--- gop_fixup/gop_fixup.c	Sun Feb  9 19:27:47 2003
+++ gop_fixup.new/gop_fixup.c	Tue Apr 22 22:38:30 2003
@@ -1,8 +1,12 @@
 #include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 #include <fcntl.h>
-#include <unistd.h>
 #include "sysdep.h"
+#include <unistd.h>
 #include <assert.h>
+#include <error.h>
+#include <errno.h>
 
 int fixed=0;
 
@@ -70,23 +74,58 @@
   unsigned char b7=0xb7;
   unsigned char end[]={0x00,0x00,0x01,0xb7};
   //unsigned char end[]="abcd";
-  OFF_T eofpos, len, fpos;
 
   for (fi=1; fi<argc; fi++) {
+    __off64_t eofpos, len, fpos, mmap_offset = 0, mmap_len = 0;
+    size_t pagesize, mmap_max = MMAP_WINDOW;
+
+    /* get page size for mmap */
+    pagesize = getpagesize();
+
     fd = open_rw(argv[fi]);
-    if (!fd) {
-      printf("Couldn't open file %s\n",argv[fi]);
-      return(-1);
+    if (fd == -1) {
+						error(-1, errno, "opening file %s failed\n", argv[fi]);
+      /*printf("Couldn't open file %s\n",argv[fi]);
+      return(-1);*/
     }
-    
+
     len = lseek(fd,0,SEEK_END);
+		if (len == -1)
+		{
+						error(-1, errno, "lseek failed");
+		}
+#ifdef DEBUG
+		printf("len='%d'\n", len);
+#endif
     lseek(fd,0,SEEK_SET);
-    mem = mmap(0,len,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);
+
+    mmap_len = MIN(mmap_max, len);
+
     x = 0;
     eofpos=-1;
 
-    for (fpos=0; fpos<len; fpos++) {
-
+    while (mmap_offset < len)
+    {
+      if (mmap_len + mmap_offset > len)
+      {
+        mmap_len = len - mmap_offset;
+      }
+      mem = mmap(NULL,mmap_len,PROT_READ|PROT_WRITE,MAP_SHARED,fd,mmap_offset);
+		  if (mem == MAP_FAILED)
+		  {
+						error(-1, errno, "mmap failed");
+		  }
+
+    for (fpos=0; fpos<mmap_len; fpos++) {
+      if (fpos+4 >= mmap_len)
+      {
+        off_t pagedloc;
+        /* handle the case where we need to look at memory that isn't mapped in! */
+        pagedloc = (fpos + 4) / pagesize;
+        pagedloc *= pagesize;
+        mmap_offset += (fpos - pagedloc) + 4;
+        break;
+      }
       if ((mem[fpos]==0) &&
 	  (mem[fpos+1]==0) &&
 	  (mem[fpos+2]==1))
@@ -108,6 +147,16 @@
 	  }
 	}
     }
+      if (mmap_len + mmap_offset < len)
+      {
+        /* unmap the memory since we have more to process. */
+        if(munmap(mem,mmap_len) != 0)
+        {
+                error(-1, errno, "munmap failed");
+        }
+      }
+      mmap_offset += mmap_len;
+    }
     if (eofpos>0) {
       mem[eofpos] = 1;
       mem[eofpos+1] = 0xb7;
@@ -115,7 +164,11 @@
     printf("\nfinished %s \n",argv[fi]);
     printf("fixed %d GOP timestamps\n",fixed);
     fixed=0;
-    munmap(mem,len);
+    /* munmap(mem,mmap_len); */
+    if(munmap(mem,mmap_len) != 0)
+		{
+						error(-1, errno, "munmap failed");
+		}
     close(fd);
     if (eofpos==-1) {
       printf("Found no end-stamp. Adding...%s\n",end);