Initial Commit

.svn/pristine/6a/6a41019e79b88376a29f21f64eb20e0217417ce1.svn-base

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+/* ENCODE.C - Encode message blocks. */
+
+/* Copyright (c) 1995-2012 by Radford M. Neal.
+ *
+ * Permission is granted for anyone to copy, use, modify, and distribute
+ * these programs and accompanying documents for any purpose, provided
+ * this copyright notice is retained and prominently displayed, and note
+ * is made of any changes made to these programs.  These programs and
+ * documents are distributed without any warranty, express or implied.
+ * As the programs were written for research purposes only, they have not
+ * been tested to the degree that would be advisable in any important
+ * application.  All use of these programs is entirely at the user's own
+ * risk.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#include "rand.h"
+#include "alloc.h"
+#include "blockio.h"
+#include "open.h"
+#include "mod2sparse.h"
+#include "mod2dense.h"
+#include "mod2convert.h"
+#include "rcode.h"
+#include "enc.h"
+
+void usage(void);
+
+
+/* MAIN PROGRAM. */
+
+int main
+( int argc,
+  char **argv
+)
+{
+  char *source_file, *encoded_file;
+  char *pchk_file, *gen_file;
+  mod2dense *u, *v;
+
+  FILE *srcf, *encf;
+  char *sblk, *cblk, *chks;
+  int i, n;
+
+  /* Look at initial flag arguments. */
+
+  blockio_flush = 0;
+
+  while (argc>1)
+  {
+    if (strcmp(argv[1],"-f")==0)
+    { if (blockio_flush!=0) usage();
+      blockio_flush = 1;
+    }
+    else 
+    { break;
+    }
+
+    argc -= 1;
+    argv += 1;
+  }
+
+  /* Look at remaining arguments. */
+
+  if (!(pchk_file = argv[1])
+   || !(gen_file = argv[2])
+   || !(source_file = argv[3])
+   || !(encoded_file = argv[4])
+   || argv[5])
+  { usage();
+  }
+
+  if ((strcmp(pchk_file,"-")==0) 
+    + (strcmp(gen_file,"-")==0) 
+    + (strcmp(source_file,"-")==0) > 1)
+  { fprintf(stderr,"Can't read more than one stream from standard input\n");
+    exit(1);
+  }
+
+  /* Read parity check file */
+
+  read_pchk(pchk_file);
+
+  if (N<=M)
+  { fprintf(stderr,
+ "Can't encode if number of bits (%d) not greater than number of checks (%d)\n",
+      N,M);
+    exit(1);
+  }
+
+  /* Read generator matrix file. */
+
+  read_gen(gen_file,0,0);
+
+  /* Allocate needed space. */
+
+  if (type=='d')
+  { u = mod2dense_allocate(N-M,1);
+    v = mod2dense_allocate(M,1);
+  }
+
+  if (type=='m')
+  { u = mod2dense_allocate(M,1);
+    v = mod2dense_allocate(M,1);
+  }
+
+  /* Open source file. */
+
+  srcf = open_file_std(source_file,"r");
+  if (srcf==NULL)
+  { fprintf(stderr,"Can't open source file: %s\n",source_file);
+    exit(1);
+  }
+
+  /* Create encoded output file. */
+
+  encf = open_file_std(encoded_file,"w");
+  if (encf==NULL)
+  { fprintf(stderr,"Can't create file for encoded data: %s\n",encoded_file);
+    exit(1);
+  }
+
+  sblk = chk_alloc (N-M, sizeof *sblk);
+  cblk = chk_alloc (N, sizeof *cblk);
+  chks = chk_alloc (M, sizeof *chks);
+
+  /* Encode successive blocks. */
+
+  for (n = 0; ; n++)
+  { 
+    /* Read block from source file. */
+
+    if (blockio_read(srcf,sblk,N-M)==EOF) 
+    { break;
+    }
+
+    /* Compute encoded block. */
+
+    switch (type)
+    { case 's':
+      { sparse_encode (sblk, cblk);
+        break;
+      }
+      case 'd':
+      { dense_encode (sblk, cblk, u, v);
+        break;
+      }
+      case 'm':
+      { mixed_encode (sblk, cblk, u, v);
+        break;
+      }
+    }
+
+    /* Check that encoded block is a code word. */
+
+    mod2sparse_mulvec (H, cblk, chks);
+
+    for (i = 0; i<M; i++) 
+    { if (chks[i]==1)
+      { fprintf(stderr,"Output block %d is not a code word!  (Fails check %d)\n",n,i);
+        abort(); 
+      }
+    }
+
+    /* Write encoded block to encoded output file. */
+
+    blockio_write(encf,cblk,N);
+    if (ferror(encf))
+    { break;
+    }
+  }
+
+//  fprintf(stderr,
+//    "Encoded %d blocks, source block size %d, encoded block size %d\n",n,N-M,N);
+
+  if (ferror(encf) || fclose(encf)!=0)
+  { fprintf(stderr,"Error writing encoded blocks to %s\n",encoded_file);
+    exit(1);
+  }
+
+  return 0;
+}
+
+
+/* PRINT USAGE MESSAGE AND EXIT. */
+
+void usage(void)
+{ fprintf(stderr,
+   "Usage:  encode [ -f ] pchk-file gen-file source-file encoded-file\n");
+  exit(1);
+}