Fix free of uninitialized memory if seek fails in ov_raw_seek
[platform/upstream/libvorbis.git] / lib / vorbisfile.c
index 5308696..831cb39 100644 (file)
@@ -5,13 +5,12 @@
  * 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 1994-2007             *
+ * 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: $Id$
 
  ********************************************************************/
 
@@ -22,6 +21,9 @@
 #include <math.h>
 
 #include "vorbis/codec.h"
+
+/* we don't need or want the static callback symbols here */
+#define OV_EXCLUDE_STATIC_CALLBACKS
 #include "vorbis/vorbisfile.h"
 
 #include "os.h"
    we only want coarse navigation through the stream. */
 
 /*************************************************************************
- * Many, many internal helpers.  The intention is not to be confusing; 
- * rampant duplication and monolithic function implementation would be 
+ * Many, many internal helpers.  The intention is not to be confusing;
+ * rampant duplication and monolithic function implementation would be
  * harder to understand anyway.  The high level functions are last.  Begin
  * grokking near the end of the file */
 
 /* read a little more data from the file/pipe into the ogg_sync framer
 */
-#define CHUNKSIZE 65536
+#define CHUNKSIZE 65536 /* greater-than-page-size granularity seeking */
+#define READSIZE 2048 /* a smaller read size is needed for low-rate streaming. */
 
 static long _get_data(OggVorbis_File *vf){
   errno=0;
   if(!(vf->callbacks.read_func))return(-1);
   if(vf->datasource){
-    char *buffer=ogg_sync_buffer(&vf->oy,CHUNKSIZE);
-    long bytes=(vf->callbacks.read_func)(buffer,1,CHUNKSIZE,vf->datasource);
+    char *buffer=ogg_sync_buffer(&vf->oy,READSIZE);
+    long bytes=(vf->callbacks.read_func)(buffer,1,READSIZE,vf->datasource);
     if(bytes>0)ogg_sync_wrote(&vf->oy,bytes);
     if(bytes==0 && errno)return(-1);
     return(bytes);
@@ -75,12 +78,15 @@ 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);
+  if(vf->datasource){
+    /* 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;
@@ -96,52 +102,50 @@ static int _seek_helper(OggVorbis_File *vf,ogg_int64_t offset){
 
    boundary: -1) unbounded search
               0) read no additional data; use cached only
-             n) search for a new page beginning for n bytes
+              n) search for a new page beginning for n bytes
 
    return:   <0) did not find a page (OV_FALSE, OV_EOF, OV_EREAD)
               n) found a page at absolute offset n */
 
 static ogg_int64_t _get_next_page(OggVorbis_File *vf,ogg_page *og,
-                                 ogg_int64_t boundary){
+                                  ogg_int64_t boundary){
   if(boundary>0)boundary+=vf->offset;
   while(1){
     long more;
 
     if(boundary>0 && vf->offset>=boundary)return(OV_FALSE);
     more=ogg_sync_pageseek(&vf->oy,og);
-    
+
     if(more<0){
       /* skipped n bytes */
       vf->offset-=more;
     }else{
       if(more==0){
-       /* send more paramedics */
-       if(!boundary)return(OV_FALSE);
-       {
-         long ret=_get_data(vf);
-         if(ret==0)return(OV_EOF);
-         if(ret<0)return(OV_EREAD);
-       }
+        /* send more paramedics */
+        if(!boundary)return(OV_FALSE);
+        {
+          long ret=_get_data(vf);
+          if(ret==0)return(OV_EOF);
+          if(ret<0)return(OV_EREAD);
+        }
       }else{
-       /* got a page.  Return the offset at the page beginning,
+        /* got a page.  Return the offset at the page beginning,
            advance the internal offset past the page end */
-       ogg_int64_t ret=vf->offset;
-       vf->offset+=more;
-       return(ret);
-       
+        ogg_int64_t ret=vf->offset;
+        vf->offset+=more;
+        return(ret);
+
       }
     }
   }
 }
 
-/* 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;
 
@@ -158,9 +162,9 @@ static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_page *og){
       ret=_get_next_page(vf,og,end-vf->offset);
       if(ret==OV_EREAD)return(OV_EREAD);
       if(ret<0){
-       break;
+        break;
       }else{
-       offset=ret;
+        offset=ret;
       }
     }
   }
@@ -181,22 +185,52 @@ static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_page *og){
   return(offset);
 }
 
+static void _add_serialno(ogg_page *og,long **serialno_list, int *n){
+  long s = ogg_page_serialno(og);
+  (*n)++;
+
+  if(*serialno_list){
+    *serialno_list = _ogg_realloc(*serialno_list, sizeof(**serialno_list)*(*n));
+  }else{
+    *serialno_list = _ogg_malloc(sizeof(**serialno_list));
+  }
+
+  (*serialno_list)[(*n)-1] = s;
+}
+
+/* returns nonzero if found */
+static int _lookup_serialno(long s, long *serialno_list, int n){
+  if(serialno_list){
+    while(n--){
+      if(*serialno_list == s) return 1;
+      serialno_list++;
+    }
+  }
+  return 0;
+}
+
+static int _lookup_page_serialno(ogg_page *og, long *serialno_list, int n){
+  long s = ogg_page_serialno(og);
+  return _lookup_serialno(s,serialno_list,n);
+}
+
 /* performs the same search as _get_prev_page, but prefers pages of
    the specified serial number. If a page of the specified serialno is
    spotted during the seek-back-and-read-forward, it will return the
    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,int *serialno, ogg_int64_t *granpos){
+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;
 
   ogg_int64_t prefoffset=-1;
   ogg_int64_t offset=-1;
-  ogg_int64_t ret_serialno;
-  ogg_int64_t ret_gran;
+  ogg_int64_t ret_serialno=-1;
+  ogg_int64_t ret_gran=-1;
 
   while(offset==-1){
     begin-=CHUNKSIZE;
@@ -210,17 +244,24 @@ static ogg_int64_t _get_prev_page_serial(OggVorbis_File *vf,int *serialno, ogg_i
       ret=_get_next_page(vf,&og,end-vf->offset);
       if(ret==OV_EREAD)return(OV_EREAD);
       if(ret<0){
-       break;
+        break;
       }else{
-       ret_serialno=ogg_page_serialno(&og);
-       ret_gran=ogg_page_granulepos(&og);
-       offset=ret;
-
-       if(ret_serialno == *serialno){
-         prefoffset=ret;
-         *granpos=ret_gran;
-       }
-       
+        ret_serialno=ogg_page_serialno(&og);
+        ret_gran=ogg_page_granulepos(&og);
+        offset=ret;
+
+        if(ret_serialno == *serialno){
+          prefoffset=ret;
+          *granpos=ret_gran;
+        }
+
+        if(!_lookup_serialno(ret_serialno,serial_list,serial_n)){
+          /* we fell off the end of the link, which means we seeked
+             back too far and shouldn't have been looking in that link
+             to begin with.  If we found the preferred serial number,
+             forget that we saw it. */
+          prefoffset=-1;
+        }
       }
     }
   }
@@ -234,39 +275,10 @@ static ogg_int64_t _get_prev_page_serial(OggVorbis_File *vf,int *serialno, ogg_i
 
 }
 
-static void _add_serialno(ogg_page *og,long **serialno_list, int *n){
-  long s = ogg_page_serialno(og);
-  (*n)++;
-
-  if(serialno_list){
-    *serialno_list = _ogg_realloc(*serialno_list, sizeof(*serialno_list)*(*n));
-  }else{
-    *serialno_list = _ogg_malloc(sizeof(**serialno_list));
-  }
-  
-  (*serialno_list)[(*n)-1] = s;
-}
-
-/* returns nonzero if found */
-static int _lookup_serialno(long s, long *serialno_list, int n){
-  if(serialno_list){
-    while(n--){
-      if(*serialno_list == s) return 1;
-      serialno_list++;
-    }
-  }
-  return 0;
-}
-
-static int _lookup_page_serialno(ogg_page *og, long *serialno_list, int n){
-  long s = ogg_page_serialno(og);
-  return _lookup_serialno(s,serialno_list,n);
-}
-
 /* uses the local ogg_stream storage in vf; this is important for
    non-streaming input sources */
 static int _fetch_headers(OggVorbis_File *vf,vorbis_info *vi,vorbis_comment *vc,
-                         long **serialno_list, int *serialno_n,
+                          long **serialno_list, int *serialno_n,
                           ogg_page *og_ptr){
   ogg_page og;
   ogg_packet op;
@@ -297,7 +309,7 @@ static int _fetch_headers(OggVorbis_File *vf,vorbis_info *vi,vorbis_comment *vc,
         ret=OV_EBADHEADER;
         goto bail_header;
       }
-      
+
       _add_serialno(og_ptr,serialno_list,serialno_n);
     }
 
@@ -331,12 +343,12 @@ static int _fetch_headers(OggVorbis_File *vf,vorbis_info *vi,vorbis_comment *vc,
       }
 
       /* if this page also belongs to our vorbis stream, submit it and break */
-      if(vf->ready_state==STREAMSET && 
+      if(vf->ready_state==STREAMSET &&
          vf->os.serialno == ogg_page_serialno(og_ptr)){
         ogg_stream_pagein(&vf->os,og_ptr);
         break;
-      } 
-    } 
+      }
+    }
   }
 
   if(vf->ready_state!=STREAMSET){
@@ -345,37 +357,37 @@ static int _fetch_headers(OggVorbis_File *vf,vorbis_info *vi,vorbis_comment *vc,
   }
 
   while(1){
-  
+
     i=0;
     while(i<2){ /* get a page loop */
-      
+
       while(i<2){ /* get a packet loop */
-        
+
         int result=ogg_stream_packetout(&vf->os,&op);
         if(result==0)break;
         if(result==-1){
           ret=OV_EBADHEADER;
           goto bail_header;
         }
-       
+
         if((ret=vorbis_synthesis_headerin(vi,vc,&op)))
           goto bail_header;
-        
+
         i++;
       }
-      
+
       while(i<2){
         if(_get_next_page(vf,og_ptr,CHUNKSIZE)<0){
           ret=OV_EBADHEADER;
           goto bail_header;
         }
-        
+
         /* if this page belongs to the correct stream, go parse it */
         if(vf->os.serialno == ogg_page_serialno(og_ptr)){
           ogg_stream_pagein(&vf->os,og_ptr);
           break;
         }
-        
+
         /* if we never see the final vorbis headers before the link
            ends, abort */
         if(ogg_page_bos(og_ptr)){
@@ -385,12 +397,12 @@ static int _fetch_headers(OggVorbis_File *vf,vorbis_info *vi,vorbis_comment *vc,
           }else
             allbos=1;
         }
-        
+
         /* otherwise, keep looking */
       }
     }
-    
-    return 0; 
+
+    return 0;
   }
 
  bail_header:
@@ -416,18 +428,20 @@ static ogg_int64_t _initial_pcmoffset(OggVorbis_File *vf, vorbis_info *vi){
     ogg_packet op;
     if(_get_next_page(vf,&og,-1)<0)
       break; /* should not be possible unless the file is truncated/mangled */
-       
+
     if(ogg_page_bos(&og)) break;
     if(ogg_page_serialno(&og)!=serialno) continue;
-       
+
     /* count blocksizes of all frames in the page */
     ogg_stream_pagein(&vf->os,&og);
     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;
+        long thisblock=vorbis_packet_blocksize(vi,&op);
+        if(thisblock>=0){
+          if(lastblock!=-1)
+            accumulated+=(lastblock+thisblock)>>2;
+          lastblock=thisblock;
+        }
       }
     }
 
@@ -438,10 +452,11 @@ static ogg_int64_t _initial_pcmoffset(OggVorbis_File *vf, vorbis_info *vi){
     }
   }
 
-  /* less than zero?  This is a stream with samples trimmed off
-     the beginning, a normal occurrence; set the offset to zero */
+  /* less than zero?  Either a corrupt file or a stream with samples
+     trimmed off the beginning, a normal occurrence; in both cases set
+     the offset to zero */
   if(accumulated<0)accumulated=0;
-  
+
   return accumulated;
 }
 
@@ -450,14 +465,14 @@ static ogg_int64_t _initial_pcmoffset(OggVorbis_File *vf, vorbis_info *vi){
    Recurses for each link so it can alloc the link storage after
    finding them all, then unroll and fill the cache at the same time */
 static int _bisect_forward_serialno(OggVorbis_File *vf,
-                                   ogg_int64_t begin,
-                                   ogg_int64_t searched,
-                                   ogg_int64_t end,
-                                   ogg_int64_t endgran,
-                                   int endserial,
-                                   long *currentno_list,
-                                   int  currentnos,
-                                   long m){
+                                    ogg_int64_t begin,
+                                    ogg_int64_t searched,
+                                    ogg_int64_t end,
+                                    ogg_int64_t endgran,
+                                    int endserial,
+                                    long *currentno_list,
+                                    int  currentnos,
+                                    long m){
   ogg_int64_t pcmoffset;
   ogg_int64_t dataoffset=searched;
   ogg_int64_t endsearched=end;
@@ -467,9 +482,9 @@ static int _bisect_forward_serialno(OggVorbis_File *vf,
   ogg_int64_t ret,last;
   int serialno = vf->os.serialno;
 
-  /* invariants: 
+  /* invariants:
      we have the headers and serialnos for the link beginning at 'begin'
-     we have the offset and granpos of the last page in the file (potentially 
+     we have the offset and granpos of the last page in the file (potentially
        not a page we care about)
   */
 
@@ -480,10 +495,10 @@ 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,&endserial,&endgran);
+      searched=_get_prev_page_serial(vf,searched,currentno_list,currentnos,&endserial,&endgran);
     }
 
     vf->links=m+1;
@@ -500,71 +515,70 @@ static int _bisect_forward_serialno(OggVorbis_File *vf,
 
     vf->offsets[m+1]=end;
     vf->offsets[m]=begin;
-    vf->pcmlengths[m*2+1]=endgran; 
+    vf->pcmlengths[m*2+1]=(endgran<0?0:endgran);
 
   }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. */
     while(searched<endsearched){
       ogg_int64_t bisect;
-      
+
       if(endsearched-searched<CHUNKSIZE){
-       bisect=searched;
+        bisect=searched;
       }else{
-       bisect=(searched+endsearched)/2;
+        bisect=(searched+endsearched)/2;
       }
-      
+
       ret=_seek_helper(vf,bisect);
       if(ret)return(ret);
 
       last=_get_next_page(vf,&og,-1);
       if(last==OV_EREAD)return(OV_EREAD);
       if(last<0 || !_lookup_page_serialno(&og,currentno_list,currentnos)){
-       endsearched=bisect;
-       if(last>=0)next=last;
+        endsearched=bisect;
+        if(last>=0)next=last;
       }else{
-       searched=last+og.header_len+og.body_len;
+        searched=vf->offset;
       }
     }
 
     /* 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,&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);
 
     ret=_bisect_forward_serialno(vf,next,vf->offset,end,endgran,endserial,
-                                next_serialno_list,next_serialnos,m+1);
+                                 next_serialno_list,next_serialnos,m+1);
     if(ret)return(ret);
-    
+
     if(next_serialno_list)_ogg_free(next_serialno_list);
-    
+
     vf->offsets[m+1]=next;
     vf->serialnos[m+1]=serialno;
     vf->dataoffsets[m+1]=dataoffset;
@@ -575,7 +589,7 @@ static int _bisect_forward_serialno(OggVorbis_File *vf,
     vf->pcmlengths[m*2+1]=searchgran;
     vf->pcmlengths[m*2+2]=pcmoffset;
     vf->pcmlengths[m*2+3]-=pcmoffset;
-
+    if(vf->pcmlengths[m*2+3]<0)vf->pcmlengths[m*2+3]=0;
   }
   return(0);
 }
@@ -589,7 +603,7 @@ static int _make_decode_ready(OggVorbis_File *vf){
   }else{
     if(vorbis_synthesis_init(&vf->vd,vf->vi))
       return OV_EBADLINK;
-  }    
+  }
   vorbis_block_init(&vf->vd,&vf->vb);
   vf->ready_state=INITSET;
   vf->bittrack=0.f;
@@ -622,23 +636,24 @@ 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,&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,end+1,endgran,endserial,
-                             vf->serialnos+2,vf->serialnos[1],0)<0)return(OV_EREAD);  
+  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;
   vf->serialnos[0]=serialno;
   vf->dataoffsets[0]=dataoffset;
   vf->pcmlengths[0]=pcmoffset;
   vf->pcmlengths[1]-=pcmoffset;
+  if(vf->pcmlengths[1]<0)vf->pcmlengths[1]=0;
 
   return(ov_raw_seek(vf,dataoffset));
 }
 
-/* clear out the current logical bitstream decoder */ 
+/* clear out the current logical bitstream decoder */
 static void _decode_clear(OggVorbis_File *vf){
   vorbis_dsp_clear(&vf->vd);
   vorbis_block_clear(&vf->vb);
@@ -649,147 +664,154 @@ static void _decode_clear(OggVorbis_File *vf){
    bitstream boundary and dumps the decoding machine.  If the decoding
    machine is unloaded, it loads it.  It also keeps pcm_offset up to
    date (seek and read both use this.  seek uses a special hack with
-   readp). 
+   readp).
 
    return: <0) error, OV_HOLE (lost packet) or OV_EOF
             0) need more data (only if readp==0)
-           1) got a packet 
+            1) got a packet
 */
 
 static int _fetch_and_process_packet(OggVorbis_File *vf,
-                                    ogg_packet *op_in,
-                                    int readp,
-                                    int spanp){
+                                     ogg_packet *op_in,
+                                     int readp,
+                                     int spanp){
   ogg_page og;
 
   /* handle one packet.  Try to fetch it from current stream state */
   /* extract packets from page */
   while(1){
-    
-    /* process a packet if we can.  If the machine isn't loaded,
-       neither is a page */
+
+    if(vf->ready_state==STREAMSET){
+      int ret=_make_decode_ready(vf);
+      if(ret<0)return ret;
+    }
+
+    /* process a packet if we can. */
+
     if(vf->ready_state==INITSET){
+      int hs=vorbis_synthesis_halfrate_p(vf->vi);
+
       while(1) {
-       ogg_packet op;
-       ogg_packet *op_ptr=(op_in?op_in:&op);
-       int result=ogg_stream_packetout(&vf->os,op_ptr);
-       ogg_int64_t granulepos;
-
-       op_in=NULL;
-       if(result==-1)return(OV_HOLE); /* hole in the data. */
-       if(result>0){
-         /* got a packet.  process it */
-         granulepos=op_ptr->granulepos;
-         if(!vorbis_synthesis(&vf->vb,op_ptr)){ /* lazy check for lazy
-                                                   header handling.  The
-                                                   header packets aren't
-                                                   audio, so if/when we
-                                                   submit them,
-                                                   vorbis_synthesis will
-                                                   reject them */
-
-           /* suck in the synthesis data and track bitrate */
-           {
-             int oldsamples=vorbis_synthesis_pcmout(&vf->vd,NULL);
-             /* for proper use of libvorbis within libvorbisfile,
+              ogg_packet op;
+              ogg_packet *op_ptr=(op_in?op_in:&op);
+        int result=ogg_stream_packetout(&vf->os,op_ptr);
+        ogg_int64_t granulepos;
+
+        op_in=NULL;
+        if(result==-1)return(OV_HOLE); /* hole in the data. */
+        if(result>0){
+          /* got a packet.  process it */
+          granulepos=op_ptr->granulepos;
+          if(!vorbis_synthesis(&vf->vb,op_ptr)){ /* lazy check for lazy
+                                                    header handling.  The
+                                                    header packets aren't
+                                                    audio, so if/when we
+                                                    submit them,
+                                                    vorbis_synthesis will
+                                                    reject them */
+
+            /* suck in the synthesis data and track bitrate */
+            {
+              int oldsamples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+              /* for proper use of libvorbis within libvorbisfile,
                  oldsamples will always be zero. */
-             if(oldsamples)return(OV_EFAULT);
-             
-             vorbis_synthesis_blockin(&vf->vd,&vf->vb);
-             vf->samptrack+=vorbis_synthesis_pcmout(&vf->vd,NULL)-oldsamples;
-             vf->bittrack+=op_ptr->bytes*8;
-           }
-         
-           /* update the pcm offset. */
-           if(granulepos!=-1 && !op_ptr->e_o_s){
-             int link=(vf->seekable?vf->current_link:0);
-             int i,samples;
-           
-             /* this packet has a pcm_offset on it (the last packet
-                completed on a page carries the offset) After processing
-                (above), we know the pcm position of the *last* sample
-                ready to be returned. Find the offset of the *first*
-
-                As an aside, this trick is inaccurate if we begin
-                reading anew right at the last page; the end-of-stream
-                granulepos declares the last frame in the stream, and the
-                last packet of the last page may be a partial frame.
-                So, we need a previous granulepos from an in-sequence page
-                to have a reference point.  Thus the !op_ptr->e_o_s clause
-                above */
-
-             if(vf->seekable && link>0)
-               granulepos-=vf->pcmlengths[link*2];
-             if(granulepos<0)granulepos=0; /* actually, this
-                                              shouldn't be possible
-                                              here unless the stream
-                                              is very broken */
-
-             samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
-           
-             granulepos-=samples;
-             for(i=0;i<link;i++)
-               granulepos+=vf->pcmlengths[i*2+1];
-             vf->pcm_offset=granulepos;
-           }
-           return(1);
-         }
-       }
-       else 
-         break;
+              if(oldsamples)return(OV_EFAULT);
+
+              vorbis_synthesis_blockin(&vf->vd,&vf->vb);
+              vf->samptrack+=(vorbis_synthesis_pcmout(&vf->vd,NULL)<<hs);
+              vf->bittrack+=op_ptr->bytes*8;
+            }
+
+            /* update the pcm offset. */
+            if(granulepos!=-1 && !op_ptr->e_o_s){
+              int link=(vf->seekable?vf->current_link:0);
+              int i,samples;
+
+              /* this packet has a pcm_offset on it (the last packet
+                 completed on a page carries the offset) After processing
+                 (above), we know the pcm position of the *last* sample
+                 ready to be returned. Find the offset of the *first*
+
+                 As an aside, this trick is inaccurate if we begin
+                 reading anew right at the last page; the end-of-stream
+                 granulepos declares the last frame in the stream, and the
+                 last packet of the last page may be a partial frame.
+                 So, we need a previous granulepos from an in-sequence page
+                 to have a reference point.  Thus the !op_ptr->e_o_s clause
+                 above */
+
+              if(vf->seekable && link>0)
+                granulepos-=vf->pcmlengths[link*2];
+              if(granulepos<0)granulepos=0; /* actually, this
+                                               shouldn't be possible
+                                               here unless the stream
+                                               is very broken */
+
+              samples=(vorbis_synthesis_pcmout(&vf->vd,NULL)<<hs);
+
+              granulepos-=samples;
+              for(i=0;i<link;i++)
+                granulepos+=vf->pcmlengths[i*2+1];
+              vf->pcm_offset=granulepos;
+            }
+            return(1);
+          }
+        }
+        else
+          break;
       }
     }
 
     if(vf->ready_state>=OPENED){
       ogg_int64_t ret;
-      
-      while(1){ 
-       /* the loop is not strictly necessary, but there's no sense in
-          doing the extra checks of the larger loop for the common
-          case in a multiplexed bistream where the page is simply
-          part of a different logical bitstream; keep reading until
-          we get one with the correct serialno */
-       
-       if(!readp)return(0);
-       if((ret=_get_next_page(vf,&og,-1))<0){
-         return(OV_EOF); /* eof. leave unitialized */
-       }
-
-       /* bitrate tracking; add the header's bytes here, the body bytes
-          are done by packet above */
-       vf->bittrack+=og.header_len*8;
-       
-       if(vf->ready_state==INITSET){
-         if(vf->current_serialno!=ogg_page_serialno(&og)){
-           
-           /* two possibilities: 
-              1) our decoding just traversed a bitstream boundary
-              2) another stream is multiplexed into this logical section */
-           
-           if(ogg_page_bos(&og)){
-             /* boundary case */
-             if(!spanp)
-               return(OV_EOF);
-             
-             _decode_clear(vf);
-             
-             if(!vf->seekable){
-               vorbis_info_clear(vf->vi);
-               vorbis_comment_clear(vf->vc);
-             }
-             break;
-
-           }else
-             continue; /* possibility #2 */
-         }
-       }
-
-       break;
+
+      while(1){
+        /* the loop is not strictly necessary, but there's no sense in
+           doing the extra checks of the larger loop for the common
+           case in a multiplexed bistream where the page is simply
+           part of a different logical bitstream; keep reading until
+           we get one with the correct serialno */
+
+        if(!readp)return(0);
+        if((ret=_get_next_page(vf,&og,-1))<0){
+          return(OV_EOF); /* eof. leave unitialized */
+        }
+
+        /* bitrate tracking; add the header's bytes here, the body bytes
+           are done by packet above */
+        vf->bittrack+=og.header_len*8;
+
+        if(vf->ready_state==INITSET){
+          if(vf->current_serialno!=ogg_page_serialno(&og)){
+
+            /* two possibilities:
+               1) our decoding just traversed a bitstream boundary
+               2) another stream is multiplexed into this logical section */
+
+            if(ogg_page_bos(&og)){
+              /* boundary case */
+              if(!spanp)
+                return(OV_EOF);
+
+              _decode_clear(vf);
+
+              if(!vf->seekable){
+                vorbis_info_clear(vf->vi);
+                vorbis_comment_clear(vf->vc);
+              }
+              break;
+
+            }else
+              continue; /* possibility #2 */
+          }
+        }
+
+        break;
       }
     }
 
     /* Do we need to load a new machine before submitting the page? */
-    /* This is different in the seekable and non-seekable cases.  
+    /* This is different in the seekable and non-seekable cases.
 
        In the seekable case, we already have all the header
        information loaded and cached; we just initialize the machine
@@ -800,45 +822,40 @@ static int _fetch_and_process_packet(OggVorbis_File *vf,
        we're now nominally at the header of the next bitstream
     */
 
-    if(vf->ready_state!=INITSET){ 
+    if(vf->ready_state!=INITSET){
       int link;
 
       if(vf->ready_state<STREAMSET){
-       if(vf->seekable){
-         long serialno = ogg_page_serialno(&og);
-
-         /* match the serialno to bitstream section.  We use this rather than
-            offset positions to avoid problems near logical bitstream
-            boundaries */
-
-         for(link=0;link<vf->links;link++)
-           if(vf->serialnos[link]==serialno)break;
-
-         if(link==vf->links) continue; /* not the desired Vorbis
-                                          bitstream section; keep
-                                          trying */
-
-         vf->current_serialno=serialno;
-         vf->current_link=link;
-         
-         ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
-         vf->ready_state=STREAMSET;
-         
-       }else{
-         /* we're streaming */
-         /* fetch the three header packets, build the info struct */
-         
-         int ret=_fetch_headers(vf,vf->vi,vf->vc,NULL,NULL,&og);
-         if(ret)return(ret);
-         vf->current_serialno=vf->os.serialno;
-         vf->current_link++;
-         link=0;
-       }
-      }
-      
-      {
-       int ret=_make_decode_ready(vf);
-       if(ret<0)return ret;
+        if(vf->seekable){
+          long serialno = ogg_page_serialno(&og);
+
+          /* match the serialno to bitstream section.  We use this rather than
+             offset positions to avoid problems near logical bitstream
+             boundaries */
+
+          for(link=0;link<vf->links;link++)
+            if(vf->serialnos[link]==serialno)break;
+
+          if(link==vf->links) continue; /* not the desired Vorbis
+                                           bitstream section; keep
+                                           trying */
+
+          vf->current_serialno=serialno;
+          vf->current_link=link;
+
+          ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
+          vf->ready_state=STREAMSET;
+
+        }else{
+          /* we're streaming */
+          /* fetch the three header packets, build the info struct */
+
+          int ret=_fetch_headers(vf,vf->vi,vf->vc,NULL,NULL,&og);
+          if(ret)return(ret);
+          vf->current_serialno=vf->os.serialno;
+          vf->current_link++;
+          link=0;
+        }
       }
     }
 
@@ -856,13 +873,13 @@ static int _fseek64_wrap(FILE *f,ogg_int64_t off,int whence){
   return fseek(f,off,whence);
 }
 
-static int _ov_open1(void *f,OggVorbis_File *vf,char *initial,
-                    long ibytes, ov_callbacks callbacks){
+static int _ov_open1(void *f,OggVorbis_File *vf,const char *initial,
+                     long ibytes, ov_callbacks callbacks){
   int offsettest=((f && callbacks.seek_func)?callbacks.seek_func(f,0,SEEK_CUR):-1);
   long *serialno_list=NULL;
   int serialno_list_size=0;
   int ret;
-  
+
   memset(vf,0,sizeof(*vf));
   vf->datasource=f;
   vf->callbacks = callbacks;
@@ -900,15 +917,14 @@ static int _ov_open1(void *f,OggVorbis_File *vf,char *initial,
        for second stage of seekable stream open; this saves having to
        seek/reread first link's serialnumber data then. */
     vf->serialnos=_ogg_calloc(serialno_list_size+2,sizeof(*vf->serialnos));
-    vf->serialnos[0]=vf->current_serialno;
+    vf->serialnos[0]=vf->current_serialno=vf->os.serialno;
     vf->serialnos[1]=serialno_list_size;
     memcpy(vf->serialnos+2,serialno_list,serialno_list_size*sizeof(*vf->serialnos));
-    
+
     vf->offsets=_ogg_calloc(1,sizeof(*vf->offsets));
     vf->dataoffsets=_ogg_calloc(1,sizeof(*vf->dataoffsets));
     vf->offsets[0]=0;
     vf->dataoffsets[0]=vf->offset;
-    vf->current_serialno=vf->os.serialno;
 
     vf->ready_state=PARTOPEN;
   }
@@ -939,12 +955,12 @@ int ov_clear(OggVorbis_File *vf){
     vorbis_block_clear(&vf->vb);
     vorbis_dsp_clear(&vf->vd);
     ogg_stream_clear(&vf->os);
-    
+
     if(vf->vi && vf->links){
       int i;
       for(i=0;i<vf->links;i++){
-       vorbis_info_clear(vf->vi+i);
-       vorbis_comment_clear(vf->vc+i);
+        vorbis_info_clear(vf->vi+i);
+        vorbis_comment_clear(vf->vc+i);
       }
       _ogg_free(vf->vi);
       _ogg_free(vf->vc);
@@ -966,20 +982,20 @@ int ov_clear(OggVorbis_File *vf){
 
 /* inspects the OggVorbis file and finds/documents all the logical
    bitstreams contained in it.  Tries to be tolerant of logical
-   bitstream sections that are truncated/woogie. 
+   bitstream sections that are truncated/woogie.
 
    return: -1) error
             0) OK
 */
 
-int ov_open_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
-    ov_callbacks callbacks){
+int ov_open_callbacks(void *f,OggVorbis_File *vf,
+    const char *initial,long ibytes,ov_callbacks callbacks){
   int ret=_ov_open1(f,vf,initial,ibytes,callbacks);
   if(ret)return ret;
   return _ov_open2(vf);
 }
 
-int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
+int ov_open(FILE *f,OggVorbis_File *vf,const char *initial,long ibytes){
   ov_callbacks callbacks = {
     (size_t (*)(void *, size_t, size_t, void *))  fread,
     (int (*)(void *, ogg_int64_t, int))              _fseek64_wrap,
@@ -990,7 +1006,7 @@ int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
   return ov_open_callbacks((void *)f, vf, initial, ibytes, callbacks);
 }
 
-int ov_fopen(char *path,OggVorbis_File *vf){
+int ov_fopen(const char *path,OggVorbis_File *vf){
   int ret;
   FILE *f = fopen(path,"rb");
   if(!f) return -1;
@@ -1000,24 +1016,29 @@ int ov_fopen(char *path,OggVorbis_File *vf){
   return ret;
 }
 
+
 /* cheap hack for game usage where downsampling is desirable; there's
    no need for SRC as we can just do it cheaply in libvorbis. */
+
 int ov_halfrate(OggVorbis_File *vf,int flag){
   int i;
   if(vf->vi==NULL)return OV_EINVAL;
-  if(!vf->seekable)return OV_EINVAL;
-  if(vf->ready_state>=STREAMSET)
-    _decode_clear(vf); /* clear out stream state; later on libvorbis
-                          will be able to swap this on the fly, but
-                          for now dumping the decode machine is needed
-                          to reinit the MDCT lookups.  1.1 libvorbis
-                          is planned to be able to switch on the fly */
-  
+  if(vf->ready_state>STREAMSET){
+    /* clear out stream state; dumping the decode machine is needed to
+       reinit the MDCT lookups. */
+    vorbis_dsp_clear(&vf->vd);
+    vorbis_block_clear(&vf->vb);
+    vf->ready_state=STREAMSET;
+    if(vf->pcm_offset>=0){
+      ogg_int64_t pos=vf->pcm_offset;
+      vf->pcm_offset=-1; /* make sure the pos is dumped if unseekable */
+      ov_pcm_seek(vf,pos);
+    }
+  }
+
   for(i=0;i<vf->links;i++){
     if(vorbis_synthesis_halfrate(vf->vi+i,flag)){
-      ov_halfrate(vf,0);
+      if(flag) ov_halfrate(vf,0);
       return OV_EINVAL;
     }
   }
@@ -1032,15 +1053,19 @@ int ov_halfrate_p(OggVorbis_File *vf){
 /* Only partially open the vorbis file; test for Vorbisness, and load
    the headers for the first chain.  Do not seek (although test for
    seekability).  Use ov_test_open to finish opening the file, else
-   ov_clear to close/free it. Same return codes as open. */
+   ov_clear to close/free it. Same return codes as open.
 
-int ov_test_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
-    ov_callbacks callbacks)
+   Note that vorbisfile does _not_ take ownership of the file if the
+   call fails; the calling applicaiton is responsible for closing the file
+   if this call returns an error. */
+
+int ov_test_callbacks(void *f,OggVorbis_File *vf,
+    const char *initial,long ibytes,ov_callbacks callbacks)
 {
   return _ov_open1(f,vf,initial,ibytes,callbacks);
 }
 
-int ov_test(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
+int ov_test(FILE *f,OggVorbis_File *vf,const char *initial,long ibytes){
   ov_callbacks callbacks = {
     (size_t (*)(void *, size_t, size_t, void *))  fread,
     (int (*)(void *, ogg_int64_t, int))              _fseek64_wrap,
@@ -1050,7 +1075,7 @@ int ov_test(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
 
   return ov_test_callbacks((void *)f, vf, initial, ibytes, callbacks);
 }
-  
+
 int ov_test_open(OggVorbis_File *vf){
   if(vf->ready_state!=PARTOPEN)return(OV_EINVAL);
   return _ov_open2(vf);
@@ -1098,16 +1123,16 @@ long ov_bitrate(OggVorbis_File *vf,int i){
     }else{
       /* return nominal if set */
       if(vf->vi[i].bitrate_nominal>0){
-       return vf->vi[i].bitrate_nominal;
+        return vf->vi[i].bitrate_nominal;
       }else{
-       if(vf->vi[i].bitrate_upper>0){
-         if(vf->vi[i].bitrate_lower>0){
-           return (vf->vi[i].bitrate_upper+vf->vi[i].bitrate_lower)/2;
-         }else{
-           return vf->vi[i].bitrate_upper;
-         }
-       }
-       return(OV_FALSE);
+        if(vf->vi[i].bitrate_upper>0){
+          if(vf->vi[i].bitrate_lower>0){
+            return (vf->vi[i].bitrate_upper+vf->vi[i].bitrate_lower)/2;
+          }else{
+            return vf->vi[i].bitrate_upper;
+          }
+        }
+        return(OV_FALSE);
       }
     }
   }
@@ -1115,7 +1140,7 @@ long ov_bitrate(OggVorbis_File *vf,int i){
 
 /* returns the actual bitrate since last call.  returns -1 if no
    additional data to offer since last call (or at beginning of stream),
-   EINVAL if stream is only partially open 
+   EINVAL if stream is only partially open
 */
 long ov_bitrate_instant(OggVorbis_File *vf){
   int link=(vf->seekable?vf->current_link:0);
@@ -1141,8 +1166,8 @@ long ov_serialnumber(OggVorbis_File *vf,int i){
 
 /* returns: total raw (compressed) length of content if i==-1
             raw (compressed) length of that logical bitstream for i==0 to n
-           OV_EINVAL if the stream is not seekable (we can't know the length)
-           or if stream is only partially open
+            OV_EINVAL if the stream is not seekable (we can't know the length)
+            or if stream is only partially open
 */
 ogg_int64_t ov_raw_total(OggVorbis_File *vf,int i){
   if(vf->ready_state<OPENED)return(OV_EINVAL);
@@ -1159,9 +1184,9 @@ ogg_int64_t ov_raw_total(OggVorbis_File *vf,int i){
 }
 
 /* returns: total PCM length (samples) of content if i==-1 PCM length
-           (samples) of that logical bitstream for i==0 to n
-           OV_EINVAL if the stream is not seekable (we can't know the
-           length) or only partially open 
+            (samples) of that logical bitstream for i==0 to n
+            OV_EINVAL if the stream is not seekable (we can't know the
+            length) or only partially open
 */
 ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){
   if(vf->ready_state<OPENED)return(OV_EINVAL);
@@ -1179,8 +1204,8 @@ ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){
 
 /* returns: total seconds of content if i==-1
             seconds in that logical bitstream for i==0 to n
-           OV_EINVAL if the stream is not seekable (we can't know the
-           length) or only partially open 
+            OV_EINVAL if the stream is not seekable (we can't know the
+            length) or only partially open
 */
 double ov_time_total(OggVorbis_File *vf,int i){
   if(vf->ready_state<OPENED)return(OV_EINVAL);
@@ -1205,7 +1230,6 @@ double ov_time_total(OggVorbis_File *vf,int i){
 
 int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
   ogg_stream_state work_os;
-  int ret;
 
   if(vf->ready_state<OPENED)return(OV_EINVAL);
   if(!vf->seekable)
@@ -1213,17 +1237,27 @@ int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
 
   if(pos<0 || pos>vf->end)return(OV_EINVAL);
 
+  /* is the seek position outside our current link [if any]? */
+  if(vf->ready_state>=STREAMSET){
+    if(pos<vf->offsets[vf->current_link] || pos>=vf->offsets[vf->current_link+1])
+      _decode_clear(vf); /* clear out stream state */
+  }
+
   /* don't yet clear out decoding machine (if it's initialized), in
      the case we're in the same link.  Restart the decode lapping, and
      let _fetch_and_process_packet deal with a potential bitstream
      boundary */
   vf->pcm_offset=-1;
   ogg_stream_reset_serialno(&vf->os,
-                           vf->current_serialno); /* must set serialno */
+                            vf->current_serialno); /* must set serialno */
   vorbis_synthesis_restart(&vf->vd);
-    
-  ret=_seek_helper(vf,pos);
-  if(ret)goto seek_error;
+
+  if(_seek_helper(vf,pos)) {
+    /* dump the machine so we're in a known state */
+    vf->pcm_offset=-1;
+    _decode_clear(vf);
+    return OV_EBADLINK;
+  }
 
   /* we need to make sure the pcm_offset is set, but we don't want to
      advance the raw cursor past good packets just to get to the first
@@ -1232,12 +1266,12 @@ int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
 
      So, a hack.  We use two stream states; a local scratch state and
      the shared vf->os stream state.  We use the local state to
-     scan, and the shared state as a buffer for later decode. 
+     scan, and the shared state as a buffer for later decode.
 
      Unfortuantely, on the last page we still advance to last packet
      because the granulepos on the last page is not necessarily on a
      packet boundary, and we need to make sure the granpos is
-     correct. 
+     correct.
   */
 
   {
@@ -1246,7 +1280,9 @@ int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
     int lastblock=0;
     int accblock=0;
     int thisblock=0;
-    int eosflag=0; 
+    int lastflag=0;
+    int firstflag=0;
+    ogg_int64_t pagepos=-1;
 
     ogg_stream_init(&work_os,vf->current_serialno); /* get the memory ready */
     ogg_stream_reset(&work_os); /* eliminate the spurious OV_HOLE
@@ -1255,89 +1291,99 @@ int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
 
     while(1){
       if(vf->ready_state>=STREAMSET){
-       /* snarf/scan a packet if we can */
-       int result=ogg_stream_packetout(&work_os,&op);
-      
-       if(result>0){
-
-         if(vf->vi[vf->current_link].codec_setup){
-           thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
-           if(thisblock<0){
-             ogg_stream_packetout(&vf->os,NULL);
-             thisblock=0;
-           }else{
-             
-             if(eosflag)
-               ogg_stream_packetout(&vf->os,NULL);
-             else
-               if(lastblock)accblock+=(lastblock+thisblock)>>2;
-           }       
-
-           if(op.granulepos!=-1){
-             int i,link=vf->current_link;
-             ogg_int64_t granulepos=op.granulepos-vf->pcmlengths[link*2];
-             if(granulepos<0)granulepos=0;
-             
-             for(i=0;i<link;i++)
-               granulepos+=vf->pcmlengths[i*2+1];
-             vf->pcm_offset=granulepos-accblock;
-             break;
-           }
-           lastblock=thisblock;
-           continue;
-         }else
-           ogg_stream_packetout(&vf->os,NULL);
-       }
+        /* snarf/scan a packet if we can */
+        int result=ogg_stream_packetout(&work_os,&op);
+
+        if(result>0){
+
+          if(vf->vi[vf->current_link].codec_setup){
+            thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
+            if(thisblock<0){
+              ogg_stream_packetout(&vf->os,NULL);
+              thisblock=0;
+            }else{
+
+              /* We can't get a guaranteed correct pcm position out of the
+                 last page in a stream because it might have a 'short'
+                 granpos, which can only be detected in the presence of a
+                 preceding page.  However, if the last page is also the first
+                 page, the granpos rules of a first page take precedence.  Not
+                 only that, but for first==last, the EOS page must be treated
+                 as if its a normal first page for the stream to open/play. */
+              if(lastflag && !firstflag)
+                ogg_stream_packetout(&vf->os,NULL);
+              else
+                if(lastblock)accblock+=(lastblock+thisblock)>>2;
+            }
+
+            if(op.granulepos!=-1){
+              int i,link=vf->current_link;
+              ogg_int64_t granulepos=op.granulepos-vf->pcmlengths[link*2];
+              if(granulepos<0)granulepos=0;
+
+              for(i=0;i<link;i++)
+                granulepos+=vf->pcmlengths[i*2+1];
+              vf->pcm_offset=granulepos-accblock;
+              if(vf->pcm_offset<0)vf->pcm_offset=0;
+              break;
+            }
+            lastblock=thisblock;
+            continue;
+          }else
+            ogg_stream_packetout(&vf->os,NULL);
+        }
       }
-      
+
       if(!lastblock){
-       if(_get_next_page(vf,&og,-1)<0){
-         vf->pcm_offset=ov_pcm_total(vf,-1);
-         break;
-       }
+        pagepos=_get_next_page(vf,&og,-1);
+        if(pagepos<0){
+          vf->pcm_offset=ov_pcm_total(vf,-1);
+          break;
+        }
       }else{
-       /* huh?  Bogus stream with packets but no granulepos */
-       vf->pcm_offset=-1;
-       break;
+        /* huh?  Bogus stream with packets but no granulepos */
+        vf->pcm_offset=-1;
+        break;
       }
-      
+
       /* has our decoding just traversed a bitstream boundary? */
       if(vf->ready_state>=STREAMSET){
-       if(vf->current_serialno!=ogg_page_serialno(&og)){
-         
-         /* two possibilities: 
-            1) our decoding just traversed a bitstream boundary
-            2) another stream is multiplexed into this logical section? */
-            
-         if(ogg_page_bos(&og)){
-           /* we traversed */
-           _decode_clear(vf); /* clear out stream state */
-           ogg_stream_clear(&work_os);
-         } /* else, do nothing; next loop will scoop another page */
-       }
+        if(vf->current_serialno!=ogg_page_serialno(&og)){
+
+          /* two possibilities:
+             1) our decoding just traversed a bitstream boundary
+             2) another stream is multiplexed into this logical section? */
+
+          if(ogg_page_bos(&og)){
+            /* we traversed */
+            _decode_clear(vf); /* clear out stream state */
+            ogg_stream_clear(&work_os);
+          } /* else, do nothing; next loop will scoop another page */
+        }
       }
 
       if(vf->ready_state<STREAMSET){
-       int link;
-       long serialno = ogg_page_serialno(&og);
-
-       for(link=0;link<vf->links;link++)
-         if(vf->serialnos[link]==serialno)break;
-
-       if(link==vf->links) continue; /* not the desired Vorbis
-                                        bitstream section; keep
-                                        trying */
-       vf->current_link=link;
-       vf->current_serialno=serialno;
-       ogg_stream_reset_serialno(&vf->os,serialno);
-       ogg_stream_reset_serialno(&work_os,serialno); 
-       vf->ready_state=STREAMSET;
-       
+        int link;
+        long serialno = ogg_page_serialno(&og);
+
+        for(link=0;link<vf->links;link++)
+          if(vf->serialnos[link]==serialno)break;
+
+        if(link==vf->links) continue; /* not the desired Vorbis
+                                         bitstream section; keep
+                                         trying */
+        vf->current_link=link;
+        vf->current_serialno=serialno;
+        ogg_stream_reset_serialno(&vf->os,serialno);
+        ogg_stream_reset_serialno(&work_os,serialno);
+        vf->ready_state=STREAMSET;
+        firstflag=(pagepos<=vf->dataoffsets[link]);
       }
-    
+
       ogg_stream_pagein(&vf->os,&og);
       ogg_stream_pagein(&work_os,&og);
-      eosflag=ogg_page_eos(&og);
+      lastflag=ogg_page_eos(&og);
+
     }
   }
 
@@ -1345,143 +1391,223 @@ int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
   vf->bittrack=0.f;
   vf->samptrack=0.f;
   return(0);
-
- seek_error:
-  /* dump the machine so we're in a known state */
-  vf->pcm_offset=-1;
-  ogg_stream_clear(&work_os);
-  _decode_clear(vf);
-  return OV_EBADLINK;
 }
 
 /* Page granularity seek (faster than sample granularity because we
    don't do the last bit of decode to find a specific sample).
 
-   Seek to the last [granule marked] page preceeding the specified pos
+   Seek to the last [granule marked] page preceding the specified pos
    location, such that decoding past the returned point will quickly
    arrive at the requested position. */
 int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
   int link=-1;
   ogg_int64_t result=0;
   ogg_int64_t total=ov_pcm_total(vf,-1);
-  
+
   if(vf->ready_state<OPENED)return(OV_EINVAL);
   if(!vf->seekable)return(OV_ENOSEEK);
 
   if(pos<0 || pos>total)return(OV_EINVAL);
+
   /* which bitstream section does this pcm offset occur in? */
   for(link=vf->links-1;link>=0;link--){
     total-=vf->pcmlengths[link*2+1];
     if(pos>=total)break;
   }
 
-  /* search within the logical bitstream for the page with the highest
-     pcm_pos preceeding (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;
-      
+
       if(end-begin<CHUNKSIZE){
-       bisect=begin;
+        bisect=begin;
       }else{
-       /* take a (pretty decent) guess. */
-       bisect=begin +
-         (ogg_int64_t)((double)(target-begintime)*(end-begin)/(endtime-begintime))
-         - CHUNKSIZE;
-       if(bisect<=begin)
-         bisect=begin+1;
+        /* take a (pretty decent) guess. */
+        bisect=begin +
+          (ogg_int64_t)((double)(target-begintime)*(end-begin)/(endtime-begintime))
+          - CHUNKSIZE;
+        if(bisect<begin+CHUNKSIZE)
+          bisect=begin;
       }
-      
+
       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){
-         if(bisect<=begin+1)
-           end=begin; /* found it */
-         else{
-           if(bisect==0) goto seek_error;
-           bisect-=CHUNKSIZE;
-           if(bisect<=begin)bisect=begin+1;
-           result=_seek_helper(vf,bisect);
-           if(result) goto seek_error;
-         }
-       }else{
-         ogg_int64_t granulepos;
-
-         if(ogg_page_serialno(&og)!=vf->serialnos[link])
-           continue;
-
-         granulepos=ogg_page_granulepos(&og);
-         if(granulepos==-1)continue;
-         
-         if(granulepos<target){
-           best=result;  /* raw offset of packet with granulepos */ 
-           begin=vf->offset; /* raw offset of next page */
-           begintime=granulepos;
-           
-           if(target-begintime>44100)break;
-           bisect=begin; /* *not* begin + 1 */
-         }else{
-           if(bisect<=begin+1)
-             end=begin;  /* found it */
-           else{
-             if(end==vf->offset){ /* we're pretty close - we'd be stuck in */
-               end=result;
-               bisect-=CHUNKSIZE; /* an endless loop otherwise. */
-               if(bisect<=begin)bisect=begin+1;
-               result=_seek_helper(vf,bisect);
-               if(result) goto seek_error;
-             }else{
-               end=bisect;
-               endtime=granulepos;
-               break;
-             }
-           }
-         }
-       }
+        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)
+              /* 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 as above */
+          }else{
+
+            /* 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;
+                if(bisect<=begin)bisect=begin+1;
+                result=_seek_helper(vf,bisect);
+                if(result) goto seek_error;
+              }else{
+                /* Normal bisection */
+                end=bisect;
+                endtime=granulepos;
+                break;
+              }
+            }
+          }
+        }
       }
     }
 
-    /* found our page. seek to it, update pcm offset. Easier case than
-       raw_seek, don't keep packets preceeding 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;
-      
+
       /* seek */
       result=_seek_helper(vf,best);
       vf->pcm_offset=-1;
       if(result) goto seek_error;
       result=_get_next_page(vf,&og,-1);
       if(result<0) goto seek_error;
-      
+
       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;
-       
+        /* 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);
+        vorbis_synthesis_restart(&vf->vd);
       }
 
       ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
@@ -1489,42 +1615,42 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
 
       /* pull out all but last packet; the one with granulepos */
       while(1){
-       result=ogg_stream_packetpeek(&vf->os,&op);
-       if(result==0){
-         /* !!! the packet finishing this page originated on a
-             preceeding 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);
-           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){
-         result = OV_EBADPACKET; 
-         goto seek_error;
-       }
-       if(op.granulepos!=-1){
-         vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
-         if(vf->pcm_offset<0)vf->pcm_offset=0;
-         vf->pcm_offset+=total;
-         break;
-       }else
-         result=ogg_stream_packetout(&vf->os,NULL);
+        result=ogg_stream_packetpeek(&vf->os,&op);
+        if(result==0){
+          /* 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);
+            }
+          }
+        }
+        if(result<0){
+          result = OV_EBADPACKET;
+          goto seek_error;
+        }
+        if(op.granulepos!=-1){
+          vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
+          if(vf->pcm_offset<0)vf->pcm_offset=0;
+          vf->pcm_offset+=total;
+          break;
+        }else
+          result=ogg_stream_packetout(&vf->os,NULL);
       }
     }
   }
-  
+
   /* verify result */
   if(vf->pcm_offset>pos || pos>ov_pcm_total(vf,-1)){
     result=OV_EFAULT;
@@ -1533,7 +1659,7 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
   vf->bittrack=0.f;
   vf->samptrack=0.f;
   return(0);
-  
+
  seek_error:
   /* dump machine so we're in a known state */
   vf->pcm_offset=-1;
@@ -1541,7 +1667,7 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
   return (int)result;
 }
 
-/* seek to a sample offset relative to the decompressed pcm stream 
+/* seek to a sample offset relative to the decompressed pcm stream
    returns zero on success, nonzero on failure */
 
 int ov_pcm_seek(OggVorbis_File *vf,ogg_int64_t pos){
@@ -1561,57 +1687,57 @@ int ov_pcm_seek(OggVorbis_File *vf,ogg_int64_t pos){
     if(ret>0){
       thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
       if(thisblock<0){
-       ogg_stream_packetout(&vf->os,NULL);
-       continue; /* non audio packet */
+        ogg_stream_packetout(&vf->os,NULL);
+        continue; /* non audio packet */
       }
       if(lastblock)vf->pcm_offset+=(lastblock+thisblock)>>2;
-      
+
       if(vf->pcm_offset+((thisblock+
-                         vorbis_info_blocksize(vf->vi,1))>>2)>=pos)break;
-      
+                          vorbis_info_blocksize(vf->vi,1))>>2)>=pos)break;
+
       /* remove the packet from packet queue and track its granulepos */
       ogg_stream_packetout(&vf->os,NULL);
       vorbis_synthesis_trackonly(&vf->vb,&op);  /* set up a vb with
                                                    only tracking, no
                                                    pcm_decode */
-      vorbis_synthesis_blockin(&vf->vd,&vf->vb); 
-      
+      vorbis_synthesis_blockin(&vf->vd,&vf->vb);
+
       /* end of logical stream case is hard, especially with exact
-        length positioning. */
-      
+         length positioning. */
+
       if(op.granulepos>-1){
-       int i;
-       /* always believe the stream markers */
-       vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
-       if(vf->pcm_offset<0)vf->pcm_offset=0;
-       for(i=0;i<vf->current_link;i++)
-         vf->pcm_offset+=vf->pcmlengths[i*2+1];
+        int i;
+        /* always believe the stream markers */
+        vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
+        if(vf->pcm_offset<0)vf->pcm_offset=0;
+        for(i=0;i<vf->current_link;i++)
+          vf->pcm_offset+=vf->pcmlengths[i*2+1];
       }
-       
+
       lastblock=thisblock;
-      
+
     }else{
       if(ret<0 && ret!=OV_HOLE)break;
-      
+
       /* suck in a new page */
       if(_get_next_page(vf,&og,-1)<0)break;
       if(ogg_page_bos(&og))_decode_clear(vf);
-      
+
       if(vf->ready_state<STREAMSET){
-       long serialno=ogg_page_serialno(&og);
-       int link;
-       
-       for(link=0;link<vf->links;link++)
-         if(vf->serialnos[link]==serialno)break;
-       if(link==vf->links) continue; 
-       vf->current_link=link;
-       
-       vf->ready_state=STREAMSET;      
-       vf->current_serialno=ogg_page_serialno(&og);
-       ogg_stream_reset_serialno(&vf->os,serialno); 
-       ret=_make_decode_ready(vf);
-       if(ret)return ret;
-       lastblock=0;
+        long serialno=ogg_page_serialno(&og);
+        int link;
+
+        for(link=0;link<vf->links;link++)
+          if(vf->serialnos[link]==serialno)break;
+        if(link==vf->links) continue;
+        vf->current_link=link;
+
+        vf->ready_state=STREAMSET;
+        vf->current_serialno=ogg_page_serialno(&og);
+        ogg_stream_reset_serialno(&vf->os,serialno);
+        ret=_make_decode_ready(vf);
+        if(ret)return ret;
+        lastblock=0;
       }
 
       ogg_stream_pagein(&vf->os,&og);
@@ -1622,22 +1748,27 @@ int ov_pcm_seek(OggVorbis_File *vf,ogg_int64_t pos){
   vf->samptrack=0.f;
   /* discard samples until we reach the desired position. Crossing a
      logical bitstream boundary with abandon is OK. */
-  while(vf->pcm_offset<pos){
-    ogg_int64_t target=pos-vf->pcm_offset;
-    long samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
-
-    if(samples>target)samples=target;
-    vorbis_synthesis_read(&vf->vd,samples);
-    vf->pcm_offset+=samples;
-    
-    if(samples<target)
-      if(_fetch_and_process_packet(vf,NULL,1,1)<=0)
-       vf->pcm_offset=ov_pcm_total(vf,-1); /* eof */
+  {
+    /* note that halfrate could be set differently in each link, but
+       vorbisfile encoforces all links are set or unset */
+    int hs=vorbis_synthesis_halfrate_p(vf->vi);
+    while(vf->pcm_offset<((pos>>hs)<<hs)){
+      ogg_int64_t target=(pos-vf->pcm_offset)>>hs;
+      long samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+
+      if(samples>target)samples=target;
+      vorbis_synthesis_read(&vf->vd,samples);
+      vf->pcm_offset+=samples<<hs;
+
+      if(samples<target)
+        if(_fetch_and_process_packet(vf,NULL,1,1)<=0)
+          vf->pcm_offset=ov_pcm_total(vf,-1); /* eof */
+    }
   }
   return 0;
 }
 
-/* seek to a playback time relative to the decompressed pcm stream 
+/* seek to a playback time relative to the decompressed pcm stream
    returns zero on success, nonzero on failure */
 int ov_time_seek(OggVorbis_File *vf,double seconds){
   /* translate time to PCM position and call ov_pcm_seek */
@@ -1649,7 +1780,7 @@ int ov_time_seek(OggVorbis_File *vf,double seconds){
   if(vf->ready_state<OPENED)return(OV_EINVAL);
   if(!vf->seekable)return(OV_ENOSEEK);
   if(seconds<0)return(OV_EINVAL);
-  
+
   /* which bitstream section does this time offset occur in? */
   for(link=0;link<vf->links;link++){
     double addsec = ov_time_total(vf,link);
@@ -1667,7 +1798,7 @@ int ov_time_seek(OggVorbis_File *vf,double seconds){
   }
 }
 
-/* page-granularity version of ov_time_seek 
+/* page-granularity version of ov_time_seek
    returns zero on success, nonzero on failure */
 int ov_time_seek_page(OggVorbis_File *vf,double seconds){
   /* translate time to PCM position and call ov_pcm_seek */
@@ -1679,7 +1810,7 @@ int ov_time_seek_page(OggVorbis_File *vf,double seconds){
   if(vf->ready_state<OPENED)return(OV_EINVAL);
   if(!vf->seekable)return(OV_ENOSEEK);
   if(seconds<0)return(OV_EINVAL);
-  
+
   /* which bitstream section does this time offset occur in? */
   for(link=0;link<vf->links;link++){
     double addsec = ov_time_total(vf,link);
@@ -1715,12 +1846,12 @@ double ov_time_tell(OggVorbis_File *vf){
   int link=0;
   ogg_int64_t pcm_total=0;
   double time_total=0.f;
-  
+
   if(vf->ready_state<OPENED)return(OV_EINVAL);
   if(vf->seekable){
     pcm_total=ov_pcm_total(vf,-1);
     time_total=ov_time_total(vf,-1);
-  
+
     /* which bitstream section does this time offset occur in? */
     for(link=vf->links-1;link>=0;link--){
       pcm_total-=vf->pcmlengths[link*2+1];
@@ -1735,7 +1866,7 @@ double ov_time_tell(OggVorbis_File *vf){
 /*  link:   -1) return the vorbis_info struct for the bitstream section
                 currently being decoded
            0-n) to request information for a specific bitstream section
-    
+
     In the case of a non-seekable bitstream, any call returns the
     current bitstream.  NULL in the case that the machine is not
     initialized */
@@ -1744,14 +1875,14 @@ vorbis_info *ov_info(OggVorbis_File *vf,int link){
   if(vf->seekable){
     if(link<0)
       if(vf->ready_state>=STREAMSET)
-       return vf->vi+vf->current_link;
+        return vf->vi+vf->current_link;
       else
       return vf->vi;
     else
       if(link>=vf->links)
-       return NULL;
+        return NULL;
       else
-       return vf->vi+link;
+        return vf->vi+link;
   }else{
     return vf->vi;
   }
@@ -1762,14 +1893,14 @@ vorbis_comment *ov_comment(OggVorbis_File *vf,int link){
   if(vf->seekable){
     if(link<0)
       if(vf->ready_state>=STREAMSET)
-       return vf->vc+vf->current_link;
+        return vf->vc+vf->current_link;
       else
-       return vf->vc;
+        return vf->vc;
     else
       if(link>=vf->links)
-       return NULL;
+        return NULL;
       else
-       return vf->vc+link;
+        return vf->vc+link;
   }else{
     return vf->vc;
   }
@@ -1803,26 +1934,27 @@ static int host_is_big_endian() {
    after the audio has been converted into integral PCM.
 
    input values: buffer) a buffer to hold packed PCM data for return
-                length) the byte length requested to be placed into buffer
-                bigendianp) should the data be packed LSB first (0) or
-                            MSB first (1)
-                word) word size for output.  currently 1 (byte) or 
-                      2 (16 bit short)
+                 length) the byte length requested to be placed into buffer
+                 bigendianp) should the data be packed LSB first (0) or
+                             MSB first (1)
+                 word) word size for output.  currently 1 (byte) or
+                       2 (16 bit short)
 
    return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL)
                    0) EOF
-                  n) number of bytes of PCM actually returned.  The
-                  below works on a packet-by-packet basis, so the
-                  return length is not related to the 'length' passed
-                  in, just guaranteed to fit.
+                   n) number of bytes of PCM actually returned.  The
+                   below works on a packet-by-packet basis, so the
+                   return length is not related to the 'length' passed
+                   in, just guaranteed to fit.
 
-           *section) set to the logical bitstream number */
+            *section) set to the logical bitstream number */
 
 long ov_read_filter(OggVorbis_File *vf,char *buffer,int length,
-                   int bigendianp,int word,int sgned,int *bitstream,
-                   void (*filter)(float **pcm,long channels,long samples,void *filter_param),void *filter_param){
+                    int bigendianp,int word,int sgned,int *bitstream,
+                    void (*filter)(float **pcm,long channels,long samples,void *filter_param),void *filter_param){
   int i,j;
   int host_endian = host_is_big_endian();
+  int hs;
 
   float **pcm;
   long samples;
@@ -1839,17 +1971,17 @@ long ov_read_filter(OggVorbis_File *vf,char *buffer,int length,
     {
       int ret=_fetch_and_process_packet(vf,NULL,1,1);
       if(ret==OV_EOF)
-       return(0);
+        return(0);
       if(ret<=0)
-       return(ret);
+        return(ret);
     }
 
   }
 
   if(samples>0){
-  
+
     /* yay! proceed to pack data into the byte buffer */
-    
+
     long channels=ov_info(vf,-1)->channels;
     long bytespersample=word * channels;
     vorbis_fpu_control fpu;
@@ -1857,7 +1989,7 @@ long ov_read_filter(OggVorbis_File *vf,char *buffer,int length,
 
     if(samples <= 0)
       return OV_EINVAL;
-    
+
     /* Here. */
     if(filter)
       filter(pcm,channels,samples,filter_param);
@@ -1866,87 +1998,88 @@ long ov_read_filter(OggVorbis_File *vf,char *buffer,int length,
     {
       int val;
       if(word==1){
-       int off=(sgned?0:128);
-       vorbis_fpu_setround(&fpu);
-       for(j=0;j<samples;j++)
-         for(i=0;i<channels;i++){
-           val=vorbis_ftoi(pcm[i][j]*128.f);
-           if(val>127)val=127;
-           else if(val<-128)val=-128;
-           *buffer++=val+off;
-         }
-       vorbis_fpu_restore(fpu);
+        int off=(sgned?0:128);
+        vorbis_fpu_setround(&fpu);
+        for(j=0;j<samples;j++)
+          for(i=0;i<channels;i++){
+            val=vorbis_ftoi(pcm[i][j]*128.f);
+            if(val>127)val=127;
+            else if(val<-128)val=-128;
+            *buffer++=val+off;
+          }
+        vorbis_fpu_restore(fpu);
       }else{
-       int off=(sgned?0:32768);
-       
-       if(host_endian==bigendianp){
-         if(sgned){
-           
-           vorbis_fpu_setround(&fpu);
-           for(i=0;i<channels;i++) { /* It's faster in this order */
-             float *src=pcm[i];
-             short *dest=((short *)buffer)+i;
-             for(j=0;j<samples;j++) {
-               val=vorbis_ftoi(src[j]*32768.f);
-               if(val>32767)val=32767;
-               else if(val<-32768)val=-32768;
-               *dest=val;
-               dest+=channels;
-             }
-           }
-           vorbis_fpu_restore(fpu);
-           
-         }else{
-           
-           vorbis_fpu_setround(&fpu);
-           for(i=0;i<channels;i++) {
-             float *src=pcm[i];
-             short *dest=((short *)buffer)+i;
-             for(j=0;j<samples;j++) {
-               val=vorbis_ftoi(src[j]*32768.f);
-               if(val>32767)val=32767;
-               else if(val<-32768)val=-32768;
-               *dest=val+off;
-               dest+=channels;
-             }
-           }
-           vorbis_fpu_restore(fpu);
-           
-         }
-       }else if(bigendianp){
-         
-         vorbis_fpu_setround(&fpu);
-         for(j=0;j<samples;j++)
-           for(i=0;i<channels;i++){
-             val=vorbis_ftoi(pcm[i][j]*32768.f);
-             if(val>32767)val=32767;
-             else if(val<-32768)val=-32768;
-             val+=off;
-             *buffer++=(val>>8);
-             *buffer++=(val&0xff);
-           }
-         vorbis_fpu_restore(fpu);
-         
-       }else{
-         int val;
-         vorbis_fpu_setround(&fpu);
-         for(j=0;j<samples;j++)
-           for(i=0;i<channels;i++){
-             val=vorbis_ftoi(pcm[i][j]*32768.f);
-             if(val>32767)val=32767;
-             else if(val<-32768)val=-32768;
-             val+=off;
-             *buffer++=(val&0xff);
-             *buffer++=(val>>8);
-               }
-         vorbis_fpu_restore(fpu);  
-         
-       }
+        int off=(sgned?0:32768);
+
+        if(host_endian==bigendianp){
+          if(sgned){
+
+            vorbis_fpu_setround(&fpu);
+            for(i=0;i<channels;i++) { /* It's faster in this order */
+              float *src=pcm[i];
+              short *dest=((short *)buffer)+i;
+              for(j=0;j<samples;j++) {
+                val=vorbis_ftoi(src[j]*32768.f);
+                if(val>32767)val=32767;
+                else if(val<-32768)val=-32768;
+                *dest=val;
+                dest+=channels;
+              }
+            }
+            vorbis_fpu_restore(fpu);
+
+          }else{
+
+            vorbis_fpu_setround(&fpu);
+            for(i=0;i<channels;i++) {
+              float *src=pcm[i];
+              short *dest=((short *)buffer)+i;
+              for(j=0;j<samples;j++) {
+                val=vorbis_ftoi(src[j]*32768.f);
+                if(val>32767)val=32767;
+                else if(val<-32768)val=-32768;
+                *dest=val+off;
+                dest+=channels;
+              }
+            }
+            vorbis_fpu_restore(fpu);
+
+          }
+        }else if(bigendianp){
+
+          vorbis_fpu_setround(&fpu);
+          for(j=0;j<samples;j++)
+            for(i=0;i<channels;i++){
+              val=vorbis_ftoi(pcm[i][j]*32768.f);
+              if(val>32767)val=32767;
+              else if(val<-32768)val=-32768;
+              val+=off;
+              *buffer++=(val>>8);
+              *buffer++=(val&0xff);
+            }
+          vorbis_fpu_restore(fpu);
+
+        }else{
+          int val;
+          vorbis_fpu_setround(&fpu);
+          for(j=0;j<samples;j++)
+            for(i=0;i<channels;i++){
+              val=vorbis_ftoi(pcm[i][j]*32768.f);
+              if(val>32767)val=32767;
+              else if(val<-32768)val=-32768;
+              val+=off;
+              *buffer++=(val&0xff);
+              *buffer++=(val>>8);
+                  }
+          vorbis_fpu_restore(fpu);
+
+        }
       }
     }
-    
+
     vorbis_synthesis_read(&vf->vd,samples);
-    vf->pcm_offset+=samples;
+    hs=vorbis_synthesis_halfrate_p(vf->vi);
+    vf->pcm_offset+=(samples<<hs);
     if(bitstream)*bitstream=vf->current_link;
     return(samples*bytespersample);
   }else{
@@ -1955,26 +2088,26 @@ long ov_read_filter(OggVorbis_File *vf,char *buffer,int length,
 }
 
 long ov_read(OggVorbis_File *vf,char *buffer,int length,
-            int bigendianp,int word,int sgned,int *bitstream){
+             int bigendianp,int word,int sgned,int *bitstream){
   return ov_read_filter(vf, buffer, length, bigendianp, word, sgned, bitstream, NULL, NULL);
 }
 
 /* input values: pcm_channels) a float vector per channel of output
-                length) the sample length being read by the app
+                 length) the sample length being read by the app
 
    return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL)
                    0) EOF
-                  n) number of samples of PCM actually returned.  The
-                  below works on a packet-by-packet basis, so the
-                  return length is not related to the 'length' passed
-                  in, just guaranteed to fit.
+                   n) number of samples of PCM actually returned.  The
+                   below works on a packet-by-packet basis, so the
+                   return length is not related to the 'length' passed
+                   in, just guaranteed to fit.
 
-           *section) set to the logical bitstream number */
+            *section) set to the logical bitstream number */
 
 
 
 long ov_read_float(OggVorbis_File *vf,float ***pcm_channels,int length,
-                  int *bitstream){
+                   int *bitstream){
 
   if(vf->ready_state<OPENED)return(OV_EINVAL);
 
@@ -1983,12 +2116,13 @@ long ov_read_float(OggVorbis_File *vf,float ***pcm_channels,int length,
       float **pcm;
       long samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
       if(samples){
-       if(pcm_channels)*pcm_channels=pcm;
-       if(samples>length)samples=length;
-       vorbis_synthesis_read(&vf->vd,samples);
-       vf->pcm_offset+=samples;
-       if(bitstream)*bitstream=vf->current_link;
-       return samples;
+        int hs=vorbis_synthesis_halfrate_p(vf->vi);
+        if(pcm_channels)*pcm_channels=pcm;
+        if(samples>length)samples=length;
+        vorbis_synthesis_read(&vf->vd,samples);
+        vf->pcm_offset+=samples<<hs;
+        if(bitstream)*bitstream=vf->current_link;
+        return samples;
 
       }
     }
@@ -2003,16 +2137,14 @@ long ov_read_float(OggVorbis_File *vf,float ***pcm_channels,int length,
   }
 }
 
-extern float *vorbis_window(vorbis_dsp_state *v,int W);
-extern void _analysis_output_always(char *base,int i,float *v,int n,int bark,int dB,
-                            ogg_int64_t off);
+extern const float *vorbis_window(vorbis_dsp_state *v,int W);
 
 static void _ov_splice(float **pcm,float **lappcm,
-                      int n1, int n2,
-                      int ch1, int ch2,
-                      float *w1, float *w2){
+                       int n1, int n2,
+                       int ch1, int ch2,
+                       const float *w1, const float *w2){
   int i,j;
-  float *w=w1;
+  const float *w=w1;
   int n=n1;
 
   if(n1>n2){
@@ -2041,7 +2173,7 @@ static void _ov_splice(float **pcm,float **lappcm,
   }
 
 }
-               
+
 /* make sure vf is INITSET */
 static int _ov_initset(OggVorbis_File *vf){
   while(1){
@@ -2063,13 +2195,13 @@ static int _ov_initprime(OggVorbis_File *vf){
   while(1){
     if(vf->ready_state==INITSET)
       if(vorbis_synthesis_pcmout(vd,NULL))break;
-    
+
     /* suck in another packet */
     {
       int ret=_fetch_and_process_packet(vf,NULL,1,0);
       if(ret<0 && ret!=OV_HOLE)return(ret);
     }
-  }  
+  }
   return 0;
 }
 
@@ -2077,7 +2209,7 @@ static int _ov_initprime(OggVorbis_File *vf){
    unreturned, already-decoded pcm, remaining PCM we will need to
    decode, or synthetic postextrapolation from last packets. */
 static void _ov_getlap(OggVorbis_File *vf,vorbis_info *vi,vorbis_dsp_state *vd,
-                      float **lappcm,int lapsize){
+                       float **lappcm,int lapsize){
   int lapcount=0,i;
   float **pcm;
 
@@ -2087,7 +2219,7 @@ static void _ov_getlap(OggVorbis_File *vf,vorbis_info *vi,vorbis_dsp_state *vd,
     if(samples){
       if(samples>lapsize-lapcount)samples=lapsize-lapcount;
       for(i=0;i<vi->channels;i++)
-       memcpy(lappcm[i]+lapcount,pcm[i],sizeof(**pcm)*samples);
+        memcpy(lappcm[i]+lapcount,pcm[i],sizeof(**pcm)*samples);
       lapcount+=samples;
       vorbis_synthesis_read(vd,samples);
     }else{
@@ -2103,12 +2235,12 @@ static void _ov_getlap(OggVorbis_File *vf,vorbis_info *vi,vorbis_dsp_state *vd,
     int samples=vorbis_synthesis_lapout(&vf->vd,&pcm);
     if(samples==0){
       for(i=0;i<vi->channels;i++)
-       memset(lappcm[i]+lapcount,0,sizeof(**pcm)*lapsize-lapcount);
+        memset(lappcm[i]+lapcount,0,sizeof(**pcm)*lapsize-lapcount);
       lapcount=lapsize;
     }else{
       if(samples>lapsize-lapcount)samples=lapsize-lapcount;
       for(i=0;i<vi->channels;i++)
-       memcpy(lappcm[i]+lapcount,pcm[i],sizeof(**pcm)*samples);
+        memcpy(lappcm[i]+lapcount,pcm[i],sizeof(**pcm)*samples);
       lapcount+=samples;
     }
   }
@@ -2120,7 +2252,7 @@ int ov_crosslap(OggVorbis_File *vf1, OggVorbis_File *vf2){
   vorbis_info *vi1,*vi2;
   float **lappcm;
   float **pcm;
-  float *w1,*w2;
+  const float *w1,*w2;
   int n1,n2,i,ret,hs1,hs2;
 
   if(vf1==vf2)return(0); /* degenerate case */
@@ -2156,22 +2288,25 @@ int ov_crosslap(OggVorbis_File *vf1, OggVorbis_File *vf2){
      buffer of vf2 */
   /* consolidate and expose the buffer. */
   vorbis_synthesis_lapout(&vf2->vd,&pcm);
+
+#if 0
   _analysis_output_always("pcmL",0,pcm[0],n1*2,0,0,0);
   _analysis_output_always("pcmR",0,pcm[1],n1*2,0,0,0);
+#endif
 
   /* splice */
   _ov_splice(pcm,lappcm,n1,n2,vi1->channels,vi2->channels,w1,w2);
-  
+
   /* done */
   return(0);
 }
 
 static int _ov_64_seek_lap(OggVorbis_File *vf,ogg_int64_t pos,
-                          int (*localseek)(OggVorbis_File *,ogg_int64_t)){
+                           int (*localseek)(OggVorbis_File *,ogg_int64_t)){
   vorbis_info *vi;
   float **lappcm;
   float **pcm;
-  float *w1,*w2;
+  const float *w1,*w2;
   int n1,n2,ch1,ch2,hs;
   int i,ret;
 
@@ -2180,13 +2315,13 @@ static int _ov_64_seek_lap(OggVorbis_File *vf,ogg_int64_t pos,
   if(ret)return(ret);
   vi=ov_info(vf,-1);
   hs=ov_halfrate_p(vf);
-  
+
   ch1=vi->channels;
   n1=vorbis_info_blocksize(vi,0)>>(1+hs);
   w1=vorbis_window(&vf->vd,0);  /* window arrays from libvorbis are
-                                  persistent; even if the decode state
-                                  from this link gets dumped, this
-                                  window array continues to exist */
+                                   persistent; even if the decode state
+                                   from this link gets dumped, this
+                                   window array continues to exist */
 
   lappcm=alloca(sizeof(*lappcm)*ch1);
   for(i=0;i<ch1;i++)
@@ -2228,11 +2363,11 @@ int ov_pcm_seek_page_lap(OggVorbis_File *vf,ogg_int64_t pos){
 }
 
 static int _ov_d_seek_lap(OggVorbis_File *vf,double pos,
-                          int (*localseek)(OggVorbis_File *,double)){
+                           int (*localseek)(OggVorbis_File *,double)){
   vorbis_info *vi;
   float **lappcm;
   float **pcm;
-  float *w1,*w2;
+  const float *w1,*w2;
   int n1,n2,ch1,ch2,hs;
   int i,ret;
 
@@ -2245,9 +2380,9 @@ static int _ov_d_seek_lap(OggVorbis_File *vf,double pos,
   ch1=vi->channels;
   n1=vorbis_info_blocksize(vi,0)>>(1+hs);
   w1=vorbis_window(&vf->vd,0);  /* window arrays from libvorbis are
-                                  persistent; even if the decode state
-                                  from this link gets dumped, this
-                                  window array continues to exist */
+                                   persistent; even if the decode state
+                                   from this link gets dumped, this
+                                   window array continues to exist */
 
   lappcm=alloca(sizeof(*lappcm)*ch1);
   for(i=0;i<ch1;i++)