ENH: Final -hopefully- change to jpeg lib. In order to match ITK structure, and be...

[gdcm.git] / src / gdcmjpeg / jchuff.h

diff --git a/src/gdcmjpeg/jchuff.h b/src/gdcmjpeg/jchuff.h
new file mode 100644 (file)
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+++ b/src/gdcmjpeg/jchuff.h
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+/*
+ * jchuff.h
+ *
+ * Copyright (C) 1991-1997, 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 Huffman entropy encoding routines
+ * that are shared between the sequential encoder (jchuff.c) and the
+ * progressive encoder (jcphuff.c).  No other modules need to see these.
+ */
+
+/* The legal range of a DCT coefficient is
+ *  -1024 .. +1023  for 8-bit data;
+ * -16384 .. +16383 for 12-bit data.
+ * Hence the magnitude should always fit in 10 or 14 bits respectively.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define MAX_COEF_BITS 10
+#else
+#define MAX_COEF_BITS 14
+#endif
+
+/* The legal range of a spatial difference is
+ * -32767 .. +32768.
+ * Hence the magnitude should always fit in 16 bits.
+ */
+
+#define MAX_DIFF_BITS 16
+
+/* Derived data constructed for each Huffman table */
+
+typedef struct {
+  unsigned int ehufco[256];  /* code for each symbol */
+  char ehufsi[256];    /* length of code for each symbol */
+  /* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */
+} c_derived_tbl;
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jpeg_make_c_derived_tbl  jMkCDerived
+#define jpeg_gen_optimal_table  jGenOptTbl
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+/* Expand a Huffman table definition into the derived format */
+EXTERN(void) jpeg_make_c_derived_tbl
+  JPP((j_compress_ptr cinfo, boolean isDC, int tblno,
+       c_derived_tbl ** pdtbl));
+
+/* Generate an optimal table definition given the specified counts */
+EXTERN(void) jpeg_gen_optimal_table
+  JPP((j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[]));