Imported Upstream version 1.1.11upstream/1.1.11upstream

1 files changed, 1741 insertions, 0 deletions

diff --git a/libparanoia/paranoia.c b/libparanoia/paranoia.c
new file mode 100644
index 0000000..56a7be4
--- /dev/null
+++ b/libparanoia/paranoia.c
@@ -0,0 +1,1741 @@
+/*
+ * This file has been modified for the cdrkit suite.
+ *
+ * The behaviour and appearence of the program code below can differ to a major
+ * extent from the version distributed by the original author(s).
+ *
+ * For details, see Changelog file distributed with the cdrkit package. If you
+ * received this file from another source then ask the distributing person for
+ * a log of modifications.
+ *
+ */
+
+/* @(#)paranoia.c	1.33 04/08/17 J. Schilling from cdparanoia-III-alpha9.8 */
+/*
+ *	Modifications to make the code portable Copyright (c) 2002 J. Schilling
+ */
+/*
+ * CopyPolicy: GNU Public License 2 applies
+ * Copyright (C) by Monty (xiphmont@mit.edu)
+ *
+ * Toplevel file for the paranoia abstraction over the cdda lib
+ *
+ */
+
+/* immediate todo:: */
+/* Allow disabling of root fixups? */
+
+/*
+ * Dupe bytes are creeping into cases that require greater overlap
+ * than a single fragment can provide.  We need to check against a
+ * larger area* (+/-32 sectors of root?) to better eliminate
+ *  dupes. Of course this leads to other problems... Is it actually a
+ *  practically solvable problem?
+ */
+/* Bimodal overlap distributions break us. */
+/* scratch detection/tolerance not implemented yet */
+
+/*
+ * Da new shtick: verification now a two-step assymetric process.
+ *
+ * A single 'verified/reconstructed' data segment cache, and then the
+ * multiple fragment cache
+ *
+ * verify a newly read block against previous blocks; do it only this
+ * once. We maintain a list of 'verified sections' from these matches.
+ *
+ * We then glom these verified areas into a new data buffer.
+ * Defragmentation fixups are allowed here alone.
+ *
+ * We also now track where read boundaries actually happened; do not
+ * verify across matching boundaries.
+ */
+
+/*
+ * Silence.  "It's BAAAAAAaaack."
+ *
+ * audio is now treated as great continents of values floating on a
+ * mantle of molten silence.  Silence is not handled by basic
+ * verification at all; we simply anchor sections of nonzero audio to a
+ * position and fill in everything else as silence.  We also note the
+ * audio that interfaces with silence; an edge must be 'wet'.
+ */
+
+#include <mconfig.h>
+#include <allocax.h>
+#include <stdxlib.h>
+#include <unixstd.h>
+#include <standard.h>
+#include <utypes.h>
+#include <stdio.h>
+#include <strdefs.h>
+#include "p_block.h"
+#include "cdda_paranoia.h"
+#include "overlap.h"
+#include "gap.h"
+#include "isort.h"
+#include "pmalloc.h"
+
+/*
+ * used by: i_iterate_stage2() / i_stage2_each()
+ */
+typedef struct sync_result {
+	long		offset;
+	long		begin;
+	long		end;
+} sync_result;
+
+static inline long re(root_block *root);
+static inline long rb(root_block *root);
+static inline long rs(root_block *root);
+static inline Int16_t *rv(root_block *root);
+static inline long i_paranoia_overlap(Int16_t *buffA, Int16_t *buffB,
+                                      long offsetA, long offsetB,
+                                      long sizeA, long sizeB,
+                                      long *ret_begin, long *ret_end);
+static inline long i_paranoia_overlap2(Int16_t *buffA, Int16_t *buffB,
+                                       Uchar *flagsA, Uchar *flagsB,
+                                       long offsetA, long offsetB,
+                                       long sizeA, long sizeB,
+                                       long *ret_begin, long *ret_end);
+static inline long do_const_sync(c_block *A,
+                                 sort_info *B, Uchar *flagB,
+                                 long posA, long posB,
+                                 long *begin, long *end, long *offset);
+static inline long try_sort_sync(cdrom_paranoia *p,
+                                 sort_info *A, Uchar *Aflags,
+                                 c_block *B,
+                                 long post, long *begin, long *end,
+                                 long *offset, void (*callback) (long, int));
+static inline void stage1_matched(c_block *old, c_block *new,
+                                  long matchbegin, long matchend, 
+											 long matchoffset, 
+											 void (*callback) (long, int));
+static long i_iterate_stage1(cdrom_paranoia *p, c_block *old, c_block *new,
+                             void (*callback) (long, int));
+static long i_stage1(cdrom_paranoia *p, c_block *new, 
+							void (*callback) (long, int));
+static long i_iterate_stage2(cdrom_paranoia *p, v_fragment *v, sync_result *r, 
+									  void (*callback)(long, int));
+static void i_silence_test(root_block *root);
+static long i_silence_match(root_block *root, v_fragment *v,
+                            void (*callback) (long, int));
+static long i_stage2_each(root_block *root, v_fragment *v,
+                          void (*callback) (long, int));
+static int i_init_root(root_block *root, v_fragment *v, 
+                       long begin, void (*callback)(long, int));
+static int vsort(const void *a, const void *b);
+static int i_stage2(cdrom_paranoia *p, long beginword, long endword, 
+						  void (*callback)(long, int));
+static void i_end_case(cdrom_paranoia *p, long endword, 
+                       void (*callback)(long, int));
+static void verify_skip_case(cdrom_paranoia *p, 
+                             void (*callback)(long, int));
+void paranoia_free(cdrom_paranoia *p);
+void paranoia_modeset(cdrom_paranoia *p, int enable);
+long paranoia_seek(cdrom_paranoia *p, long seek, int mode);
+c_block *i_read_c_block(cdrom_paranoia *p, long beginword, long endword, 
+								void (*callback)(long,int));
+Int16_t *paranoia_read(cdrom_paranoia *p, void (*callback)(long, int));
+Int16_t *paranoia_read_limited(cdrom_paranoia *p, void (*callback)(long, int),
+                               int max_retries);
+void paranoia_overlapset(cdrom_paranoia *p, long overlap);
+
+
+static inline long re(root_block *root)
+{
+	if (!root)
+		return (-1);
+	if (!root->vector)
+		return (-1);
+	return (ce(root->vector));
+}
+
+static inline long rb(root_block *root)
+{
+	if (!root)
+		return (-1);
+	if (!root->vector)
+		return (-1);
+	return (cb(root->vector));
+}
+
+static inline long rs(root_block *root)
+{
+	if (!root)
+		return (-1);
+	if (!root->vector)
+		return (-1);
+	return (cs(root->vector));
+}
+
+static inline Int16_t *rv(root_block *root)
+{
+	if (!root)
+		return (NULL);
+	if (!root->vector)
+		return (NULL);
+	return (cv(root->vector));
+}
+
+#define	rc(r)	((r)->vector)
+
+/*
+ * matching and analysis code
+ */
+static inline long
+i_paranoia_overlap(Int16_t *buffA, Int16_t *buffB, long offsetA, long offsetB, 
+                   long sizeA, long sizeB, long *ret_begin, long *ret_end)
+{
+	long	beginA = offsetA;
+	long	endA = offsetA;
+	long	beginB = offsetB;
+	long	endB = offsetB;
+
+	for (; beginA >= 0 && beginB >= 0; beginA--, beginB--)
+		if (buffA[beginA] != buffB[beginB])
+			break;
+	beginA++;
+	beginB++;
+
+	for (; endA < sizeA && endB < sizeB; endA++, endB++)
+		if (buffA[endA] != buffB[endB])
+			break;
+
+	if (ret_begin)
+		*ret_begin = beginA;
+	if (ret_end)
+		*ret_end = endA;
+	return (endA - beginA);
+}
+
+static inline long
+i_paranoia_overlap2(Int16_t *buffA, Int16_t *buffB, Uchar *flagsA, 
+                    Uchar *flagsB, long offsetA, long offsetB, long sizeA, 
+                    long sizeB, long *ret_begin, long *ret_end)
+{
+	long		beginA = offsetA;
+	long		endA = offsetA;
+	long		beginB = offsetB;
+	long		endB = offsetB;
+
+	for (; beginA >= 0 && beginB >= 0; beginA--, beginB--) {
+		if (buffA[beginA] != buffB[beginB])
+			break;
+		/*
+		 * don't allow matching across matching sector boundaries
+		 */
+		if ((flagsA[beginA] & flagsB[beginB] & 1)) {
+			beginA--;
+			beginB--;
+			break;
+		}
+		/*
+		 * don't allow matching through known missing data
+		 */
+		if ((flagsA[beginA] & 2) || (flagsB[beginB] & 2))
+			break;
+	}
+	beginA++;
+	beginB++;
+
+	for (; endA < sizeA && endB < sizeB; endA++, endB++) {
+		if (buffA[endA] != buffB[endB])
+			break;
+		/*
+		 * don't allow matching across matching sector boundaries
+		 */
+		if ((flagsA[endA] & flagsB[endB] & 1) && endA != beginA) {
+			break;
+		}
+		/*
+		 * don't allow matching through known missing data
+		 */
+		if ((flagsA[endA] & 2) || (flagsB[endB] & 2))
+			break;
+	}
+
+	if (ret_begin)
+		*ret_begin = beginA;
+	if (ret_end)
+		*ret_end = endA;
+	return (endA - beginA);
+}
+
+/* Top level of the first stage matcher */
+
+/*
+ * We match each analysis point of new to the preexisting blocks
+ * recursively.  We can also optionally maintain a list of fragments of
+ * the preexisting block that didn't match anything, and match them back
+ * afterward.
+ */
+#define	OVERLAP_ADJ	(MIN_WORDS_OVERLAP/2-1)
+
+static inline long
+do_const_sync(c_block *A, sort_info *B, Uchar *flagB, long posA, long posB, 
+              long *begin, long *end, long *offset)
+{
+	Uchar		*flagA = A->flags;
+	long		ret = 0;
+
+	if (flagB == NULL)
+		ret = i_paranoia_overlap(cv(A), iv(B), posA, posB,
+			cs(A), is(B), begin, end);
+	else if ((flagB[posB] & 2) == 0)
+		ret = i_paranoia_overlap2(cv(A), iv(B), flagA, flagB, posA, posB, cs(A),
+			is(B), begin, end);
+
+	if (ret > MIN_WORDS_SEARCH) {
+		*offset = (posA + cb(A)) - (posB + ib(B));
+		*begin += cb(A);
+		*end += cb(A);
+		return (ret);
+	}
+	return (0);
+}
+
+/*
+ * post is w.r.t. B.  in stage one, we post from old.  In stage 2 we
+ * post from root. Begin, end, offset count from B's frame of
+ * reference
+ */
+static inline long
+try_sort_sync(cdrom_paranoia *p, sort_info *A, Uchar *Aflags, c_block *B, 
+              long post, long *begin, long *end, long *offset,
+              void (*callback)(long, int))
+{
+
+	long		dynoverlap = p->dynoverlap;
+	sort_link	*ptr = NULL;
+	Uchar		*Bflags = B->flags;
+
+	/*
+	 * block flag matches 0x02 (unmatchable)
+	 */
+	if (Bflags == NULL || (Bflags[post - cb(B)] & 2) == 0) {
+		/*
+		 * always try absolute offset zero first!
+		 */
+		{
+			long		zeropos = post - ib(A);
+
+			if (zeropos >= 0 && zeropos < is(A)) {
+				if (cv(B)[post - cb(B)] == iv(A)[zeropos]) {
+					if (do_const_sync(B, A, Aflags,
+							post - cb(B), zeropos,
+							begin, end, offset)) {
+
+						offset_add_value(p, &(p->stage1), *offset, callback);
+
+						return (1);
+					}
+				}
+			}
+		}
+	} else
+		return (0);
+
+	ptr = sort_getmatch(A, post - ib(A), dynoverlap, cv(B)[post - cb(B)]);
+
+	while (ptr) {
+
+		if (do_const_sync(B, A, Aflags,
+				post - cb(B), ipos(A, ptr),
+				begin, end, offset)) {
+			offset_add_value(p, &(p->stage1), *offset, callback);
+			return (1);
+		}
+		ptr = sort_nextmatch(A, ptr);
+	}
+
+	*begin = -1;
+	*end = -1;
+	*offset = -1;
+	return (0);
+}
+
+static inline void
+stage1_matched(c_block *old, c_block *new, long matchbegin, long matchend, 
+               long matchoffset, void (*callback)(long, int))
+{
+	long		i;
+	long		oldadjbegin = matchbegin - cb(old);
+	long		oldadjend = matchend - cb(old);
+	long		newadjbegin = matchbegin - matchoffset - cb(new);
+	long		newadjend = matchend - matchoffset - cb(new);
+
+	if (matchbegin - matchoffset <= cb(new) ||
+		matchbegin <= cb(old) ||
+		(new->flags[newadjbegin] & 1) ||
+		(old->flags[oldadjbegin] & 1)) {
+		if (matchoffset)
+			if (callback)
+				(*callback) (matchbegin, PARANOIA_CB_FIXUP_EDGE);
+	} else if (callback)
+		(*callback) (matchbegin, PARANOIA_CB_FIXUP_ATOM);
+
+	if (matchend - matchoffset >= ce(new) ||
+		(new->flags[newadjend] & 1) ||
+		matchend >= ce(old) ||
+		(old->flags[oldadjend] & 1)) {
+		if (matchoffset)
+			if (callback)
+				(*callback) (matchend, PARANOIA_CB_FIXUP_EDGE);
+	} else if (callback)
+		(*callback) (matchend, PARANOIA_CB_FIXUP_ATOM);
+
+	/*
+	 * Mark the verification flags.  Don't mark the first or last OVERLAP/2
+	 * elements so that overlapping fragments have to overlap by OVERLAP to
+	 * actually merge. We also remove elements from the sort such that
+	 * later sorts do not have to sift through already matched data
+	 */
+	newadjbegin += OVERLAP_ADJ;
+	newadjend -= OVERLAP_ADJ;
+	for (i = newadjbegin; i < newadjend; i++)
+		new->flags[i] |= 4;	/* mark verified */
+
+	oldadjbegin += OVERLAP_ADJ;
+	oldadjend -= OVERLAP_ADJ;
+	for (i = oldadjbegin; i < oldadjend; i++)
+		old->flags[i] |= 4;	/* mark verified */
+
+}
+
+#define	CB_NULL		(void (*)(long, int))0
+
+static long 
+i_iterate_stage1(cdrom_paranoia *p, c_block *old, c_block *new, 
+                 void (*callback)(long, int))
+{
+
+	long		matchbegin = -1;
+	long		matchend = -1;
+	long		matchoffset;
+
+	/*
+	 * we no longer try to spread the stage one search area by dynoverlap
+	 */
+	long		searchend = min(ce(old), ce(new));
+	long		searchbegin = max(cb(old), cb(new));
+	long		searchsize = searchend - searchbegin;
+	sort_info	*i = p->sortcache;
+	long		ret = 0;
+	long		j;
+
+	long		tried = 0;
+	long		matched = 0;
+
+	if (searchsize <= 0)
+		return (0);
+
+	/*
+	 * match return values are in terms of the new vector, not old
+	 */
+	for (j = searchbegin; j < searchend; j += 23) {
+		if ((new->flags[j - cb(new)] & 6) == 0) {
+			tried++;
+			if (try_sort_sync(p, i, new->flags, old, j, &matchbegin, &matchend, &matchoffset,
+					callback) == 1) {
+
+				matched += matchend - matchbegin;
+
+				/*
+				 * purely cosmetic: if we're matching zeros,
+				 * don't use the callback because they will
+				 * appear to be all skewed
+				 */
+				{
+					long		jj = matchbegin - cb(old);
+					long		end = matchend - cb(old);
+
+					for (; jj < end; jj++)
+						if (cv(old)[jj] != 0)
+							break;
+					if (jj < end) {
+						stage1_matched(old, new, matchbegin, matchend, matchoffset, callback);
+					} else {
+						stage1_matched(old, new, matchbegin, matchend, matchoffset, CB_NULL);
+					}
+				}
+				ret++;
+				if (matchend - 1 > j)
+					j = matchend - 1;
+			}
+		}
+	}
+#ifdef NOISY
+	fprintf(stderr, "iterate_stage1: search area=%ld[%ld-%ld] tried=%ld matched=%ld spans=%ld\n",
+		searchsize, searchbegin, searchend, tried, matched, ret);
+#endif
+
+	return (ret);
+}
+
+static long 
+i_stage1(cdrom_paranoia *p, c_block *new, void (*callback)(long, int))
+{
+
+	long		size = cs(new);
+	c_block		*ptr = c_last(p);
+	int		ret = 0;
+	long		begin = 0;
+	long		end;
+
+	if (ptr)
+		sort_setup(p->sortcache, cv(new), &cb(new), cs(new),
+			cb(new), ce(new));
+
+	while (ptr && ptr != new) {
+
+		if (callback)
+			(*callback) (cb(new), PARANOIA_CB_VERIFY);
+		i_iterate_stage1(p, ptr, new, callback);
+
+		ptr = c_prev(ptr);
+	}
+
+	/*
+	 * parse the verified areas of new into v_fragments
+	 */
+	begin = 0;
+	while (begin < size) {
+		for (; begin < size; begin++)
+			if (new->flags[begin] & 4)
+				break;
+		for (end = begin; end < size; end++)
+			if ((new->flags[end] & 4) == 0)
+				break;
+		if (begin >= size)
+			break;
+
+		ret++;
+
+		new_v_fragment(p, new, cb(new) + max(0, begin - OVERLAP_ADJ),
+			cb(new) + min(size, end + OVERLAP_ADJ),
+			(end + OVERLAP_ADJ >= size && new->lastsector));
+
+		begin = end;
+	}
+
+	return (ret);
+}
+
+/*
+ * reconcile v_fragments to root buffer.  Free if matched, fragment/fixup root
+ * if necessary
+ *
+ * do *not* match using zero posts
+ */
+static long 
+i_iterate_stage2(cdrom_paranoia *p, v_fragment *v, sync_result *r, 
+                 void (*callback)(long, int))
+{
+	root_block	*root = &(p->root);
+	long		matchbegin = -1;
+	long		matchend = -1;
+	long		offset;
+	long		fbv;
+	long		fev;
+
+#ifdef NOISY
+	fprintf(stderr, "Stage 2 search: fbv=%ld fev=%ld\n", fb(v), fe(v));
+#endif
+
+	if (min(fe(v) + p->dynoverlap, re(root)) -
+		max(fb(v) - p->dynoverlap, rb(root)) <= 0)
+		return (0);
+
+	if (callback)
+		(*callback) (fb(v), PARANOIA_CB_VERIFY);
+
+	/*
+	 * just a bit of v; determine the correct area
+	 */
+	fbv = max(fb(v), rb(root) - p->dynoverlap);
+
+	/*
+	 * we want to avoid zeroes
+	 */
+	while (fbv < fe(v) && fv(v)[fbv - fb(v)] == 0)
+		fbv++;
+	if (fbv == fe(v))
+		return (0);
+	fev = min(min(fbv + 256, re(root) + p->dynoverlap), fe(v));
+
+	{
+		/*
+		 * spread the search area a bit.  We post from root, so
+		 * containment must strictly adhere to root
+		 */
+		long		searchend = min(fev + p->dynoverlap, re(root));
+		long		searchbegin = max(fbv - p->dynoverlap, rb(root));
+		sort_info	*i = p->sortcache;
+		long		j;
+
+		sort_setup(i, fv(v), &fb(v), fs(v), fbv, fev);
+		for (j = searchbegin; j < searchend; j += 23) {
+			while (j < searchend && rv(root)[j - rb(root)] == 0)
+				j++;
+			if (j == searchend)
+				break;
+
+			if (try_sort_sync(p, i, (Uchar *)0, rc(root), j,
+					&matchbegin, &matchend, &offset, callback)) {
+
+				r->begin = matchbegin;
+				r->end = matchend;
+				r->offset = -offset;
+				if (offset)
+					if (callback)
+						(*callback) (r->begin, PARANOIA_CB_FIXUP_EDGE);
+				return (1);
+			}
+		}
+	}
+	return (0);
+}
+
+/*
+ * simple test for a root vector that ends in silence
+ */
+static void i_silence_test(root_block *root)
+{
+	Int16_t		*vec = rv(root);
+	long		end = re(root) - rb(root) - 1;
+	long		j;
+
+	for (j = end - 1; j >= 0; j--)
+		if (vec[j] != 0)
+			break;
+	if (j < 0 || end - j > MIN_SILENCE_BOUNDARY) {
+		if (j < 0)
+			j = 0;
+		root->silenceflag = 1;
+		root->silencebegin = rb(root) + j;
+		if (root->silencebegin < root->returnedlimit)
+			root->silencebegin = root->returnedlimit;
+	}
+}
+
+/*
+ * match into silence vectors at offset zero if at all possible.  This
+ * also must be called with vectors in ascending begin order in case
+ * there are nonzero islands
+ */
+static long
+i_silence_match(root_block *root, v_fragment *v, void (*callback)(long, int))
+{
+
+	cdrom_paranoia	*p = v->p;
+	Int16_t	*vec = fv(v);
+	long		end = fs(v);
+	long		begin;
+	long		j;
+
+	/*
+	 * does this vector begin wet?
+	 */
+	if (end < MIN_SILENCE_BOUNDARY)
+		return (0);
+	for (j = 0; j < end; j++)
+		if (vec[j] != 0)
+			break;
+	if (j < MIN_SILENCE_BOUNDARY)
+		return (0);
+	j += fb(v);
+
+	/*
+	 * is the new silent section ahead of the end of the old
+	 * by < p->dynoverlap?
+	 */
+	if (fb(v) >= re(root) && fb(v) - p->dynoverlap < re(root)) {
+		/*
+		 * extend the zeroed area of root
+		 * XXX dynarrays are not needed here.
+		 */
+		long		addto = fb(v) + MIN_SILENCE_BOUNDARY - re(root);
+/*		Int16_t		avec[addto];*/
+#ifdef	HAVE_ALLOCA
+		Int16_t		*avec = alloca(addto * sizeof (Int16_t));
+#else
+		Int16_t		*avec = _pmalloc(addto * sizeof (Int16_t));
+#endif
+
+		memset(avec, 0, sizeof (avec));
+		c_append(rc(root), avec, addto);
+#ifndef	HAVE_ALLOCA
+		_pfree(avec);
+#endif
+	}
+	/*
+	 * do we have an 'effortless' overlap?
+	 */
+	begin = max(fb(v), root->silencebegin);
+	end = min(j, re(root));
+
+	if (begin < end) {
+		/*
+		 * don't use it unless it will extend...
+		 */
+		if (fe(v) > re(root)) {
+			long		voff = begin - fb(v);
+
+			c_remove(rc(root), begin - rb(root), -1);
+			c_append(rc(root), vec + voff, fs(v) - voff);
+		}
+		offset_add_value(p, &p->stage2, 0, callback);
+
+	} else {
+		if (j < begin) {
+			/*
+			 * OK, we'll have to force it a bit as the root is
+			 * jittered forward
+			 */
+			long		voff = j - fb(v);
+
+			/*
+			 * don't use it unless it will extend...
+			 */
+			if (begin + fs(v) - voff > re(root)) {
+				c_remove(rc(root), root->silencebegin - rb(root), -1);
+				c_append(rc(root), vec + voff, fs(v) - voff);
+			}
+			offset_add_value(p, &p->stage2, end - begin, callback);
+		} else
+			return (0);
+	}
+
+	/*
+	 * test the new root vector for ending in silence
+	 */
+	root->silenceflag = 0;
+	i_silence_test(root);
+
+	if (v->lastsector)
+		root->lastsector = 1;
+	free_v_fragment(v);
+	return (1);
+}
+
+static long
+i_stage2_each(root_block *root, v_fragment *v, void (*callback)(long, int))
+{
+
+	cdrom_paranoia *p = v->p;
+	long		dynoverlap = p->dynoverlap / 2 * 2;
+
+	if (!v || !v->one)
+		return (0);
+
+	if (!rv(root)) {
+		return (0);
+	} else {
+		sync_result	r;
+
+		if (i_iterate_stage2(p, v, &r, callback)) {
+
+			long		begin = r.begin - rb(root);
+			long		end = r.end - rb(root);
+			long		offset = r.begin + r.offset - fb(v) - begin;
+			long		temp;
+			c_block		*l = NULL;
+
+			/*
+			 * we have a match! We don't rematch off rift, we chase
+			 * the match all the way to both extremes doing rift
+			 * analysis.
+			 */
+#ifdef NOISY
+			fprintf(stderr, "Stage 2 match\n");
+#endif
+
+			/*
+			 * chase backward
+			 * note that we don't extend back right now, only
+			 * forward.
+			 */
+			while ((begin + offset > 0 && begin > 0)) {
+				long		matchA = 0,
+						matchB = 0,
+						matchC = 0;
+				long		beginL = begin + offset;
+
+				if (l == NULL) {
+					Int16_t	*buff = _pmalloc(fs(v) * sizeof (Int16_t));
+
+					l = c_alloc(buff, fb(v), fs(v));
+					memcpy(buff, fv(v), fs(v) * sizeof (Int16_t));
+				}
+				i_analyze_rift_r(rv(root), cv(l),
+					rs(root), cs(l),
+					begin - 1, beginL - 1,
+					&matchA, &matchB, &matchC);
+
+#ifdef NOISY
+				fprintf(stderr, "matching rootR: matchA:%ld matchB:%ld matchC:%ld\n",
+					matchA, matchB, matchC);
+#endif
+
+				if (matchA) {
+					/*
+					 * a problem with root
+					 */
+					if (matchA > 0) {
+						/*
+						 * dropped bytes; add back from v
+						 */
+						if (callback)
+							(*callback) (begin + rb(root) - 1, PARANOIA_CB_FIXUP_DROPPED);
+						if (rb(root) + begin < p->root.returnedlimit)
+							break;
+						else {
+							c_insert(rc(root), begin, cv(l) + beginL - matchA,
+								matchA);
+							offset -= matchA;
+							begin += matchA;
+							end += matchA;
+						}
+					} else {
+						/*
+						 * duplicate bytes; drop from root
+						 */
+						if (callback)
+							(*callback) (begin + rb(root) - 1, PARANOIA_CB_FIXUP_DUPED);
+						if (rb(root) + begin + matchA < p->root.returnedlimit)
+							break;
+						else {
+							c_remove(rc(root), begin + matchA, -matchA);
+							offset -= matchA;
+							begin += matchA;
+							end += matchA;
+						}
+					}
+				} else if (matchB) {
+					/*
+					 * a problem with the fragment
+					 */
+					if (matchB > 0) {
+						/*
+						 * dropped bytes
+						 */
+						if (callback)
+							(*callback) (begin + rb(root) - 1, PARANOIA_CB_FIXUP_DROPPED);
+						c_insert(l, beginL, rv(root) + begin - matchB,
+							matchB);
+						offset += matchB;
+					} else {
+						/*
+						 * duplicate bytes
+						 */
+						if (callback)
+							(*callback) (begin + rb(root) - 1, PARANOIA_CB_FIXUP_DUPED);
+						c_remove(l, beginL + matchB, -matchB);
+						offset += matchB;
+					}
+				} else if (matchC) {
+					/*
+					 * Uhh... problem with both
+					 * Set 'disagree' flags in root
+					 */
+					if (rb(root) + begin - matchC < p->root.returnedlimit)
+						break;
+					c_overwrite(rc(root), begin - matchC,
+						cv(l) + beginL - matchC, matchC);
+
+				} else {
+					/*
+					 * do we have a mismatch due to silence
+					 * beginning/end case?
+					 * in the 'chase back' case, we don't
+					 * do anything.
+					 * Did not determine nature of
+					 * difficulty... report and bail
+					 */
+					/* RRR(*callback)(post,PARANOIA_CB_XXX); */
+					break;
+				}
+				/*
+				 * not the most efficient way, but it will do
+				 * for now
+				 */
+				beginL = begin + offset;
+				i_paranoia_overlap(rv(root), cv(l),
+					begin, beginL,
+					rs(root), cs(l),
+					&begin, &end);
+			}
+
+			/*
+			 * chase forward
+			 */
+			temp = l ? cs(l) : fs(v);
+			while (end + offset < temp && end < rs(root)) {
+				long	matchA = 0,
+					matchB = 0,
+					matchC = 0;
+				long	beginL = begin + offset;
+				long	endL = end + offset;
+
+				if (l == NULL) {
+					Int16_t	*buff = _pmalloc(fs(v) * sizeof (Int16_t));
+
+					l = c_alloc(buff, fb(v), fs(v));
+					memcpy(buff, fv(v), fs(v) * sizeof (Int16_t));
+				}
+				i_analyze_rift_f(rv(root), cv(l),
+					rs(root), cs(l),
+					end, endL,
+					&matchA, &matchB, &matchC);
+
+#ifdef NOISY
+				fprintf(stderr, "matching rootF: matchA:%ld matchB:%ld matchC:%ld\n",
+					matchA, matchB, matchC);
+#endif
+
+				if (matchA) {
+					/*
+					 * a problem with root
+					 */
+					if (matchA > 0) {
+						/*
+						 * dropped bytes; add back from v
+						 */
+						if (callback)
+							(*callback) (end + rb(root), PARANOIA_CB_FIXUP_DROPPED);
+						if (end + rb(root) < p->root.returnedlimit)
+							break;
+						c_insert(rc(root), end, cv(l) + endL, matchA);
+					} else {
+						/*
+						 * duplicate bytes; drop from root
+						 */
+						if (callback)
+							(*callback) (end + rb(root), PARANOIA_CB_FIXUP_DUPED);
+						if (end + rb(root) < p->root.returnedlimit)
+							break;
+						c_remove(rc(root), end, -matchA);
+					}
+				} else if (matchB) {
+					/*
+					 * a problem with the fragment
+					 */
+					if (matchB > 0) {
+						/*
+						 * dropped bytes
+						 */
+						if (callback)
+							(*callback) (end + rb(root), PARANOIA_CB_FIXUP_DROPPED);
+						c_insert(l, endL, rv(root) + end, matchB);
+					} else {
+						/*
+						 * duplicate bytes
+						 */
+						if (callback)
+							(*callback) (end + rb(root), PARANOIA_CB_FIXUP_DUPED);
+						c_remove(l, endL, -matchB);
+					}
+				} else if (matchC) {
+					/*
+					 * Uhh... problem with both
+					 * Set 'disagree' flags in root
+					 */
+					if (end + rb(root) < p->root.returnedlimit)
+						break;
+					c_overwrite(rc(root), end, cv(l) + endL, matchC);
+				} else {
+					analyze_rift_silence_f(rv(root), cv(l),
+						rs(root), cs(l),
+						end, endL,
+						&matchA, &matchB);
+					if (matchA) {
+						/*
+						 * silence in root
+						 * Can only do this if we haven't
+						 * already returned data
+						 */
+						if (end + rb(root) >= p->root.returnedlimit) {
+							c_remove(rc(root), end, -1);
+						}
+					} else if (matchB) {
+						/*
+						 * silence in fragment; lose it
+						 */
+						if (l)
+							i_cblock_destructor(l);
+						free_v_fragment(v);
+						return (1);
+
+					} else {
+						/*
+						 * Could not determine nature of
+						 * difficulty... report and bail
+						 */
+						/* RRR(*callback)(post,PARANOIA_CB_XXX); */
+					}
+					break;
+				}
+				/*
+				 * not the most efficient way, but it will do for now
+				 */
+				i_paranoia_overlap(rv(root), cv(l),
+					begin, beginL,
+					rs(root), cs(l),
+					(long *)0, &end);
+			}
+
+			/*
+			 * if this extends our range, let's glom
+			 */
+			{
+				long	sizeA = rs(root);
+				long	sizeB;
+				long	vecbegin;
+				Int16_t	*vector;
+
+				if (l) {
+					sizeB = cs(l);
+					vector = cv(l);
+					vecbegin = cb(l);
+				} else {
+					sizeB = fs(v);
+					vector = fv(v);
+					vecbegin = fb(v);
+				}
+
+				if (sizeB - offset > sizeA || v->lastsector) {
+					if (v->lastsector) {
+						root->lastsector = 1;
+					}
+					if (end < sizeA)
+						c_remove(rc(root), end, -1);
+
+					if (sizeB - offset - end)
+						c_append(rc(root), vector + end + offset,
+							sizeB - offset - end);
+
+					i_silence_test(root);
+
+					/*
+					 * add offset into dynoverlap stats
+					 */
+					offset_add_value(p, &p->stage2, offset + vecbegin - rb(root), callback);
+				}
+			}
+			if (l)
+				i_cblock_destructor(l);
+			free_v_fragment(v);
+			return (1);
+
+		} else {
+			/*
+			 * D'oh.  No match.  What to do with the fragment?
+			 */
+			if (fe(v) + dynoverlap < re(root) && !root->silenceflag) {
+				/*
+				 * It *should* have matched.  No good; free it.
+				 */
+				free_v_fragment(v);
+			}
+			/*
+			 * otherwise, we likely want this for an upcoming match
+			 * we don't free the sort info (if it was collected)
+			 */
+			return (0);
+
+		}
+	}
+}
+
+static int
+i_init_root(root_block *root, v_fragment *v, long begin, 
+            void (*callback)(long, int))
+{
+	if (fb(v) <= begin && fe(v) > begin) {
+
+		root->lastsector = v->lastsector;
+		root->returnedlimit = begin;
+
+		if (rv(root)) {
+			i_cblock_destructor(rc(root));
+			rc(root) = NULL;
+		}
+		{
+			Int16_t		*buff = _pmalloc(fs(v) * sizeof (Int16_t));
+
+			memcpy(buff, fv(v), fs(v) * sizeof (Int16_t));
+			root->vector = c_alloc(buff, fb(v), fs(v));
+		}
+		i_silence_test(root);
+
+		return (1);
+	} else
+		return (0);
+}
+
+static int vsort(const void *a, const void *b)
+{
+	return ((*(v_fragment **) a)->begin - (*(v_fragment **) b)->begin);
+}
+
+static int
+i_stage2(cdrom_paranoia *p, long beginword, long endword, 
+         void (*callback)(long, int))
+{
+
+	int		flag = 1;
+	int		ret = 0;
+	root_block	*root = &(p->root);
+
+#ifdef NOISY
+	fprintf(stderr, "Fragments:%ld\n", p->fragments->active);
+	fflush(stderr);
+#endif
+
+	/*
+	 * even when the 'silence flag' is lit, we try to do non-silence
+	 * matching in the event that there are still audio vectors with
+	 * content to be sunk before the silence
+	 */
+	while (flag) {
+		/*
+		 * loop through all the current fragments
+		 */
+		v_fragment	*first = v_first(p);
+		long		active = p->fragments->active,
+				count = 0;
+#ifdef	HAVE_DYN_ARRAYS
+		v_fragment	*list[active];
+#else
+		v_fragment	**list = _pmalloc(active * sizeof (v_fragment *));
+#endif
+
+		while (first) {
+			v_fragment	*next = v_next(first);
+
+			list[count++] = first;
+			first = next;
+		}
+
+		flag = 0;
+		if (count) {
+			/*
+			 * sorted in ascending order of beginning
+			 */
+			qsort(list, active, sizeof (v_fragment *), vsort);
+
+			/*
+			 * we try a nonzero based match even if in silent mode
+			 * in the case that there are still cached vectors to
+			 * sink behind continent->ocean boundary
+			 */
+			for (count = 0; count < active; count++) {
+				first = list[count];
+				if (first->one) {
+					if (rv(root) == NULL) {
+						if (i_init_root(&(p->root), first, beginword, callback)) {
+							free_v_fragment(first);
+							flag = 1;
+							ret++;
+						}
+					} else {
+						if (i_stage2_each(root, first, callback)) {
+							ret++;
+							flag = 1;
+						}
+					}
+				}
+			}
+
+			/*
+			 * silence handling
+			 */
+			if (!flag && p->root.silenceflag) {
+				for (count = 0; count < active; count++) {
+					first = list[count];
+					if (first->one) {
+						if (rv(root) != NULL) {
+							if (i_silence_match(root, first, callback)) {
+								ret++;
+								flag = 1;
+							}
+						}
+					}
+				}
+			}
+		}
+#ifndef	HAVE_DYN_ARRAYS
+		_pfree(list);
+#endif
+	}
+	return (ret);
+}
+
+static void
+i_end_case(cdrom_paranoia *p, long endword, void (*callback)(long, int))
+{
+
+	root_block	*root = &p->root;
+
+	/*
+	 * have an 'end' flag; if we've just read in the last sector in a
+	 * session, set the flag.  If we verify to the end of a fragment
+	 * which has the end flag set, we're done (set a done flag).
+	 * Pad zeroes to the end of the read
+	 */
+	if (root->lastsector == 0)
+		return;
+	if (endword < re(root))
+		return;
+
+	{
+		long		addto = endword - re(root);
+		char		*temp = _pcalloc(addto, sizeof (char) * 2);
+
+		c_append(rc(root), (void *) temp, addto);
+		_pfree(temp);
+
+		/*
+		 * trash da cache
+		 */
+		paranoia_resetcache(p);
+
+	}
+}
+
+/*
+ * We want to add a sector. Look through the caches for something that
+ * spans.  Also look at the flags on the c_block... if this is an
+ * obliterated sector, get a bit of a chunk past the obliteration.
+ *
+ * Not terribly smart right now, actually.  We can probably find
+ * *some* match with a cache block somewhere.  Take it and continue it
+ * through the skip
+ */
+static void
+verify_skip_case(cdrom_paranoia *p, void (*callback)(long, int))
+{
+
+	root_block	*root = &(p->root);
+	c_block		*graft = NULL;
+	int		vflag = 0;
+	int		gend = 0;
+	long		post;
+
+#ifdef NOISY
+	fprintf(stderr, "\nskipping\n");
+#endif
+
+	if (rv(root) == NULL) {
+		post = 0;
+	} else {
+		post = re(root);
+	}
+	if (post == -1)
+		post = 0;
+
+	if (callback)
+		(*callback) (post, PARANOIA_CB_SKIP);
+
+	if (p->enable & PARANOIA_MODE_NEVERSKIP)
+		return;
+
+	/*
+	 * We want to add a sector.  Look for a c_block that spans,
+	 * preferrably a verified area
+	 */
+	{
+		c_block		*c = c_first(p);
+
+		while (c) {
+			long		cbegin = cb(c);
+			long		cend = ce(c);
+
+			if (cbegin <= post && cend > post) {
+				long		vend = post;
+
+				if (c->flags[post - cbegin] & 4) {
+					/*
+					 * verified area!
+					 */
+					while (vend < cend && (c->flags[vend - cbegin] & 4))
+						vend++;
+					if (!vflag || vend > vflag) {
+						graft = c;
+						gend = vend;
+					}
+					vflag = 1;
+				} else {
+					/*
+					 * not a verified area
+					 */
+					if (!vflag) {
+						while (vend < cend && (c->flags[vend - cbegin] & 4) == 0)
+							vend++;
+						if (graft == NULL || gend > vend) {
+							/*
+							 * smallest unverified area
+							 */
+							graft = c;
+							gend = vend;
+						}
+					}
+				}
+			}
+			c = c_next(c);
+		}
+
+		if (graft) {
+			long		cbegin = cb(graft);
+			long		cend = ce(graft);
+
+			while (gend < cend && (graft->flags[gend - cbegin] & 4))
+				gend++;
+			gend = min(gend + OVERLAP_ADJ, cend);
+
+			if (rv(root) == NULL) {
+				Int16_t	*buff = _pmalloc(cs(graft));
+
+				memcpy(buff, cv(graft), cs(graft));
+				rc(root) = c_alloc(buff, cb(graft), cs(graft));
+			} else {
+				c_append(rc(root), cv(graft) + post - cbegin,
+					gend - post);
+			}
+
+			root->returnedlimit = re(root);
+			return;
+		}
+	}
+
+	/*
+	 * No?  Fine.  Great.  Write in some zeroes :-P
+	 */
+	{
+		void	*temp = _pcalloc(CD_FRAMESIZE_RAW, sizeof (Int16_t));
+
+		if (rv(root) == NULL) {
+			rc(root) = c_alloc(temp, post, CD_FRAMESIZE_RAW);
+		} else {
+			c_append(rc(root), temp, CD_FRAMESIZE_RAW);
+			_pfree(temp);
+		}
+		root->returnedlimit = re(root);
+	}
+}
+
+/*
+ * toplevel
+ */
+void paranoia_free(cdrom_paranoia *p)
+{
+	paranoia_resetall(p);
+	sort_free(p->sortcache);
+	_pfree(p);
+}
+
+void paranoia_modeset(cdrom_paranoia *p, int enable)
+{
+	p->enable = enable;
+}
+
+long paranoia_seek(cdrom_paranoia *p, long seek, int mode)
+{
+	long	sector;
+	long	ret;
+
+	switch (mode) {
+	case SEEK_SET:
+		sector = seek;
+		break;
+	case SEEK_END:
+		sector = cdda_disc_lastsector(p->d) + seek;
+		break;
+	default:
+		sector = p->cursor + seek;
+		break;
+	}
+
+	if (cdda_sector_gettrack(p->d, sector) == -1)
+		return (-1);
+
+	i_cblock_destructor(p->root.vector);
+	p->root.vector = NULL;
+	p->root.lastsector = 0;
+	p->root.returnedlimit = 0;
+
+	ret = p->cursor;
+	p->cursor = sector;
+
+	i_paranoia_firstlast(p);
+
+	/*
+	 * Evil hack to fix pregap patch for NEC drives! To be rooted out in a10
+	 */
+	p->current_firstsector = sector;
+
+	return (ret);
+}
+
+/*
+ * returns last block read, -1 on error
+ */
+c_block *i_read_c_block(cdrom_paranoia *p, long beginword, long endword, 
+                        void (*callback)(long, int))
+{
+	/*
+	 * why do it this way?  We need to read lots of sectors to kludge
+	 * around stupid read ahead buffers on cheap drives, as well as avoid
+	 * expensive back-seeking. We also want to 'jiggle' the start address
+	 * to try to break borderline drives more noticeably (and make broken
+	 * drives with unaddressable sectors behave more often).
+	 */
+	long		readat;
+	long		firstread;
+	long		totaltoread = p->readahead;
+	long		sectatonce = p->nsectors;
+	long		driftcomp = (float) p->dyndrift / CD_FRAMEWORDS + .5;
+	c_block		*new = NULL;
+	root_block	*root = &p->root;
+	Int16_t		*buffer = NULL;
+	void		*bufbase = NULL;
+	Uchar		*flags = NULL;
+	long		sofar;
+	long		dynoverlap = (p->dynoverlap + CD_FRAMEWORDS - 1) / CD_FRAMEWORDS;
+	long		anyflag = 0;
+	int		reduce = 0;
+static	int		pagesize = -1;
+#define	valign(x, a)	(((char *)(x)) + ((a) - 1 - ((((UIntptr_t)(x))-1)%(a))))
+
+	/*
+	 * What is the first sector to read?  want some pre-buffer if we're not
+	 * at the extreme beginning of the disc
+	 */
+	if (p->enable & (PARANOIA_MODE_VERIFY | PARANOIA_MODE_OVERLAP)) {
+
+		/*
+		 * we want to jitter the read alignment boundary
+		 */
+		long	target;
+
+		if (rv(root) == NULL || rb(root) > beginword)
+			target = p->cursor - dynoverlap;
+		else
+			target = re(root) / (CD_FRAMEWORDS) - dynoverlap;
+
+		if (target + MIN_SECTOR_BACKUP > p->lastread && target <= p->lastread)
+			target = p->lastread - MIN_SECTOR_BACKUP;
+
+		/*
+		 * we want to jitter the read alignment boundary, as some
+		 * drives, beginning from a specific point, will tend to
+		 * lose bytes between sectors in the same place.  Also, as
+		 * our vectors are being made up of multiple reads, we want
+		 * the overlap boundaries to move....
+		 */
+		readat = (target & (~((long) JIGGLE_MODULO - 1))) + p->jitter;
+		if (readat > target)
+			readat -= JIGGLE_MODULO;
+		p->jitter++;
+		if (p->jitter >= JIGGLE_MODULO)
+			p->jitter = 0;
+
+	} else {
+		readat = p->cursor;
+	}
+
+	readat += driftcomp;
+
+	if (p->enable & (PARANOIA_MODE_OVERLAP | PARANOIA_MODE_VERIFY)) {
+		flags = _pcalloc(totaltoread * CD_FRAMEWORDS, 1);
+		new = new_c_block(p);
+		recover_cache(p);
+	} else {
+		/*
+		 * in the case of root it's just the buffer
+		 */
+		paranoia_resetall(p);
+		new = new_c_block(p);
+	}
+
+	/*
+	 * Do not use valloc() as valloc() in glibc is buggy and returns memory
+	 * that cannot be passed to free().
+	 */
+	if (pagesize < 0) {
+		pagesize = getpagesize();
+		if (pagesize < 0)
+			pagesize = 4096;	/* Just a guess */
+	}
+	reduce = pagesize / CD_FRAMESIZE_RAW;
+	bufbase = _pmalloc(totaltoread * CD_FRAMESIZE_RAW + pagesize);
+	buffer = (Int16_t *)valign(bufbase, pagesize);
+	sofar = 0;
+	firstread = -1;
+
+	/*
+	 * actual read loop
+	 */
+	while (sofar < totaltoread) {
+		long	secread = sectatonce;
+		long	adjread = readat;
+		long	thisread;
+
+		/*
+		 * don't under/overflow the audio session
+		 */
+		if (adjread < p->current_firstsector) {
+			secread -= p->current_firstsector - adjread;
+			adjread = p->current_firstsector;
+		}
+		if (adjread + secread - 1 > p->current_lastsector)
+			secread = p->current_lastsector - adjread + 1;
+
+		if (sofar + secread > totaltoread)
+			secread = totaltoread - sofar;
+
+		/*
+		 * If we are inside the buffer, the transfers are no longer
+		 * page aligned. Reduce the transfer size to avoid problems.
+		 * Such problems are definitely known to appear on FreeBSD.
+		 */
+		if ((sofar > 0) && (secread > (sectatonce - reduce)))
+			secread = sectatonce - reduce;
+
+		if (secread > 0) {
+
+			if (firstread < 0)
+				firstread = adjread;
+			if ((thisread = cdda_read(p->d, buffer + sofar * CD_FRAMEWORDS, adjread,
+						secread)) < secread) {
+
+				if (thisread < 0)
+					thisread = 0;
+
+				/*
+				 * Uhhh... right.  Make something up. But
+				 * don't make us seek backward!
+				 */
+				if (callback)
+					(*callback) ((adjread + thisread) * CD_FRAMEWORDS, PARANOIA_CB_READERR);
+				memset(buffer + (sofar + thisread) * CD_FRAMEWORDS, 0,
+					CD_FRAMESIZE_RAW * (secread - thisread));
+				if (flags)
+					memset(flags + (sofar + thisread) * CD_FRAMEWORDS, 2,
+						CD_FRAMEWORDS * (secread - thisread));
+			}
+			if (thisread != 0)
+				anyflag = 1;
+
+			if (flags && sofar != 0) {
+				/*
+				 * Don't verify across overlaps that are too
+				 * close to one another
+				 */
+				int	i = 0;
+
+				for (i = -MIN_WORDS_OVERLAP / 2; i < MIN_WORDS_OVERLAP / 2; i++)
+					flags[sofar * CD_FRAMEWORDS + i] |= 1;
+			}
+			p->lastread = adjread + secread;
+
+			if (adjread + secread - 1 == p->current_lastsector)
+				new->lastsector = -1;
+
+			if (callback)
+				(*callback) ((adjread + secread - 1) * CD_FRAMEWORDS, PARANOIA_CB_READ);
+
+			sofar += secread;
+			readat = adjread + secread;
+		} else if (readat < p->current_firstsector) {
+			readat += sectatonce;
+						/*
+						 * due to being before the
+						 * readable area
+						 */
+		} else {
+			break;	/* due to being past the readable area */
+		}
+	}
+
+	if (anyflag) {
+		new->vector = _pmalloc(totaltoread * CD_FRAMESIZE_RAW);
+		memcpy(new->vector, buffer, totaltoread * CD_FRAMESIZE_RAW);
+		_pfree(bufbase);
+
+		new->begin = firstread * CD_FRAMEWORDS - p->dyndrift;
+		new->size = sofar * CD_FRAMEWORDS;
+		new->flags = flags;
+	} else {
+		if (new)
+			free_c_block(new);
+		if (bufbase)
+			_pfree(bufbase);
+		if (flags)
+			_pfree(flags);
+		new = NULL;
+		bufbase = NULL;
+		flags = NULL;
+	}
+	return (new);
+}
+
+/*
+ * The returned buffer is *not* to be freed by the caller.  It will
+ * persist only until the next call to paranoia_read() for this p
+ */
+Int16_t *paranoia_read(cdrom_paranoia *p, void (*callback)(long, int))
+{
+	return (paranoia_read_limited(p, callback, 20));
+}
+
+/*
+ * I added max_retry functionality this way in order to avoid breaking any
+ * old apps using the nerw libs.  cdparanoia 9.8 will need the updated libs,
+ * but nothing else will require it.
+ */
+Int16_t *paranoia_read_limited(cdrom_paranoia *p, void (*callback)(long, int),
+                               int max_retries)
+{
+	long		beginword = p->cursor * (CD_FRAMEWORDS);
+	long		endword = beginword + CD_FRAMEWORDS;
+	long		retry_count = 0;
+	long		lastend = -2;
+	root_block	*root = &p->root;
+
+	if (beginword > p->root.returnedlimit)
+		p->root.returnedlimit = beginword;
+	lastend = re(root);
+
+	/*
+	 * First, is the sector we want already in the root?
+	 */
+	while (rv(root) == NULL ||
+		rb(root) > beginword ||
+		(re(root) < endword + p->maxdynoverlap &&
+			p->enable & (PARANOIA_MODE_VERIFY | PARANOIA_MODE_OVERLAP)) ||
+		re(root) < endword) {
+
+		/*
+		 * Nope; we need to build or extend the root verified range
+		 */
+		if (p->enable & (PARANOIA_MODE_VERIFY | PARANOIA_MODE_OVERLAP)) {
+			i_paranoia_trim(p, beginword, endword);
+			recover_cache(p);
+			if (rb(root) != -1 && p->root.lastsector)
+				i_end_case(p, endword + p->maxdynoverlap,
+					callback);
+			else
+				i_stage2(p, beginword,
+					endword + p->maxdynoverlap,
+					callback);
+		} else
+			i_end_case(p, endword + p->maxdynoverlap,
+				callback);	/* only trips if we're already */
+						/* done */
+
+		if (!(rb(root) == -1 || rb(root) > beginword ||
+				re(root) < endword + p->maxdynoverlap))
+			break;
+
+		/*
+		 * Hmm, need more.  Read another block
+		 */
+		{
+			c_block	*new = i_read_c_block(p, beginword, endword, callback);
+
+			if (new) {
+				if (p->enable & (PARANOIA_MODE_OVERLAP | PARANOIA_MODE_VERIFY)) {
+
+					if (p->enable & PARANOIA_MODE_VERIFY)
+						i_stage1(p, new, callback);
+					else {
+						/*
+						 * just make v_fragments from the
+						 * boundary information.
+						 */
+						long	begin = 0,
+							end = 0;
+
+						while (begin < cs(new)) {
+							while (end < cs(new) && (new->flags[begin] & 1))
+								begin++;
+							end = begin + 1;
+							while (end < cs(new) && (new->flags[end] & 1) == 0)
+								end++;
+							{
+								new_v_fragment(p, new, begin + cb(new),
+									end + cb(new),
+									(new->lastsector && cb(new) + end == ce(new)));
+							}
+							begin = end;
+						}
+					}
+
+				} else {
+
+					if (p->root.vector)
+						i_cblock_destructor(p->root.vector);
+					free_elem(new->e, 0);
+					p->root.vector = new;
+
+					i_end_case(p, endword + p->maxdynoverlap,
+						callback);
+
+				}
+			}
+		}
+
+		/*
+		 * Are we doing lots of retries?  **********************
+		 *
+		 * Check unaddressable sectors first.  There's no backoff
+		 * here; jiggle and minimum backseek handle that for us
+		 */
+		if (rb(root) != -1 && lastend + 588 < re(root)) {
+			/*
+			 * If we've not grown half a sector
+			 */
+			lastend = re(root);
+			retry_count = 0;
+		} else {
+			/*
+			 * increase overlap or bail
+			 */
+			retry_count++;
+
+			/*
+			 * The better way to do this is to look at how many
+			 * actual matches we're getting and what kind of gap
+			 */
+			if (retry_count % 5 == 0) {
+				if (p->dynoverlap == p->maxdynoverlap ||
+						retry_count == max_retries) {
+					verify_skip_case(p, callback);
+					retry_count = 0;
+				} else {
+					if (p->stage1.offpoints != -1) {	/* hack */
+						p->dynoverlap *= 1.5;
+						if (p->dynoverlap > p->maxdynoverlap)
+							p->dynoverlap = p->maxdynoverlap;
+						if (callback)
+							(*callback) (p->dynoverlap, PARANOIA_CB_OVERLAP);
+					}
+				}
+			}
+		}
+	}
+	p->cursor++;
+
+	return (rv(root) + (beginword - rb(root)));
+}
+
+/*
+ * a temporary hack
+ */
+void paranoia_overlapset(cdrom_paranoia *p, long overlap)
+{
+	p->dynoverlap = overlap * CD_FRAMEWORDS;
+	p->stage1.offpoints = -1;
+}