This software is available under 2 licenses -- choose whichever you prefer.
------------------------------------------------------------------------------
ALTERNATIVE A - MIT License
Copyright (c) 2017 Sean Barrett
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
------------------------------------------------------------------------------
ALTERNATIVE B - Public Domain (www.unlicense.org)
This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
software, either in source code form or as a compiled binary, for any purpose,
commercial or non-commercial, and by any means.
In jurisdictions that recognize copyright laws, the author or authors of this
software dedicate any and all copyright interest in the software to the public
domain. We make this dedication for the benefit of the public at large and to
the detriment of our heirs and successors. We intend this dedication to be an
overt act of relinquishment in perpetuity of all present and future rights to
this software under copyright law.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
------------------------------------------------------------------------------
*/
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