diff --git a/code/libvorbis-1.3.4/lib/block.c b/code/libvorbis-1.3.4/lib/block.c
index 57dfe896..345c0427 100644
--- a/code/libvorbis-1.3.4/lib/block.c
+++ b/code/libvorbis-1.3.4/lib/block.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: PCM data vector blocking, windowing and dis/reassembly
- last mod: $Id: block.c 19031 2013-12-03 19:20:50Z tterribe $
+ last mod: $Id: block.c 19457 2015-03-03 00:15:29Z giles $
 
  Handle windowing, overlap-add, etc of the PCM vectors.  This is made
  more amusing by Vorbis' current two allowed block sizes.
@@ -31,16 +31,6 @@
 #include "registry.h"
 #include "misc.h"
 
-static int ilog2(unsigned int v){
-  int ret=0;
-  if(v)--v;
-  while(v){
-    ret++;
-    v>>=1;
-  }
-  return(ret);
-}
-
 /* pcm accumulator examples (not exhaustive):
 
  <-------------- lW ---------------->
@@ -184,14 +174,19 @@ static int _vds_shared_init(vorbis_dsp_state *v,vorbis_info *vi,int encp){
   private_state *b=NULL;
   int hs;
 
-  if(ci==NULL) return 1;
+  if(ci==NULL||
+     ci->modes<=0||
+     ci->blocksizes[0]<64||
+     ci->blocksizes[1]<ci->blocksizes[0]){
+    return 1;
+  }
   hs=ci->halfrate_flag;
 
   memset(v,0,sizeof(*v));
   b=v->backend_state=_ogg_calloc(1,sizeof(*b));
 
   v->vi=vi;
-  b->modebits=ilog2(ci->modes);
+  b->modebits=ov_ilog(ci->modes-1);
 
   b->transform[0]=_ogg_calloc(VI_TRANSFORMB,sizeof(*b->transform[0]));
   b->transform[1]=_ogg_calloc(VI_TRANSFORMB,sizeof(*b->transform[1]));
@@ -204,8 +199,14 @@ static int _vds_shared_init(vorbis_dsp_state *v,vorbis_info *vi,int encp){
   mdct_init(b->transform[1][0],ci->blocksizes[1]>>hs);
 
   /* Vorbis I uses only window type 0 */
-  b->window[0]=ilog2(ci->blocksizes[0])-6;
-  b->window[1]=ilog2(ci->blocksizes[1])-6;
+  /* note that the correct computation below is technically:
+       b->window[0]=ov_ilog(ci->blocksizes[0]-1)-6;
+       b->window[1]=ov_ilog(ci->blocksizes[1]-1)-6;
+    but since blocksizes are always powers of two,
+    the below is equivalent.
+   */
+  b->window[0]=ov_ilog(ci->blocksizes[0])-7;
+  b->window[1]=ov_ilog(ci->blocksizes[1])-7;
 
   if(encp){ /* encode/decode differ here */
 
diff --git a/code/libvorbis-1.3.4/lib/codebook.c b/code/libvorbis-1.3.4/lib/codebook.c
index 72e514a4..72f8a17a 100644
--- a/code/libvorbis-1.3.4/lib/codebook.c
+++ b/code/libvorbis-1.3.4/lib/codebook.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: basic codebook pack/unpack/code/decode operations
- last mod: $Id: codebook.c 19057 2014-01-22 12:32:31Z xiphmont $
+ last mod: $Id: codebook.c 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -57,12 +57,12 @@ int vorbis_staticbook_pack(const static_codebook *c,oggpack_buffer *opb){
       char last=c->lengthlist[i-1];
       if(this>last){
         for(j=last;j<this;j++){
-          oggpack_write(opb,i-count,_ilog(c->entries-count));
+          oggpack_write(opb,i-count,ov_ilog(c->entries-count));
           count=i;
         }
       }
     }
-    oggpack_write(opb,i-count,_ilog(c->entries-count));
+    oggpack_write(opb,i-count,ov_ilog(c->entries-count));
 
   }else{
     /* length random.  Again, we don't code the codeword itself, just
@@ -159,7 +159,7 @@ static_codebook *vorbis_staticbook_unpack(oggpack_buffer *opb){
   s->entries=oggpack_read(opb,24);
   if(s->entries==-1)goto _eofout;
 
-  if(_ilog(s->dim)+_ilog(s->entries)>24)goto _eofout;
+  if(ov_ilog(s->dim)+ov_ilog(s->entries)>24)goto _eofout;
 
   /* codeword ordering.... length ordered or unordered? */
   switch((int)oggpack_read(opb,1)){
@@ -203,7 +203,7 @@ static_codebook *vorbis_staticbook_unpack(oggpack_buffer *opb){
       s->lengthlist=_ogg_malloc(sizeof(*s->lengthlist)*s->entries);
 
       for(i=0;i<s->entries;){
-        long num=oggpack_read(opb,_ilog(s->entries-i));
+        long num=oggpack_read(opb,ov_ilog(s->entries-i));
         if(num==-1)goto _eofout;
         if(length>32 || num>s->entries-i ||
            (num>0 && (num-1)>>(length-1)>1)){
@@ -312,6 +312,12 @@ STIN long decode_packed_entry_number(codebook *book, oggpack_buffer *b){
     hi=book->used_entries;
   }
 
+  /* Single entry codebooks use a firsttablen of 1 and a
+     dec_maxlength of 1.  If a single-entry codebook gets here (due to
+     failure to read one bit above), the next look attempt will also
+     fail and we'll correctly kick out instead of trying to walk the
+     underformed tree */
+
   lok = oggpack_look(b, read);
 
   while(lok<0 && read>1)
diff --git a/code/libvorbis-1.3.4/lib/codebook.h b/code/libvorbis-1.3.4/lib/codebook.h
index 15ad90f8..537d6c12 100644
--- a/code/libvorbis-1.3.4/lib/codebook.h
+++ b/code/libvorbis-1.3.4/lib/codebook.h
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2014             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: basic shared codebook operations
- last mod: $Id: codebook.h 19057 2014-01-22 12:32:31Z xiphmont $
+ last mod: $Id: codebook.h 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -89,7 +89,6 @@ extern float *_book_logdist(const static_codebook *b,float *vals);
 extern float _float32_unpack(long val);
 extern long   _float32_pack(float val);
 extern int  _best(codebook *book, float *a, int step);
-extern int _ilog(unsigned int v);
 extern long _book_maptype1_quantvals(const static_codebook *b);
 
 extern int vorbis_book_besterror(codebook *book,float *a,int step,int addmul);
diff --git a/code/libvorbis-1.3.4/lib/floor0.c b/code/libvorbis-1.3.4/lib/floor0.c
index 0b5652f4..213cce4e 100644
--- a/code/libvorbis-1.3.4/lib/floor0.c
+++ b/code/libvorbis-1.3.4/lib/floor0.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: floor backend 0 implementation
- last mod: $Id: floor0.c 19031 2013-12-03 19:20:50Z tterribe $
+ last mod: $Id: floor0.c 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -168,7 +168,7 @@ static void *floor0_inverse1(vorbis_block *vb,vorbis_look_floor *i){
   if(ampraw>0){ /* also handles the -1 out of data case */
     long maxval=(1<<info->ampbits)-1;
     float amp=(float)ampraw/maxval*info->ampdB;
-    int booknum=oggpack_read(&vb->opb,_ilog(info->numbooks));
+    int booknum=oggpack_read(&vb->opb,ov_ilog(info->numbooks));
 
     if(booknum!=-1 && booknum<info->numbooks){ /* be paranoid */
       codec_setup_info  *ci=vb->vd->vi->codec_setup;
diff --git a/code/libvorbis-1.3.4/lib/floor1.c b/code/libvorbis-1.3.4/lib/floor1.c
index c0515021..d8bd4645 100644
--- a/code/libvorbis-1.3.4/lib/floor1.c
+++ b/code/libvorbis-1.3.4/lib/floor1.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: floor backend 1 implementation
- last mod: $Id: floor1.c 19031 2013-12-03 19:20:50Z tterribe $
+ last mod: $Id: floor1.c 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -72,25 +72,6 @@ static void floor1_free_look(vorbis_look_floor *i){
   }
 }
 
-static int ilog(unsigned int v){
-  int ret=0;
-  while(v){
-    ret++;
-    v>>=1;
-  }
-  return(ret);
-}
-
-static int ilog2(unsigned int v){
-  int ret=0;
-  if(v)--v;
-  while(v){
-    ret++;
-    v>>=1;
-  }
-  return(ret);
-}
-
 static void floor1_pack (vorbis_info_floor *i,oggpack_buffer *opb){
   vorbis_info_floor1 *info=(vorbis_info_floor1 *)i;
   int j,k;
@@ -117,8 +98,10 @@ static void floor1_pack (vorbis_info_floor *i,oggpack_buffer *opb){
 
   /* save out the post list */
   oggpack_write(opb,info->mult-1,2);     /* only 1,2,3,4 legal now */
-  oggpack_write(opb,ilog2(maxposit),4);
-  rangebits=ilog2(maxposit);
+  /* maxposit cannot legally be less than 1; this is encode-side, we
+     can assume our setup is OK */
+  oggpack_write(opb,ov_ilog(maxposit-1),4);
+  rangebits=ov_ilog(maxposit-1);
 
   for(j=0,k=0;j<info->partitions;j++){
     count+=info->class_dim[info->partitionclass[j]];
@@ -854,9 +837,9 @@ int floor1_encode(oggpack_buffer *opb,vorbis_block *vb,
 
     /* beginning/end post */
     look->frames++;
-    look->postbits+=ilog(look->quant_q-1)*2;
-    oggpack_write(opb,out[0],ilog(look->quant_q-1));
-    oggpack_write(opb,out[1],ilog(look->quant_q-1));
+    look->postbits+=ov_ilog(look->quant_q-1)*2;
+    oggpack_write(opb,out[0],ov_ilog(look->quant_q-1));
+    oggpack_write(opb,out[1],ov_ilog(look->quant_q-1));
 
 
     /* partition by partition */
@@ -872,7 +855,9 @@ int floor1_encode(oggpack_buffer *opb,vorbis_block *vb,
 
       /* generate the partition's first stage cascade value */
       if(csubbits){
-        int maxval[8] = {0};
+        int maxval[8]={0,0,0,0,0,0,0,0}; /* gcc's static analysis
+                                            issues a warning without
+                                            initialization */
         for(k=0;k<csub;k++){
           int booknum=info->class_subbook[class][k];
           if(booknum<0){
@@ -980,8 +965,8 @@ static void *floor1_inverse1(vorbis_block *vb,vorbis_look_floor *in){
   if(oggpack_read(&vb->opb,1)==1){
     int *fit_value=_vorbis_block_alloc(vb,(look->posts)*sizeof(*fit_value));
 
-    fit_value[0]=oggpack_read(&vb->opb,ilog(look->quant_q-1));
-    fit_value[1]=oggpack_read(&vb->opb,ilog(look->quant_q-1));
+    fit_value[0]=oggpack_read(&vb->opb,ov_ilog(look->quant_q-1));
+    fit_value[1]=oggpack_read(&vb->opb,ov_ilog(look->quant_q-1));
 
     /* partition by partition */
     for(i=0,j=2;i<info->partitions;i++){
diff --git a/code/libvorbis-1.3.4/lib/info.c b/code/libvorbis-1.3.4/lib/info.c
index c4706b00..8a2a001f 100644
--- a/code/libvorbis-1.3.4/lib/info.c
+++ b/code/libvorbis-1.3.4/lib/info.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2010             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: maintain the info structure, info <-> header packets
- last mod: $Id: info.c 19058 2014-01-22 18:03:15Z xiphmont $
+ last mod: $Id: info.c 19441 2015-01-21 01:17:41Z xiphmont $
 
  ********************************************************************/
 
@@ -31,20 +31,10 @@
 #include "misc.h"
 #include "os.h"
 
-#define GENERAL_VENDOR_STRING "Xiph.Org libVorbis 1.3.4"
-#define ENCODE_VENDOR_STRING "Xiph.Org libVorbis I 20140122 (Turpakäräjiin)"
+#define GENERAL_VENDOR_STRING "Xiph.Org libVorbis 1.3.5"
+#define ENCODE_VENDOR_STRING "Xiph.Org libVorbis I 20150105 (⛄⛄⛄⛄)"
 
 /* helpers */
-static int ilog2(unsigned int v){
-  int ret=0;
-  if(v)--v;
-  while(v){
-    ret++;
-    v>>=1;
-  }
-  return(ret);
-}
-
 static void _v_writestring(oggpack_buffer *o,const char *s, int bytes){
 
   while(bytes--){
@@ -272,7 +262,6 @@ static int _vorbis_unpack_comment(vorbis_comment *vc,oggpack_buffer *opb){
 static int _vorbis_unpack_books(vorbis_info *vi,oggpack_buffer *opb){
   codec_setup_info     *ci=vi->codec_setup;
   int i;
-  if(!ci)return(OV_EFAULT);
 
   /* codebooks */
   ci->books=oggpack_read(opb,8)+1;
@@ -411,6 +400,10 @@ int vorbis_synthesis_headerin(vorbis_info *vi,vorbis_comment *vc,ogg_packet *op)
           /* um... we didn't get the initial header */
           return(OV_EBADHEADER);
         }
+        if(vc->vendor!=NULL){
+          /* previously initialized comment header */
+          return(OV_EBADHEADER);
+        }
 
         return(_vorbis_unpack_comment(vc,&opb));
 
@@ -419,6 +412,14 @@ int vorbis_synthesis_headerin(vorbis_info *vi,vorbis_comment *vc,ogg_packet *op)
           /* um... we didn;t get the initial header or comments yet */
           return(OV_EBADHEADER);
         }
+        if(vi->codec_setup==NULL){
+          /* improperly initialized vorbis_info */
+          return(OV_EFAULT);
+        }
+        if(((codec_setup_info *)vi->codec_setup)->books>0){
+          /* previously initialized setup header */
+          return(OV_EBADHEADER);
+        }
 
         return(_vorbis_unpack_books(vi,&opb));
 
@@ -436,7 +437,11 @@ int vorbis_synthesis_headerin(vorbis_info *vi,vorbis_comment *vc,ogg_packet *op)
 
 static int _vorbis_pack_info(oggpack_buffer *opb,vorbis_info *vi){
   codec_setup_info     *ci=vi->codec_setup;
-  if(!ci)return(OV_EFAULT);
+  if(!ci||
+     ci->blocksizes[0]<64||
+     ci->blocksizes[1]<ci->blocksizes[0]){
+    return(OV_EFAULT);
+  }
 
   /* preamble */
   oggpack_write(opb,0x01,8);
@@ -451,8 +456,8 @@ static int _vorbis_pack_info(oggpack_buffer *opb,vorbis_info *vi){
   oggpack_write(opb,vi->bitrate_nominal,32);
   oggpack_write(opb,vi->bitrate_lower,32);
 
-  oggpack_write(opb,ilog2(ci->blocksizes[0]),4);
-  oggpack_write(opb,ilog2(ci->blocksizes[1]),4);
+  oggpack_write(opb,ov_ilog(ci->blocksizes[0]-1),4);
+  oggpack_write(opb,ov_ilog(ci->blocksizes[1]-1),4);
   oggpack_write(opb,1,1);
 
   return(0);
@@ -578,7 +583,7 @@ int vorbis_analysis_headerout(vorbis_dsp_state *v,
   oggpack_buffer opb;
   private_state *b=v->backend_state;
 
-  if(!b){
+  if(!b||vi->channels<=0){
     ret=OV_EFAULT;
     goto err_out;
   }
diff --git a/code/libvorbis-1.3.4/lib/lsp.c b/code/libvorbis-1.3.4/lib/lsp.c
index b1b3aa6e..6a619f7b 100644
--- a/code/libvorbis-1.3.4/lib/lsp.c
+++ b/code/libvorbis-1.3.4/lib/lsp.c
@@ -11,7 +11,7 @@
  ********************************************************************
 
   function: LSP (also called LSF) conversion routines
-  last mod: $Id: lsp.c 17538 2010-10-15 02:52:29Z tterribe $
+  last mod: $Id: lsp.c 19453 2015-03-02 22:35:34Z xiphmont $
 
   The LSP generation code is taken (with minimal modification and a
   few bugfixes) from "On the Computation of the LSP Frequencies" by
diff --git a/code/libvorbis-1.3.4/lib/mapping0.c b/code/libvorbis-1.3.4/lib/mapping0.c
index 7d279a85..85c7d22d 100644
--- a/code/libvorbis-1.3.4/lib/mapping0.c
+++ b/code/libvorbis-1.3.4/lib/mapping0.c
@@ -11,7 +11,7 @@
  ********************************************************************
 
  function: channel mapping 0 implementation
- last mod: $Id: mapping0.c 17022 2010-03-25 03:45:42Z xiphmont $
+ last mod: $Id: mapping0.c 19441 2015-01-21 01:17:41Z xiphmont $
 
  ********************************************************************/
 
@@ -45,16 +45,6 @@ static void mapping0_free_info(vorbis_info_mapping *i){
   }
 }
 
-static int ilog(unsigned int v){
-  int ret=0;
-  if(v)--v;
-  while(v){
-    ret++;
-    v>>=1;
-  }
-  return(ret);
-}
-
 static void mapping0_pack(vorbis_info *vi,vorbis_info_mapping *vm,
                           oggpack_buffer *opb){
   int i;
@@ -78,8 +68,8 @@ static void mapping0_pack(vorbis_info *vi,vorbis_info_mapping *vm,
     oggpack_write(opb,info->coupling_steps-1,8);
 
     for(i=0;i<info->coupling_steps;i++){
-      oggpack_write(opb,info->coupling_mag[i],ilog(vi->channels));
-      oggpack_write(opb,info->coupling_ang[i],ilog(vi->channels));
+      oggpack_write(opb,info->coupling_mag[i],ov_ilog(vi->channels-1));
+      oggpack_write(opb,info->coupling_ang[i],ov_ilog(vi->channels-1));
     }
   }else
     oggpack_write(opb,0,1);
@@ -104,6 +94,7 @@ static vorbis_info_mapping *mapping0_unpack(vorbis_info *vi,oggpack_buffer *opb)
   vorbis_info_mapping0 *info=_ogg_calloc(1,sizeof(*info));
   codec_setup_info     *ci=vi->codec_setup;
   memset(info,0,sizeof(*info));
+  if(vi->channels<=0)goto err_out;
 
   b=oggpack_read(opb,1);
   if(b<0)goto err_out;
@@ -119,8 +110,11 @@ static vorbis_info_mapping *mapping0_unpack(vorbis_info *vi,oggpack_buffer *opb)
     info->coupling_steps=oggpack_read(opb,8)+1;
     if(info->coupling_steps<=0)goto err_out;
     for(i=0;i<info->coupling_steps;i++){
-      int testM=info->coupling_mag[i]=oggpack_read(opb,ilog(vi->channels));
-      int testA=info->coupling_ang[i]=oggpack_read(opb,ilog(vi->channels));
+      /* vi->channels > 0 is enforced in the caller */
+      int testM=info->coupling_mag[i]=
+        oggpack_read(opb,ov_ilog(vi->channels-1));
+      int testA=info->coupling_ang[i]=
+        oggpack_read(opb,ov_ilog(vi->channels-1));
 
       if(testM<0 ||
          testA<0 ||
diff --git a/code/libvorbis-1.3.4/lib/misc.h b/code/libvorbis-1.3.4/lib/misc.h
index 85fe3074..73b45198 100644
--- a/code/libvorbis-1.3.4/lib/misc.h
+++ b/code/libvorbis-1.3.4/lib/misc.h
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: miscellaneous prototypes
- last mod: $Id: misc.h 16227 2009-07-08 06:58:46Z xiphmont $
+ last mod: $Id: misc.h 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -21,6 +21,7 @@
 
 extern void *_vorbis_block_alloc(vorbis_block *vb,long bytes);
 extern void _vorbis_block_ripcord(vorbis_block *vb);
+extern int ov_ilog(ogg_uint32_t v);
 
 #ifdef ANALYSIS
 extern int analysis_noisy;
diff --git a/code/libvorbis-1.3.4/lib/os.h b/code/libvorbis-1.3.4/lib/os.h
index 79dea351..8bc3e5fe 100644
--- a/code/libvorbis-1.3.4/lib/os.h
+++ b/code/libvorbis-1.3.4/lib/os.h
@@ -7,13 +7,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: #ifdef jail to whip a few platforms into the UNIX ideal.
- last mod: $Id: os.h 19031 2013-12-03 19:20:50Z tterribe $
+ last mod: $Id: os.h 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -119,8 +119,9 @@ static inline int vorbis_ftoi(double f){  /* yes, double!  Otherwise,
 
 
 /* MSVC inline assembly. 32 bit only; inline ASM isn't implemented in the
- * 64 bit compiler */
-#if defined(_MSC_VER) && !defined(_WIN64) && !defined(_WIN32_WCE)
+ * 64 bit compiler and doesn't work on arm. */
+#if defined(_MSC_VER) && !defined(_WIN64) && \
+      !defined(_WIN32_WCE) && !defined(_M_ARM)
 #  define VORBIS_FPU_CONTROL
 
 typedef ogg_int16_t vorbis_fpu_control;
diff --git a/code/libvorbis-1.3.4/lib/res0.c b/code/libvorbis-1.3.4/lib/res0.c
index 97cdbba9..ec11488c 100644
--- a/code/libvorbis-1.3.4/lib/res0.c
+++ b/code/libvorbis-1.3.4/lib/res0.c
@@ -11,7 +11,7 @@
  ********************************************************************
 
  function: residue backend 0, 1 and 2 implementation
- last mod: $Id: res0.c 19031 2013-12-03 19:20:50Z tterribe $
+ last mod: $Id: res0.c 19441 2015-01-21 01:17:41Z xiphmont $
 
  ********************************************************************/
 
@@ -152,15 +152,6 @@ void res0_free_look(vorbis_look_residue *i){
   }
 }
 
-static int ilog(unsigned int v){
-  int ret=0;
-  while(v){
-    ret++;
-    v>>=1;
-  }
-  return(ret);
-}
-
 static int icount(unsigned int v){
   int ret=0;
   while(v){
@@ -186,7 +177,7 @@ void res0_pack(vorbis_info_residue *vr,oggpack_buffer *opb){
      bitmask of one indicates this partition class has bits to write
      this pass */
   for(j=0;j<info->partitions;j++){
-    if(ilog(info->secondstages[j])>3){
+    if(ov_ilog(info->secondstages[j])>3){
       /* yes, this is a minor hack due to not thinking ahead */
       oggpack_write(opb,info->secondstages[j],3);
       oggpack_write(opb,1,1);
@@ -284,7 +275,7 @@ vorbis_look_residue *res0_look(vorbis_dsp_state *vd,
   look->partbooks=_ogg_calloc(look->parts,sizeof(*look->partbooks));
 
   for(j=0;j<look->parts;j++){
-    int stages=ilog(info->secondstages[j]);
+    int stages=ov_ilog(info->secondstages[j]);
     if(stages){
       if(stages>maxstage)maxstage=stages;
       look->partbooks[j]=_ogg_calloc(stages,sizeof(*look->partbooks[j]));
diff --git a/code/libvorbis-1.3.4/lib/sharedbook.c b/code/libvorbis-1.3.4/lib/sharedbook.c
index 250717da..6bfdf731 100644
--- a/code/libvorbis-1.3.4/lib/sharedbook.c
+++ b/code/libvorbis-1.3.4/lib/sharedbook.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: basic shared codebook operations
- last mod: $Id: sharedbook.c 19057 2014-01-22 12:32:31Z xiphmont $
+ last mod: $Id: sharedbook.c 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -26,13 +26,11 @@
 #include "scales.h"
 
 /**** pack/unpack helpers ******************************************/
-int _ilog(unsigned int v){
-  int ret=0;
-  while(v){
-    ret++;
-    v>>=1;
-  }
-  return(ret);
+
+int ov_ilog(ogg_uint32_t v){
+  int ret;
+  for(ret=0;v;ret++)v>>=1;
+  return ret;
 }
 
 /* 32 bit float (not IEEE; nonnormalized mantissa +
@@ -125,16 +123,15 @@ ogg_uint32_t *_make_words(char *l,long n,long sparsecount){
       if(sparsecount==0)count++;
   }
 
-  /* sanity check the huffman tree; an underpopulated tree must be
-     rejected. The only exception is the one-node pseudo-nil tree,
-     which appears to be underpopulated because the tree doesn't
-     really exist; there's only one possible 'codeword' or zero bits,
-     but the above tree-gen code doesn't mark that. */
-  if(sparsecount != 1){
+  /* any underpopulated tree must be rejected. */
+  /* Single-entry codebooks are a retconned extension to the spec.
+     They have a single codeword '0' of length 1 that results in an
+     underpopulated tree.  Shield that case from the underformed tree check. */
+  if(!(count==1 && marker[2]==2)){
     for(i=1;i<33;i++)
       if(marker[i] & (0xffffffffUL>>(32-i))){
-	_ogg_free(r);
-	return(NULL);
+        _ogg_free(r);
+        return(NULL);
       }
   }
 
@@ -313,9 +310,10 @@ static int sort32a(const void *a,const void *b){
 int vorbis_book_init_decode(codebook *c,const static_codebook *s){
   int i,j,n=0,tabn;
   int *sortindex;
+
   memset(c,0,sizeof(*c));
 
-  /* count actually used entries */
+  /* count actually used entries and find max length */
   for(i=0;i<s->entries;i++)
     if(s->lengthlist[i]>0)
       n++;
@@ -325,7 +323,6 @@ int vorbis_book_init_decode(codebook *c,const static_codebook *s){
   c->dim=s->dim;
 
   if(n>0){
-
     /* two different remappings go on here.
 
     First, we collapse the likely sparse codebook down only to
@@ -361,7 +358,6 @@ int vorbis_book_init_decode(codebook *c,const static_codebook *s){
       c->codelist[sortindex[i]]=codes[i];
     _ogg_free(codes);
 
-
     c->valuelist=_book_unquantize(s,n,sortindex);
     c->dec_index=_ogg_malloc(n*sizeof(*c->dec_index));
 
@@ -370,51 +366,62 @@ int vorbis_book_init_decode(codebook *c,const static_codebook *s){
         c->dec_index[sortindex[n++]]=i;
 
     c->dec_codelengths=_ogg_malloc(n*sizeof(*c->dec_codelengths));
-    for(n=0,i=0;i<s->entries;i++)
-      if(s->lengthlist[i]>0)
-        c->dec_codelengths[sortindex[n++]]=s->lengthlist[i];
-
-    c->dec_firsttablen=_ilog(c->used_entries)-4; /* this is magic */
-    if(c->dec_firsttablen<5)c->dec_firsttablen=5;
-    if(c->dec_firsttablen>8)c->dec_firsttablen=8;
-
-    tabn=1<<c->dec_firsttablen;
-    c->dec_firsttable=_ogg_calloc(tabn,sizeof(*c->dec_firsttable));
     c->dec_maxlength=0;
-
-    for(i=0;i<n;i++){
-      if(c->dec_maxlength<c->dec_codelengths[i])
-        c->dec_maxlength=c->dec_codelengths[i];
-      if(c->dec_codelengths[i]<=c->dec_firsttablen){
-        ogg_uint32_t orig=bitreverse(c->codelist[i]);
-        for(j=0;j<(1<<(c->dec_firsttablen-c->dec_codelengths[i]));j++)
-          c->dec_firsttable[orig|(j<<c->dec_codelengths[i])]=i+1;
+    for(n=0,i=0;i<s->entries;i++)
+      if(s->lengthlist[i]>0){
+        c->dec_codelengths[sortindex[n++]]=s->lengthlist[i];
+        if(s->lengthlist[i]>c->dec_maxlength)
+          c->dec_maxlength=s->lengthlist[i];
       }
-    }
 
-    /* now fill in 'unused' entries in the firsttable with hi/lo search
-       hints for the non-direct-hits */
-    {
-      ogg_uint32_t mask=0xfffffffeUL<<(31-c->dec_firsttablen);
-      long lo=0,hi=0;
+    if(n==1 && c->dec_maxlength==1){
+      /* special case the 'single entry codebook' with a single bit
+       fastpath table (that always returns entry 0 )in order to use
+       unmodified decode paths. */
+      c->dec_firsttablen=1;
+      c->dec_firsttable=_ogg_calloc(2,sizeof(*c->dec_firsttable));
+      c->dec_firsttable[0]=c->dec_firsttable[1]=1;
 
-      for(i=0;i<tabn;i++){
-        ogg_uint32_t word=i<<(32-c->dec_firsttablen);
-        if(c->dec_firsttable[bitreverse(word)]==0){
-          while((lo+1)<n && c->codelist[lo+1]<=word)lo++;
-          while(    hi<n && word>=(c->codelist[hi]&mask))hi++;
+    }else{
+      c->dec_firsttablen=ov_ilog(c->used_entries)-4; /* this is magic */
+      if(c->dec_firsttablen<5)c->dec_firsttablen=5;
+      if(c->dec_firsttablen>8)c->dec_firsttablen=8;
 
-          /* we only actually have 15 bits per hint to play with here.
-             In order to overflow gracefully (nothing breaks, efficiency
-             just drops), encode as the difference from the extremes. */
-          {
-            unsigned long loval=lo;
-            unsigned long hival=n-hi;
+      tabn=1<<c->dec_firsttablen;
+      c->dec_firsttable=_ogg_calloc(tabn,sizeof(*c->dec_firsttable));
 
-            if(loval>0x7fff)loval=0x7fff;
-            if(hival>0x7fff)hival=0x7fff;
-            c->dec_firsttable[bitreverse(word)]=
-              0x80000000UL | (loval<<15) | hival;
+      for(i=0;i<n;i++){
+        if(c->dec_codelengths[i]<=c->dec_firsttablen){
+          ogg_uint32_t orig=bitreverse(c->codelist[i]);
+          for(j=0;j<(1<<(c->dec_firsttablen-c->dec_codelengths[i]));j++)
+            c->dec_firsttable[orig|(j<<c->dec_codelengths[i])]=i+1;
+        }
+      }
+
+      /* now fill in 'unused' entries in the firsttable with hi/lo search
+         hints for the non-direct-hits */
+      {
+        ogg_uint32_t mask=0xfffffffeUL<<(31-c->dec_firsttablen);
+        long lo=0,hi=0;
+
+        for(i=0;i<tabn;i++){
+          ogg_uint32_t word=i<<(32-c->dec_firsttablen);
+          if(c->dec_firsttable[bitreverse(word)]==0){
+            while((lo+1)<n && c->codelist[lo+1]<=word)lo++;
+            while(    hi<n && word>=(c->codelist[hi]&mask))hi++;
+
+            /* we only actually have 15 bits per hint to play with here.
+               In order to overflow gracefully (nothing breaks, efficiency
+               just drops), encode as the difference from the extremes. */
+            {
+              unsigned long loval=lo;
+              unsigned long hival=n-hi;
+
+              if(loval>0x7fff)loval=0x7fff;
+              if(hival>0x7fff)hival=0x7fff;
+              c->dec_firsttable[bitreverse(word)]=
+                0x80000000UL | (loval<<15) | hival;
+            }
           }
         }
       }
diff --git a/code/libvorbis-1.3.4/lib/synthesis.c b/code/libvorbis-1.3.4/lib/synthesis.c
index 1af211d0..932d271a 100644
--- a/code/libvorbis-1.3.4/lib/synthesis.c
+++ b/code/libvorbis-1.3.4/lib/synthesis.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: single-block PCM synthesis
- last mod: $Id: synthesis.c 17474 2010-09-30 03:41:41Z gmaxwell $
+ last mod: $Id: synthesis.c 19441 2015-01-21 01:17:41Z xiphmont $
 
  ********************************************************************/
 
@@ -145,6 +145,11 @@ long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
   oggpack_buffer       opb;
   int                  mode;
 
+  if(ci==NULL || ci->modes<=0){
+    /* codec setup not properly intialized */
+    return(OV_EFAULT);
+  }
+
   oggpack_readinit(&opb,op->packet,op->bytes);
 
   /* Check the packet type */
@@ -153,18 +158,9 @@ long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
     return(OV_ENOTAUDIO);
   }
 
-  {
-    int modebits=0;
-    int v=ci->modes;
-    while(v>1){
-      modebits++;
-      v>>=1;
-    }
-
-    /* read our mode and pre/post windowsize */
-    mode=oggpack_read(&opb,modebits);
-  }
-  if(mode==-1)return(OV_EBADPACKET);
+  /* read our mode and pre/post windowsize */
+  mode=oggpack_read(&opb,ov_ilog(ci->modes-1));
+  if(mode==-1 || !ci->mode_param[mode])return(OV_EBADPACKET);
   return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
 }
 
diff --git a/code/libvorbis-1.3.4/lib/vorbisenc.c b/code/libvorbis-1.3.4/lib/vorbisenc.c
index f0f7c085..b5d621e9 100644
--- a/code/libvorbis-1.3.4/lib/vorbisenc.c
+++ b/code/libvorbis-1.3.4/lib/vorbisenc.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: simple programmatic interface for encoder mode setup
- last mod: $Id: vorbisenc.c 17028 2010-03-25 05:22:15Z xiphmont $
+ last mod: $Id: vorbisenc.c 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -903,8 +903,12 @@ int vorbis_encode_setup_vbr(vorbis_info *vi,
                             long  channels,
                             long  rate,
                             float quality){
-  codec_setup_info *ci=vi->codec_setup;
-  highlevel_encode_setup *hi=&ci->hi;
+  codec_setup_info *ci;
+  highlevel_encode_setup *hi;
+  if(rate<=0) return OV_EINVAL;
+
+  ci=vi->codec_setup;
+  hi=&ci->hi;
 
   quality+=.0000001;
   if(quality>=1.)quality=.9999;
@@ -948,9 +952,14 @@ int vorbis_encode_setup_managed(vorbis_info *vi,
                                 long nominal_bitrate,
                                 long min_bitrate){
 
-  codec_setup_info *ci=vi->codec_setup;
-  highlevel_encode_setup *hi=&ci->hi;
-  double tnominal=nominal_bitrate;
+  codec_setup_info *ci;
+  highlevel_encode_setup *hi;
+  double tnominal;
+  if(rate<=0) return OV_EINVAL;
+
+  ci=vi->codec_setup;
+  hi=&ci->hi;
+  tnominal=nominal_bitrate;
 
   if(nominal_bitrate<=0.){
     if(max_bitrate>0.){
diff --git a/code/libvorbis-1.3.4/lib/vorbisfile.c b/code/libvorbis-1.3.4/lib/vorbisfile.c
index a20d0428..1998e63f 100644
--- a/code/libvorbis-1.3.4/lib/vorbisfile.c
+++ b/code/libvorbis-1.3.4/lib/vorbisfile.c
@@ -5,13 +5,13 @@
  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
  *                                                                  *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015             *
  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
 
  function: stdio-based convenience library for opening/seeking/decoding
- last mod: $Id: vorbisfile.c 19031 2013-12-03 19:20:50Z tterribe $
+ last mod: $Id: vorbisfile.c 19457 2015-03-03 00:15:29Z giles $
 
  ********************************************************************/
 
@@ -80,11 +80,14 @@ static long _get_data(OggVorbis_File *vf){
 /* save a tiny smidge of verbosity to make the code more readable */
 static int _seek_helper(OggVorbis_File *vf,ogg_int64_t offset){
   if(vf->datasource){
-    if(!(vf->callbacks.seek_func)||
-       (vf->callbacks.seek_func)(vf->datasource, offset, SEEK_SET) == -1)
-      return OV_EREAD;
-    vf->offset=offset;
-    ogg_sync_reset(&vf->oy);
+    /* only seek if the file position isn't already there */
+    if(vf->offset != offset){
+      if(!(vf->callbacks.seek_func)||
+         (vf->callbacks.seek_func)(vf->datasource, offset, SEEK_SET) == -1)
+        return OV_EREAD;
+      vf->offset=offset;
+      ogg_sync_reset(&vf->oy);
+    }
   }else{
     /* shouldn't happen unless someone writes a broken callback */
     return OV_EFAULT;
@@ -138,14 +141,12 @@ static ogg_int64_t _get_next_page(OggVorbis_File *vf,ogg_page *og,
   }
 }
 
-/* find the latest page beginning before the current stream cursor
-   position. Much dirtier than the above as Ogg doesn't have any
-   backward search linkage.  no 'readp' as it will certainly have to
-   read. */
+/* find the latest page beginning before the passed in position. Much
+   dirtier than the above as Ogg doesn't have any backward search
+   linkage.  no 'readp' as it will certainly have to read. */
 /* returns offset or OV_EREAD, OV_FAULT */
-static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_page *og){
-  ogg_int64_t begin=vf->offset;
-  ogg_int64_t end=begin;
+static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_int64_t begin,ogg_page *og){
+  ogg_int64_t end = begin;
   ogg_int64_t ret;
   ogg_int64_t offset=-1;
 
@@ -220,11 +221,10 @@ static int _lookup_page_serialno(ogg_page *og, long *serialno_list, int n){
    info of last page of the matching serial number instead of the very
    last page.  If no page of the specified serialno is seen, it will
    return the info of last page and alter *serialno.  */
-static ogg_int64_t _get_prev_page_serial(OggVorbis_File *vf,
+static ogg_int64_t _get_prev_page_serial(OggVorbis_File *vf, ogg_int64_t begin,
                                          long *serial_list, int serial_n,
                                          int *serialno, ogg_int64_t *granpos){
   ogg_page og;
-  ogg_int64_t begin=vf->offset;
   ogg_int64_t end=begin;
   ogg_int64_t ret;
 
@@ -438,9 +438,11 @@ static ogg_int64_t _initial_pcmoffset(OggVorbis_File *vf, vorbis_info *vi){
     while((result=ogg_stream_packetout(&vf->os,&op))){
       if(result>0){ /* ignore holes */
         long thisblock=vorbis_packet_blocksize(vi,&op);
-        if(lastblock!=-1)
-          accumulated+=(lastblock+thisblock)>>2;
-        lastblock=thisblock;
+        if(thisblock>=0){
+          if(lastblock!=-1)
+            accumulated+=(lastblock+thisblock)>>2;
+          lastblock=thisblock;
+        }
       }
     }
 
@@ -494,10 +496,10 @@ static int _bisect_forward_serialno(OggVorbis_File *vf,
        down to (or just started with) a single link.  Now we need to
        find the last vorbis page belonging to the first vorbis stream
        for this link. */
-
+    searched = end;
     while(endserial != serialno){
       endserial = serialno;
-      vf->offset=_get_prev_page_serial(vf,currentno_list,currentnos,&endserial,&endgran);
+      searched=_get_prev_page_serial(vf,searched,currentno_list,currentnos,&endserial,&endgran);
     }
 
     vf->links=m+1;
@@ -518,10 +520,15 @@ static int _bisect_forward_serialno(OggVorbis_File *vf,
 
   }else{
 
+    /* last page is not in the starting stream's serial number list,
+       so we have multiple links.  Find where the stream that begins
+       our bisection ends. */
+
     long *next_serialno_list=NULL;
     int next_serialnos=0;
     vorbis_info vi;
     vorbis_comment vc;
+    int testserial = serialno+1;
 
     /* the below guards against garbage seperating the last and
        first pages of two links. */
@@ -534,10 +541,8 @@ static int _bisect_forward_serialno(OggVorbis_File *vf,
         bisect=(searched+endsearched)/2;
       }
 
-      if(bisect != vf->offset){
-        ret=_seek_helper(vf,bisect);
-        if(ret)return(ret);
-      }
+      ret=_seek_helper(vf,bisect);
+      if(ret)return(ret);
 
       last=_get_next_page(vf,&og,-1);
       if(last==OV_EREAD)return(OV_EREAD);
@@ -550,28 +555,22 @@ static int _bisect_forward_serialno(OggVorbis_File *vf,
     }
 
     /* Bisection point found */
-
     /* for the time being, fetch end PCM offset the simple way */
-    {
-      int testserial = serialno+1;
-      vf->offset = next;
-      while(testserial != serialno){
-        testserial = serialno;
-        vf->offset=_get_prev_page_serial(vf,currentno_list,currentnos,&testserial,&searchgran);
-      }
+    searched = next;
+    while(testserial != serialno){
+      testserial = serialno;
+      searched = _get_prev_page_serial(vf,searched,currentno_list,currentnos,&testserial,&searchgran);
     }
 
-    if(vf->offset!=next){
-      ret=_seek_helper(vf,next);
-      if(ret)return(ret);
-    }
+    ret=_seek_helper(vf,next);
+    if(ret)return(ret);
 
     ret=_fetch_headers(vf,&vi,&vc,&next_serialno_list,&next_serialnos,NULL);
     if(ret)return(ret);
     serialno = vf->os.serialno;
     dataoffset = vf->offset;
 
-    /* this will consume a page, however the next bistection always
+    /* this will consume a page, however the next bisection always
        starts with a raw seek */
     pcmoffset = _initial_pcmoffset(vf,&vi);
 
@@ -638,11 +637,11 @@ static int _open_seekable2(OggVorbis_File *vf){
   /* Get the offset of the last page of the physical bitstream, or, if
      we're lucky the last vorbis page of this link as most OggVorbis
      files will contain a single logical bitstream */
-  end=_get_prev_page_serial(vf,vf->serialnos+2,vf->serialnos[1],&endserial,&endgran);
+  end=_get_prev_page_serial(vf,vf->end,vf->serialnos+2,vf->serialnos[1],&endserial,&endgran);
   if(end<0)return(end);
 
   /* now determine bitstream structure recursively */
-  if(_bisect_forward_serialno(vf,0,dataoffset,vf->offset,endgran,endserial,
+  if(_bisect_forward_serialno(vf,0,dataoffset,end,endgran,endserial,
                               vf->serialnos+2,vf->serialnos[1],0)<0)return(OV_EREAD);
 
   vf->offsets[0]=0;
@@ -1421,22 +1420,41 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
     if(pos>=total)break;
   }
 
-  /* search within the logical bitstream for the page with the highest
-     pcm_pos preceding (or equal to) pos.  There is a danger here;
-     missing pages or incorrect frame number information in the
-     bitstream could make our task impossible.  Account for that (it
-     would be an error condition) */
+  /* Search within the logical bitstream for the page with the highest
+     pcm_pos preceding pos.  If we're looking for a position on the
+     first page, bisection will halt without finding our position as
+     it's before the first explicit granulepos fencepost. That case is
+     handled separately below.
+
+     There is a danger here; missing pages or incorrect frame number
+     information in the bitstream could make our task impossible.
+     Account for that (it would be an error condition) */
+
+  /* new search algorithm originally by HB (Nicholas Vinen) */
 
-  /* new search algorithm by HB (Nicholas Vinen) */
   {
     ogg_int64_t end=vf->offsets[link+1];
-    ogg_int64_t begin=vf->offsets[link];
+    ogg_int64_t begin=vf->dataoffsets[link];
     ogg_int64_t begintime = vf->pcmlengths[link*2];
     ogg_int64_t endtime = vf->pcmlengths[link*2+1]+begintime;
     ogg_int64_t target=pos-total+begintime;
-    ogg_int64_t best=begin;
+    ogg_int64_t best=-1;
+    int         got_page=0;
 
     ogg_page og;
+
+    /* if we have only one page, there will be no bisection.  Grab the page here */
+    if(begin==end){
+      result=_seek_helper(vf,begin);
+      if(result) goto seek_error;
+
+      result=_get_next_page(vf,&og,1);
+      if(result<0) goto seek_error;
+
+      got_page=1;
+    }
+
+    /* bisection loop */
     while(begin<end){
       ogg_int64_t bisect;
 
@@ -1451,51 +1469,80 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
           bisect=begin;
       }
 
-      if(bisect!=vf->offset){
-        result=_seek_helper(vf,bisect);
-        if(result) goto seek_error;
-      }
+      result=_seek_helper(vf,bisect);
+      if(result) goto seek_error;
 
+      /* read loop within the bisection loop */
       while(begin<end){
         result=_get_next_page(vf,&og,end-vf->offset);
         if(result==OV_EREAD) goto seek_error;
         if(result<0){
+          /* there is no next page! */
           if(bisect<=begin+1)
-            end=begin; /* found it */
+              /* No bisection left to perform.  We've either found the
+                 best candidate already or failed. Exit loop. */
+            end=begin;
           else{
+            /* We tried to load a fraction of the last page; back up a
+               bit and try to get the whole last page */
             if(bisect==0) goto seek_error;
             bisect-=CHUNKSIZE;
+
+            /* don't repeat/loop on a read we've already performed */
             if(bisect<=begin)bisect=begin+1;
+
+            /* seek and cntinue bisection */
             result=_seek_helper(vf,bisect);
             if(result) goto seek_error;
           }
         }else{
           ogg_int64_t granulepos;
+          got_page=1;
 
+          /* got a page. analyze it */
+          /* only consider pages from primary vorbis stream */
           if(ogg_page_serialno(&og)!=vf->serialnos[link])
             continue;
 
+          /* only consider pages with the granulepos set */
           granulepos=ogg_page_granulepos(&og);
           if(granulepos==-1)continue;
 
           if(granulepos<target){
+            /* this page is a successful candidate! Set state */
+
             best=result;  /* raw offset of packet with granulepos */
             begin=vf->offset; /* raw offset of next page */
             begintime=granulepos;
 
+            /* if we're before our target but within a short distance,
+               don't bisect; read forward */
             if(target-begintime>44100)break;
-            bisect=begin; /* *not* begin + 1 */
+
+            bisect=begin; /* *not* begin + 1 as above */
           }else{
-            if(bisect<=begin+1)
-              end=begin;  /* found it */
-            else{
-              if(end==vf->offset){ /* we're pretty close - we'd be stuck in */
+
+            /* This is one of our pages, but the granpos is
+               post-target; it is not a bisection return
+               candidate. (The only way we'd use it is if it's the
+               first page in the stream; we handle that case later
+               outside the bisection) */
+            if(bisect<=begin+1){
+              /* No bisection left to perform.  We've either found the
+                 best candidate already or failed. Exit loop. */
+              end=begin;
+            }else{
+              if(end==vf->offset){
+                /* bisection read to the end; use the known page
+                   boundary (result) to update bisection, back up a
+                   little bit, and try again */
                 end=result;
-                bisect-=CHUNKSIZE; /* an endless loop otherwise. */
+                bisect-=CHUNKSIZE;
                 if(bisect<=begin)bisect=begin+1;
                 result=_seek_helper(vf,bisect);
                 if(result) goto seek_error;
               }else{
+                /* Normal bisection */
                 end=bisect;
                 endtime=granulepos;
                 break;
@@ -1506,9 +1553,46 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
       }
     }
 
-    /* found our page. seek to it, update pcm offset. Easier case than
-       raw_seek, don't keep packets preceding granulepos. */
-    {
+    /* Out of bisection: did it 'fail?' */
+    if(best == -1){
+
+      /* Check the 'looking for data in first page' special case;
+         bisection would 'fail' because our search target was before the
+         first PCM granule position fencepost. */
+
+      if(got_page &&
+         begin == vf->dataoffsets[link] &&
+         ogg_page_serialno(&og)==vf->serialnos[link]){
+
+        /* Yes, this is the beginning-of-stream case. We already have
+           our page, right at the beginning of PCM data.  Set state
+           and return. */
+
+        vf->pcm_offset=total;
+
+        if(link!=vf->current_link){
+          /* Different link; dump entire decode machine */
+          _decode_clear(vf);
+
+          vf->current_link=link;
+          vf->current_serialno=vf->serialnos[link];
+          vf->ready_state=STREAMSET;
+
+        }else{
+          vorbis_synthesis_restart(&vf->vd);
+        }
+
+        ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
+        ogg_stream_pagein(&vf->os,&og);
+
+      }else
+        goto seek_error;
+
+    }else{
+
+      /* Bisection found our page. seek to it, update pcm offset. Easier case than
+         raw_seek, don't keep packets preceding granulepos. */
+
       ogg_page og;
       ogg_packet op;
 
@@ -1538,23 +1622,23 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
       while(1){
         result=ogg_stream_packetpeek(&vf->os,&op);
         if(result==0){
-          /* !!! the packet finishing this page originated on a
-             preceding page. Keep fetching previous pages until we
-             get one with a granulepos or without the 'continued' flag
-             set.  Then just use raw_seek for simplicity. */
-
-          result=_seek_helper(vf,best);
-          if(result<0) goto seek_error;
-
-          while(1){
-            result=_get_prev_page(vf,&og);
+          /* No packet returned; we exited the bisection with 'best'
+             pointing to a page with a granule position, so the packet
+             finishing this page ('best') originated on a preceding
+             page. Keep fetching previous pages until we get one with
+             a granulepos or without the 'continued' flag set.  Then
+             just use raw_seek for simplicity. */
+          /* Do not rewind past the beginning of link data; if we do,
+             it's either a bug or a broken stream */
+          result=best;
+          while(result>vf->dataoffsets[link]){
+            result=_get_prev_page(vf,result,&og);
             if(result<0) goto seek_error;
             if(ogg_page_serialno(&og)==vf->current_serialno &&
                (ogg_page_granulepos(&og)>-1 ||
                 !ogg_page_continued(&og))){
               return ov_raw_seek(vf,result);
             }
-            vf->offset=result;
           }
         }
         if(result<0){