diff --git a/xorriso/aux_objects.c b/xorriso/aux_objects.c
index e125c238..bd598d24 100644
--- a/xorriso/aux_objects.c
+++ b/xorriso/aux_objects.c
@@ -20,6 +20,8 @@
 
    - LinkiteM, PermiteM which temporarily record relations and states.
 
+   - NumbermappeR which maps off_t numbers to other off_t numbers.
+
 */
 
 #ifdef HAVE_CONFIG_H
@@ -1082,3 +1084,330 @@ int Permstack_peek(struct PermiteM **o, struct PermiteM *stopper,
 
 /* ---------------------------- End PermstacK ----------------------------- */
 
+
+/* ----------------------------- NumbermappeR ----------------------------- */
+
+struct NumbermappinG {
+ off_t from_low;
+ off_t from_high;
+ off_t to_low;
+ off_t to_high;
+
+ struct NumbermappinG *next;
+};
+
+
+off_t Numbermapping__curb(off_t num, off_t min, off_t max, int flag)
+{
+ if(num < min)
+   return(min);
+ if(num > max)
+   return(max);
+ return(num);
+}
+
+
+int Numbermapping_new(struct NumbermappinG **o,
+                      off_t from_low, off_t from_high,
+                      off_t to_low, off_t to_high,
+                      struct NumbermappinG *next,
+                      off_t min, off_t max,  int flag)
+{
+ struct NumbermappinG *m;
+
+ m= TSOB_FELD(struct NumbermappinG, 1);
+ if(m == NULL)
+   return(-1);
+ m->from_low= Numbermapping__curb(from_low, min, max, 0);
+ m->from_high= Numbermapping__curb(from_high, min, max, 0);
+ m->to_low= Numbermapping__curb(to_low, min, max, 0);
+ m->to_high= Numbermapping__curb(to_high, min, max, 0);
+ m->next= next;
+ *o= m;
+ return(1);
+}
+
+
+int Numbermapping_destroy(struct NumbermappinG **o, int flag)
+{
+ if(*o == NULL)
+   return(2);
+ free(*o);
+ *o= NULL;
+ return(1);
+}
+
+
+int Numbermapping_destroy_all(struct NumbermappinG **o, int flag)
+{
+ struct NumbermappinG *m, *m_next;
+
+ if(*o == NULL)
+   return(2);
+ for(m= *o; m != NULL; m= m_next) {
+   m_next= m->next;
+   Numbermapping_destroy(&m, 0);
+ }
+ *o= NULL;
+ return(1);
+}
+
+
+/* @return  0=no match, 1=good mapping, 2=curbed mapping
+*/
+int Numbermapping_map(struct NumbermappinG *o, off_t from, off_t *to, 
+                      off_t min, off_t max, int flag)
+{
+ struct NumbermappinG *m;
+ off_t diff;
+
+ if(from < min)
+   from= min;
+ else if(from > max)
+   from= max;
+ 
+ for(m= o; m != NULL; m= m->next) {
+   if(from > m->from_high || from < m->from_low)
+ continue;
+   diff= from - m->from_low;
+   if(m->to_low + diff > m->to_high) {
+     *to= m->to_high;
+     return(2);
+   } else {
+     *to= m->to_low + diff;
+     return(1);
+   }
+ }
+ *to= from;
+ return(0);
+}
+
+
+struct NumbermappeR {
+ off_t min;   /* lowest permissible number : - 2 exp 60 to + 2 exp 60 - 1 */
+ off_t max;   /* highest permissible number : - 2 exp 60 to + 2 exp 60 - 1 */
+
+ int count;   /* count of interval mappings */
+ struct NumbermappinG *mappings;
+};
+
+
+int Numbermapper_new(struct NumbermappeR **o, off_t min, off_t max, int flag)
+{
+ struct NumbermappeR *m;
+
+ if(min < -(((off_t) 1) << 60) || min >= (((off_t) 1) << 60) ||
+    max < -(((off_t) 1) << 60) || max >= (((off_t) 1) << 60))
+   return(0);
+ if(min > max)
+   return(0);
+ m= TSOB_FELD(struct NumbermappeR, 1);
+ if(m == NULL)
+   return(-1);
+ m->min= min;
+ m->max= max;
+ m->count= 0;
+ m->mappings= NULL;
+ *o= m;
+ return(1);
+}
+
+
+int Numbermapper_destroy(struct NumbermappeR **o, int flag)
+{
+ if(*o == NULL)
+   return(2);
+ Numbermapping_destroy_all(&((*o)->mappings), 0);
+ free(*o);
+ *o= NULL;
+ return(1);
+}
+
+
+int Numbermapper_add(struct NumbermappeR *o, off_t from_low, off_t from_high,
+                     off_t to_low, off_t to_high, int flag)
+{
+ int ret;
+ struct NumbermappinG *nm;
+
+ ret= Numbermapping_new(&nm, from_low, from_high, to_low, to_high,
+                        o->mappings, o->min, o->max, 0);
+ if(ret <= 0)
+   return(ret);
+ o->count++;
+ o->mappings= nm;
+ return(1);
+}
+
+
+int Numbermapper_map(struct NumbermappeR *o, off_t from, off_t *to, int flag)
+{
+ int ret;
+
+ if(o == NULL) {
+   *to= from;
+   return(2);
+ }
+ ret= Numbermapping_map(o->mappings, from, to, o->min, o->max, 0);
+ if(ret <= 0)
+   return(ret);
+ return(1);
+}
+
+
+/*
+   @param errmsg  character array of at least size 80
+   @param flag bit0= accept end-of-text as separator
+*/
+int Numbermapper_decode_one(struct NumbermappeR *o, char *cpt, char separator,
+                            off_t *num, char **separator_pos,
+                            char *errmsg, int flag)
+{
+ int ret;
+ char *npt, num_text[32];
+
+ npt= strchr(cpt, separator);
+ if(npt == NULL) {
+   if(flag & 1) {
+     npt= cpt + strlen(cpt);
+   } else {
+     sprintf(errmsg, "Expected separator '%c'", separator);
+     return(0);
+   }
+ }
+ *separator_pos= npt;
+ if(npt - cpt >= 32) {
+   sprintf(errmsg, "Number text is too long");
+   return(0);
+ }
+ strncpy(num_text, cpt, npt - cpt);
+ num_text[npt - cpt]= 0;
+ ret= Sfile_text_to_off_t(num_text, num, 0);
+ if(ret <= 0) {
+   sprintf(errmsg, "Number text cannot be converted to a number: %s",
+                   num_text);
+   return(0);
+ }
+ if(*num < o->min) {
+   sprintf(errmsg, "Number %s is too small", num_text);
+   return(0);
+ }
+ if(*num > o->max) {
+   sprintf(errmsg, "Number %s is too large", num_text);
+   return(0);
+ }
+ return(1);
+}
+
+
+/* Decode from_low","from_high"="to_low"[","[to_high]]
+   @param errmsg  character array of at least size 80
+*/
+int Numbermapper_decode(struct NumbermappeR *o, char *text,
+                        off_t *from_low, off_t *from_high,
+                        off_t *to_low, off_t *to_high,
+                        char *errmsg, int flag)
+{
+ int ret;
+ char *cpt, *npt;
+
+ *from_low= *to_low= (((off_t) 1) << 61);
+ *from_high= *to_high= -(((off_t) 1) << 61);
+ errmsg[0]= 0;
+ cpt= text;
+
+ ret= Numbermapper_decode_one(o, cpt, ',', from_low, &npt, errmsg, 0);
+ if(ret <= 0)
+   return(ret);
+ cpt= npt + 1;
+ ret= Numbermapper_decode_one(o, cpt, '=', from_high, &npt, errmsg, 0);
+ if(ret <= 0)
+   return(ret);
+ cpt= npt + 1;
+ ret= Numbermapper_decode_one(o, cpt, ',', to_low, &npt, errmsg, 1);
+ if(ret <= 0)
+   return(ret);
+ if(*npt == 0) {
+   *to_high= *to_low;
+ } else {
+   cpt= npt + 1;
+   ret= Numbermapper_decode_one(o, cpt, ':', to_high, &npt, errmsg, 1);
+   if(ret <= 0) {
+     if(npt <= cpt + 1) {
+       *to_high= o->max;
+       errmsg[0]= 0;
+     } else {
+       return(0);
+     }
+   }
+ }
+ return(1);
+}
+
+
+/* @param text  character array of at least size 4 * 32 + 4 = 132
+*/
+int Numbermapper_encode(struct NumbermappeR *o, int idx, char *text, int size,
+                        int flag)
+{
+ int i, ret;
+ char num_text[80];
+ struct NumbermappinG *nm;
+
+ text[0]= 0;
+ if(idx < 0 || idx >= o->count)
+   return(0);
+ nm= o->mappings;
+ if(nm == NULL)
+   return(0);
+ for(i= 0; i < idx; i++) {
+   nm= nm->next;
+   if(nm == 0)
+     return(0);
+ }
+ ret= Sfile_off_t_text(num_text, nm->from_low, 0);
+ if(ret <= 0)
+   return(0);
+ if(strlen(text) + strlen(num_text) + 1 >= (size_t) size)
+   return(0);
+ strcat(text, num_text);
+ strcat(text, ",");
+ ret= Sfile_off_t_text(num_text, nm->from_high, 0);
+ if(ret <= 0)
+   return(0);
+ if(strlen(text) + strlen(num_text) + 1 >= (size_t) size)
+   return(0);
+ strcat(text, num_text);
+ strcat(text, "=");
+ ret= Sfile_off_t_text(num_text, nm->to_low, 0);
+ if(ret <= 0)
+   return(0);
+ if(strlen(text) + strlen(num_text) + 1 >= (size_t) size)
+   return(0);
+ strcat(text, num_text);
+ if(nm->to_low == nm->to_high)
+   return(1);
+ strcat(text, ",");
+ if(nm->to_high == o->max)
+   return(1);
+ ret= Sfile_off_t_text(num_text, nm->to_high, 0);
+ if(ret <= 0)
+   return(0);
+ if(strlen(text) + strlen(num_text) + 1 >= (size_t) size)
+   return(0);
+ strcat(text, num_text);
+ return(1);
+}
+
+
+int Numbermapper_get_count(struct NumbermappeR *o, int flag)
+{
+ if(o == NULL)
+   return(0);
+ return(o->count);
+}
+
+
+
+/* --------------------------- End NumbermappeR --------------------------- */
+
diff --git a/xorriso/aux_objects.h b/xorriso/aux_objects.h
index 16f6d5ae..103bf283 100644
--- a/xorriso/aux_objects.h
+++ b/xorriso/aux_objects.h
@@ -191,5 +191,27 @@ int Permstack_peek(struct PermiteM **o, struct PermiteM *stopper,
                    char *disk_path, struct stat **stbuf, int *chattr_flags,
                    int flag);
 
+
+struct NumbermappeR; /* interval driven number conversion up to 2 exp 60 */
+
+int Numbermapper_new(struct NumbermappeR **o, off_t min, off_t max, int flag);
+
+int Numbermapper_destroy(struct NumbermappeR **o, int flag);
+
+int Numbermapper_add(struct NumbermappeR *o, off_t from_low, off_t from_high,
+                     off_t to_low, off_t to_high, int flag);
+
+int Numbermapper_map(struct NumbermappeR *o, off_t from, off_t *to, int flag);
+
+int Numbermapper_decode(struct NumbermappeR *o, char *text,
+                        off_t *from_low, off_t *from_high,
+                        off_t *to_low, off_t *to_high,
+                        char *errmsg,  int flag);
+
+int Numbermapper_get_count(struct NumbermappeR *o, int flag);
+
+int Numbermapper_encode(struct NumbermappeR *o, int idx, char *text, int size,
+                        int flag);
+
 #endif /* ! Xorriso_pvt_auxobj_includeD */
 
diff --git a/xorriso/xorriso_timestamp.h b/xorriso/xorriso_timestamp.h
index df198fec..2b0e2903 100644
--- a/xorriso/xorriso_timestamp.h
+++ b/xorriso/xorriso_timestamp.h
@@ -1 +1 @@
-#define Xorriso_timestamP "2025.03.01.150925"
+#define Xorriso_timestamP "2025.03.27.204229"