Index: third_party/libjpeg_turbo/transupp.h |
=================================================================== |
--- third_party/libjpeg_turbo/transupp.h (revision 0) |
+++ third_party/libjpeg_turbo/transupp.h (revision 0) |
@@ -0,0 +1,135 @@ |
+/* |
+ * transupp.h |
+ * |
+ * Copyright (C) 1997, Thomas G. Lane. |
+ * This file is part of the Independent JPEG Group's software. |
+ * For conditions of distribution and use, see the accompanying README file. |
+ * |
+ * This file contains declarations for image transformation routines and |
+ * other utility code used by the jpegtran sample application. These are |
+ * NOT part of the core JPEG library. But we keep these routines separate |
+ * from jpegtran.c to ease the task of maintaining jpegtran-like programs |
+ * that have other user interfaces. |
+ * |
+ * NOTE: all the routines declared here have very specific requirements |
+ * about when they are to be executed during the reading and writing of the |
+ * source and destination files. See the comments in transupp.c, or see |
+ * jpegtran.c for an example of correct usage. |
+ */ |
+ |
+/* If you happen not to want the image transform support, disable it here */ |
+#ifndef TRANSFORMS_SUPPORTED |
+#define TRANSFORMS_SUPPORTED 1 /* 0 disables transform code */ |
+#endif |
+ |
+/* Short forms of external names for systems with brain-damaged linkers. */ |
+ |
+#ifdef NEED_SHORT_EXTERNAL_NAMES |
+#define jtransform_request_workspace jTrRequest |
+#define jtransform_adjust_parameters jTrAdjust |
+#define jtransform_execute_transformation jTrExec |
+#define jcopy_markers_setup jCMrkSetup |
+#define jcopy_markers_execute jCMrkExec |
+#endif /* NEED_SHORT_EXTERNAL_NAMES */ |
+ |
+ |
+/* |
+ * Codes for supported types of image transformations. |
+ */ |
+ |
+typedef enum { |
+ JXFORM_NONE, /* no transformation */ |
+ JXFORM_FLIP_H, /* horizontal flip */ |
+ JXFORM_FLIP_V, /* vertical flip */ |
+ JXFORM_TRANSPOSE, /* transpose across UL-to-LR axis */ |
+ JXFORM_TRANSVERSE, /* transpose across UR-to-LL axis */ |
+ JXFORM_ROT_90, /* 90-degree clockwise rotation */ |
+ JXFORM_ROT_180, /* 180-degree rotation */ |
+ JXFORM_ROT_270 /* 270-degree clockwise (or 90 ccw) */ |
+} JXFORM_CODE; |
+ |
+/* |
+ * Although rotating and flipping data expressed as DCT coefficients is not |
+ * hard, there is an asymmetry in the JPEG format specification for images |
+ * whose dimensions aren't multiples of the iMCU size. The right and bottom |
+ * image edges are padded out to the next iMCU boundary with junk data; but |
+ * no padding is possible at the top and left edges. If we were to flip |
+ * the whole image including the pad data, then pad garbage would become |
+ * visible at the top and/or left, and real pixels would disappear into the |
+ * pad margins --- perhaps permanently, since encoders & decoders may not |
+ * bother to preserve DCT blocks that appear to be completely outside the |
+ * nominal image area. So, we have to exclude any partial iMCUs from the |
+ * basic transformation. |
+ * |
+ * Transpose is the only transformation that can handle partial iMCUs at the |
+ * right and bottom edges completely cleanly. flip_h can flip partial iMCUs |
+ * at the bottom, but leaves any partial iMCUs at the right edge untouched. |
+ * Similarly flip_v leaves any partial iMCUs at the bottom edge untouched. |
+ * The other transforms are defined as combinations of these basic transforms |
+ * and process edge blocks in a way that preserves the equivalence. |
+ * |
+ * The "trim" option causes untransformable partial iMCUs to be dropped; |
+ * this is not strictly lossless, but it usually gives the best-looking |
+ * result for odd-size images. Note that when this option is active, |
+ * the expected mathematical equivalences between the transforms may not hold. |
+ * (For example, -rot 270 -trim trims only the bottom edge, but -rot 90 -trim |
+ * followed by -rot 180 -trim trims both edges.) |
+ * |
+ * We also offer a "force to grayscale" option, which simply discards the |
+ * chrominance channels of a YCbCr image. This is lossless in the sense that |
+ * the luminance channel is preserved exactly. It's not the same kind of |
+ * thing as the rotate/flip transformations, but it's convenient to handle it |
+ * as part of this package, mainly because the transformation routines have to |
+ * be aware of the option to know how many components to work on. |
+ */ |
+ |
+typedef struct { |
+ /* Options: set by caller */ |
+ JXFORM_CODE transform; /* image transform operator */ |
+ boolean trim; /* if TRUE, trim partial MCUs as needed */ |
+ boolean force_grayscale; /* if TRUE, convert color image to grayscale */ |
+ |
+ /* Internal workspace: caller should not touch these */ |
+ int num_components; /* # of components in workspace */ |
+ jvirt_barray_ptr * workspace_coef_arrays; /* workspace for transformations */ |
+} jpeg_transform_info; |
+ |
+ |
+#if TRANSFORMS_SUPPORTED |
+ |
+/* Request any required workspace */ |
+EXTERN(void) jtransform_request_workspace |
+ JPP((j_decompress_ptr srcinfo, jpeg_transform_info *info)); |
+/* Adjust output image parameters */ |
+EXTERN(jvirt_barray_ptr *) jtransform_adjust_parameters |
+ JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo, |
+ jvirt_barray_ptr *src_coef_arrays, |
+ jpeg_transform_info *info)); |
+/* Execute the actual transformation, if any */ |
+EXTERN(void) jtransform_execute_transformation |
+ JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo, |
+ jvirt_barray_ptr *src_coef_arrays, |
+ jpeg_transform_info *info)); |
+ |
+#endif /* TRANSFORMS_SUPPORTED */ |
+ |
+ |
+/* |
+ * Support for copying optional markers from source to destination file. |
+ */ |
+ |
+typedef enum { |
+ JCOPYOPT_NONE, /* copy no optional markers */ |
+ JCOPYOPT_COMMENTS, /* copy only comment (COM) markers */ |
+ JCOPYOPT_ALL /* copy all optional markers */ |
+} JCOPY_OPTION; |
+ |
+#define JCOPYOPT_DEFAULT JCOPYOPT_COMMENTS /* recommended default */ |
+ |
+/* Setup decompression object to save desired markers in memory */ |
+EXTERN(void) jcopy_markers_setup |
+ JPP((j_decompress_ptr srcinfo, JCOPY_OPTION option)); |
+/* Copy markers saved in the given source object to the destination object */ |
+EXTERN(void) jcopy_markers_execute |
+ JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo, |
+ JCOPY_OPTION option)); |