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4940 lines
156 KiB
4940 lines
156 KiB
/* stbi-1.28 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c |
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when you control the images you're loading |
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no warranty implied; use at your own risk |
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QUICK NOTES: |
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Primarily of interest to game developers and other people who can |
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avoid problematic images and only need the trivial interface |
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JPEG baseline (no JPEG progressive) |
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PNG 8-bit only |
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TGA (not sure what subset, if a subset) |
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BMP non-1bpp, non-RLE |
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PSD (composited view only, no extra channels) |
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GIF (*comp always reports as 4-channel) |
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HDR (radiance rgbE format) |
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PIC (Softimage PIC) |
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- decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code) |
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- supports installable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD) |
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Latest revisions: |
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1.28 (2010-08-01) fix bug in GIF palette transparency (SpartanJ) |
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1.27 (2010-08-01) cast-to-uint8 to fix warnings (Laurent Gomila) |
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allow trailing 0s at end of image data (Laurent Gomila) |
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1.26 (2010-07-24) fix bug in file buffering for PNG reported by SpartanJ |
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1.25 (2010-07-17) refix trans_data warning (Won Chun) |
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1.24 (2010-07-12) perf improvements reading from files |
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minor perf improvements for jpeg |
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deprecated type-specific functions in hope of feedback |
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attempt to fix trans_data warning (Won Chun) |
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1.23 fixed bug in iPhone support |
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1.22 (2010-07-10) removed image *writing* support to stb_image_write.h |
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stbi_info support from Jetro Lauha |
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GIF support from Jean-Marc Lienher |
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iPhone PNG-extensions from James Brown |
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warning-fixes from Nicolas Schulz and Janez Zemva |
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1.21 fix use of 'uint8' in header (reported by jon blow) |
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1.20 added support for Softimage PIC, by Tom Seddon |
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See end of file for full revision history. |
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TODO: |
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stbi_info support for BMP,PSD,HDR,PIC |
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rewrite stbi_info and load_file variations to share file handling code |
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(current system allows individual functions to be called directly, |
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since each does all the work, but I doubt anyone uses this in practice) |
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============================ Contributors ========================= |
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Image formats Optimizations & bugfixes |
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Sean Barrett (jpeg, png, bmp) Fabian "ryg" Giesen |
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Nicolas Schulz (hdr, psd) |
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Jonathan Dummer (tga) Bug fixes & warning fixes |
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Jean-Marc Lienher (gif) Marc LeBlanc |
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Tom Seddon (pic) Christpher Lloyd |
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Thatcher Ulrich (psd) Dave Moore |
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Won Chun |
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the Horde3D community |
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Extensions, features Janez Zemva |
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Jetro Lauha (stbi_info) Jonathan Blow |
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James "moose2000" Brown (iPhone PNG) Laurent Gomila |
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If your name should be here but isn't, let Sean know. |
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*/ |
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#ifndef STBI_INCLUDE_STB_IMAGE_H |
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#define STBI_INCLUDE_STB_IMAGE_H |
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// To get a header file for this, either cut and paste the header, |
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// or create stb_image.h, #define STBI_HEADER_FILE_ONLY, and |
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// then include stb_image.c from it. |
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//// begin header file //////////////////////////////////////////////////// |
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// |
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// Limitations: |
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// - no jpeg progressive support |
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// - non-HDR formats support 8-bit samples only (jpeg, png) |
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// - no delayed line count (jpeg) -- IJG doesn't support either |
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// - no 1-bit BMP |
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// - GIF always returns *comp=4 |
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// |
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// Basic usage (see HDR discussion below): |
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// int x,y,n; |
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// unsigned char *data = stbi_load(filename, &x, &y, &n, 0); |
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// // ... process data if not NULL ... |
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// // ... x = width, y = height, n = # 8-bit components per pixel ... |
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// // ... replace '0' with '1'..'4' to force that many components per pixel |
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// stbi_image_free(data) |
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// |
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// Standard parameters: |
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// int *x -- outputs image width in pixels |
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// int *y -- outputs image height in pixels |
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// int *comp -- outputs # of image components in image file |
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// int req_comp -- if non-zero, # of image components requested in result |
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// |
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// The return value from an image loader is an 'unsigned char *' which points |
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// to the pixel data. The pixel data consists of *y scanlines of *x pixels, |
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// with each pixel consisting of N interleaved 8-bit components; the first |
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// pixel pointed to is top-left-most in the image. There is no padding between |
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// image scanlines or between pixels, regardless of format. The number of |
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// components N is 'req_comp' if req_comp is non-zero, or *comp otherwise. |
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// If req_comp is non-zero, *comp has the number of components that _would_ |
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// have been output otherwise. E.g. if you set req_comp to 4, you will always |
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// get RGBA output, but you can check *comp to easily see if it's opaque. |
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// |
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// An output image with N components has the following components interleaved |
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// in this order in each pixel: |
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// |
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// N=#comp components |
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// 1 grey |
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// 2 grey, alpha |
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// 3 red, green, blue |
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// 4 red, green, blue, alpha |
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// |
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// If image loading fails for any reason, the return value will be NULL, |
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// and *x, *y, *comp will be unchanged. The function stbi_failure_reason() |
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// can be queried for an extremely brief, end-user unfriendly explanation |
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// of why the load failed. Define STBI_NO_FAILURE_STRINGS to avoid |
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// compiling these strings at all, and STBI_FAILURE_USERMSG to get slightly |
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// more user-friendly ones. |
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// |
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// Paletted PNG, BMP, GIF, and PIC images are automatically depalettized. |
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// |
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// =========================================================================== |
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// |
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// iPhone PNG support: |
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// |
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// By default we convert iphone-formatted PNGs back to RGB; nominally they |
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// would silently load as BGR, except the existing code should have just |
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// failed on such iPhone PNGs. But you can disable this conversion by |
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// by calling stbi_convert_iphone_png_to_rgb(0), in which case |
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// you will always just get the native iphone "format" through. |
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// |
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// Call stbi_set_unpremultiply_on_load(1) as well to force a divide per |
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// pixel to remove any premultiplied alpha *only* if the image file explicitly |
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// says there's premultiplied data (currently only happens in iPhone images, |
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// and only if iPhone convert-to-rgb processing is on). |
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// |
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// =========================================================================== |
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// |
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// HDR image support (disable by defining STBI_NO_HDR) |
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// |
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// stb_image now supports loading HDR images in general, and currently |
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// the Radiance .HDR file format, although the support is provided |
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// generically. You can still load any file through the existing interface; |
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// if you attempt to load an HDR file, it will be automatically remapped to |
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// LDR, assuming gamma 2.2 and an arbitrary scale factor defaulting to 1; |
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// both of these constants can be reconfigured through this interface: |
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// |
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// stbi_hdr_to_ldr_gamma(2.2f); |
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// stbi_hdr_to_ldr_scale(1.0f); |
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// |
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// (note, do not use _inverse_ constants; stbi_image will invert them |
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// appropriately). |
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// |
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// Additionally, there is a new, parallel interface for loading files as |
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// (linear) floats to preserve the full dynamic range: |
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// |
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// float *data = stbi_loadf(filename, &x, &y, &n, 0); |
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// |
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// If you load LDR images through this interface, those images will |
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// be promoted to floating point values, run through the inverse of |
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// constants corresponding to the above: |
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// |
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// stbi_ldr_to_hdr_scale(1.0f); |
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// stbi_ldr_to_hdr_gamma(2.2f); |
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// |
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// Finally, given a filename (or an open file or memory block--see header |
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// file for details) containing image data, you can query for the "most |
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// appropriate" interface to use (that is, whether the image is HDR or |
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// not), using: |
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// |
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// stbi_is_hdr(char *filename); |
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#ifndef STBI_NO_STDIO |
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#include <stdio.h> |
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#endif |
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#define STBI_VERSION 1 |
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enum |
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{ |
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STBI_default = 0, // only used for req_comp |
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STBI_grey = 1, |
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STBI_grey_alpha = 2, |
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STBI_rgb = 3, |
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STBI_rgb_alpha = 4, |
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}; |
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typedef unsigned char stbi_uc; |
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#ifdef __cplusplus |
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extern "C" { |
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#endif |
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// PRIMARY API - works on images of any type |
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// load image by filename, open file, or memory buffer |
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extern stbi_uc *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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extern stbi_uc *stbi_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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// for stbi_load_from_file, file pointer is left pointing immediately after image |
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#endif |
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#ifndef STBI_NO_HDR |
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extern float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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extern float *stbi_loadf (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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#endif |
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extern void stbi_hdr_to_ldr_gamma(float gamma); |
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extern void stbi_hdr_to_ldr_scale(float scale); |
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extern void stbi_ldr_to_hdr_gamma(float gamma); |
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extern void stbi_ldr_to_hdr_scale(float scale); |
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#endif // STBI_NO_HDR |
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// get a VERY brief reason for failure |
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// NOT THREADSAFE |
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extern const char *stbi_failure_reason (void); |
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// free the loaded image -- this is just free() |
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extern void stbi_image_free (void *retval_from_stbi_load); |
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// get image dimensions & components without fully decoding |
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extern int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
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extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len); |
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#ifndef STBI_NO_STDIO |
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extern int stbi_info (char const *filename, int *x, int *y, int *comp); |
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extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp); |
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extern int stbi_is_hdr (char const *filename); |
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extern int stbi_is_hdr_from_file(FILE *f); |
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#endif |
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// for image formats that explicitly notate that they have premultiplied alpha, |
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// we just return the colors as stored in the file. set this flag to force |
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// unpremultiplication. results are undefined if the unpremultiply overflow. |
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extern void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply); |
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// indicate whether we should process iphone images back to canonical format, |
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// or just pass them through "as-is" |
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extern void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert); |
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// ZLIB client - used by PNG, available for other purposes |
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extern char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen); |
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extern char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen); |
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extern int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); |
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extern char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen); |
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extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); |
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// define new loaders |
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typedef struct |
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{ |
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int (*test_memory)(stbi_uc const *buffer, int len); |
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stbi_uc * (*load_from_memory)(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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int (*test_file)(FILE *f); |
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stbi_uc * (*load_from_file)(FILE *f, int *x, int *y, int *comp, int req_comp); |
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#endif |
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} stbi_loader; |
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// register a loader by filling out the above structure (you must define ALL functions) |
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// returns 1 if added or already added, 0 if not added (too many loaders) |
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// NOT THREADSAFE |
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extern int stbi_register_loader(stbi_loader *loader); |
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// define faster low-level operations (typically SIMD support) |
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#if STBI_SIMD |
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typedef void (*stbi_idct_8x8)(stbi_uc *out, int out_stride, short data[64], unsigned short *dequantize); |
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// compute an integer IDCT on "input" |
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// input[x] = data[x] * dequantize[x] |
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// write results to 'out': 64 samples, each run of 8 spaced by 'out_stride' |
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// CLAMP results to 0..255 |
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typedef void (*stbi_YCbCr_to_RGB_run)(stbi_uc *output, stbi_uc const *y, stbi_uc const *cb, stbi_uc const *cr, int count, int step); |
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// compute a conversion from YCbCr to RGB |
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// 'count' pixels |
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// write pixels to 'output'; each pixel is 'step' bytes (either 3 or 4; if 4, write '255' as 4th), order R,G,B |
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// y: Y input channel |
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// cb: Cb input channel; scale/biased to be 0..255 |
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// cr: Cr input channel; scale/biased to be 0..255 |
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extern void stbi_install_idct(stbi_idct_8x8 func); |
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extern void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func); |
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#endif // STBI_SIMD |
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// TYPE-SPECIFIC ACCESS |
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#ifdef STBI_TYPE_SPECIFIC_FUNCTIONS |
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// is it a jpeg? |
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extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len); |
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extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
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#ifndef STBI_NO_STDIO |
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extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_jpeg_test_file (FILE *f); |
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extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); |
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extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); |
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#endif |
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// is it a png? |
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extern int stbi_png_test_memory (stbi_uc const *buffer, int len); |
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extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
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#ifndef STBI_NO_STDIO |
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extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_png_info (char const *filename, int *x, int *y, int *comp); |
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extern int stbi_png_test_file (FILE *f); |
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extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp); |
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#endif |
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// is it a bmp? |
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extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len); |
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extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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extern int stbi_bmp_test_file (FILE *f); |
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extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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#endif |
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// is it a tga? |
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extern int stbi_tga_test_memory (stbi_uc const *buffer, int len); |
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extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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extern int stbi_tga_test_file (FILE *f); |
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extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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#endif |
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// is it a psd? |
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extern int stbi_psd_test_memory (stbi_uc const *buffer, int len); |
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extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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extern int stbi_psd_test_file (FILE *f); |
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extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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#endif |
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// is it an hdr? |
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extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len); |
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extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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extern int stbi_hdr_test_file (FILE *f); |
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extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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#endif |
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// is it a pic? |
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extern int stbi_pic_test_memory (stbi_uc const *buffer, int len); |
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extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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#ifndef STBI_NO_STDIO |
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extern int stbi_pic_test_file (FILE *f); |
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extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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#endif |
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// is it a gif? |
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extern int stbi_gif_test_memory (stbi_uc const *buffer, int len); |
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extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
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extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
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#ifndef STBI_NO_STDIO |
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extern int stbi_gif_test_file (FILE *f); |
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extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
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extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp); |
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extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp); |
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#endif |
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#endif//STBI_TYPE_SPECIFIC_FUNCTIONS |
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#ifdef __cplusplus |
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} |
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#endif |
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// |
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// |
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//// end header file ///////////////////////////////////////////////////// |
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#endif // STBI_INCLUDE_STB_IMAGE_H |
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#ifndef STBI_HEADER_FILE_ONLY |
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#ifndef STBI_NO_HDR |
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#include <math.h> // ldexp |
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#include <string.h> // strcmp |
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#endif |
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#ifndef STBI_NO_STDIO |
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#include <stdio.h> |
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#endif |
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#include <stdlib.h> |
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#include <string.h> |
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#include <malloc.h> |
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//#include <memory.h> |
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#include <assert.h> |
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#include <stdarg.h> |
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#ifndef _MSC_VER |
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#ifdef __cplusplus |
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#define __forceinline inline |
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#else |
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#define __forceinline |
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#endif |
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#endif |
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// implementation: |
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typedef unsigned char uint8; |
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typedef unsigned short uint16; |
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typedef signed short int16; |
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typedef unsigned int uint32; |
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typedef signed int int32; |
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typedef unsigned int uint; |
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// should produce compiler error if size is wrong |
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typedef unsigned char validate_uint32[sizeof(uint32)==4 ? 1 : -1]; |
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#if defined(STBI_NO_STDIO) && !defined(STBI_NO_WRITE) |
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#define STBI_NO_WRITE |
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#endif |
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#define STBI_NOTUSED(v) v=v |
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#ifdef _MSC_VER |
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#define STBI_HAS_LRTOL |
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#endif |
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|
|
#ifdef STBI_HAS_LRTOL |
|
#define stbi_lrot(x,y) _lrotl(x,y) |
|
#else |
|
#define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (32 - (y)))) |
|
#endif |
|
|
|
////////////////////////////////////////////////////////////////////////////// |
|
// |
|
// Generic API that works on all image types |
|
// |
|
|
|
// deprecated functions |
|
|
|
// is it a jpeg? |
|
extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len); |
|
extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
|
|
|
#ifndef STBI_NO_STDIO |
|
extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern int stbi_jpeg_test_file (FILE *f); |
|
extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
|
|
extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); |
|
extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); |
|
#endif |
|
|
|
// is it a png? |
|
extern int stbi_png_test_memory (stbi_uc const *buffer, int len); |
|
extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
|
|
|
#ifndef STBI_NO_STDIO |
|
extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern int stbi_png_info (char const *filename, int *x, int *y, int *comp); |
|
extern int stbi_png_test_file (FILE *f); |
|
extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp); |
|
#endif |
|
|
|
// is it a bmp? |
|
extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len); |
|
|
|
extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_bmp_test_file (FILE *f); |
|
extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
#endif |
|
|
|
// is it a tga? |
|
extern int stbi_tga_test_memory (stbi_uc const *buffer, int len); |
|
|
|
extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_tga_test_file (FILE *f); |
|
extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
#endif |
|
|
|
// is it a psd? |
|
extern int stbi_psd_test_memory (stbi_uc const *buffer, int len); |
|
|
|
extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_psd_test_file (FILE *f); |
|
extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
#endif |
|
|
|
// is it an hdr? |
|
extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len); |
|
|
|
extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_hdr_test_file (FILE *f); |
|
extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
#endif |
|
|
|
// is it a pic? |
|
extern int stbi_pic_test_memory (stbi_uc const *buffer, int len); |
|
|
|
extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_pic_test_file (FILE *f); |
|
extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
#endif |
|
|
|
// is it a gif? |
|
extern int stbi_gif_test_memory (stbi_uc const *buffer, int len); |
|
|
|
extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp); |
|
extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); |
|
extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
|
|
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_gif_test_file (FILE *f); |
|
extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); |
|
extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp); |
|
extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp); |
|
#endif |
|
|
|
|
|
// this is not threadsafe |
|
static const char *failure_reason; |
|
|
|
const char *stbi_failure_reason(void) |
|
{ |
|
return failure_reason; |
|
} |
|
|
|
static int e(const char *str) |
|
{ |
|
failure_reason = str; |
|
return 0; |
|
} |
|
|
|
#ifdef STBI_NO_FAILURE_STRINGS |
|
#define e(x,y) 0 |
|
#elif defined(STBI_FAILURE_USERMSG) |
|
#define e(x,y) e(y) |
|
#else |
|
#define e(x,y) e(x) |
|
#endif |
|
|
|
#define epf(x,y) ((float *) (e(x,y)?NULL:NULL)) |
|
#define epuc(x,y) ((unsigned char *) (e(x,y)?NULL:NULL)) |
|
|
|
void stbi_image_free(void *retval_from_stbi_load) |
|
{ |
|
free(retval_from_stbi_load); |
|
} |
|
|
|
#define MAX_LOADERS 32 |
|
stbi_loader *loaders[MAX_LOADERS]; |
|
static int max_loaders = 0; |
|
|
|
int stbi_register_loader(stbi_loader *loader) |
|
{ |
|
int i; |
|
for (i=0; i < MAX_LOADERS; ++i) { |
|
// already present? |
|
if (loaders[i] == loader) |
|
return 1; |
|
// end of the list? |
|
if (loaders[i] == NULL) { |
|
loaders[i] = loader; |
|
max_loaders = i+1; |
|
return 1; |
|
} |
|
} |
|
// no room for it |
|
return 0; |
|
} |
|
|
|
#ifndef STBI_NO_HDR |
|
static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp); |
|
static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp); |
|
#endif |
|
|
|
#ifndef STBI_NO_STDIO |
|
unsigned char *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
FILE *f = fopen(filename, "rb"); |
|
unsigned char *result; |
|
if (!f) return epuc("can't fopen", "Unable to open file"); |
|
result = stbi_load_from_file(f,x,y,comp,req_comp); |
|
fclose(f); |
|
return result; |
|
} |
|
|
|
unsigned char *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
int i; |
|
if (stbi_jpeg_test_file(f)) return stbi_jpeg_load_from_file(f,x,y,comp,req_comp); |
|
if (stbi_png_test_file(f)) return stbi_png_load_from_file(f,x,y,comp,req_comp); |
|
if (stbi_bmp_test_file(f)) return stbi_bmp_load_from_file(f,x,y,comp,req_comp); |
|
if (stbi_gif_test_file(f)) return stbi_gif_load_from_file(f,x,y,comp,req_comp); |
|
if (stbi_psd_test_file(f)) return stbi_psd_load_from_file(f,x,y,comp,req_comp); |
|
if (stbi_pic_test_file(f)) return stbi_pic_load_from_file(f,x,y,comp,req_comp); |
|
|
|
#ifndef STBI_NO_HDR |
|
if (stbi_hdr_test_file(f)) { |
|
float *hdr = stbi_hdr_load_from_file(f, x,y,comp,req_comp); |
|
return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); |
|
} |
|
#endif |
|
|
|
for (i=0; i < max_loaders; ++i) |
|
if (loaders[i]->test_file(f)) |
|
return loaders[i]->load_from_file(f,x,y,comp,req_comp); |
|
// test tga last because it's a crappy test! |
|
if (stbi_tga_test_file(f)) |
|
return stbi_tga_load_from_file(f,x,y,comp,req_comp); |
|
return epuc("unknown image type", "Image not of any known type, or corrupt"); |
|
} |
|
#endif |
|
|
|
unsigned char *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
int i; |
|
if (stbi_jpeg_test_memory(buffer,len)) return stbi_jpeg_load_from_memory(buffer,len,x,y,comp,req_comp); |
|
if (stbi_png_test_memory(buffer,len)) return stbi_png_load_from_memory(buffer,len,x,y,comp,req_comp); |
|
if (stbi_bmp_test_memory(buffer,len)) return stbi_bmp_load_from_memory(buffer,len,x,y,comp,req_comp); |
|
if (stbi_gif_test_memory(buffer,len)) return stbi_gif_load_from_memory(buffer,len,x,y,comp,req_comp); |
|
if (stbi_psd_test_memory(buffer,len)) return stbi_psd_load_from_memory(buffer,len,x,y,comp,req_comp); |
|
if (stbi_pic_test_memory(buffer,len)) return stbi_pic_load_from_memory(buffer,len,x,y,comp,req_comp); |
|
|
|
#ifndef STBI_NO_HDR |
|
if (stbi_hdr_test_memory(buffer, len)) { |
|
float *hdr = stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); |
|
return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); |
|
} |
|
#endif |
|
|
|
for (i=0; i < max_loaders; ++i) |
|
if (loaders[i]->test_memory(buffer,len)) |
|
return loaders[i]->load_from_memory(buffer,len,x,y,comp,req_comp); |
|
// test tga last because it's a crappy test! |
|
if (stbi_tga_test_memory(buffer,len)) |
|
return stbi_tga_load_from_memory(buffer,len,x,y,comp,req_comp); |
|
return epuc("unknown image type", "Image not of any known type, or corrupt"); |
|
} |
|
|
|
#ifndef STBI_NO_HDR |
|
|
|
#ifndef STBI_NO_STDIO |
|
float *stbi_loadf(char const *filename, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
FILE *f = fopen(filename, "rb"); |
|
float *result; |
|
if (!f) return epf("can't fopen", "Unable to open file"); |
|
result = stbi_loadf_from_file(f,x,y,comp,req_comp); |
|
fclose(f); |
|
return result; |
|
} |
|
|
|
float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
unsigned char *data; |
|
#ifndef STBI_NO_HDR |
|
if (stbi_hdr_test_file(f)) |
|
return stbi_hdr_load_from_file(f,x,y,comp,req_comp); |
|
#endif |
|
data = stbi_load_from_file(f, x, y, comp, req_comp); |
|
if (data) |
|
return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); |
|
return epf("unknown image type", "Image not of any known type, or corrupt"); |
|
} |
|
#endif |
|
|
|
float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
stbi_uc *data; |
|
#ifndef STBI_NO_HDR |
|
if (stbi_hdr_test_memory(buffer, len)) |
|
return stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); |
|
#endif |
|
data = stbi_load_from_memory(buffer, len, x, y, comp, req_comp); |
|
if (data) |
|
return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); |
|
return epf("unknown image type", "Image not of any known type, or corrupt"); |
|
} |
|
#endif |
|
|
|
// these is-hdr-or-not is defined independent of whether STBI_NO_HDR is |
|
// defined, for API simplicity; if STBI_NO_HDR is defined, it always |
|
// reports false! |
|
|
|
int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len) |
|
{ |
|
#ifndef STBI_NO_HDR |
|
return stbi_hdr_test_memory(buffer, len); |
|
#else |
|
return 0; |
|
#endif |
|
} |
|
|
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_is_hdr (char const *filename) |
|
{ |
|
FILE *f = fopen(filename, "rb"); |
|
int result=0; |
|
if (f) { |
|
result = stbi_is_hdr_from_file(f); |
|
fclose(f); |
|
} |
|
return result; |
|
} |
|
|
|
extern int stbi_is_hdr_from_file(FILE *f) |
|
{ |
|
#ifndef STBI_NO_HDR |
|
return stbi_hdr_test_file(f); |
|
#else |
|
return 0; |
|
#endif |
|
} |
|
|
|
#endif |
|
|
|
#ifndef STBI_NO_HDR |
|
static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f; |
|
static float l2h_gamma=2.2f, l2h_scale=1.0f; |
|
|
|
void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; } |
|
void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; } |
|
|
|
void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; } |
|
void stbi_ldr_to_hdr_scale(float scale) { l2h_scale = scale; } |
|
#endif |
|
|
|
|
|
////////////////////////////////////////////////////////////////////////////// |
|
// |
|
// Common code used by all image loaders |
|
// |
|
|
|
enum |
|
{ |
|
SCAN_load=0, |
|
SCAN_type, |
|
SCAN_header, |
|
}; |
|
|
|
typedef struct |
|
{ |
|
uint32 img_x, img_y; |
|
int img_n, img_out_n; |
|
|
|
#ifndef STBI_NO_STDIO |
|
FILE *img_file; |
|
int buflen; |
|
uint8 buffer_start[128]; |
|
int from_file; |
|
#endif |
|
uint8 *img_buffer, *img_buffer_end; |
|
} stbi; |
|
|
|
#ifndef STBI_NO_STDIO |
|
static void start_file(stbi *s, FILE *f) |
|
{ |
|
s->img_file = f; |
|
s->buflen = sizeof(s->buffer_start); |
|
s->img_buffer_end = s->buffer_start + s->buflen; |
|
s->img_buffer = s->img_buffer_end; |
|
s->from_file = 1; |
|
} |
|
#endif |
|
|
|
static void start_mem(stbi *s, uint8 const *buffer, int len) |
|
{ |
|
#ifndef STBI_NO_STDIO |
|
s->img_file = NULL; |
|
s->from_file = 0; |
|
#endif |
|
s->img_buffer = (uint8 *) buffer; |
|
s->img_buffer_end = (uint8 *) buffer+len; |
|
} |
|
|
|
#ifndef STBI_NO_STDIO |
|
static void refill_buffer(stbi *s) |
|
{ |
|
int n = fread(s->buffer_start, 1, s->buflen, s->img_file); |
|
if (n == 0) { |
|
s->from_file = 0; |
|
s->img_buffer = s->img_buffer_end-1; |
|
*s->img_buffer = 0; |
|
} else { |
|
s->img_buffer = s->buffer_start; |
|
s->img_buffer_end = s->buffer_start + n; |
|
} |
|
} |
|
#endif |
|
|
|
__forceinline static int get8(stbi *s) |
|
{ |
|
if (s->img_buffer < s->img_buffer_end) |
|
return *s->img_buffer++; |
|
#ifndef STBI_NO_STDIO |
|
if (s->from_file) { |
|
refill_buffer(s); |
|
return *s->img_buffer++; |
|
} |
|
#endif |
|
return 0; |
|
} |
|
|
|
__forceinline static int at_eof(stbi *s) |
|
{ |
|
#ifndef STBI_NO_STDIO |
|
if (s->img_file) { |
|
if (!feof(s->img_file)) return 0; |
|
// if feof() is true, check if buffer = end |
|
// special case: we've only got the special 0 character at the end |
|
if (s->from_file == 0) return 1; |
|
} |
|
#endif |
|
return s->img_buffer >= s->img_buffer_end; |
|
} |
|
|
|
__forceinline static uint8 get8u(stbi *s) |
|
{ |
|
return (uint8) get8(s); |
|
} |
|
|
|
static void skip(stbi *s, int n) |
|
{ |
|
#ifndef STBI_NO_STDIO |
|
if (s->img_file) { |
|
int blen = s->img_buffer_end - s->img_buffer; |
|
if (blen < n) { |
|
s->img_buffer = s->img_buffer_end; |
|
fseek(s->img_file, n - blen, SEEK_CUR); |
|
return; |
|
} |
|
} |
|
#endif |
|
s->img_buffer += n; |
|
} |
|
|
|
static int getn(stbi *s, stbi_uc *buffer, int n) |
|
{ |
|
#ifndef STBI_NO_STDIO |
|
if (s->img_file) { |
|
int blen = s->img_buffer_end - s->img_buffer; |
|
if (blen < n) { |
|
int res; |
|
memcpy(buffer, s->img_buffer, blen); |
|
res = ((int) fread(buffer + blen, 1, n - blen, s->img_file) == (n-blen)); |
|
s->img_buffer = s->img_buffer_end; |
|
return res; |
|
} |
|
} |
|
#endif |
|
if (s->img_buffer+n <= s->img_buffer_end) { |
|
memcpy(buffer, s->img_buffer, n); |
|
s->img_buffer += n; |
|
return 1; |
|
} else |
|
return 0; |
|
} |
|
|
|
static int get16(stbi *s) |
|
{ |
|
int z = get8(s); |
|
return (z << 8) + get8(s); |
|
} |
|
|
|
static uint32 get32(stbi *s) |
|
{ |
|
uint32 z = get16(s); |
|
return (z << 16) + get16(s); |
|
} |
|
|
|
static int get16le(stbi *s) |
|
{ |
|
int z = get8(s); |
|
return z + (get8(s) << 8); |
|
} |
|
|
|
static uint32 get32le(stbi *s) |
|
{ |
|
uint32 z = get16le(s); |
|
return z + (get16le(s) << 16); |
|
} |
|
|
|
////////////////////////////////////////////////////////////////////////////// |
|
// |
|
// generic converter from built-in img_n to req_comp |
|
// individual types do this automatically as much as possible (e.g. jpeg |
|
// does all cases internally since it needs to colorspace convert anyway, |
|
// and it never has alpha, so very few cases ). png can automatically |
|
// interleave an alpha=255 channel, but falls back to this for other cases |
|
// |
|
// assume data buffer is malloced, so malloc a new one and free that one |
|
// only failure mode is malloc failing |
|
|
|
static uint8 compute_y(int r, int g, int b) |
|
{ |
|
return (uint8) (((r*77) + (g*150) + (29*b)) >> 8); |
|
} |
|
|
|
static unsigned char *convert_format(unsigned char *data, int img_n, int req_comp, uint x, uint y) |
|
{ |
|
int i,j; |
|
unsigned char *good; |
|
|
|
if (req_comp == img_n) return data; |
|
assert(req_comp >= 1 && req_comp <= 4); |
|
|
|
good = (unsigned char *) malloc(req_comp * x * y); |
|
if (good == NULL) { |
|
free(data); |
|
return epuc("outofmem", "Out of memory"); |
|
} |
|
|
|
for (j=0; j < (int) y; ++j) { |
|
unsigned char *src = data + j * x * img_n ; |
|
unsigned char *dest = good + j * x * req_comp; |
|
|
|
#define COMBO(a,b) ((a)*8+(b)) |
|
#define CASE(a,b) case COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b) |
|
// convert source image with img_n components to one with req_comp components; |
|
// avoid switch per pixel, so use switch per scanline and massive macros |
|
switch (COMBO(img_n, req_comp)) { |
|
CASE(1,2) dest[0]=src[0], dest[1]=255; break; |
|
CASE(1,3) dest[0]=dest[1]=dest[2]=src[0]; break; |
|
CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; break; |
|
CASE(2,1) dest[0]=src[0]; break; |
|
CASE(2,3) dest[0]=dest[1]=dest[2]=src[0]; break; |
|
CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; break; |
|
CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; break; |
|
CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]); break; |
|
CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255; break; |
|
CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]); break; |
|
CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3]; break; |
|
CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; break; |
|
default: assert(0); |
|
} |
|
#undef CASE |
|
} |
|
|
|
free(data); |
|
return good; |
|
} |
|
|
|
#ifndef STBI_NO_HDR |
|
static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp) |
|
{ |
|
int i,k,n; |
|
float *output = (float *) malloc(x * y * comp * sizeof(float)); |
|
if (output == NULL) { free(data); return epf("outofmem", "Out of memory"); } |
|
// compute number of non-alpha components |
|
if (comp & 1) n = comp; else n = comp-1; |
|
for (i=0; i < x*y; ++i) { |
|
for (k=0; k < n; ++k) { |
|
output[i*comp + k] = (float) pow(data[i*comp+k]/255.0f, l2h_gamma) * l2h_scale; |
|
} |
|
if (k < comp) output[i*comp + k] = data[i*comp+k]/255.0f; |
|
} |
|
free(data); |
|
return output; |
|
} |
|
|
|
#define float2int(x) ((int) (x)) |
|
static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp) |
|
{ |
|
int i,k,n; |
|
stbi_uc *output = (stbi_uc *) malloc(x * y * comp); |
|
if (output == NULL) { free(data); return epuc("outofmem", "Out of memory"); } |
|
// compute number of non-alpha components |
|
if (comp & 1) n = comp; else n = comp-1; |
|
for (i=0; i < x*y; ++i) { |
|
for (k=0; k < n; ++k) { |
|
float z = (float) pow(data[i*comp+k]*h2l_scale_i, h2l_gamma_i) * 255 + 0.5f; |
|
if (z < 0) z = 0; |
|
if (z > 255) z = 255; |
|
output[i*comp + k] = (uint8) float2int(z); |
|
} |
|
if (k < comp) { |
|
float z = data[i*comp+k] * 255 + 0.5f; |
|
if (z < 0) z = 0; |
|
if (z > 255) z = 255; |
|
output[i*comp + k] = (uint8) float2int(z); |
|
} |
|
} |
|
free(data); |
|
return output; |
|
} |
|
#endif |
|
|
|
////////////////////////////////////////////////////////////////////////////// |
|
// |
|
// "baseline" JPEG/JFIF decoder (not actually fully baseline implementation) |
|
// |
|
// simple implementation |
|
// - channel subsampling of at most 2 in each dimension |
|
// - doesn't support delayed output of y-dimension |
|
// - simple interface (only one output format: 8-bit interleaved RGB) |
|
// - doesn't try to recover corrupt jpegs |
|
// - doesn't allow partial loading, loading multiple at once |
|
// - still fast on x86 (copying globals into locals doesn't help x86) |
|
// - allocates lots of intermediate memory (full size of all components) |
|
// - non-interleaved case requires this anyway |
|
// - allows good upsampling (see next) |
|
// high-quality |
|
// - upsampled channels are bilinearly interpolated, even across blocks |
|
// - quality integer IDCT derived from IJG's 'slow' |
|
// performance |
|
// - fast huffman; reasonable integer IDCT |
|
// - uses a lot of intermediate memory, could cache poorly |
|
// - load http://nothings.org/remote/anemones.jpg 3 times on 2.8Ghz P4 |
|
// stb_jpeg: 1.34 seconds (MSVC6, default release build) |
|
// stb_jpeg: 1.06 seconds (MSVC6, processor = Pentium Pro) |
|
// IJL11.dll: 1.08 seconds (compiled by intel) |
|
// IJG 1998: 0.98 seconds (MSVC6, makefile provided by IJG) |
|
// IJG 1998: 0.95 seconds (MSVC6, makefile + proc=PPro) |
|
|
|
// huffman decoding acceleration |
|
#define FAST_BITS 9 // larger handles more cases; smaller stomps less cache |
|
|
|
typedef struct |
|
{ |
|
uint8 fast[1 << FAST_BITS]; |
|
// weirdly, repacking this into AoS is a 10% speed loss, instead of a win |
|
uint16 code[256]; |
|
uint8 values[256]; |
|
uint8 size[257]; |
|
unsigned int maxcode[18]; |
|
int delta[17]; // old 'firstsymbol' - old 'firstcode' |
|
} huffman; |
|
|
|
typedef struct |
|
{ |
|
#if STBI_SIMD |
|
unsigned short dequant2[4][64]; |
|
#endif |
|
stbi s; |
|
huffman huff_dc[4]; |
|
huffman huff_ac[4]; |
|
uint8 dequant[4][64]; |
|
|
|
// sizes for components, interleaved MCUs |
|
int img_h_max, img_v_max; |
|
int img_mcu_x, img_mcu_y; |
|
int img_mcu_w, img_mcu_h; |
|
|
|
// definition of jpeg image component |
|
struct |
|
{ |
|
int id; |
|
int h,v; |
|
int tq; |
|
int hd,ha; |
|
int dc_pred; |
|
|
|
int x,y,w2,h2; |
|
uint8 *data; |
|
void *raw_data; |
|
uint8 *linebuf; |
|
} img_comp[4]; |
|
|
|
uint32 code_buffer; // jpeg entropy-coded buffer |
|
int code_bits; // number of valid bits |
|
unsigned char marker; // marker seen while filling entropy buffer |
|
int nomore; // flag if we saw a marker so must stop |
|
|
|
int scan_n, order[4]; |
|
int restart_interval, todo; |
|
} jpeg; |
|
|
|
static int build_huffman(huffman *h, int *count) |
|
{ |
|
int i,j,k=0,code; |
|
// build size list for each symbol (from JPEG spec) |
|
for (i=0; i < 16; ++i) |
|
for (j=0; j < count[i]; ++j) |
|
h->size[k++] = (uint8) (i+1); |
|
h->size[k] = 0; |
|
|
|
// compute actual symbols (from jpeg spec) |
|
code = 0; |
|
k = 0; |
|
for(j=1; j <= 16; ++j) { |
|
// compute delta to add to code to compute symbol id |
|
h->delta[j] = k - code; |
|
if (h->size[k] == j) { |
|
while (h->size[k] == j) |
|
h->code[k++] = (uint16) (code++); |
|
if (code-1 >= (1 << j)) return e("bad code lengths","Corrupt JPEG"); |
|
} |
|
// compute largest code + 1 for this size, preshifted as needed later |
|
h->maxcode[j] = code << (16-j); |
|
code <<= 1; |
|
} |
|
h->maxcode[j] = 0xffffffff; |
|
|
|
// build non-spec acceleration table; 255 is flag for not-accelerated |
|
memset(h->fast, 255, 1 << FAST_BITS); |
|
for (i=0; i < k; ++i) { |
|
int s = h->size[i]; |
|
if (s <= FAST_BITS) { |
|
int c = h->code[i] << (FAST_BITS-s); |
|
int m = 1 << (FAST_BITS-s); |
|
for (j=0; j < m; ++j) { |
|
h->fast[c+j] = (uint8) i; |
|
} |
|
} |
|
} |
|
return 1; |
|
} |
|
|
|
static void grow_buffer_unsafe(jpeg *j) |
|
{ |
|
do { |
|
int b = j->nomore ? 0 : get8(&j->s); |
|
if (b == 0xff) { |
|
int c = get8(&j->s); |
|
if (c != 0) { |
|
j->marker = (unsigned char) c; |
|
j->nomore = 1; |
|
return; |
|
} |
|
} |
|
j->code_buffer |= b << (24 - j->code_bits); |
|
j->code_bits += 8; |
|
} while (j->code_bits <= 24); |
|
} |
|
|
|
// (1 << n) - 1 |
|
static uint32 bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535}; |
|
|
|
// decode a jpeg huffman value from the bitstream |
|
__forceinline static int decode(jpeg *j, huffman *h) |
|
{ |
|
unsigned int temp; |
|
int c,k; |
|
|
|
if (j->code_bits < 16) grow_buffer_unsafe(j); |
|
|
|
// look at the top FAST_BITS and determine what symbol ID it is, |
|
// if the code is <= FAST_BITS |
|
c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1); |
|
k = h->fast[c]; |
|
if (k < 255) { |
|
int s = h->size[k]; |
|
if (s > j->code_bits) |
|
return -1; |
|
j->code_buffer <<= s; |
|
j->code_bits -= s; |
|
return h->values[k]; |
|
} |
|
|
|
// naive test is to shift the code_buffer down so k bits are |
|
// valid, then test against maxcode. To speed this up, we've |
|
// preshifted maxcode left so that it has (16-k) 0s at the |
|
// end; in other words, regardless of the number of bits, it |
|
// wants to be compared against something shifted to have 16; |
|
// that way we don't need to shift inside the loop. |
|
temp = j->code_buffer >> 16; |
|
for (k=FAST_BITS+1 ; ; ++k) |
|
if (temp < h->maxcode[k]) |
|
break; |
|
if (k == 17) { |
|
// error! code not found |
|
j->code_bits -= 16; |
|
return -1; |
|
} |
|
|
|
if (k > j->code_bits) |
|
return -1; |
|
|
|
// convert the huffman code to the symbol id |
|
c = ((j->code_buffer >> (32 - k)) & bmask[k]) + h->delta[k]; |
|
assert((((j->code_buffer) >> (32 - h->size[c])) & bmask[h->size[c]]) == h->code[c]); |
|
|
|
// convert the id to a symbol |
|
j->code_bits -= k; |
|
j->code_buffer <<= k; |
|
return h->values[c]; |
|
} |
|
|
|
// combined JPEG 'receive' and JPEG 'extend', since baseline |
|
// always extends everything it receives. |
|
__forceinline static int extend_receive(jpeg *j, int n) |
|
{ |
|
unsigned int m = 1 << (n-1); |
|
unsigned int k; |
|
if (j->code_bits < n) grow_buffer_unsafe(j); |
|
|
|
#if 1 |
|
k = stbi_lrot(j->code_buffer, n); |
|
j->code_buffer = k & ~bmask[n]; |
|
k &= bmask[n]; |
|
j->code_bits -= n; |
|
#else |
|
k = (j->code_buffer >> (32 - n)) & bmask[n]; |
|
j->code_bits -= n; |
|
j->code_buffer <<= n; |
|
#endif |
|
// the following test is probably a random branch that won't |
|
// predict well. I tried to table accelerate it but failed. |
|
// maybe it's compiling as a conditional move? |
|
if (k < m) |
|
return (-1 << n) + k + 1; |
|
else |
|
return k; |
|
} |
|
|
|
// given a value that's at position X in the zigzag stream, |
|
// where does it appear in the 8x8 matrix coded as row-major? |
|
static uint8 dezigzag[64+15] = |
|
{ |
|
0, 1, 8, 16, 9, 2, 3, 10, |
|
17, 24, 32, 25, 18, 11, 4, 5, |
|
12, 19, 26, 33, 40, 48, 41, 34, |
|
27, 20, 13, 6, 7, 14, 21, 28, |
|
35, 42, 49, 56, 57, 50, 43, 36, |
|
29, 22, 15, 23, 30, 37, 44, 51, |
|
58, 59, 52, 45, 38, 31, 39, 46, |
|
53, 60, 61, 54, 47, 55, 62, 63, |
|
// let corrupt input sample past end |
|
63, 63, 63, 63, 63, 63, 63, 63, |
|
63, 63, 63, 63, 63, 63, 63 |
|
}; |
|
|
|
// decode one 64-entry block-- |
|
static int decode_block(jpeg *j, short data[64], huffman *hdc, huffman *hac, int b) |
|
{ |
|
int diff,dc,k; |
|
int t = decode(j, hdc); |
|
if (t < 0) return e("bad huffman code","Corrupt JPEG"); |
|
|
|
// 0 all the ac values now so we can do it 32-bits at a time |
|
memset(data,0,64*sizeof(data[0])); |
|
|
|
diff = t ? extend_receive(j, t) : 0; |
|
dc = j->img_comp[b].dc_pred + diff; |
|
j->img_comp[b].dc_pred = dc; |
|
data[0] = (short) dc; |
|
|
|
// decode AC components, see JPEG spec |
|
k = 1; |
|
do { |
|
int r,s; |
|
int rs = decode(j, hac); |
|
if (rs < 0) return e("bad huffman code","Corrupt JPEG"); |
|
s = rs & 15; |
|
r = rs >> 4; |
|
if (s == 0) { |
|
if (rs != 0xf0) break; // end block |
|
k += 16; |
|
} else { |
|
k += r; |
|
// decode into unzigzag'd location |
|
data[dezigzag[k++]] = (short) extend_receive(j,s); |
|
} |
|
} while (k < 64); |
|
return 1; |
|
} |
|
|
|
// take a -128..127 value and clamp it and convert to 0..255 |
|
__forceinline static uint8 clamp(int x) |
|
{ |
|
// trick to use a single test to catch both cases |
|
if ((unsigned int) x > 255) { |
|
if (x < 0) return 0; |
|
if (x > 255) return 255; |
|
} |
|
return (uint8) x; |
|
} |
|
|
|
#define f2f(x) (int) (((x) * 4096 + 0.5)) |
|
#define fsh(x) ((x) << 12) |
|
|
|
// derived from jidctint -- DCT_ISLOW |
|
#define IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \ |
|
int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \ |
|
p2 = s2; \ |
|
p3 = s6; \ |
|
p1 = (p2+p3) * f2f(0.5411961f); \ |
|
t2 = p1 + p3*f2f(-1.847759065f); \ |
|
t3 = p1 + p2*f2f( 0.765366865f); \ |
|
p2 = s0; \ |
|
p3 = s4; \ |
|
t0 = fsh(p2+p3); \ |
|
t1 = fsh(p2-p3); \ |
|
x0 = t0+t3; \ |
|
x3 = t0-t3; \ |
|
x1 = t1+t2; \ |
|
x2 = t1-t2; \ |
|
t0 = s7; \ |
|
t1 = s5; \ |
|
t2 = s3; \ |
|
t3 = s1; \ |
|
p3 = t0+t2; \ |
|
p4 = t1+t3; \ |
|
p1 = t0+t3; \ |
|
p2 = t1+t2; \ |
|
p5 = (p3+p4)*f2f( 1.175875602f); \ |
|
t0 = t0*f2f( 0.298631336f); \ |
|
t1 = t1*f2f( 2.053119869f); \ |
|
t2 = t2*f2f( 3.072711026f); \ |
|
t3 = t3*f2f( 1.501321110f); \ |
|
p1 = p5 + p1*f2f(-0.899976223f); \ |
|
p2 = p5 + p2*f2f(-2.562915447f); \ |
|
p3 = p3*f2f(-1.961570560f); \ |
|
p4 = p4*f2f(-0.390180644f); \ |
|
t3 += p1+p4; \ |
|
t2 += p2+p3; \ |
|
t1 += p2+p4; \ |
|
t0 += p1+p3; |
|
|
|
#if STBI_SIMD |
|
typedef unsigned short stbi_dequantize_t; |
|
#else |
|
typedef uint8 stbi_dequantize_t; |
|
#endif |
|
|
|
// .344 seconds on 3*anemones.jpg |
|
static void idct_block(uint8 *out, int out_stride, short data[64], stbi_dequantize_t *dequantize) |
|
{ |
|
int i,val[64],*v=val; |
|
stbi_dequantize_t *dq = dequantize; |
|
uint8 *o; |
|
short *d = data; |
|
|
|
// columns |
|
for (i=0; i < 8; ++i,++d,++dq, ++v) { |
|
// if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing |
|
if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0 |
|
&& d[40]==0 && d[48]==0 && d[56]==0) { |
|
// no shortcut 0 seconds |
|
// (1|2|3|4|5|6|7)==0 0 seconds |
|
// all separate -0.047 seconds |
|
// 1 && 2|3 && 4|5 && 6|7: -0.047 seconds |
|
int dcterm = d[0] * dq[0] << 2; |
|
v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm; |
|
} else { |
|
IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24], |
|
d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[56]) |
|
// constants scaled things up by 1<<12; let's bring them back |
|
// down, but keep 2 extra bits of precision |
|
x0 += 512; x1 += 512; x2 += 512; x3 += 512; |
|
v[ 0] = (x0+t3) >> 10; |
|
v[56] = (x0-t3) >> 10; |
|
v[ 8] = (x1+t2) >> 10; |
|
v[48] = (x1-t2) >> 10; |
|
v[16] = (x2+t1) >> 10; |
|
v[40] = (x2-t1) >> 10; |
|
v[24] = (x3+t0) >> 10; |
|
v[32] = (x3-t0) >> 10; |
|
} |
|
} |
|
|
|
for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) { |
|
// no fast case since the first 1D IDCT spread components out |
|
IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7]) |
|
// constants scaled things up by 1<<12, plus we had 1<<2 from first |
|
// loop, plus horizontal and vertical each scale by sqrt(8) so together |
|
// we've got an extra 1<<3, so 1<<17 total we need to remove. |
|
// so we want to round that, which means adding 0.5 * 1<<17, |
|
// aka 65536. Also, we'll end up with -128 to 127 that we want |
|
// to encode as 0..255 by adding 128, so we'll add that before the shift |
|
x0 += 65536 + (128<<17); |
|
x1 += 65536 + (128<<17); |
|
x2 += 65536 + (128<<17); |
|
x3 += 65536 + (128<<17); |
|
// tried computing the shifts into temps, or'ing the temps to see |
|
// if any were out of range, but that was slower |
|
o[0] = clamp((x0+t3) >> 17); |
|
o[7] = clamp((x0-t3) >> 17); |
|
o[1] = clamp((x1+t2) >> 17); |
|
o[6] = clamp((x1-t2) >> 17); |
|
o[2] = clamp((x2+t1) >> 17); |
|
o[5] = clamp((x2-t1) >> 17); |
|
o[3] = clamp((x3+t0) >> 17); |
|
o[4] = clamp((x3-t0) >> 17); |
|
} |
|
} |
|
|
|
#ifdef STBI_SIMD |
|
static stbi_idct_8x8 stbi_idct_installed = idct_block; |
|
|
|
extern void stbi_install_idct(stbi_idct_8x8 func) |
|
{ |
|
stbi_idct_installed = func; |
|
} |
|
#endif |
|
|
|
#define MARKER_none 0xff |
|
// if there's a pending marker from the entropy stream, return that |
|
// otherwise, fetch from the stream and get a marker. if there's no |
|
// marker, return 0xff, which is never a valid marker value |
|
static uint8 get_marker(jpeg *j) |
|
{ |
|
uint8 x; |
|
if (j->marker != MARKER_none) { x = j->marker; j->marker = MARKER_none; return x; } |
|
x = get8u(&j->s); |
|
if (x != 0xff) return MARKER_none; |
|
while (x == 0xff) |
|
x = get8u(&j->s); |
|
return x; |
|
} |
|
|
|
// in each scan, we'll have scan_n components, and the order |
|
// of the components is specified by order[] |
|
#define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7) |
|
|
|
// after a restart interval, reset the entropy decoder and |
|
// the dc prediction |
|
static void reset(jpeg *j) |
|
{ |
|
j->code_bits = 0; |
|
j->code_buffer = 0; |
|
j->nomore = 0; |
|
j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = 0; |
|
j->marker = MARKER_none; |
|
j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff; |
|
// no more than 1<<31 MCUs if no restart_interal? that's plenty safe, |
|
// since we don't even allow 1<<30 pixels |
|
} |
|
|
|
static int parse_entropy_coded_data(jpeg *z) |
|
{ |
|
reset(z); |
|
if (z->scan_n == 1) { |
|
int i,j; |
|
#if STBI_SIMD |
|
__declspec(align(16)) |
|
#endif |
|
short data[64]; |
|
int n = z->order[0]; |
|
// non-interleaved data, we just need to process one block at a time, |
|
// in trivial scanline order |
|
// number of blocks to do just depends on how many actual "pixels" this |
|
// component has, independent of interleaved MCU blocking and such |
|
int w = (z->img_comp[n].x+7) >> 3; |
|
int h = (z->img_comp[n].y+7) >> 3; |
|
for (j=0; j < h; ++j) { |
|
for (i=0; i < w; ++i) { |
|
if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; |
|
#if STBI_SIMD |
|
stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); |
|
#else |
|
idct_block(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); |
|
#endif |
|
// every data block is an MCU, so countdown the restart interval |
|
if (--z->todo <= 0) { |
|
if (z->code_bits < 24) grow_buffer_unsafe(z); |
|
// if it's NOT a restart, then just bail, so we get corrupt data |
|
// rather than no data |
|
if (!RESTART(z->marker)) return 1; |
|
reset(z); |
|
} |
|
} |
|
} |
|
} else { // interleaved! |
|
int i,j,k,x,y; |
|
short data[64]; |
|
for (j=0; j < z->img_mcu_y; ++j) { |
|
for (i=0; i < z->img_mcu_x; ++i) { |
|
// scan an interleaved mcu... process scan_n components in order |
|
for (k=0; k < z->scan_n; ++k) { |
|
int n = z->order[k]; |
|
// scan out an mcu's worth of this component; that's just determined |
|
// by the basic H and V specified for the component |
|
for (y=0; y < z->img_comp[n].v; ++y) { |
|
for (x=0; x < z->img_comp[n].h; ++x) { |
|
int x2 = (i*z->img_comp[n].h + x)*8; |
|
int y2 = (j*z->img_comp[n].v + y)*8; |
|
if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; |
|
#if STBI_SIMD |
|
stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); |
|
#else |
|
idct_block(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); |
|
#endif |
|
} |
|
} |
|
} |
|
// after all interleaved components, that's an interleaved MCU, |
|
// so now count down the restart interval |
|
if (--z->todo <= 0) { |
|
if (z->code_bits < 24) grow_buffer_unsafe(z); |
|
// if it's NOT a restart, then just bail, so we get corrupt data |
|
// rather than no data |
|
if (!RESTART(z->marker)) return 1; |
|
reset(z); |
|
} |
|
} |
|
} |
|
} |
|
return 1; |
|
} |
|
|
|
static int process_marker(jpeg *z, int m) |
|
{ |
|
int L; |
|
switch (m) { |
|
case MARKER_none: // no marker found |
|
return e("expected marker","Corrupt JPEG"); |
|
|
|
case 0xC2: // SOF - progressive |
|
return e("progressive jpeg","JPEG format not supported (progressive)"); |
|
|
|
case 0xDD: // DRI - specify restart interval |
|
if (get16(&z->s) != 4) return e("bad DRI len","Corrupt JPEG"); |
|
z->restart_interval = get16(&z->s); |
|
return 1; |
|
|
|
case 0xDB: // DQT - define quantization table |
|
L = get16(&z->s)-2; |
|
while (L > 0) { |
|
int q = get8(&z->s); |
|
int p = q >> 4; |
|
int t = q & 15,i; |
|
if (p != 0) return e("bad DQT type","Corrupt JPEG"); |
|
if (t > 3) return e("bad DQT table","Corrupt JPEG"); |
|
for (i=0; i < 64; ++i) |
|
z->dequant[t][dezigzag[i]] = get8u(&z->s); |
|
#if STBI_SIMD |
|
for (i=0; i < 64; ++i) |
|
z->dequant2[t][i] = z->dequant[t][i]; |
|
#endif |
|
L -= 65; |
|
} |
|
return L==0; |
|
|
|
case 0xC4: // DHT - define huffman table |
|
L = get16(&z->s)-2; |
|
while (L > 0) { |
|
uint8 *v; |
|
int sizes[16],i,m=0; |
|
int q = get8(&z->s); |
|
int tc = q >> 4; |
|
int th = q & 15; |
|
if (tc > 1 || th > 3) return e("bad DHT header","Corrupt JPEG"); |
|
for (i=0; i < 16; ++i) { |
|
sizes[i] = get8(&z->s); |
|
m += sizes[i]; |
|
} |
|
L -= 17; |
|
if (tc == 0) { |
|
if (!build_huffman(z->huff_dc+th, sizes)) return 0; |
|
v = z->huff_dc[th].values; |
|
} else { |
|
if (!build_huffman(z->huff_ac+th, sizes)) return 0; |
|
v = z->huff_ac[th].values; |
|
} |
|
for (i=0; i < m; ++i) |
|
v[i] = get8u(&z->s); |
|
L -= m; |
|
} |
|
return L==0; |
|
} |
|
// check for comment block or APP blocks |
|
if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) { |
|
skip(&z->s, get16(&z->s)-2); |
|
return 1; |
|
} |
|
return 0; |
|
} |
|
|
|
// after we see SOS |
|
static int process_scan_header(jpeg *z) |
|
{ |
|
int i; |
|
int Ls = get16(&z->s); |
|
z->scan_n = get8(&z->s); |
|
if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int) z->s.img_n) return e("bad SOS component count","Corrupt JPEG"); |
|
if (Ls != 6+2*z->scan_n) return e("bad SOS len","Corrupt JPEG"); |
|
for (i=0; i < z->scan_n; ++i) { |
|
int id = get8(&z->s), which; |
|
int q = get8(&z->s); |
|
for (which = 0; which < z->s.img_n; ++which) |
|
if (z->img_comp[which].id == id) |
|
break; |
|
if (which == z->s.img_n) return 0; |
|
z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return e("bad DC huff","Corrupt JPEG"); |
|
z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return e("bad AC huff","Corrupt JPEG"); |
|
z->order[i] = which; |
|
} |
|
if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); |
|
get8(&z->s); // should be 63, but might be 0 |
|
if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); |
|
|
|
return 1; |
|
} |
|
|
|
static int process_frame_header(jpeg *z, int scan) |
|
{ |
|
stbi *s = &z->s; |
|
int Lf,p,i,q, h_max=1,v_max=1,c; |
|
Lf = get16(s); if (Lf < 11) return e("bad SOF len","Corrupt JPEG"); // JPEG |
|
p = get8(s); if (p != 8) return e("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline |
|
s->img_y = get16(s); if (s->img_y == 0) return e("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG |
|
s->img_x = get16(s); if (s->img_x == 0) return e("0 width","Corrupt JPEG"); // JPEG requires |
|
c = get8(s); |
|
if (c != 3 && c != 1) return e("bad component count","Corrupt JPEG"); // JFIF requires |
|
s->img_n = c; |
|
for (i=0; i < c; ++i) { |
|
z->img_comp[i].data = NULL; |
|
z->img_comp[i].linebuf = NULL; |
|
} |
|
|
|
if (Lf != 8+3*s->img_n) return e("bad SOF len","Corrupt JPEG"); |
|
|
|
for (i=0; i < s->img_n; ++i) { |
|
z->img_comp[i].id = get8(s); |
|
if (z->img_comp[i].id != i+1) // JFIF requires |
|
if (z->img_comp[i].id != i) // some version of jpegtran outputs non-JFIF-compliant files! |
|
return e("bad component ID","Corrupt JPEG"); |
|
q = get8(s); |
|
z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return e("bad H","Corrupt JPEG"); |
|
z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return e("bad V","Corrupt JPEG"); |
|
z->img_comp[i].tq = get8(s); if (z->img_comp[i].tq > 3) return e("bad TQ","Corrupt JPEG"); |
|
} |
|
|
|
if (scan != SCAN_load) return 1; |
|
|
|
if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode"); |
|
|
|
for (i=0; i < s->img_n; ++i) { |
|
if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h; |
|
if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v; |
|
} |
|
|
|
// compute interleaved mcu info |
|
z->img_h_max = h_max; |
|
z->img_v_max = v_max; |
|
z->img_mcu_w = h_max * 8; |
|
z->img_mcu_h = v_max * 8; |
|
z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w; |
|
z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h; |
|
|
|
for (i=0; i < s->img_n; ++i) { |
|
// number of effective pixels (e.g. for non-interleaved MCU) |
|
z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max; |
|
z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max; |
|
// to simplify generation, we'll allocate enough memory to decode |
|
// the bogus oversized data from using interleaved MCUs and their |
|
// big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't |
|
// discard the extra data until colorspace conversion |
|
z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8; |
|
z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8; |
|
z->img_comp[i].raw_data = malloc(z->img_comp[i].w2 * z->img_comp[i].h2+15); |
|
if (z->img_comp[i].raw_data == NULL) { |
|
for(--i; i >= 0; --i) { |
|
free(z->img_comp[i].raw_data); |
|
z->img_comp[i].data = NULL; |
|
} |
|
return e("outofmem", "Out of memory"); |
|
} |
|
// align blocks for installable-idct using mmx/sse |
|
z->img_comp[i].data = (uint8*) (((size_t) z->img_comp[i].raw_data + 15) & ~15); |
|
z->img_comp[i].linebuf = NULL; |
|
} |
|
|
|
return 1; |
|
} |
|
|
|
// use comparisons since in some cases we handle more than one case (e.g. SOF) |
|
#define DNL(x) ((x) == 0xdc) |
|
#define SOI(x) ((x) == 0xd8) |
|
#define EOI(x) ((x) == 0xd9) |
|
#define SOF(x) ((x) == 0xc0 || (x) == 0xc1) |
|
#define SOS(x) ((x) == 0xda) |
|
|
|
static int decode_jpeg_header(jpeg *z, int scan) |
|
{ |
|
int m; |
|
z->marker = MARKER_none; // initialize cached marker to empty |
|
m = get_marker(z); |
|
if (!SOI(m)) return e("no SOI","Corrupt JPEG"); |
|
if (scan == SCAN_type) return 1; |
|
m = get_marker(z); |
|
while (!SOF(m)) { |
|
if (!process_marker(z,m)) return 0; |
|
m = get_marker(z); |
|
while (m == MARKER_none) { |
|
// some files have extra padding after their blocks, so ok, we'll scan |
|
if (at_eof(&z->s)) return e("no SOF", "Corrupt JPEG"); |
|
m = get_marker(z); |
|
} |
|
} |
|
if (!process_frame_header(z, scan)) return 0; |
|
return 1; |
|
} |
|
|
|
static int decode_jpeg_image(jpeg *j) |
|
{ |
|
int m; |
|
j->restart_interval = 0; |
|
if (!decode_jpeg_header(j, SCAN_load)) return 0; |
|
m = get_marker(j); |
|
while (!EOI(m)) { |
|
if (SOS(m)) { |
|
if (!process_scan_header(j)) return 0; |
|
if (!parse_entropy_coded_data(j)) return 0; |
|
if (j->marker == MARKER_none ) { |
|
// handle 0s at the end of image data from IP Kamera 9060 |
|
while (!at_eof(&j->s)) { |
|
int x = get8(&j->s); |
|
if (x == 255) { |
|
j->marker = get8u(&j->s); |
|
break; |
|
} else if (x != 0) { |
|
return 0; |
|
} |
|
} |
|
// if we reach eof without hitting a marker, get_marker() below will fail and we'll eventually return 0 |
|
} |
|
} else { |
|
if (!process_marker(j, m)) return 0; |
|
} |
|
m = get_marker(j); |
|
} |
|
return 1; |
|
} |
|
|
|
// static jfif-centered resampling (across block boundaries) |
|
|
|
typedef uint8 *(*resample_row_func)(uint8 *out, uint8 *in0, uint8 *in1, |
|
int w, int hs); |
|
|
|
#define div4(x) ((uint8) ((x) >> 2)) |
|
|
|
static uint8 *resample_row_1(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
|
{ |
|
STBI_NOTUSED(out); |
|
STBI_NOTUSED(in_far); |
|
STBI_NOTUSED(w); |
|
STBI_NOTUSED(hs); |
|
return in_near; |
|
} |
|
|
|
static uint8* resample_row_v_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
|
{ |
|
// need to generate two samples vertically for every one in input |
|
int i; |
|
STBI_NOTUSED(hs); |
|
for (i=0; i < w; ++i) |
|
out[i] = div4(3*in_near[i] + in_far[i] + 2); |
|
return out; |
|
} |
|
|
|
static uint8* resample_row_h_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
|
{ |
|
// need to generate two samples horizontally for every one in input |
|
int i; |
|
uint8 *input = in_near; |
|
|
|
if (w == 1) { |
|
// if only one sample, can't do any interpolation |
|
out[0] = out[1] = input[0]; |
|
return out; |
|
} |
|
|
|
out[0] = input[0]; |
|
out[1] = div4(input[0]*3 + input[1] + 2); |
|
for (i=1; i < w-1; ++i) { |
|
int n = 3*input[i]+2; |
|
out[i*2+0] = div4(n+input[i-1]); |
|
out[i*2+1] = div4(n+input[i+1]); |
|
} |
|
out[i*2+0] = div4(input[w-2]*3 + input[w-1] + 2); |
|
out[i*2+1] = input[w-1]; |
|
|
|
STBI_NOTUSED(in_far); |
|
STBI_NOTUSED(hs); |
|
|
|
return out; |
|
} |
|
|
|
#define div16(x) ((uint8) ((x) >> 4)) |
|
|
|
static uint8 *resample_row_hv_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
|
{ |
|
// need to generate 2x2 samples for every one in input |
|
int i,t0,t1; |
|
if (w == 1) { |
|
out[0] = out[1] = div4(3*in_near[0] + in_far[0] + 2); |
|
return out; |
|
} |
|
|
|
t1 = 3*in_near[0] + in_far[0]; |
|
out[0] = div4(t1+2); |
|
for (i=1; i < w; ++i) { |
|
t0 = t1; |
|
t1 = 3*in_near[i]+in_far[i]; |
|
out[i*2-1] = div16(3*t0 + t1 + 8); |
|
out[i*2 ] = div16(3*t1 + t0 + 8); |
|
} |
|
out[w*2-1] = div4(t1+2); |
|
|
|
STBI_NOTUSED(hs); |
|
|
|
return out; |
|
} |
|
|
|
static uint8 *resample_row_generic(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
|
{ |
|
// resample with nearest-neighbor |
|
int i,j; |
|
in_far = in_far; |
|
for (i=0; i < w; ++i) |
|
for (j=0; j < hs; ++j) |
|
out[i*hs+j] = in_near[i]; |
|
return out; |
|
} |
|
|
|
#define float2fixed(x) ((int) ((x) * 65536 + 0.5)) |
|
|
|
// 0.38 seconds on 3*anemones.jpg (0.25 with processor = Pro) |
|
// VC6 without processor=Pro is generating multiple LEAs per multiply! |
|
static void YCbCr_to_RGB_row(uint8 *out, const uint8 *y, const uint8 *pcb, const uint8 *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] = (uint8)r; |
|
out[1] = (uint8)g; |
|
out[2] = (uint8)b; |
|
out[3] = 255; |
|
out += step; |
|
} |
|
} |
|
|
|
#if STBI_SIMD |
|
static stbi_YCbCr_to_RGB_run stbi_YCbCr_installed = YCbCr_to_RGB_row; |
|
|
|
void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func) |
|
{ |
|
stbi_YCbCr_installed = func; |
|
} |
|
#endif |
|
|
|
|
|
// clean up the temporary component buffers |
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static void cleanup_jpeg(jpeg *j) |
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{ |
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int i; |
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for (i=0; i < j->s.img_n; ++i) { |
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if (j->img_comp[i].data) { |
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free(j->img_comp[i].raw_data); |
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j->img_comp[i].data = NULL; |
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} |
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if (j->img_comp[i].linebuf) { |
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free(j->img_comp[i].linebuf); |
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j->img_comp[i].linebuf = NULL; |
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} |
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} |
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} |
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|
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typedef struct |
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{ |
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resample_row_func resample; |
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uint8 *line0,*line1; |
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int hs,vs; // expansion factor in each axis |
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int w_lores; // horizontal pixels pre-expansion |
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int ystep; // how far through vertical expansion we are |
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int ypos; // which pre-expansion row we're on |
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} stbi_resample; |
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|
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static uint8 *load_jpeg_image(jpeg *z, int *out_x, int *out_y, int *comp, int req_comp) |
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{ |
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int n, decode_n; |
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// validate req_comp |
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if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error"); |
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z->s.img_n = 0; |
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|
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// load a jpeg image from whichever source |
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if (!decode_jpeg_image(z)) { cleanup_jpeg(z); return NULL; } |
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|
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// determine actual number of components to generate |
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n = req_comp ? req_comp : z->s.img_n; |
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|
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if (z->s.img_n == 3 && n < 3) |
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decode_n = 1; |
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else |
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decode_n = z->s.img_n; |
|
|
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// resample and color-convert |
|
{ |
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int k; |
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uint i,j; |
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uint8 *output; |
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uint8 *coutput[4]; |
|
|
|
stbi_resample res_comp[4]; |
|
|
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for (k=0; k < decode_n; ++k) { |
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stbi_resample *r = &res_comp[k]; |
|
|
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// allocate line buffer big enough for upsampling off the edges |
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// with upsample factor of 4 |
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z->img_comp[k].linebuf = (uint8 *) malloc(z->s.img_x + 3); |
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if (!z->img_comp[k].linebuf) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } |
|
|
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r->hs = z->img_h_max / z->img_comp[k].h; |
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r->vs = z->img_v_max / z->img_comp[k].v; |
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r->ystep = r->vs >> 1; |
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r->w_lores = (z->s.img_x + r->hs-1) / r->hs; |
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r->ypos = 0; |
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r->line0 = r->line1 = z->img_comp[k].data; |
|
|
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if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1; |
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else if (r->hs == 1 && r->vs == 2) r->resample = resample_row_v_2; |
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else if (r->hs == 2 && r->vs == 1) r->resample = resample_row_h_2; |
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else if (r->hs == 2 && r->vs == 2) r->resample = resample_row_hv_2; |
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else r->resample = resample_row_generic; |
|
} |
|
|
|
// can't error after this so, this is safe |
|
output = (uint8 *) malloc(n * z->s.img_x * z->s.img_y + 1); |
|
if (!output) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } |
|
|
|
// now go ahead and resample |
|
for (j=0; j < z->s.img_y; ++j) { |
|
uint8 *out = output + n * z->s.img_x * j; |
|
for (k=0; k < decode_n; ++k) { |
|
stbi_resample *r = &res_comp[k]; |
|
int y_bot = r->ystep >= (r->vs >> 1); |
|
coutput[k] = r->resample(z->img_comp[k].linebuf, |
|
y_bot ? r->line1 : r->line0, |
|
y_bot ? r->line0 : r->line1, |
|
r->w_lores, r->hs); |
|
if (++r->ystep >= r->vs) { |
|
r->ystep = 0; |
|
r->line0 = r->line1; |
|
if (++r->ypos < z->img_comp[k].y) |
|
r->line1 += z->img_comp[k].w2; |
|
} |
|
} |
|
if (n >= 3) { |
|
uint8 *y = coutput[0]; |
|
if (z->s.img_n == 3) { |
|
#if STBI_SIMD |
|
stbi_YCbCr_installed(out, y, coutput[1], coutput[2], z->s.img_x, n); |
|
#else |
|
YCbCr_to_RGB_row(out, y, coutput[1], coutput[2], z->s.img_x, n); |
|
#endif |
|
} else |
|
for (i=0; i < z->s.img_x; ++i) { |
|
out[0] = out[1] = out[2] = y[i]; |
|
out[3] = 255; // not used if n==3 |
|
out += n; |
|
} |
|
} else { |
|
uint8 *y = coutput[0]; |
|
if (n == 1) |
|
for (i=0; i < z->s.img_x; ++i) out[i] = y[i]; |
|
else |
|
for (i=0; i < z->s.img_x; ++i) *out++ = y[i], *out++ = 255; |
|
} |
|
} |
|
cleanup_jpeg(z); |
|
*out_x = z->s.img_x; |
|
*out_y = z->s.img_y; |
|
if (comp) *comp = z->s.img_n; // report original components, not output |
|
return output; |
|
} |
|
} |
|
|
|
#ifndef STBI_NO_STDIO |
|
unsigned char *stbi_jpeg_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
jpeg j; |
|
start_file(&j.s, f); |
|
return load_jpeg_image(&j, x,y,comp,req_comp); |
|
} |
|
|
|
unsigned char *stbi_jpeg_load(char const *filename, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
unsigned char *data; |
|
FILE *f = fopen(filename, "rb"); |
|
if (!f) return NULL; |
|
data = stbi_jpeg_load_from_file(f,x,y,comp,req_comp); |
|
fclose(f); |
|
return data; |
|
} |
|
#endif |
|
|
|
unsigned char *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
|
{ |
|
jpeg j; |
|
start_mem(&j.s, buffer,len); |
|
return load_jpeg_image(&j, x,y,comp,req_comp); |
|
} |
|
|
|
static int stbi_jpeg_info_raw(jpeg *j, int *x, int *y, int *comp) |
|
{ |
|
if (!decode_jpeg_header(j, SCAN_header)) |
|
return 0; |
|
if (x) *x = j->s.img_x; |
|
if (y) *y = j->s.img_y; |
|
if (comp) *comp = j->s.img_n; |
|
return 1; |
|
} |
|
|
|
#ifndef STBI_NO_STDIO |
|
int stbi_jpeg_test_file(FILE *f) |
|
{ |
|
int n,r; |
|
jpeg j; |
|
n = ftell(f); |
|
start_file(&j.s, f); |
|
r = decode_jpeg_header(&j, SCAN_type); |
|
fseek(f,n,SEEK_SET); |
|
return r; |
|
} |
|
|
|
int stbi_jpeg_info_from_file(FILE *f, int *x, int *y, int *comp) |
|
{ |
|
jpeg j; |
|
long n = ftell(f); |
|
int res; |
|
start_file(&j.s, f); |
|
res = stbi_jpeg_info_raw(&j, x, y, comp); |
|
fseek(f, n, SEEK_SET); |
|
return res; |
|
} |
|
|
|
int stbi_jpeg_info(char const *filename, int *x, int *y, int *comp) |
|
{ |
|
FILE *f = fopen(filename, "rb"); |
|
int result; |
|
if (!f) return e("can't fopen", "Unable to open file"); |
|
result = stbi_jpeg_info_from_file(f, x, y, comp); |
|
fclose(f); |
|
return result; |
|
} |
|
#endif |
|
|
|
int stbi_jpeg_test_memory(stbi_uc const *buffer, int len) |
|
{ |
|
jpeg j; |
|
start_mem(&j.s, buffer,len); |
|
return decode_jpeg_header(&j, SCAN_type); |
|
} |
|
|
|
int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) |
|
{ |
|
jpeg j; |
|
start_mem(&j.s, buffer, len); |
|
return stbi_jpeg_info_raw(&j, x, y, comp); |
|
} |
|
|
|
#ifndef STBI_NO_STDIO |
|
extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); |
|
extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); |
|
#endif |
|
extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
|
|
|
// public domain zlib decode v0.2 Sean Barrett 2006-11-18 |
|
// simple implementation |
|
// - all input must be provided in an upfront buffer |
|
// - all output is written to a single output buffer (can malloc/realloc) |
|
// performance |
|
// - fast huffman |
|
|
|
// fast-way is faster to check than jpeg huffman, but slow way is slower |
|
#define ZFAST_BITS 9 // accelerate all cases in default tables |
|
#define ZFAST_MASK ((1 << ZFAST_BITS) - 1) |
|
|
|
// zlib-style huffman encoding |
|
// (jpegs packs from left, zlib from right, so can't share code) |
|
typedef struct |
|
{ |
|
uint16 fast[1 << ZFAST_BITS]; |
|
uint16 firstcode[16]; |
|
int maxcode[17]; |
|
uint16 firstsymbol[16]; |
|
uint8 size[288]; |
|
uint16 value[288]; |
|
} zhuffman; |
|
|
|
__forceinline static int bitreverse16(int n) |
|
{ |
|
n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1); |
|
n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2); |
|
n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4); |
|
n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8); |
|
return n; |
|
} |
|
|
|
__forceinline static int bit_reverse(int v, int bits) |
|
{ |
|
assert(bits <= 16); |
|
// to bit reverse n bits, reverse 16 and shift |
|
// e.g. 11 bits, bit reverse and shift away 5 |
|
return bitreverse16(v) >> (16-bits); |
|
} |
|
|
|
static int zbuild_huffman(zhuffman *z, uint8 *sizelist, int num) |
|
{ |
|
int i,k=0; |
|
int code, next_code[16], sizes[17]; |
|
|
|
// DEFLATE spec for generating codes |
|
memset(sizes, 0, sizeof(sizes)); |
|
memset(z->fast, 255, sizeof(z->fast)); |
|