diff --git a/libjpegtwrp/ckconfig.c b/libjpegtwrp/ckconfig.c
new file mode 100644
index 0000000..34baf79
--- /dev/null
+++ b/libjpegtwrp/ckconfig.c
@@ -0,0 +1,402 @@
+/*
+ * ckconfig.c
+ *
+ * Copyright (C) 1991-1994, 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 program is intended to help you determine how to configure the JPEG
+ * software for installation on a particular system.  The idea is to try to
+ * compile and execute this program.  If your compiler fails to compile the
+ * program, make changes as indicated in the comments below.  Once you can
+ * compile the program, run it, and it will produce a "jconfig.h" file for
+ * your system.
+ *
+ * As a general rule, each time you try to compile this program,
+ * pay attention only to the *first* error message you get from the compiler.
+ * Many C compilers will issue lots of spurious error messages once they
+ * have gotten confused.  Go to the line indicated in the first error message,
+ * and read the comments preceding that line to see what to change.
+ *
+ * Almost all of the edits you may need to make to this program consist of
+ * changing a line that reads "#define SOME_SYMBOL" to "#undef SOME_SYMBOL",
+ * or vice versa.  This is called defining or undefining that symbol.
+ */
+
+
+/* First we must see if your system has the include files we need.
+ * We start out with the assumption that your system has all the ANSI-standard
+ * include files.  If you get any error trying to include one of these files,
+ * undefine the corresponding HAVE_xxx symbol.
+ */
+
+#define HAVE_STDDEF_H		/* replace 'define' by 'undef' if error here */
+#ifdef HAVE_STDDEF_H		/* next line will be skipped if you undef... */
+#include <stddef.h>
+#endif
+
+#define HAVE_STDLIB_H		/* same thing for stdlib.h */
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
+#include <stdio.h>		/* If you ain't got this, you ain't got C. */
+
+/* We have to see if your string functions are defined by
+ * strings.h (old BSD convention) or string.h (everybody else).
+ * We try the non-BSD convention first; define NEED_BSD_STRINGS
+ * if the compiler says it can't find string.h.
+ */
+
+#undef NEED_BSD_STRINGS
+
+#ifdef NEED_BSD_STRINGS
+#include <strings.h>
+#else
+#include <string.h>
+#endif
+
+/* On some systems (especially older Unix machines), type size_t is
+ * defined only in the include file <sys/types.h>.  If you get a failure
+ * on the size_t test below, try defining NEED_SYS_TYPES_H.
+ */
+
+#undef NEED_SYS_TYPES_H		/* start by assuming we don't need it */
+#ifdef NEED_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+
+/* Usually type size_t is defined in one of the include files we've included
+ * above.  If not, you'll get an error on the "typedef size_t my_size_t;" line.
+ * In that case, first try defining NEED_SYS_TYPES_H just above.
+ * If that doesn't work, you'll have to search through your system library
+ * to figure out which include file defines "size_t".  Look for a line that
+ * says "typedef something-or-other size_t;".  Then, change the line below
+ * that says "#include <someincludefile.h>" to instead include the file
+ * you found size_t in, and define NEED_SPECIAL_INCLUDE.  If you can't find
+ * type size_t anywhere, try replacing "#include <someincludefile.h>" with
+ * "typedef unsigned int size_t;".
+ */
+
+#undef NEED_SPECIAL_INCLUDE	/* assume we DON'T need it, for starters */
+
+#ifdef NEED_SPECIAL_INCLUDE
+#include <someincludefile.h>
+#endif
+
+typedef size_t my_size_t;	/* The payoff: do we have size_t now? */
+
+
+/* The next question is whether your compiler supports ANSI-style function
+ * prototypes.  You need to know this in order to choose between using
+ * makefile.ansi and using makefile.unix.
+ * The #define line below is set to assume you have ANSI function prototypes.
+ * If you get an error in this group of lines, undefine HAVE_PROTOTYPES.
+ */
+
+#define HAVE_PROTOTYPES
+
+#ifdef HAVE_PROTOTYPES
+int testfunction (int arg1, int * arg2); /* check prototypes */
+
+struct methods_struct {		/* check method-pointer declarations */
+  int (*error_exit) (char *msgtext);
+  int (*trace_message) (char *msgtext);
+  int (*another_method) (void);
+};
+
+int testfunction (int arg1, int * arg2) /* check definitions */
+{
+  return arg2[arg1];
+}
+
+int test2function (void)	/* check void arg list */
+{
+  return 0;
+}
+#endif
+
+
+/* Now we want to find out if your compiler knows what "unsigned char" means.
+ * If you get an error on the "unsigned char un_char;" line,
+ * then undefine HAVE_UNSIGNED_CHAR.
+ */
+
+#define HAVE_UNSIGNED_CHAR
+
+#ifdef HAVE_UNSIGNED_CHAR
+unsigned char un_char;
+#endif
+
+
+/* Now we want to find out if your compiler knows what "unsigned short" means.
+ * If you get an error on the "unsigned short un_short;" line,
+ * then undefine HAVE_UNSIGNED_SHORT.
+ */
+
+#define HAVE_UNSIGNED_SHORT
+
+#ifdef HAVE_UNSIGNED_SHORT
+unsigned short un_short;
+#endif
+
+
+/* Now we want to find out if your compiler understands type "void".
+ * If you get an error anywhere in here, undefine HAVE_VOID.
+ */
+
+#define HAVE_VOID
+
+#ifdef HAVE_VOID
+/* Caution: a C++ compiler will insist on complete prototypes */
+typedef void * void_ptr;	/* check void * */
+#ifdef HAVE_PROTOTYPES		/* check ptr to function returning void */
+typedef void (*void_func) (int a, int b);
+#else
+typedef void (*void_func) ();
+#endif
+
+#ifdef HAVE_PROTOTYPES		/* check void function result */
+void test3function (void_ptr arg1, void_func arg2)
+#else
+void test3function (arg1, arg2)
+     void_ptr arg1;
+     void_func arg2;
+#endif
+{
+  char * locptr = (char *) arg1; /* check casting to and from void * */
+  arg1 = (void *) locptr;
+  (*arg2) (1, 2);		/* check call of fcn returning void */
+}
+#endif
+
+
+/* Now we want to find out if your compiler knows what "const" means.
+ * If you get an error here, undefine HAVE_CONST.
+ */
+
+#define HAVE_CONST
+
+#ifdef HAVE_CONST
+static const int carray[3] = {1, 2, 3};
+
+#ifdef HAVE_PROTOTYPES
+int test4function (const int arg1)
+#else
+int test4function (arg1)
+     const int arg1;
+#endif
+{
+  return carray[arg1];
+}
+#endif
+
+
+/* If you get an error or warning about this structure definition,
+ * define INCOMPLETE_TYPES_BROKEN.
+ */
+
+#undef INCOMPLETE_TYPES_BROKEN
+
+#ifndef INCOMPLETE_TYPES_BROKEN
+typedef struct undefined_structure * undef_struct_ptr;
+#endif
+
+
+/* If you get an error about duplicate names,
+ * define NEED_SHORT_EXTERNAL_NAMES.
+ */
+
+#undef NEED_SHORT_EXTERNAL_NAMES
+
+#ifndef NEED_SHORT_EXTERNAL_NAMES
+
+int possibly_duplicate_function ()
+{
+  return 0;
+}
+
+int possibly_dupli_function ()
+{
+  return 1;
+}
+
+#endif
+
+
+
+/************************************************************************
+ *  OK, that's it.  You should not have to change anything beyond this
+ *  point in order to compile and execute this program.  (You might get
+ *  some warnings, but you can ignore them.)
+ *  When you run the program, it will make a couple more tests that it
+ *  can do automatically, and then it will create jconfig.h and print out
+ *  any additional suggestions it has.
+ ************************************************************************
+ */
+
+
+#ifdef HAVE_PROTOTYPES
+int is_char_signed (int arg)
+#else
+int is_char_signed (arg)
+     int arg;
+#endif
+{
+  if (arg == 189) {		/* expected result for unsigned char */
+    return 0;			/* type char is unsigned */
+  }
+  else if (arg != -67) {	/* expected result for signed char */
+    printf("Hmm, it seems 'char' is not eight bits wide on your machine.\n");
+    printf("I fear the JPEG software will not work at all.\n\n");
+  }
+  return 1;			/* assume char is signed otherwise */
+}
+
+
+#ifdef HAVE_PROTOTYPES
+int is_shifting_signed (long arg)
+#else
+int is_shifting_signed (arg)
+     long arg;
+#endif
+/* See whether right-shift on a long is signed or not. */
+{
+  long res = arg >> 4;
+
+  if (res == -0x7F7E80CL) {	/* expected result for signed shift */
+    return 1;			/* right shift is signed */
+  }
+  /* see if unsigned-shift hack will fix it. */
+  /* we can't just test exact value since it depends on width of long... */
+  res |= (~0L) << (32-4);
+  if (res == -0x7F7E80CL) {	/* expected result now? */
+    return 0;			/* right shift is unsigned */
+  }
+  printf("Right shift isn't acting as I expect it to.\n");
+  printf("I fear the JPEG software will not work at all.\n\n");
+  return 0;			/* try it with unsigned anyway */
+}
+
+
+#ifdef HAVE_PROTOTYPES
+int main (int argc, char ** argv)
+#else
+int main (argc, argv)
+     int argc;
+     char ** argv;
+#endif
+{
+  char signed_char_check = (char) (-67);
+  FILE *outfile;
+
+  /* Attempt to write jconfig.h */
+  if ((outfile = fopen("jconfig.h", "w")) == NULL) {
+    printf("Failed to write jconfig.h\n");
+    return 1;
+  }
+
+  /* Write out all the info */
+  fprintf(outfile, "/* jconfig.h --- generated by ckconfig.c */\n");
+  fprintf(outfile, "/* see jconfig.doc for explanations */\n\n");
+#ifdef HAVE_PROTOTYPES
+  fprintf(outfile, "#define HAVE_PROTOTYPES\n");
+#else
+  fprintf(outfile, "#undef HAVE_PROTOTYPES\n");
+#endif
+#ifdef HAVE_UNSIGNED_CHAR
+  fprintf(outfile, "#define HAVE_UNSIGNED_CHAR\n");
+#else
+  fprintf(outfile, "#undef HAVE_UNSIGNED_CHAR\n");
+#endif
+#ifdef HAVE_UNSIGNED_SHORT
+  fprintf(outfile, "#define HAVE_UNSIGNED_SHORT\n");
+#else
+  fprintf(outfile, "#undef HAVE_UNSIGNED_SHORT\n");
+#endif
+#ifdef HAVE_VOID
+  fprintf(outfile, "/* #define void char */\n");
+#else
+  fprintf(outfile, "#define void char\n");
+#endif
+#ifdef HAVE_CONST
+  fprintf(outfile, "/* #define const */\n");
+#else
+  fprintf(outfile, "#define const\n");
+#endif
+  if (is_char_signed((int) signed_char_check))
+    fprintf(outfile, "#undef CHAR_IS_UNSIGNED\n");
+  else
+    fprintf(outfile, "#define CHAR_IS_UNSIGNED\n");
+#ifdef HAVE_STDDEF_H
+  fprintf(outfile, "#define HAVE_STDDEF_H\n");
+#else
+  fprintf(outfile, "#undef HAVE_STDDEF_H\n");
+#endif
+#ifdef HAVE_STDLIB_H
+  fprintf(outfile, "#define HAVE_STDLIB_H\n");
+#else
+  fprintf(outfile, "#undef HAVE_STDLIB_H\n");
+#endif
+#ifdef NEED_BSD_STRINGS
+  fprintf(outfile, "#define NEED_BSD_STRINGS\n");
+#else
+  fprintf(outfile, "#undef NEED_BSD_STRINGS\n");
+#endif
+#ifdef NEED_SYS_TYPES_H
+  fprintf(outfile, "#define NEED_SYS_TYPES_H\n");
+#else
+  fprintf(outfile, "#undef NEED_SYS_TYPES_H\n");
+#endif
+  fprintf(outfile, "#undef NEED_FAR_POINTERS\n");
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+  fprintf(outfile, "#define NEED_SHORT_EXTERNAL_NAMES\n");
+#else
+  fprintf(outfile, "#undef NEED_SHORT_EXTERNAL_NAMES\n");
+#endif
+#ifdef INCOMPLETE_TYPES_BROKEN
+  fprintf(outfile, "#define INCOMPLETE_TYPES_BROKEN\n");
+#else
+  fprintf(outfile, "#undef INCOMPLETE_TYPES_BROKEN\n");
+#endif
+  fprintf(outfile, "\n#ifdef JPEG_INTERNALS\n\n");
+  if (is_shifting_signed(-0x7F7E80B1L))
+    fprintf(outfile, "#undef RIGHT_SHIFT_IS_UNSIGNED\n");
+  else
+    fprintf(outfile, "#define RIGHT_SHIFT_IS_UNSIGNED\n");
+  fprintf(outfile, "\n#endif /* JPEG_INTERNALS */\n");
+  fprintf(outfile, "\n#ifdef JPEG_CJPEG_DJPEG\n\n");
+  fprintf(outfile, "#define BMP_SUPPORTED		/* BMP image file format */\n");
+  fprintf(outfile, "#define GIF_SUPPORTED		/* GIF image file format */\n");
+  fprintf(outfile, "#define PPM_SUPPORTED		/* PBMPLUS PPM/PGM image file format */\n");
+  fprintf(outfile, "#undef RLE_SUPPORTED		/* Utah RLE image file format */\n");
+  fprintf(outfile, "#define TARGA_SUPPORTED		/* Targa image file format */\n\n");
+  fprintf(outfile, "#undef TWO_FILE_COMMANDLINE	/* You may need this on non-Unix systems */\n");
+  fprintf(outfile, "#undef NEED_SIGNAL_CATCHER	/* Define this if you use jmemname.c */\n");
+  fprintf(outfile, "#undef DONT_USE_B_MODE\n");
+  fprintf(outfile, "/* #define PROGRESS_REPORT */	/* optional */\n");
+  fprintf(outfile, "\n#endif /* JPEG_CJPEG_DJPEG */\n");
+
+  /* Close the jconfig.h file */
+  fclose(outfile);
+
+  /* User report */
+  printf("Configuration check for Independent JPEG Group's software done.\n");
+  printf("\nI have written the jconfig.h file for you.\n\n");
+#ifdef HAVE_PROTOTYPES
+  printf("You should use makefile.ansi as the starting point for your Makefile.\n");
+#else
+  printf("You should use makefile.unix as the starting point for your Makefile.\n");
+#endif
+
+#ifdef NEED_SPECIAL_INCLUDE
+  printf("\nYou'll need to change jconfig.h to include the system include file\n");
+  printf("that you found type size_t in, or add a direct definition of type\n");
+  printf("size_t if that's what you used.  Just add it to the end.\n");
+#endif
+
+  return 0;
+}