X-Git-Url: https://git.distorted.org.uk/~mdw/dvdrip/blobdiff_plain/3b455ee5df3b567d76cd1ca024fc01a028ef8855..69d1ae9dda83cf77000b4939fb0cae0126d5f065:/dvd-sector-copy.c

diff --git a/dvd-sector-copy.c b/dvd-sector-copy.c
index b0cd78d..2c461e1 100644
--- a/dvd-sector-copy.c
+++ b/dvd-sector-copy.c
@@ -32,6 +32,12 @@
 #define ISDIGIT(ch) CTYPE_HACK(isdigit, ch)
 #define ISSPACE(ch) CTYPE_HACK(isspace, ch)
 
+#ifdef DEBUG
+#  define D(x) x
+#else
+#  define D(x)
+#endif
+
 #define N(v) (sizeof(v)/sizeof((v)[0]))
 
 #define SECTORSZ 2048
@@ -43,8 +49,8 @@ static int status = 0;
 static void usage(FILE *fp)
 {
   fprintf(fp,
-	  "usage: %s [-c] [-D DEV] [-R MAP] "
-		"[-b OUTMAP] [-o OUTFILE] [-r [START]-[END]]\n",
+	  "usage: %s [-c] [-R MAP] [-b OUTMAP] [-r [START]-[END]]\n"
+	  "\tDEVICE OUTFILE\n",
 	  prog);
 }
 
@@ -98,6 +104,32 @@ static void carefully_write(int fd, const void *buf, size_t sz)
   }
 }
 
+static void open_file_on_demand(const char *file, FILE **fp_inout,
+				const char *what)
+{
+  FILE *fp;
+
+  if (!*fp_inout) {
+    fp = fopen(file, "w");
+    if (!fp)
+      bail_syserr(errno, "failed to open %s file `%s'", what, file);
+    fprintf(fp, "## %s\n\n", what);
+    *fp_inout = fp;
+  }
+}
+
+static void check_write(FILE *fp, const char *what)
+{
+  fflush(fp);
+  if (ferror(fp)) bail_syserr(errno, "error writing %s file", what);
+}
+
+static void carefully_fclose(FILE *fp, const char *what)
+{
+  if (fp && (ferror(fp) || fclose(fp)))
+    bail_syserr(errno, "error writing %s file", what);
+}
+
 #define DEFVEC(vtype, etype)						\
 	typedef struct { etype *v; size_t n, sz; } vtype
 #define VEC_INIT { 0, 0, 0 }
@@ -152,6 +184,7 @@ static void store_filename(char *buf, ident id)
 
 typedef uint_least32_t secaddr;
 #define PRIuSEC PRIuLEAST32
+#define SECLIMIT 0x00400000
 
 #define MAXFILES (1 + 2*99 + 1)
 struct file {
@@ -284,9 +317,16 @@ static void put_title(dvd_reader_t *dvd, unsigned title)
 static int progresslen = 0;
 
 static void clear_progress_internal(void)
-  { while (progresslen) { fputs("\b \b", stdout); progresslen--; } }
+{
+  while (progresslen) { fputs("\b \b", stdout); progresslen--; }
+  putchar('\r');
+}
 static void clear_progress(void)
   { clear_progress_internal(); fflush(stdout); }
+#ifdef DEBUG
+static void debug_clear_progress(void)
+  { if (progresslen) { putchar('\n'); progresslen = 0; } }
+#endif
 static void vappend_progress(const char *fmt, va_list ap)
   { progresslen += vprintf(fmt, ap); }
 __attribute__((format(printf, 1, 2)))
@@ -358,7 +398,7 @@ static void report_progress(secaddr pos)
     ("copied %.1f%% (%"PRIuSEC" of %"PRIuSEC"; %.1f %sB/s, ETA %s)",
      percent, pos, limit,  rate, unit, etastr);
   if (file && id_kind(file->id) == VOB) {
-    append_progress(" -- %s %d %3.1f%%",
+    append_progress(" -- %s %d %.1f%%",
 		    id_part(file->id) ? "title" : "menu",
 		    id_title(file->id),
 		    (pos - file->start)*100.0/
@@ -369,6 +409,82 @@ static void report_progress(secaddr pos)
 #undef BETA
 }
 
+static dvd_reader_t *dvd;
+static int dvdfd = -1, outfd = -1;
+static dvd_file_t *vob;
+static const char *mapfile; static FILE *mapfp;
+
+struct badblock { secaddr start, end; };
+DEFVEC(badblock_v, struct badblock);
+static badblock_v badblocks = VEC_INIT;
+
+static int compare_badblock(const void *a, const void *b)
+{
+  const struct badblock *ba = a, *bb = b;
+
+  if (ba->start < bb->start) return (-1);
+  else if (ba->start > bb->start) return (+1);
+
+  if (ba->end < bb->end) return (-1);
+  else if (ba->end > bb->end) return (+1);
+
+  return (0);
+}
+
+static ssize_t read_sectors(secaddr pos, void *buf, secaddr want)
+{
+  ssize_t n, done;
+  size_t lo, mid, hi;
+  int fakeerr = 0;
+  struct badblock *bad, *best;
+  unsigned char *p = buf;
+
+  if (badblocks.n) {
+    best = 0; lo = 0; hi = badblocks.n;
+#ifdef DEBUG
+    debug_clear_progress();
+    printf(";; searching badblocks for %"PRIuSEC" .. %"PRIuSEC"\n",
+	   pos, pos + want);
+#endif
+    while (lo < hi) {
+      mid = lo + (hi - lo)/2; bad = &badblocks.v[mid];
+#ifdef DEBUG
+      printf(";;   try %zu (%"PRIuSEC" .. %"PRIuSEC")... ",
+	     mid, bad->start, bad->end);
+#endif
+      if (pos < bad->start) { D( printf("high\n"); ) best = bad; hi = mid; }
+      else if (pos >= bad->end) { D( printf("low\n"); ) lo = mid + 1; }
+      else { D( printf("match!\n"); ) errno = EIO; return (-1); }
+    }
+#ifdef DEBUG
+    if (best)
+      printf(";;   next is %"PRIuSEC" .. %"PRIuSEC"\n",
+	     best->start, best->end);
+#endif
+    if (best && pos + want > best->start)
+      { want = best->start - pos; fakeerr = EIO; }
+  }
+  done = 0;
+  while (want) {
+    if (vob)
+      { errno = 0; n = DVDReadBlocks(vob, pos - file->start, want, p); }
+    else if (file) {
+      if (lseek(dvdfd, (off_t)pos*SECTORSZ, SEEK_SET) < 0)
+	bail_syserr(errno, "failed to seek to sector %"PRIuSEC"", pos);
+      errno = 0; n = read(dvdfd, p, want*SECTORSZ);
+      if (n >= 0) n /= SECTORSZ;
+    } else {
+      memset(p, 0, want*SECTORSZ);
+      n = want;
+    }
+
+    if (n > 0) { done += n; pos += n; p += n*SECTORSZ; want -= n; }
+    else if (!n || errno != EINTR) break;
+  }
+  if (fakeerr && !errno) errno = fakeerr;
+  return (!done && errno ? -1 : done);
+}
+
 static void report_bad_blocks_progress(secaddr lo, secaddr hi, int err)
 {
   report_progress(hi);
@@ -377,44 +493,266 @@ static void report_bad_blocks_progress(secaddr lo, secaddr hi, int err)
   else
     append_progress(": %"PRIuSEC" bad %s",
 		    hi - lo, hi == lo + 1 ? "sector" : "sectors");
-  if (err != EIO) append_progress(" (%s)", strerror(err));
+  if (err && err != EIO) append_progress(" (%s)", strerror(err));
   fflush(stdout);
 }
 
-static dvd_reader_t *dvd;
-static int dvdfd = -1;
-static dvd_file_t *vob;
-static const char *mapfile; static FILE *mapfp;
+static void recovered(secaddr bad_lo, secaddr bad_hi)
+{
+  clear_progress();
+  moan("skipping %"PRIuSEC" bad sectors (%"PRIuSEC" .. %"PRIuSEC")",
+       bad_hi - bad_lo, bad_lo, bad_hi);
+  if (mapfile) {
+    open_file_on_demand(mapfile, &mapfp, "bad-sector region map");
+    fprintf(mapfp, "%"PRIuSEC" %"PRIuSEC"\n", bad_lo, bad_hi);
+    check_write(mapfp, "bad-sector region map");
+  }
+  if (lseek(outfd, (off_t)(bad_hi - bad_lo)*SECTORSZ, SEEK_CUR) < 0)
+    bail_syserr(errno, "failed to seek past bad sectors");
+  status = 1;
+}
 
-static ssize_t read_sectors(secaddr pos, void *buf, secaddr want)
+struct recoverybuf {
+  unsigned char *buf;
+  secaddr sz, pos, start, end;
+};
+
+static void rearrange_sectors(struct recoverybuf *r,
+			      secaddr dest, secaddr src, secaddr len)
+{
+  assert(dest + len <= r->sz);
+  assert(src + len <= r->sz);
+  memmove(r->buf + dest*SECTORSZ, r->buf + src*SECTORSZ, len*SECTORSZ);
+}
+
+#ifdef DEBUG
+__attribute__((format(printf, 2, 3)))
+static void show_recovery_buffer_map(const struct recoverybuf *r,
+				     const char *what, ...)
+{
+  va_list ap;
+
+  va_start(ap, what);
+  debug_clear_progress();
+  printf(";; recovery buffer (");
+  vprintf(what, ap);
+  printf("): "
+	 "(%"PRIuSEC") ..%"PRIuSEC".. "
+	 "[%"PRIuSEC" ..%"PRIuSEC".. %"PRIuSEC"] "
+	 "..%"PRIuSEC".. (%"PRIuSEC")\n",
+	 r->pos, r->start,
+	 r->pos + r->start, r->end - r->start, r->pos + r->end,
+	 r->sz - r->end, r->pos + r->sz);
+  va_end(ap);
+  assert(r->start <= r->end);
+  assert(r->end <= r->sz);
+}
+#endif
+
+static ssize_t recovery_read_sectors(struct recoverybuf *r,
+				     secaddr pos, secaddr off, secaddr want)
 {
   ssize_t n;
 
-again:
-  if (vob)
-    n = DVDReadBlocks(vob, pos - file->start, want, buf);
-  else if (file) {
-    if (lseek(dvdfd, (off_t)pos*SECTORSZ, SEEK_SET) < 0)
-      bail_syserr(errno, "failed to seek to sector %"PRIuSEC"", pos);
-    n = read(dvdfd, buf, want*SECTORSZ);
-    if (n >= 0) n /= SECTORSZ;
-  } else {
-    memset(buf, 0, want*SECTORSZ);
-    n = want;
+  assert(off <= r->sz); assert(want <= r->sz - off);
+  n = read_sectors(pos, r->buf + off*SECTORSZ, want);
+  return (n);
+}
+
+static ssize_t recovery_read(struct recoverybuf *r,
+			     secaddr pos, secaddr want)
+{
+  secaddr diff, pp, nn;
+  ssize_t n;
+
+#ifdef DEBUG
+  debug_clear_progress();
+  show_recovery_buffer_map(r, "begin(%"PRIuSEC", %"PRIuSEC")", pos, want);
+#endif
+
+  if (pos < r->pos) {
+    diff = r->pos - pos;
+    if (r->start + diff >= r->sz) {
+      r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "cleared; shift up by %"PRIuSEC"", diff);
+#endif
+    } else {
+      if (r->end + diff > r->sz) r->end = r->sz - diff;
+      rearrange_sectors(r, r->start + diff, r->start, r->end - r->start);
+      r->pos -= diff; r->start += diff; r->end += diff;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "shifted up by %"PRIuSEC"", diff);
+#endif
+    }
+  } else if (pos > r->pos + r->end) {
+      r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "cleared; beyond previous region");
+#endif
+  } else if (pos + want > r->pos + r->sz) {
+    diff = (pos + want) - (r->pos + r->sz);
+    if (r->end <= diff) {
+      r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "cleared; shift down by %"PRIuSEC"", diff);
+#endif
+    } else {
+      if (r->start < diff) r->start = diff;
+      rearrange_sectors(r, r->start - diff, r->start, r->end - r->start);
+      r->pos += diff; r->start -= diff; r->end -= diff;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "shifted down by %"PRIuSEC"", diff);
+#endif
+    }
   }
 
-  if (n < 0 && errno == EINTR) goto again;
+  if (pos < r->pos + r->start) {
+    pp = pos - r->pos; nn = r->start - pp;
+#ifdef DEBUG
+    printf(";; read low (%"PRIuSEC"@%"PRIuSEC", %"PRIuSEC")", pos, pp, nn);
+    fflush(stdout);
+#endif
+    n = recovery_read_sectors(r, pos, pp, nn);
+#ifdef DEBUG
+    printf(" -> %zd\n", n);
+#endif
+    if (n != nn) {
+      if (n >= 0 && n > want) n = want;
+      goto end;
+    }
+    r->start = pp;
+#ifdef DEBUG
+    show_recovery_buffer_map(r, "joined new region");
+#endif
+  }
+
+  if (pos + want > r->pos + r->end) {
+    pp = r->end; nn = (pos + want) - (r->pos + r->end);
+#ifdef DEBUG
+    printf(";; read high (%"PRIuSEC"@%"PRIuSEC", %"PRIuSEC")",
+	   r->pos + pp, pp, nn);
+    fflush(stdout);
+#endif
+    n = recovery_read_sectors(r, r->pos + pp, pp, nn);
+#ifdef DEBUG
+    printf(" -> %zd\n", n);
+#endif
+    if (n > 0) {
+      r->end += n;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "joined new region");
+#endif
+    }
+  }
+
+  n = r->pos + r->end - pos;
+  if (!n && want) n = -1;
+
+end:
+#ifdef DEBUG
+  show_recovery_buffer_map(r, "done; return %zd", n);
+#endif
   return (n);
 }
 
-static void emit(int outfd, secaddr start, secaddr end)
+static secaddr run_length_wanted(secaddr pos, secaddr badlen,
+				 secaddr sz, secaddr end)
+{
+  secaddr want;
+
+  want = 3*badlen/2;
+  if (!want) want = 1;
+  if (want > end - pos) want = end - pos;
+  if (want > sz) want = sz;
+  return (want);
+}
+
+static ssize_t find_good_sector(secaddr *pos_inout, secaddr end,
+				unsigned char *buf, secaddr sz)
+{
+  int i;
+  secaddr pos = *pos_inout, bad_lo, bad_hi, good, step, want;
+  struct recoverybuf r;
+  ssize_t n;
+
+  r.buf = buf; r.sz = sz; r.pos = r.start = r.end = 0;
+  report_bad_blocks_progress(pos, pos, errno);
+
+  want = sz; if (want > end - pos) want = end - pos;
+  for (i = 0; i < 4; i++) {
+    n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+    debug_clear_progress();
+    printf(";; [retry] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+	   pos, pos + want, n);
+#endif
+    if (n > 0) {
+      clear_progress();
+      moan("sector %"PRIuSEC" read ok after retry", pos);
+      return (n);
+    }
+  }
+
+  bad_lo = pos; bad_hi = pos + 1;
+  for (;;) {
+    report_bad_blocks_progress(bad_lo, bad_hi, errno);
+    if (bad_hi >= end) {
+      clear_progress();
+      moan("giving up on this extent");
+      recovered(bad_lo, end); *pos_inout = end; return (0);
+    }
+    step = 2*(bad_hi - bad_lo); if (step > end - bad_lo) step = end - bad_lo;
+    pos = bad_lo + step - 1;
+    want = run_length_wanted(pos, step, sz, end);
+    n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+    debug_clear_progress();
+    printf(";; [bound] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+	   pos, pos + want, n);
+#endif
+    if (n == want) break;
+    if (n < 0) n = 0;
+    bad_hi = pos + n + 1;
+  }
+
+  good = pos;
+  while (good > bad_hi) {
+    report_bad_blocks_progress(bad_lo, bad_hi, errno);
+    pos = bad_hi + (good - bad_hi)/2;
+    step = pos - bad_lo;
+    want = run_length_wanted(pos, step, sz, end);
+    n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+    debug_clear_progress();
+    printf(";; [limit] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+	   pos, pos + want, n);
+#endif
+    if (n < 0) n = 0;
+    if (n == want) good = pos;
+    else bad_hi = pos + n + 1;
+  }
+  recovered(bad_lo, bad_hi); *pos_inout = good;
+  if (good < r.pos + r.start || r.pos + r.end <= good)
+    n = 0;
+  else {
+    n = r.pos + r.end - good;
+    rearrange_sectors(&r, 0, good - r.pos, n);
+  }
+#ifdef DEBUG
+  show_recovery_buffer_map(&r, "returning %zd good sectors at %"PRIuSEC"",
+			   n, good);
+#endif
+  return (n);
+}
+
+static void emit(secaddr start, secaddr end)
 {
 #define BUFSECTORS 512
 
-  int least, i;
+  int least;
   unsigned char buf[BUFSECTORS*SECTORSZ];
   secaddr pos;
-  secaddr bad_lo, bad_hi, good, step;
   size_t want;
   ssize_t n;
   static int first_time = 1;
@@ -422,6 +760,7 @@ static void emit(int outfd, secaddr start, secaddr end)
   struct file *f;
   char fn[MAXFNSZ];
   int act = -1;
+  int i;
 #endif
 
   least = least_live();
@@ -469,68 +808,7 @@ static void emit(int outfd, secaddr start, secaddr end)
     want = end - pos; if (want > BUFSECTORS) want = BUFSECTORS;
     n = read_sectors(pos, buf, want);
 
-    if (n <= 0) {
-      report_bad_blocks_progress(pos, pos, errno);
-      for (i = 0; i < 4; i++) {
-	n = read_sectors(pos, buf, 1);
-	if (n > 0) {
-	  clear_progress();
-	  moan("sector %"PRIuSEC" read ok after retry", pos);
-	  bad_lo = bad_hi = pos;
-	  goto recovered;
-	}
-      }
-
-      bad_lo = pos; step = 1; bad_hi = pos + 1;
-      for (;;) {
-	report_bad_blocks_progress(bad_lo, bad_hi, errno);
-	if (bad_hi >= end) {
-	  clear_progress();
-	  moan("giving up on this extent");
-	  n = 0; goto recovered;
-	}
-	step *= 2;
-	if (step > end - bad_lo) step = end - bad_lo;
-	pos = bad_lo + step - 1;
-	n = read_sectors(pos, buf, 1);
-	if (n > 0) break;
-	bad_hi = pos + 1;
-      }
-
-      good = pos;
-      while (good > bad_hi) {
-	report_bad_blocks_progress(bad_lo, bad_hi, errno);
-	pos = bad_hi + (good - bad_hi)/2;
-	n = read_sectors(pos, buf, 1);
-	if (n > 0) good = pos;
-	else bad_hi = pos + 1;
-      }
-    recovered:
-      if (bad_hi > bad_lo) {
-	clear_progress();
-	moan("skipping %"PRIuSEC" bad sectors (%"PRIuSEC" .. %"PRIuSEC")",
-	     bad_hi - bad_lo, bad_lo, bad_hi);
-	if (mapfile) {
-	  if (!mapfp) {
-	    mapfp = fopen(mapfile, "w");
-	    if (!mapfp)
-	      bail_syserr(errno, "failed to open bad-sector map file `%s'",
-			  optarg);
-	    fprintf(mapfp, "## bad sector map\n\n");
-	  }
-	  fprintf(mapfp, "%"PRIuSEC" %"PRIuSEC"\n", bad_lo, bad_hi);
-	  fflush(mapfp);
-	  if (ferror(mapfp))
-	    bail_syserr(errno, "error writing bad-sector map file");
-	}
-	if (outfd >= 0 &&
-	    lseek(outfd, (off_t)(bad_hi - bad_lo)*SECTORSZ, SEEK_CUR) < 0)
-	  bail_syserr(errno, "failed to seek past bad sectors");
-	status = 1;
-      }
-      pos = bad_hi;
-    }
-
+    if (n <= 0) n = find_good_sector(&pos, end, buf, BUFSECTORS);
     if (n > 0) { carefully_write(outfd, buf, n*SECTORSZ); pos += n; }
     report_progress(pos); fflush(stdout);
   }
@@ -595,6 +873,49 @@ static int read_line(FILE *fp, struct buf *b)
   return (0);
 }
 
+#define PRF_HYPHEN 1u
+static int parse_range(const char *p, unsigned f,
+		       secaddr *start_out, secaddr *end_out)
+{
+  char *q;
+  int err, rc;
+  unsigned long start, end;
+
+  err = errno;
+
+  if (ISDIGIT(*p)) {
+    start = strtoul(p, &q, 0);
+    if (errno || start >= SECLIMIT) { rc = -1; goto end; }
+    *start_out = start; p = q;
+  } else if (!(f&PRF_HYPHEN))
+    { rc = -1; goto end; }
+  else
+    start = 0;
+
+  if (f&PRF_HYPHEN) {
+    if (*p != '-')  { rc = -1; goto end; }
+    p++;
+  } else {
+    if (!ISSPACE(*p)) { rc = -1; goto end; }
+    do p++; while (ISSPACE(*p));
+  }
+
+  if (ISDIGIT(*p)) {
+    end = strtoul(p, &q, 0);
+    if (errno || end > SECLIMIT || end < start) { rc = -1; goto end; }
+    *end_out = end; p = q;
+  } else if (!(f&PRF_HYPHEN))
+    { rc = -1; goto end; }
+
+  if (!(f&PRF_HYPHEN)) while (ISSPACE(*p)) p++;
+  if (*p) { rc = -1; goto end; }
+
+  rc = 0;
+end:
+  errno = err;
+  return (rc);
+}
+
 int main(int argc, char *argv[])
 {
   unsigned f = 0;
@@ -602,10 +923,11 @@ int main(int argc, char *argv[])
   uint64_t volsz;
   secaddr pos;
   off_t off;
-  unsigned long start, end;
+  secaddr start, end, last;
   const struct event *ev;
-  const char *device = "/dev/dvd", *outfile = 0;
-  int opt, err, outfd = -1, blksz;
+  const char *device, *outfile;
+  struct badblock *bad;
+  int opt, blksz;
   unsigned n;
   size_t i;
   FILE *fp;
@@ -623,81 +945,88 @@ int main(int argc, char *argv[])
 
   p = strrchr(argv[0], '/'); prog = p ? p + 1 : argv[0];
   for (;;) {
-    opt = getopt(argc, argv, "hD:FR:b:co:r:"); if (opt < 0) break;
+    opt = getopt(argc, argv, "hFR:X:b:cr:"); if (opt < 0) break;
     switch (opt) {
       case 'h': usage(stderr); exit(0);
-      case 'D': device = optarg; break;
       case 'F': f |= f_fixup; break;
       case 'R':
 	fp = fopen(optarg, "r");
 	if (!fp)
 	  bail_syserr(errno, "failed to open ranges file `%s'", optarg);
-	i = 0;
+	i = 0; last = -1;
 	for (;;) {
 	  BUF_REWIND(&buf); if (read_line(fp, &buf)) break;
 	  p = buf.p; i++;
 	  while (ISSPACE(*p)) p++;
 	  if (!*p || *p == '#') continue;
-	  if (!ISDIGIT(*p)) goto bad_range_file;
-	  start = strtoul(p, &p, 0);
-	  if (errno || !ISSPACE(*p)) goto bad_range_file;
-	  do p++; while (ISSPACE(*p));
-	  if (!ISDIGIT(*p)) goto bad_range_file;
-	  end = strtoul(p, &p, 0);
-	  if (errno || (*p && !ISSPACE(*p))) goto bad_range_file;
-	  while (ISSPACE(*p)) p++;
-	  if (*p) goto bad_range_file;
-	  if (start > end) goto bad_range_file;
+	  if (parse_range(p, 0, &start, &end) ||
+	      (last <= SECLIMIT && start < last))
+	    bail("bad range `%s' at `%s' line %zu", buf.p, optarg, i);
 	  if (start < end) {
-	    put_event(EV_WRITE, 0, start);
-	    put_event(EV_STOP, 0, end);
+	    if (start == last)
+	      eventq.v[eventq.n - 1].pos = end;
+	    else {
+	      put_event(EV_WRITE, 0, start);
+	      put_event(EV_STOP, 0, end);
+	    }
+	    last = end;
 	  }
 	}
 	if (ferror(fp))
 	  bail_syserr(errno, "failed to read ranges file `%s'", optarg);
 	break;
-      bad_range_file:
-	bail("bad range `%s' at `%s' line %zu", buf.p, optarg, i);
+      case 'X':
+	fp = fopen(optarg, "r");
+	if (!fp)
+	  bail_syserr(errno, "failed to open bad-blocks file `%s'", optarg);
+	i = 0; last = -1;
+	for (;;) {
+	  BUF_REWIND(&buf); if (read_line(fp, &buf)) break;
+	  p = buf.p; i++;
+	  while (ISSPACE(*p)) p++;
+	  if (!*p || *p == '#') continue;
+	  if (parse_range(p, 0, &start, &end) ||
+	      (last <= SECLIMIT && start < last))
+	    bail("bad range `%s' at `%s' line %zu", buf.p, optarg, i);
+	  if (start < end)
+	    { VEC_PUSH(bad, &badblocks); bad->start = start; bad->end = end; }
+	}
+	if (ferror(fp))
+	  bail_syserr(errno, "failed to read bad-blocks file `%s'", optarg);
+	break;
       case 'b':
 	if (mapfile) bail("can't have multiple map files");
 	mapfile = optarg;
 	break;
       case 'c': f |= f_continue; break;
-      case 'o': outfile = optarg; break;
       case 'r':
-	err = errno; errno = 0;
-	p = optarg;
-	if (*p == '-')
-	  start = 0;
-	else {
-	  if (!ISDIGIT(*p)) goto bad_range;
-	  start = strtoul(p, &p, 0);
-	  if (errno || *p != '-') goto bad_range;
-	}
-	p++;
-	if (!*p)
+	start = 0; end = -1;
+	if (parse_range(optarg, PRF_HYPHEN, &start, &end))
+	  bail("bad range `%s'", optarg);
+	if (start < end) {
 	  put_event(EV_WRITE, 0, start);
-	else {
-	  if (!ISDIGIT(*p)) goto bad_range;
-	  end = strtoul(p, &p, 0);
-	  if (errno || *p) goto bad_range;
-	  if (start > end) goto bad_range;
-	  if (start < end) {
-	    put_event(EV_WRITE, 0, start);
-	    put_event(EV_STOP, 0, end);
-	  }
+	  if (end <= SECLIMIT) put_event(EV_STOP, 0, end);
 	}
-	errno = err;
-	break;
-      bad_range:
-	bail("bad range `%s'", optarg);
 	break;
       default: f |= f_bogus; break;
     }
   }
-  if (optind < argc) f |= f_bogus;
+  if (argc - optind != 2) f |= f_bogus;
   if (f&f_bogus) { usage(stderr); exit(2); }
 
+  device = argv[optind]; outfile = argv[optind + 1];
+
+  if (badblocks.n) {
+    qsort(badblocks.v, badblocks.n, sizeof(struct badblock),
+	  compare_badblock);
+#ifdef DEBUG
+    printf(";; fake bad blocks:\n");
+    for (i = 0; i < badblocks.n; i++)
+      printf(";;\t%8"PRIuSEC" .. %"PRIuSEC"\n",
+	     badblocks.v[i].start, badblocks.v[i].end);
+#endif
+  }
+
   dvdfd = open(device, O_RDONLY);
   if (dvdfd < 0)
     bail_syserr(errno, "failed to open device `%s'", device);
@@ -727,7 +1056,6 @@ int main(int argc, char *argv[])
   }
 
   if (f&f_continue) {
-    if (!outfile) bail("can't continue without output file");
     off = lseek(outfd, 0, SEEK_END);
     if (off < 0)
       bail_syserr(errno, "failed to seek to end of output file `%s'",
@@ -774,7 +1102,7 @@ int main(int argc, char *argv[])
     switch (ev->ev) {
       case EV_WRITE:
 	if (f&f_write)
-	  bail("overlapping ranges: range from %lu still open at %"PRIuSEC"",
+	  bail("overlapping ranges: range from %"PRIuSEC" still open at %"PRIuSEC"",
 	       start, ev->pos);
 	n++; f |= f_write; start = ev->pos;
 	break;
@@ -812,10 +1140,10 @@ int main(int argc, char *argv[])
   for (pos = 0, i = 0; i < eventq.n; i++) {
     ev = &eventq.v[i];
     if (ev->pos > pos) {
-      if (f&f_write) emit(outfd, pos, ev->pos);
+      if (f&f_write) emit(pos, ev->pos);
       pos = ev->pos;
 #ifdef DEBUG
-      clear_progress();
+      debug_clear_progress();
       printf(";;\n");
 #endif
     }
@@ -824,20 +1152,19 @@ int main(int argc, char *argv[])
 	set_live(ev->file);
 #ifdef DEBUG
 	store_filename(fn, filetab.v[ev->file].id);
-	clear_progress();
+	debug_clear_progress();
 	printf(";; %8"PRIuSEC": begin `%s'\n", pos, fn);
 #endif
 	break;
       case EV_WRITE:
 	gettimeofday(&last_time, 0); last_pos = pos;
-	if (outfd >= 0 &&
-	    lseek(outfd, (off_t)ev->pos*SECTORSZ, SEEK_SET) < 0)
+	if (lseek(outfd, (off_t)ev->pos*SECTORSZ, SEEK_SET) < 0)
 	  bail_syserr(errno,
 		      "failed to seek to resume position "
 		      "(sector %"PRIuSEC") in output file `%s'",
 		      ev->pos, outfile);
 #ifdef DEBUG
-	clear_progress();
+	debug_clear_progress();
 	printf(";; %8"PRIuSEC": begin write\n", pos);
 #endif
 	f |= f_write;
@@ -845,7 +1172,7 @@ int main(int argc, char *argv[])
       case EV_STOP:
 	f &= ~f_write;
 #ifdef DEBUG
-	clear_progress();
+	debug_clear_progress();
 	printf(";; %8"PRIuSEC": end write\n", pos);
 #endif
 	break;
@@ -853,7 +1180,7 @@ int main(int argc, char *argv[])
 	clear_live(ev->file);
 #ifdef DEBUG
 	store_filename(fn, filetab.v[ev->file].id);
-	clear_progress();
+	debug_clear_progress();
 	printf(";; %8"PRIuSEC": end `%s'\n", pos, fn);
 #endif
 	break;
@@ -863,16 +1190,13 @@ int main(int argc, char *argv[])
 
   if (progresslen) putchar('\n');
 
-  if (outfd >= 0 && ftruncate(outfd, (off_t)limit*SECTORSZ) < 0)
+  if (ftruncate(outfd, (off_t)limit*SECTORSZ) < 0)
     bail_syserr(errno, "failed to set output file `%s' length", outfile);
 
   if (dvd) DVDClose(dvd);
   if (dvdfd >= 0) close(dvdfd);
   if (outfd >= 0) close(outfd);
-  if (mapfp) {
-    if (ferror(mapfp) || fclose(mapfp))
-      bail_syserr(errno, "error writing bad-sector map file");
-  }
+  carefully_fclose(mapfp, "bad-sector region map");
 
 #undef f_bogus
 #undef f_continue