Updates libjpeg-turbo to 1.1.90 (r677)

third_party/libjpeg_turbo/transupp.h

 /*
  * transupp.h
  *
- * Copyright (C) 1997, Thomas G. Lane.
+ * Copyright (C) 1997-2009, Thomas G. Lane, Guido Vollbeding.
  * 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 lossless-crop option, which discards data outside a given
+ * image region but losslessly preserves what is inside.  Like the rotate and
+ * flip transforms, lossless crop is restricted by the JPEG format: the upper
+ * left corner of the selected region must fall on an iMCU boundary.  If this
+ * does not hold for the given crop parameters, we silently move the upper left
+ * corner up and/or left to make it so, simultaneously increasing the region
+ * dimensions to keep the lower right crop corner unchanged.  (Thus, the
+ * output image covers at least the requested region, but may cover more.)
+ *
+ * We also provide a lossless-resize option, which is kind of a lossless-crop
+ * operation in the DCT coefficient block domain - it discards higher-order
+ * coefficients and losslessly preserves lower-order coefficients of a
+ * sub-block.
+ *
+ * Rotate/flip transform, resize, and crop can be requested together in a
+ * single invocation.  The crop is applied last --- that is, the crop region
+ * is specified in terms of the destination image after transform/resize.
+ *
  * 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.
  */
 
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jtransform_parse_crop_spec      jTrParCrop
+#define jtransform_request_workspace    jTrRequest
+#define jtransform_adjust_parameters    jTrAdjust
+#define jtransform_execute_transform    jTrExec
+#define jtransform_perfect_transform    jTrPerfect
+#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;
+
+/*
+ * Codes for crop parameters, which can individually be unspecified,
+ * positive, or negative.  (Negative width or height makes no sense, though.)
+ */
+
+typedef enum {
+        JCROP_UNSET,
+        JCROP_POS,
+        JCROP_NEG
+} JCROP_CODE;
+
+/*
+ * Transform parameters struct.
+ * NB: application must not change any elements of this struct after
+ * calling jtransform_request_workspace.
+ */
+
 typedef struct {
   /* Options: set by caller */
   JXFORM_CODE transform;        /* image transform operator */
+  boolean perfect;              /* if TRUE, fail if partial MCUs are requested */
   boolean trim;                 /* if TRUE, trim partial MCUs as needed */
   boolean force_grayscale;      /* if TRUE, convert color image to grayscale */
+  boolean crop;                 /* if TRUE, crop source image */
+  boolean slow_hflip;  /* For best performance, the JXFORM_FLIP_H transform
+                          normally modifies the source coefficients in place.
+                          Setting this to TRUE will instead use a slower,
+                          double-buffered algorithm, which leaves the source
+                          coefficients in tact (necessary if other transformed
+                          images must be generated from the same set of
+                          coefficients. */
+
+  /* Crop parameters: application need not set these unless crop is TRUE.
+   * These can be filled in by jtransform_parse_crop_spec().
+   */
+  JDIMENSION crop_width;        /* Width of selected region */
+  JCROP_CODE crop_width_set;
+  JDIMENSION crop_height;       /* Height of selected region */
+  JCROP_CODE crop_height_set;
+  JDIMENSION crop_xoffset;      /* X offset of selected region */
+  JCROP_CODE crop_xoffset_set;  /* (negative measures from right edge) */
+  JDIMENSION crop_yoffset;      /* Y offset of selected region */
+  JCROP_CODE crop_yoffset_set;  /* (negative measures from bottom edge) */
 
   /* Internal workspace: caller should not touch these */
   int num_components;           /* # of components in workspace */
   jvirt_barray_ptr * workspace_coef_arrays; /* workspace for transformations */
+  JDIMENSION output_width;      /* cropped destination dimensions */
+  JDIMENSION output_height;
+  JDIMENSION x_crop_offset;     /* destination crop offsets measured in iMCUs */
+  JDIMENSION y_crop_offset;
+  int iMCU_sample_width;        /* destination iMCU size */
+  int iMCU_sample_height;
 } jpeg_transform_info;
 
 
 #if TRANSFORMS_SUPPORTED
 
+/* Parse a crop specification (written in X11 geometry style) */
+EXTERN(boolean) jtransform_parse_crop_spec
+        JPP((jpeg_transform_info *info, const char *spec));
 /* Request any required workspace */
-EXTERN(void) jtransform_request_workspace
+EXTERN(boolean) 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
+EXTERN(void) jtransform_execute_transform
         JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
              jvirt_barray_ptr *src_coef_arrays,
              jpeg_transform_info *info));
+/* Determine whether lossless transformation is perfectly
+ * possible for a specified image and transformation.
+ */
+EXTERN(boolean) jtransform_perfect_transform
+        JPP((JDIMENSION image_width, JDIMENSION image_height,
+             int MCU_width, int MCU_height,
+             JXFORM_CODE transform));
+
+/* jtransform_execute_transform used to be called
+ * jtransform_execute_transformation, but some compilers complain about
+ * routine names that long.  This macro is here to avoid breaking any
+ * old source code that uses the original name...
+ */
+#define jtransform_execute_transformation       jtransform_execute_transform
 
 #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));