Fix shift by negative value when reading blocksize.

[platform/upstream/libvorbis.git] / lib / vorbisfile.c

diff --git a/lib/vorbisfile.c b/lib/vorbisfile.c
index 770a2da..b570c3c 100644 (file)
--- a/lib/vorbisfile.c
+++ b/lib/vorbisfile.c
@@ -1,27 +1,29 @@
 /********************************************************************
  *                                                                  *
  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
 /********************************************************************
  *                                                                  *
  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *

- * USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY *
- * THE GNU LESSER/LIBRARY PUBLIC LICENSE, WHICH IS INCLUDED WITH    *
- * THIS SOURCE. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.        *
+ * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
+ * 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 1994-2000             *
- * by Monty <monty@xiph.org> and the XIPHOPHORUS Company            *
- * http://www.xiph.org/                                             *
+ * 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
  *                                                                  *
  ********************************************************************
 
  function: stdio-based convenience library for opening/seeking/decoding

- last mod: $Id: vorbisfile.c,v 1.32 2000/11/14 00:05:32 xiphmont Exp $

 
  ********************************************************************/
 
 #include <stdlib.h>
 #include <stdio.h>
 
  ********************************************************************/
 
 #include <stdlib.h>
 #include <stdio.h>

+#include <errno.h>

 #include <string.h>
 #include <math.h>
 
 #include "vorbis/codec.h"
 #include <string.h>
 #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"
 #include "vorbis/vorbisfile.h"
 
 #include "os.h"


@@ -48,28 +50,48 @@
    information exists in an Ogg bitstream to seek to
    sample-granularity positions in the output.  Or, one can seek by
    picking some portion of the stream roughly in the desired area if
    information exists in an Ogg bitstream to seek to
    sample-granularity positions in the output.  Or, one can seek by
    picking some portion of the stream roughly in the desired area if

-   we only want course navigation through the stream. */
+   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 */
 
  * 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 4096
+/* read a little more data from the file/pipe into the ogg_sync framer
+*/
+#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){
 static long _get_data(OggVorbis_File *vf){

-  char *buffer=ogg_sync_buffer(&vf->oy,CHUNKSIZE);
-  long bytes=(vf->callbacks.read_func)(buffer,1,CHUNKSIZE,vf->datasource);
-  if(bytes>0)ogg_sync_wrote(&vf->oy,bytes);
-  return(bytes);
+  errno=0;
+  if(!(vf->callbacks.read_func))return(-1);
+  if(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);
+  }else
+    return(0);

 }
 
 /* save a tiny smidge of verbosity to make the code more readable */
 }
 
 /* save a tiny smidge of verbosity to make the code more readable */

-static void _seek_helper(OggVorbis_File *vf,long offset){
-  (vf->callbacks.seek_func)(vf->datasource, offset, SEEK_SET);
-  vf->offset=offset;
-  ogg_sync_reset(&vf->oy);
+static int _seek_helper(OggVorbis_File *vf,ogg_int64_t offset){
+  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;
+  }
+  return 0;

 }
 
 /* The read/seek functions track absolute position within the stream */
 }
 
 /* The read/seek functions track absolute position within the stream */


@@ -80,432 +102,716 @@ static void _seek_helper(OggVorbis_File *vf,long offset){
 
    boundary: -1) unbounded search
               0) read no additional data; use cached only
 
    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 */
 
 
    return:   <0) did not find a page (OV_FALSE, OV_EOF, OV_EREAD)
               n) found a page at absolute offset n */
 

-static long _get_next_page(OggVorbis_File *vf,ogg_page *og,int boundary){
+static ogg_int64_t _get_next_page(OggVorbis_File *vf,ogg_page *og,
+                                  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(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){
     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{
       }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 */
            advance the internal offset past the page end */

-       long 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 */
 /* returns offset or OV_EREAD, OV_FAULT */

-static long _get_prev_page(OggVorbis_File *vf,ogg_page *og){
-  long begin=vf->offset;
-  long ret;
-  int offset=-1;
+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;

 
   while(offset==-1){
     begin-=CHUNKSIZE;
 
   while(offset==-1){
     begin-=CHUNKSIZE;

-    _seek_helper(vf,begin);
-    while(vf->offset<begin+CHUNKSIZE){
-      ret=_get_next_page(vf,og,begin+CHUNKSIZE-vf->offset);
+    if(begin<0)
+      begin=0;
+
+    ret=_seek_helper(vf,begin);
+    if(ret)return(ret);
+
+    while(vf->offset<end){
+      memset(og,0,sizeof(*og));
+      ret=_get_next_page(vf,og,end-vf->offset);

       if(ret==OV_EREAD)return(OV_EREAD);
       if(ret<0){
       if(ret==OV_EREAD)return(OV_EREAD);
       if(ret<0){

-       break;
+        break;

       }else{
       }else{

-       offset=ret;
+        offset=ret;

       }
     }
   }
 
       }
     }
   }
 

-  /* we have the offset.  Actually snork and hold the page now */
-  _seek_helper(vf,offset);
-  ret=_get_next_page(vf,og,CHUNKSIZE);
-  if(ret<0)
-    /* this shouldn't be possible */
-    return(OV_EFAULT);
+  /* In a fully compliant, non-multiplexed stream, we'll still be
+     holding the last page.  In multiplexed (or noncompliant streams),
+     we will probably have to re-read the last page we saw */
+  if(og->header_len==0){
+    ret=_seek_helper(vf,offset);
+    if(ret)return(ret);
+
+    ret=_get_next_page(vf,og,CHUNKSIZE);
+    if(ret<0)
+      /* this shouldn't be possible */
+      return(OV_EFAULT);
+  }

 
   return(offset);
 }
 
 
   return(offset);
 }
 

-/* finds each bitstream link one at a time using a bisection search
-   (has to begin by knowing the offset of the lb's initial page).
-   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,
-                                   long begin,
-                                   long searched,
-                                   long end,
-                                   long currentno,
-                                   long m){
-  long endsearched=end;
-  long next=end;
-  ogg_page og;
-  long ret;
-  
-  /* the below guards against garbage seperating the last and
-     first pages of two links. */
-  while(searched<endsearched){
-    long bisect;
-    
-    if(endsearched-searched<CHUNKSIZE){
-      bisect=searched;
-    }else{
-      bisect=(searched+endsearched)/2;
-    }
-    
-    _seek_helper(vf,bisect);
-    ret=_get_next_page(vf,&og,-1);
-    if(ret==OV_EREAD)return(OV_EREAD);
-    if(ret<0 || ogg_page_serialno(&og)!=currentno){
-      endsearched=bisect;
-      if(ret>=0)next=ret;
-    }else{
-      searched=ret+og.header_len+og.body_len;
+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;
+}

 
 

-  _seek_helper(vf,next);
-  ret=_get_next_page(vf,&og,-1);
-  if(ret==OV_EREAD)return(OV_EREAD);
-  
-  if(searched>=end || ret<0){
-    vf->links=m+1;
-    vf->offsets=_ogg_malloc((m+2)*sizeof(ogg_int64_t));
-    vf->offsets[m+1]=searched;
-  }else{
-    ret=_bisect_forward_serialno(vf,next,vf->offset,
-                                end,ogg_page_serialno(&og),m+1);
-    if(ret==OV_EREAD)return(OV_EREAD);
+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, ogg_int64_t begin,
+                                         long *serial_list, int serial_n,
+                                         int *serialno, ogg_int64_t *granpos){
+  ogg_page og;
+  ogg_int64_t end=begin;
+  ogg_int64_t ret;
+
+  ogg_int64_t prefoffset=-1;
+  ogg_int64_t offset=-1;
+  ogg_int64_t ret_serialno=-1;
+  ogg_int64_t ret_gran=-1;
+
+  while(offset==-1){
+    begin-=CHUNKSIZE;
+    if(begin<0)
+      begin=0;
+
+    ret=_seek_helper(vf,begin);
+    if(ret)return(ret);
+
+    while(vf->offset<end){
+      ret=_get_next_page(vf,&og,end-vf->offset);
+      if(ret==OV_EREAD)return(OV_EREAD);
+      if(ret<0){
+        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;
+        }
+
+        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;
+        }
+      }
+    }

   }
   }

-  
-  vf->offsets[m]=begin;
-  return(0);
+
+  /* we're not interested in the page... just the serialno and granpos. */
+  if(prefoffset>=0)return(prefoffset);
+
+  *serialno = ret_serialno;
+  *granpos = ret_gran;
+  return(offset);
+

 }
 
 /* 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,
 }
 
 /* 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,ogg_page *og_ptr){
+                          long **serialno_list, int *serialno_n,
+                          ogg_page *og_ptr){

   ogg_page og;
   ogg_packet op;
   ogg_page og;
   ogg_packet op;

-  int i,ret=0;
-  
+  int i,ret;
+  int allbos=0;
+

   if(!og_ptr){
   if(!og_ptr){

-    ret=_get_next_page(vf,&og,CHUNKSIZE);
-    if(ret==OV_EREAD)return(OV_EREAD);
-    if(ret<0)return OV_ENOTVORBIS;
+    ogg_int64_t llret=_get_next_page(vf,&og,CHUNKSIZE);
+    if(llret==OV_EREAD)return(OV_EREAD);
+    if(llret<0)return(OV_ENOTVORBIS);

     og_ptr=&og;
   }
 
     og_ptr=&og;
   }
 

-  if(serialno)*serialno=ogg_page_serialno(og_ptr);
-  ogg_stream_init(&vf->os,ogg_page_serialno(og_ptr));
-  
-  /* extract the initial header from the first page and verify that the
-     Ogg bitstream is in fact Vorbis data */
-  

   vorbis_info_init(vi);
   vorbis_comment_init(vc);
   vorbis_info_init(vi);
   vorbis_comment_init(vc);

-  
-  i=0;
-  while(i<3){
-    ogg_stream_pagein(&vf->os,og_ptr);
-    while(i<3){
-      int result=ogg_stream_packetout(&vf->os,&op);
-      if(result==0)break;
-      if(result==-1){
-       ret=OV_EBADHEADER;
-       goto bail_header;
+  vf->ready_state=OPENED;
+
+  /* extract the serialnos of all BOS pages + the first set of vorbis
+     headers we see in the link */
+
+  while(ogg_page_bos(og_ptr)){
+    if(serialno_list){
+      if(_lookup_page_serialno(og_ptr,*serialno_list,*serialno_n)){
+        /* a dupe serialnumber in an initial header packet set == invalid stream */
+        if(*serialno_list)_ogg_free(*serialno_list);
+        *serialno_list=0;
+        *serialno_n=0;
+        ret=OV_EBADHEADER;
+        goto bail_header;
+      }
+
+      _add_serialno(og_ptr,serialno_list,serialno_n);
+    }
+
+    if(vf->ready_state<STREAMSET){
+      /* we don't have a vorbis stream in this link yet, so begin
+         prospective stream setup. We need a stream to get packets */
+      ogg_stream_reset_serialno(&vf->os,ogg_page_serialno(og_ptr));
+      ogg_stream_pagein(&vf->os,og_ptr);
+
+      if(ogg_stream_packetout(&vf->os,&op) > 0 &&
+         vorbis_synthesis_idheader(&op)){
+        /* vorbis header; continue setup */
+        vf->ready_state=STREAMSET;
+        if((ret=vorbis_synthesis_headerin(vi,vc,&op))){
+          ret=OV_EBADHEADER;
+          goto bail_header;
+        }
+      }
+    }
+
+    /* get next page */
+    {
+      ogg_int64_t llret=_get_next_page(vf,og_ptr,CHUNKSIZE);
+      if(llret==OV_EREAD){
+        ret=OV_EREAD;
+        goto bail_header;
+      }
+      if(llret<0){
+        ret=OV_ENOTVORBIS;
+        goto bail_header;

       }
       }

-      if((ret=vorbis_synthesis_headerin(vi,vc,&op))){
-       goto bail_header;
+
+      /* if this page also belongs to our vorbis stream, submit it and break */
+      if(vf->ready_state==STREAMSET &&
+         vf->os.serialno == ogg_page_serialno(og_ptr)){
+        ogg_stream_pagein(&vf->os,og_ptr);
+        break;

       }
       }

-      i++;

     }
     }

-    if(i<3)
-      if(_get_next_page(vf,og_ptr,1)<0){
-       ret=OV_EBADHEADER;
-       goto bail_header;
+  }
+
+  if(vf->ready_state!=STREAMSET){
+    ret = OV_ENOTVORBIS;
+    goto bail_header;
+  }
+
+  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)){
+          if(allbos){
+            ret = OV_EBADHEADER;
+            goto bail_header;
+          }else
+            allbos=1;
+        }
+
+        /* otherwise, keep looking */
+      }
+    }
+
+    return 0;

   }
   }

-  return 0; 

 
  bail_header:
   vorbis_info_clear(vi);
   vorbis_comment_clear(vc);
 
  bail_header:
   vorbis_info_clear(vi);
   vorbis_comment_clear(vc);

-  ogg_stream_clear(&vf->os);
+  vf->ready_state=OPENED;
+

   return ret;
 }
 
   return ret;
 }
 

-/* last step of the OggVorbis_File initialization; get all the
-   vorbis_info structs and PCM positions.  Only called by the seekable
-   initialization (local stream storage is hacked slightly; pay
-   attention to how that's done) */
-
-/* this is void and does not propogate errors up because we want to be
-   able to open and use damaged bitstreams as well as we can.  Just
-   watch out for missing information for links in the OggVorbis_File
-   struct */
-static void _prefetch_all_headers(OggVorbis_File *vf,vorbis_info *first_i,
-                                 vorbis_comment *first_c,
-                                 long dataoffset){
+/* Starting from current cursor position, get initial PCM offset of
+   next page.  Consumes the page in the process without decoding
+   audio, however this is only called during stream parsing upon
+   seekable open. */
+static ogg_int64_t _initial_pcmoffset(OggVorbis_File *vf, vorbis_info *vi){
+  ogg_page    og;
+  ogg_int64_t accumulated=0;
+  long        lastblock=-1;
+  int         result;
+  int         serialno = vf->os.serialno;
+
+  while(1){
+    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(thisblock>=0){
+          if(lastblock!=-1)
+            accumulated+=(lastblock+thisblock)>>2;
+          lastblock=thisblock;
+        }
+      }
+    }
+
+    if(ogg_page_granulepos(&og)!=-1){
+      /* pcm offset of last packet on the first audio page */
+      accumulated= ogg_page_granulepos(&og)-accumulated;
+      break;
+    }
+  }
+
+  /* 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;
+}
+
+/* finds each bitstream link one at a time using a bisection search
+   (has to begin by knowing the offset of the lb's initial page).
+   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 pcmoffset;
+  ogg_int64_t dataoffset=searched;
+  ogg_int64_t endsearched=end;
+  ogg_int64_t next=end;
+  ogg_int64_t searchgran=-1;

   ogg_page og;
   ogg_page og;

-  int i,ret;
-  
-  vf->vi=_ogg_calloc(vf->links,sizeof(vorbis_info));
-  vf->vc=_ogg_calloc(vf->links,sizeof(vorbis_info));
-  vf->dataoffsets=_ogg_malloc(vf->links*sizeof(ogg_int64_t));
-  vf->pcmlengths=_ogg_malloc(vf->links*sizeof(ogg_int64_t));
-  vf->serialnos=_ogg_malloc(vf->links*sizeof(long));
-  
-  for(i=0;i<vf->links;i++){
-    if(first_i && first_c && i==0){
-      /* we already grabbed the initial header earlier.  This just
-         saves the waste of grabbing it again */
-      memcpy(vf->vi+i,first_i,sizeof(vorbis_info));
-      memcpy(vf->vc+i,first_c,sizeof(vorbis_comment));
-      vf->dataoffsets[i]=dataoffset;
-    }else{
+  ogg_int64_t ret,last;
+  int serialno = vf->os.serialno;
+
+  /* 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
+       not a page we care about)
+  */
+
+  /* Is the last page in our list of current serialnumbers? */
+  if(_lookup_serialno(endserial,currentno_list,currentnos)){
+
+    /* last page is in the starting serialno list, so we've bisected
+       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;
+      searched=_get_prev_page_serial(vf,searched,currentno_list,currentnos,&endserial,&endgran);
+    }

 
 

-      /* seek to the location of the initial header */
+    vf->links=m+1;
+    if(vf->offsets)_ogg_free(vf->offsets);
+    if(vf->serialnos)_ogg_free(vf->serialnos);
+    if(vf->dataoffsets)_ogg_free(vf->dataoffsets);
+
+    vf->offsets=_ogg_malloc((vf->links+1)*sizeof(*vf->offsets));
+    vf->vi=_ogg_realloc(vf->vi,vf->links*sizeof(*vf->vi));
+    vf->vc=_ogg_realloc(vf->vc,vf->links*sizeof(*vf->vc));
+    vf->serialnos=_ogg_malloc(vf->links*sizeof(*vf->serialnos));
+    vf->dataoffsets=_ogg_malloc(vf->links*sizeof(*vf->dataoffsets));
+    vf->pcmlengths=_ogg_malloc(vf->links*2*sizeof(*vf->pcmlengths));
+
+    vf->offsets[m+1]=end;
+    vf->offsets[m]=begin;
+    vf->pcmlengths[m*2+1]=(endgran<0?0:endgran);
+
+  }else{

 
 

-      _seek_helper(vf,vf->offsets[i]);
-      if(_fetch_headers(vf,vf->vi+i,vf->vc+i,NULL,NULL)<0){
-       vf->dataoffsets[i]=-1;
+    /* 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;

       }else{
       }else{

-       vf->dataoffsets[i]=vf->offset;
-        ogg_stream_clear(&vf->os);
+        bisect=(searched+endsearched)/2;

       }
       }

-    }

 
 

-    /* get the serial number and PCM length of this link. To do this,
-       get the last page of the stream */
-    {
-      long end=vf->offsets[i+1];
-      _seek_helper(vf,end);
+      ret=_seek_helper(vf,bisect);
+      if(ret)return(ret);

 
 

-      while(1){
-       ret=_get_prev_page(vf,&og);
-       if(ret<0){
-         /* this should not be possible, actually */
-         vorbis_info_clear(vf->vi+i);
-         vorbis_comment_clear(vf->vc+i);
-         break;
-       }
-       if(ogg_page_granulepos(&og)!=-1){
-         vf->serialnos[i]=ogg_page_serialno(&og);
-         vf->pcmlengths[i]=ogg_page_granulepos(&og);
-         break;
-       }
+      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;
+      }else{
+        searched=vf->offset;

       }
     }
       }
     }

+
+    /* Bisection point found */
+    /* for the time being, fetch end PCM offset the simple way */
+    searched = next;
+    while(testserial != serialno){
+      testserial = serialno;
+      searched = _get_prev_page_serial(vf,searched,currentno_list,currentnos,&testserial,&searchgran);
+    }
+
+    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 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);
+    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;
+
+    vf->vi[m+1]=vi;
+    vf->vc[m+1]=vc;
+
+    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);

 }
 
 }
 

-static void _make_decode_ready(OggVorbis_File *vf){
-  if(vf->decode_ready)return;
+static int _make_decode_ready(OggVorbis_File *vf){
+  if(vf->ready_state>STREAMSET)return 0;
+  if(vf->ready_state<STREAMSET)return OV_EFAULT;

   if(vf->seekable){
   if(vf->seekable){

-    vorbis_synthesis_init(&vf->vd,vf->vi+vf->current_link);
+    if(vorbis_synthesis_init(&vf->vd,vf->vi+vf->current_link))
+      return OV_EBADLINK;

   }else{
   }else{

-    vorbis_synthesis_init(&vf->vd,vf->vi);
-  }    
+    if(vorbis_synthesis_init(&vf->vd,vf->vi))
+      return OV_EBADLINK;
+  }

   vorbis_block_init(&vf->vd,&vf->vb);
   vorbis_block_init(&vf->vd,&vf->vb);

-  vf->decode_ready=1;
-  return;
+  vf->ready_state=INITSET;
+  vf->bittrack=0.f;
+  vf->samptrack=0.f;
+  return 0;

 }
 
 }
 

-static int _open_seekable(OggVorbis_File *vf){
-  vorbis_info initial_i;
-  vorbis_comment initial_c;
-  long serialno,end;
-  int ret;
-  long dataoffset;
-  ogg_page og;
-  
-  /* is this even vorbis...? */
-  ret=_fetch_headers(vf,&initial_i,&initial_c,&serialno,NULL);
-  dataoffset=vf->offset;
-  ogg_stream_clear(&vf->os);
-  if(ret<0)return(ret);
-  
-  /* we can seek, so set out learning all about this file */
-  vf->seekable=1;
-  (vf->callbacks.seek_func)(vf->datasource,0,SEEK_END);
-  vf->offset=vf->end=(vf->callbacks.tell_func)(vf->datasource);
-  
-  /* We get the offset for the last page of the physical bitstream.
-     Most OggVorbis files will contain a single logical bitstream */
-  end=_get_prev_page(vf,&og);
-  if(end<0){
-    ogg_stream_clear(&vf->os);
-    return(end);
-  }
+static int _open_seekable2(OggVorbis_File *vf){
+  ogg_int64_t dataoffset=vf->dataoffsets[0],end,endgran=-1;
+  int endserial=vf->os.serialno;
+  int serialno=vf->os.serialno;

 
 

-  /* more than one logical bitstream? */
-  if(ogg_page_serialno(&og)!=serialno){
+  /* we're partially open and have a first link header state in
+     storage in vf */

 
 

-    /* Chained bitstream. Bisect-search each logical bitstream
-       section.  Do so based on serial number only */
-    if(_bisect_forward_serialno(vf,0,0,end+1,serialno,0)<0){
-      ogg_stream_clear(&vf->os);
-      return(OV_EREAD);
-    }
+  /* fetch initial PCM offset */
+  ogg_int64_t pcmoffset = _initial_pcmoffset(vf,vf->vi);

 
 

+  /* we can seek, so set out learning all about this file */
+  if(vf->callbacks.seek_func && vf->callbacks.tell_func){
+    (vf->callbacks.seek_func)(vf->datasource,0,SEEK_END);
+    vf->offset=vf->end=(vf->callbacks.tell_func)(vf->datasource);

   }else{
   }else{

-
-    /* Only one logical bitstream */
-    if(_bisect_forward_serialno(vf,0,end,end+1,serialno,0)){
-      ogg_stream_clear(&vf->os);
-      return(OV_EREAD);
-    }
-
+    vf->offset=vf->end=-1;

   }
 
   }
 

-  _prefetch_all_headers(vf,&initial_i,&initial_c,dataoffset);
-  return(ov_raw_seek(vf,0));
+  /* If seek_func is implemented, tell_func must also be implemented */
+  if(vf->end==-1) return(OV_EINVAL);

 
 

-}
+  /* 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->end,vf->serialnos+2,vf->serialnos[1],&endserial,&endgran);
+  if(end<0)return(end);

 
 

-static int _open_nonseekable(OggVorbis_File *vf){
-  int ret;
-  /* we cannot seek. Set up a 'single' (current) logical bitstream entry  */
-  vf->links=1;
-  vf->vi=_ogg_calloc(vf->links,sizeof(vorbis_info));
-  vf->vc=_ogg_calloc(vf->links,sizeof(vorbis_info));
+  /* now determine bitstream structure recursively */
+  if(_bisect_forward_serialno(vf,0,dataoffset,end,endgran,endserial,
+                              vf->serialnos+2,vf->serialnos[1],0)<0)return(OV_EREAD);

 
 

-  /* Try to fetch the headers, maintaining all the storage */
-  if((ret=_fetch_headers(vf,vf->vi,vf->vc,&vf->current_serialno,NULL))<0)
-    return(ret);
-  _make_decode_ready(vf);
+  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 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){
 static void _decode_clear(OggVorbis_File *vf){

-  ogg_stream_clear(&vf->os);

   vorbis_dsp_clear(&vf->vd);
   vorbis_block_clear(&vf->vb);
   vorbis_dsp_clear(&vf->vd);
   vorbis_block_clear(&vf->vb);

-  vf->decode_ready=0;
-
-  vf->bittrack=0.;
-  vf->samptrack=0.;
+  vf->ready_state=OPENED;

 }
 
 /* fetch and process a packet.  Handles the case where we're at a
    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
 }
 
 /* fetch and process a packet.  Handles the case where we're at a
    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)
 
    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 _process_packet(OggVorbis_File *vf,int readp){
+static int _fetch_and_process_packet(OggVorbis_File *vf,
+                                     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){
   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->decode_ready){
-      ogg_packet op;
-      int result=ogg_stream_packetout(&vf->os,&op);
-      ogg_int64_t granulepos;
-      
-      if(result==-1)return(OV_HOLE); /* hole in the data. */
-      if(result>0){
-       /* got a packet.  process it */
-       granulepos=op.granulepos;
-       if(!vorbis_synthesis(&vf->vb,&op)){ /* 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);
-           vorbis_synthesis_blockin(&vf->vd,&vf->vb);
-           vf->samptrack+=vorbis_synthesis_pcmout(&vf->vd,NULL)-oldsamples;
-           vf->bittrack+=op.bytes*8;
-         }
-         
-         /* update the pcm offset. */
-         if(granulepos!=-1 && !op.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.e_o_s clause
-              above */
-           
-           samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
-           
-           granulepos-=samples;
-           for(i=0;i<link;i++)
-             granulepos+=vf->pcmlengths[i];
-           vf->pcm_offset=granulepos;
-         }
-         return(1);
-       }
-      }
+
+    if(vf->ready_state==STREAMSET){
+      int ret=_make_decode_ready(vf);
+      if(ret<0)return ret;

     }
 
     }
 

-    if(!readp)return(0);
-    if(_get_next_page(vf,&og,-1)<0)return(OV_EOF); /* eof. leave unitialized */
+    /* 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,
+                 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)<<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;
+      }
+    }

 
 

-    /* 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>=OPENED){
+      ogg_int64_t ret;

 
 

-    /* has our decoding just traversed a bitstream boundary? */
-    if(vf->decode_ready){
-      if(vf->current_serialno!=ogg_page_serialno(&og)){
-       _decode_clear(vf);
+      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? */
       }
     }
 
     /* 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
 
        In the seekable case, we already have all the header
        information loaded and cached; we just initialize the machine


@@ -516,56 +822,145 @@ static int _process_packet(OggVorbis_File *vf,int readp){
        we're now nominally at the header of the next bitstream
     */
 
        we're now nominally at the header of the next bitstream
     */
 

-    if(!vf->decode_ready){
+    if(vf->ready_state!=INITSET){

       int link;
       int link;

-      if(vf->seekable){
-       vf->current_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]==vf->current_serialno)break;
-       if(link==vf->links)return(OV_EBADLINK); /* sign of a bogus
-                                                  stream.  error out,
-                                                  leave machine
-                                                  uninitialized */
-       
-       vf->current_link=link;
-       
-       ogg_stream_init(&vf->os,vf->current_serialno);
-       ogg_stream_reset(&vf->os); 
-       
-      }else{
-       /* we're streaming */
-       /* fetch the three header packets, build the info struct */
-       
-       _fetch_headers(vf,vf->vi,vf->vc,&vf->current_serialno,&og);
-       vf->current_link++;
-       link=0;
+
+      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;
+        }

       }
       }

-      
-      _make_decode_ready(vf);

     }
     }

+
+    /* the buffered page is the data we want, and we're ready for it;
+       add it to the stream state */

     ogg_stream_pagein(&vf->os,&og);
     ogg_stream_pagein(&vf->os,&og);

+
+  }
+}
+
+/* if, eg, 64 bit stdio is configured by default, this will build with
+   fseek64 */
+static int _fseek64_wrap(FILE *f,ogg_int64_t off,int whence){
+  if(f==NULL)return(-1);
+  return fseek(f,off,whence);
+}
+
+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;
+
+  /* init the framing state */
+  ogg_sync_init(&vf->oy);
+
+  /* perhaps some data was previously read into a buffer for testing
+     against other stream types.  Allow initialization from this
+     previously read data (especially as we may be reading from a
+     non-seekable stream) */
+  if(initial){
+    char *buffer=ogg_sync_buffer(&vf->oy,ibytes);
+    memcpy(buffer,initial,ibytes);
+    ogg_sync_wrote(&vf->oy,ibytes);
+  }
+
+  /* can we seek? Stevens suggests the seek test was portable */
+  if(offsettest!=-1)vf->seekable=1;
+
+  /* No seeking yet; Set up a 'single' (current) logical bitstream
+     entry for partial open */
+  vf->links=1;
+  vf->vi=_ogg_calloc(vf->links,sizeof(*vf->vi));
+  vf->vc=_ogg_calloc(vf->links,sizeof(*vf->vc));
+  ogg_stream_init(&vf->os,-1); /* fill in the serialno later */
+
+  /* Fetch all BOS pages, store the vorbis header and all seen serial
+     numbers, load subsequent vorbis setup headers */
+  if((ret=_fetch_headers(vf,vf->vi,vf->vc,&serialno_list,&serialno_list_size,NULL))<0){
+    vf->datasource=NULL;
+    ov_clear(vf);
+  }else{
+    /* serial number list for first link needs to be held somewhere
+       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->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->ready_state=PARTOPEN;

   }
   }

+  if(serialno_list)_ogg_free(serialno_list);
+  return(ret);

 }
 
 }
 

-/**********************************************************************
- * The helpers are over; it's all toplevel interface from here on out */
- 
+static int _ov_open2(OggVorbis_File *vf){
+  if(vf->ready_state != PARTOPEN) return OV_EINVAL;
+  vf->ready_state=OPENED;
+  if(vf->seekable){
+    int ret=_open_seekable2(vf);
+    if(ret){
+      vf->datasource=NULL;
+      ov_clear(vf);
+    }
+    return(ret);
+  }else
+    vf->ready_state=STREAMSET;
+
+  return 0;
+}
+
+

 /* clear out the OggVorbis_File struct */
 int ov_clear(OggVorbis_File *vf){
   if(vf){
     vorbis_block_clear(&vf->vb);
     vorbis_dsp_clear(&vf->vd);
     ogg_stream_clear(&vf->os);
 /* clear out the OggVorbis_File struct */
 int ov_clear(OggVorbis_File *vf){
   if(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++){
     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);
       }
       _ogg_free(vf->vi);
       _ogg_free(vf->vc);


@@ -575,8 +970,9 @@ int ov_clear(OggVorbis_File *vf){
     if(vf->serialnos)_ogg_free(vf->serialnos);
     if(vf->offsets)_ogg_free(vf->offsets);
     ogg_sync_clear(&vf->oy);
     if(vf->serialnos)_ogg_free(vf->serialnos);
     if(vf->offsets)_ogg_free(vf->offsets);
     ogg_sync_clear(&vf->oy);

-    if(vf->datasource)(vf->callbacks.close_func)(vf->datasource);
-    memset(vf,0,sizeof(OggVorbis_File));
+    if(vf->datasource && vf->callbacks.close_func)
+      (vf->callbacks.close_func)(vf->datasource);
+    memset(vf,0,sizeof(*vf));

   }
 #ifdef DEBUG_LEAKS
   _VDBG_dump();
   }
 #ifdef DEBUG_LEAKS
   _VDBG_dump();


@@ -584,19 +980,22 @@ int ov_clear(OggVorbis_File *vf){
   return(0);
 }
 
   return(0);
 }
 

-static int _fseek64_wrap(FILE *f,ogg_int64_t off,int whence){
-  return fseek(f,(int)off,whence);
-}
-

 /* inspects the OggVorbis file and finds/documents all the logical
    bitstreams contained in it.  Tries to be tolerant of logical
 /* 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
 */
 
 
    return: -1) error
             0) OK
 */
 

-int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
+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,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,
   ov_callbacks callbacks = {
     (size_t (*)(void *, size_t, size_t, void *))  fread,
     (int (*)(void *, ogg_int64_t, int))              _fseek64_wrap,


@@ -606,42 +1005,80 @@ int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
 
   return ov_open_callbacks((void *)f, vf, initial, ibytes, callbacks);
 }
 
   return ov_open_callbacks((void *)f, vf, initial, ibytes, callbacks);
 }

-  

 
 

-int ov_open_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
-    ov_callbacks callbacks)
-{
-  long offset=callbacks.seek_func(f,0,SEEK_CUR);
+int ov_fopen(const char *path,OggVorbis_File *vf){

   int ret;
   int ret;

+  FILE *f = fopen(path,"rb");
+  if(!f) return -1;

 
 

-  memset(vf,0,sizeof(OggVorbis_File));
-  vf->datasource=f;
-  vf->callbacks = callbacks;
+  ret = ov_open(f,vf,NULL,0);
+  if(ret) fclose(f);
+  return ret;
+}

 
 

-  /* init the framing state */
-  ogg_sync_init(&vf->oy);

 
 

-  /* perhaps some data was previously read into a buffer for testing
-     against other stream types.  Allow initialization from this
-     previously read data (as we may be reading from a non-seekable
-     stream) */
-  if(initial){
-    char *buffer=ogg_sync_buffer(&vf->oy,ibytes);
-    memcpy(buffer,initial,ibytes);
-    ogg_sync_wrote(&vf->oy,ibytes);
-  }
+/* cheap hack for game usage where downsampling is desirable; there's
+   no need for SRC as we can just do it cheaply in libvorbis. */

 
 

-  /* can we seek? Stevens suggests the seek test was portable */
-  if(offset!=-1){
-    ret=_open_seekable(vf);
-  }else{
-    ret=_open_nonseekable(vf);
+int ov_halfrate(OggVorbis_File *vf,int flag){
+  int i;
+  if(vf->vi==NULL)return OV_EINVAL;
+  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);
+    }

   }
   }

-  if(ret){
-    vf->datasource=NULL;
-    ov_clear(vf);
+
+  for(i=0;i<vf->links;i++){
+    if(vorbis_synthesis_halfrate(vf->vi+i,flag)){
+      if(flag) ov_halfrate(vf,0);
+      return OV_EINVAL;
+    }

   }
   }

-  return(ret);
+  return 0;
+}
+
+int ov_halfrate_p(OggVorbis_File *vf){
+  if(vf->vi==NULL)return OV_EINVAL;
+  return vorbis_synthesis_halfrate_p(vf->vi);
+}
+
+/* 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.
+
+   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,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,
+    (int (*)(void *))                             fclose,
+    (long (*)(void *))                            ftell
+  };
+
+  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);

 }
 
 /* How many logical bitstreams in this physical bitstream? */
 }
 
 /* How many logical bitstreams in this physical bitstream? */


@@ -664,14 +1101,21 @@ long ov_seekable(OggVorbis_File *vf){
    vorbis_info structs */
 
 long ov_bitrate(OggVorbis_File *vf,int i){
    vorbis_info structs */
 
 long ov_bitrate(OggVorbis_File *vf,int i){

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(i>=vf->links)return(OV_EINVAL);
   if(!vf->seekable && i!=0)return(ov_bitrate(vf,0));
   if(i<0){
     ogg_int64_t bits=0;
     int i;
   if(i>=vf->links)return(OV_EINVAL);
   if(!vf->seekable && i!=0)return(ov_bitrate(vf,0));
   if(i<0){
     ogg_int64_t bits=0;
     int i;

+    float br;

     for(i=0;i<vf->links;i++)
       bits+=(vf->offsets[i+1]-vf->dataoffsets[i])*8;
     for(i=0;i<vf->links;i++)
       bits+=(vf->offsets[i+1]-vf->dataoffsets[i])*8;

-    return(rint(bits/ov_time_total(vf,-1)));
+    /* This once read: return(rint(bits/ov_time_total(vf,-1)));
+     * gcc 3.x on x86 miscompiled this at optimisation level 2 and above,
+     * so this is slightly transformed to make it work.
+     */
+    br = bits/ov_time_total(vf,-1);
+    return(rint(br));

   }else{
     if(vf->seekable){
       /* return the actual bitrate */
   }else{
     if(vf->seekable){
       /* return the actual bitrate */


@@ -679,30 +1123,33 @@ long ov_bitrate(OggVorbis_File *vf,int i){
     }else{
       /* return nominal if set */
       if(vf->vi[i].bitrate_nominal>0){
     }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{
       }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);

       }
     }
   }
 }
 
 /* returns the actual bitrate since last call.  returns -1 if no
       }
     }
   }
 }
 
 /* returns the actual bitrate since last call.  returns -1 if no

-   additional data to offer since last call (or at beginning of stream) */
+   additional data to offer since last call (or at beginning of stream),
+   EINVAL if stream is only partially open
+*/

 long ov_bitrate_instant(OggVorbis_File *vf){
   int link=(vf->seekable?vf->current_link:0);
   long ret;
 long ov_bitrate_instant(OggVorbis_File *vf){
   int link=(vf->seekable?vf->current_link:0);
   long ret;

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(vf->samptrack==0)return(OV_FALSE);
   ret=vf->bittrack/vf->samptrack*vf->vi[link].rate+.5;
   if(vf->samptrack==0)return(OV_FALSE);
   ret=vf->bittrack/vf->samptrack*vf->vi[link].rate+.5;

-  vf->bittrack=0.;
-  vf->samptrack=0.;
+  vf->bittrack=0.f;
+  vf->samptrack=0.f;

   return(ret);
 }
 
   return(ret);
 }
 


@@ -719,12 +1166,14 @@ 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
 
 /* returns: total raw (compressed) length of content if i==-1
             raw (compressed) length of that logical bitstream for i==0 to n

-           -1 if the stream is not seekable (we can't know the length)
+            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){
 */
 ogg_int64_t ov_raw_total(OggVorbis_File *vf,int i){

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
   if(i<0){
   if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
   if(i<0){

-    long acc=0;
+    ogg_int64_t acc=0;

     int i;
     for(i=0;i<vf->links;i++)
       acc+=ov_raw_total(vf,i);
     int i;
     for(i=0;i<vf->links;i++)
       acc+=ov_raw_total(vf,i);


@@ -734,11 +1183,13 @@ 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
-           -1 if the stream is not seekable (we can't know the length)
+/* 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

 */
 ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){
 */
 ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
   if(i<0){
     ogg_int64_t acc=0;
   if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
   if(i<0){
     ogg_int64_t acc=0;


@@ -747,15 +1198,17 @@ ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){
       acc+=ov_pcm_total(vf,i);
     return(acc);
   }else{
       acc+=ov_pcm_total(vf,i);
     return(acc);
   }else{

-    return(vf->pcmlengths[i]);
+    return(vf->pcmlengths[i*2+1]);

   }
 }
 
 /* returns: total seconds of content if i==-1
             seconds in that logical bitstream for i==0 to n
   }
 }
 
 /* returns: total seconds of content if i==-1
             seconds in that logical bitstream for i==0 to n

-           -1 if the stream is not seekable (we can't know the length)
+            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){
 */
 double ov_time_total(OggVorbis_File *vf,int i){

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
   if(i<0){
     double acc=0;
   if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
   if(i<0){
     double acc=0;


@@ -764,74 +1217,182 @@ double ov_time_total(OggVorbis_File *vf,int i){
       acc+=ov_time_total(vf,i);
     return(acc);
   }else{
       acc+=ov_time_total(vf,i);
     return(acc);
   }else{

-    return((float)(vf->pcmlengths[i])/vf->vi[i].rate);
+    return((double)(vf->pcmlengths[i*2+1])/vf->vi[i].rate);

   }
 }
 
 /* seek to an offset relative to the *compressed* data. This also
   }
 }
 
 /* seek to an offset relative to the *compressed* data. This also

-   immediately sucks in and decodes pages to update the PCM cursor. It
-   will cross a logical bitstream boundary, but only if it can't get
-   any packets out of the tail of the bitstream we seek to (so no
-   surprises). 
+   scans packets to update the PCM cursor. It will cross a logical
+   bitstream boundary, but only if it can't get any packets out of the
+   tail of the bitstream we seek to (so no surprises).

 
    returns zero on success, nonzero on failure */
 
 
    returns zero on success, nonzero on failure */
 

-int ov_raw_seek(OggVorbis_File *vf,long pos){
-  int flag=0;
-  if(!vf->seekable)return(OV_ENOSEEK); /* don't dump machine if we can't seek */
-  if(pos<0 || pos>vf->offsets[vf->links])return(OV_EINVAL);
+int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
+  ogg_stream_state work_os;
+  int ret;

 
 

-  /* clear out decoding machine state */
-  vf->pcm_offset=-1;
-  _decode_clear(vf);
-  
-  /* seek */
-  _seek_helper(vf,pos);
-
-  /* we need to make sure the pcm_offset is set.  We use the
-     _fetch_packet helper to process one packet with readp set, then
-     call it until it returns '0' with readp not set (the last packet
-     from a page has the 'granulepos' field set, and that's how the
-     helper updates the offset */
-
-  while(!flag){
-    switch(_process_packet(vf,1)){
-    case 0:case OV_EOF:
-      /* oh, eof. There are no packets remaining.  Set the pcm offset to
-        the end of file */
-      vf->pcm_offset=ov_pcm_total(vf,-1);
-      return(0);
-    case OV_HOLE:
-      break;
-    case OV_EBADLINK:
-      goto seek_error;
-    default:
-      /* all OK */
-      flag=1;
-      break;
-    }
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  if(!vf->seekable)
+    return(OV_ENOSEEK); /* don't dump machine if we can't seek */
+
+  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 */

   }
   }

-  
-  while(1){
-    /* don't have to check each time through for the updated granule;
-       it's always the last complete packet on a page */
-    switch(_process_packet(vf,0)){
-    case 0:case OV_EOF:
-      /* the offset is set unless it's a bogus bitstream with no
-         offset information but that's not our fault.  We still run
-         gracefully, we're just missing the offset */
-      return(0);
-    case OV_EBADLINK:
-      goto seek_error;
-    default:
-      /* continue processing packets */
-      break;
+
+  /* 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 */
+  vorbis_synthesis_restart(&vf->vd);
+
+  ret=_seek_helper(vf,pos);
+  if(ret)goto seek_error;
+
+  /* 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
+     with a granulepos.  That's not equivalent behavior to beginning
+     decoding as immediately after the seek position as possible.
+
+     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.
+
+     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.
+  */
+
+  {
+    ogg_page og;
+    ogg_packet op;
+    int lastblock=0;
+    int accblock=0;
+    int thisblock=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
+                                   return from not necessarily
+                                   starting from the beginning */
+
+    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{
+
+              /* 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){
+        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;
+      }
+
+      /* 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->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);
+      lastflag=ogg_page_eos(&og);
+

     }
   }
     }
   }

-  
+
+  ogg_stream_clear(&work_os);
+  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;
  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;
 }
   _decode_clear(vf);
   return OV_EBADLINK;
 }


@@ -839,128 +1400,401 @@ int ov_raw_seek(OggVorbis_File *vf,long pos){
 /* Page granularity seek (faster than sample granularity because we
    don't do the last bit of decode to find a specific sample).
 
 /* 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;
    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;

-  long ret;
+  ogg_int64_t result=0;

   ogg_int64_t total=ov_pcm_total(vf,-1);
 
   ogg_int64_t total=ov_pcm_total(vf,-1);
 

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(!vf->seekable)return(OV_ENOSEEK);
   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--){
   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];
+    total-=vf->pcmlengths[link*2+1];

     if(pos>=total)break;
   }
 
     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) */
+

   {
   {

-    ogg_int64_t target=pos-total;
-    long end=vf->offsets[link+1];
-    long begin=vf->offsets[link];
-    long best=begin;
+    ogg_int64_t end=vf->offsets[link+1];
+    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=-1;
+    int         got_page=0;

 
     ogg_page og;
 
     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){
     while(begin<end){

-      long bisect;
-    
+      ogg_int64_t bisect;
+

       if(end-begin<CHUNKSIZE){
       if(end-begin<CHUNKSIZE){

-       bisect=begin;
+        bisect=begin;

       }else{
       }else{

-       bisect=(end+begin)/2;
+        /* take a (pretty decent) guess. */
+        bisect=begin +
+          (ogg_int64_t)((double)(target-begintime)*(end-begin)/(endtime-begintime))
+          - CHUNKSIZE;
+        if(bisect<begin+CHUNKSIZE)
+          bisect=begin;

       }
       }

-    
-      _seek_helper(vf,bisect);
-      ret=_get_next_page(vf,&og,end-bisect);
-      switch(ret){
-      case OV_FALSE: case OV_EOF:
-       end=bisect;
-       break;
-      case OV_EREAD:
-       goto seek_error;
-      default:
-       {
-         ogg_int64_t granulepos=ogg_page_granulepos(&og);
-         if(granulepos<target){
-           best=ret;  /* raw offset of packet with granulepos */ 
-           begin=vf->offset; /* raw offset of next packet */
-         }else{
-           end=bisect;
-         }
-       }
+
+      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)
+              /* 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 (call raw_seek). */
-    
-    if((ret=ov_raw_seek(vf,best)))goto seek_error;
+    /* 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;
+
+      }else{
+        vorbis_synthesis_restart(&vf->vd);
+      }
+
+      ogg_stream_reset_serialno(&vf->os,vf->current_serialno);
+      ogg_stream_pagein(&vf->os,&og);
+
+      /* pull out all but last packet; the one with granulepos */
+      while(1){
+        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 */
   /* verify result */

-  if(vf->pcm_offset>=pos || pos>ov_pcm_total(vf,-1)){
-    ret=OV_EFAULT;
+  if(vf->pcm_offset>pos || pos>ov_pcm_total(vf,-1)){
+    result=OV_EFAULT;

     goto seek_error;
   }
     goto seek_error;
   }

+  vf->bittrack=0.f;
+  vf->samptrack=0.f;

   return(0);
   return(0);

-  
+

  seek_error:
   /* dump machine so we're in a known state */
   vf->pcm_offset=-1;
   _decode_clear(vf);
  seek_error:
   /* dump machine so we're in a known state */
   vf->pcm_offset=-1;
   _decode_clear(vf);

-  return ret;
+  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){
    returns zero on success, nonzero on failure */
 
 int ov_pcm_seek(OggVorbis_File *vf,ogg_int64_t pos){

+  int thisblock,lastblock=0;

   int ret=ov_pcm_seek_page(vf,pos);
   if(ret<0)return(ret);
   int ret=ov_pcm_seek_page(vf,pos);
   if(ret<0)return(ret);

-  
+  if((ret=_make_decode_ready(vf)))return ret;
+
+  /* discard leading packets we don't need for the lapping of the
+     position we want; don't decode them */
+
+  while(1){
+    ogg_packet op;
+    ogg_page og;
+
+    int ret=ogg_stream_packetpeek(&vf->os,&op);
+    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 */
+      }
+      if(lastblock)vf->pcm_offset+=(lastblock+thisblock)>>2;
+
+      if(vf->pcm_offset+((thisblock+
+                          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);
+
+      /* end of logical stream case is hard, especially with exact
+         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];
+      }
+
+      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;
+      }
+
+      ogg_stream_pagein(&vf->os,&og);
+    }
+  }
+
+  vf->bittrack=0.f;
+  vf->samptrack=0.f;

   /* discard samples until we reach the desired position. Crossing a
      logical bitstream boundary with abandon is OK. */
   /* discard samples until we reach the desired position. Crossing a
      logical bitstream boundary with abandon is OK. */

-  while(vf->pcm_offset<pos){
-    float **pcm;
-    long target=pos-vf->pcm_offset;
-    long samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
-
-    if(samples>target)samples=target;
-    vorbis_synthesis_read(&vf->vd,samples);
-    vf->pcm_offset+=samples;
-    
-    if(samples<target)
-      if(_process_packet(vf,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;
 }
 
   }
   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 */
 
   int link=-1;
    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 */
 
   int link=-1;

-  ogg_int64_t pcm_total=ov_pcm_total(vf,-1);
-  double time_total=ov_time_total(vf,-1);
+  ogg_int64_t pcm_total=0;
+  double time_total=0.;

 
 

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(!vf->seekable)return(OV_ENOSEEK);
   if(!vf->seekable)return(OV_ENOSEEK);

-  if(seconds<0 || seconds>time_total)return(OV_EINVAL);
-  
+  if(seconds<0)return(OV_EINVAL);
+

   /* which bitstream section does this time offset occur in? */
   /* which bitstream section does this time offset occur in? */

-  for(link=vf->links-1;link>=0;link--){
-    pcm_total-=vf->pcmlengths[link];
-    time_total-=ov_time_total(vf,link);
-    if(seconds>=time_total)break;
+  for(link=0;link<vf->links;link++){
+    double addsec = ov_time_total(vf,link);
+    if(seconds<time_total+addsec)break;
+    time_total+=addsec;
+    pcm_total+=vf->pcmlengths[link*2+1];

   }
 
   }
 

+  if(link==vf->links)return(OV_EINVAL);
+

   /* enough information to convert time offset to pcm offset */
   {
     ogg_int64_t target=pcm_total+(seconds-time_total)*vf->vi[link].rate;
   /* enough information to convert time offset to pcm offset */
   {
     ogg_int64_t target=pcm_total+(seconds-time_total)*vf->vi[link].rate;


@@ -968,25 +1802,29 @@ 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 */
 
   int link=-1;
    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 */
 
   int link=-1;

-  ogg_int64_t pcm_total=ov_pcm_total(vf,-1);
-  double time_total=ov_time_total(vf,-1);
+  ogg_int64_t pcm_total=0;
+  double time_total=0.;

 
 

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   if(!vf->seekable)return(OV_ENOSEEK);
   if(!vf->seekable)return(OV_ENOSEEK);

-  if(seconds<0 || seconds>time_total)return(OV_EINVAL);
-  
+  if(seconds<0)return(OV_EINVAL);
+

   /* which bitstream section does this time offset occur in? */
   /* which bitstream section does this time offset occur in? */

-  for(link=vf->links-1;link>=0;link--){
-    pcm_total-=vf->pcmlengths[link];
-    time_total-=ov_time_total(vf,link);
-    if(seconds>=time_total)break;
+  for(link=0;link<vf->links;link++){
+    double addsec = ov_time_total(vf,link);
+    if(seconds<time_total+addsec)break;
+    time_total+=addsec;
+    pcm_total+=vf->pcmlengths[link*2+1];

   }
 
   }
 

+  if(link==vf->links)return(OV_EINVAL);
+

   /* enough information to convert time offset to pcm offset */
   {
     ogg_int64_t target=pcm_total+(seconds-time_total)*vf->vi[link].rate;
   /* enough information to convert time offset to pcm offset */
   {
     ogg_int64_t target=pcm_total+(seconds-time_total)*vf->vi[link].rate;


@@ -997,29 +1835,30 @@ int ov_time_seek_page(OggVorbis_File *vf,double seconds){
 /* tell the current stream offset cursor.  Note that seek followed by
    tell will likely not give the set offset due to caching */
 ogg_int64_t ov_raw_tell(OggVorbis_File *vf){
 /* tell the current stream offset cursor.  Note that seek followed by
    tell will likely not give the set offset due to caching */
 ogg_int64_t ov_raw_tell(OggVorbis_File *vf){

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   return(vf->offset);
 }
 
 /* return PCM offset (sample) of next PCM sample to be read */
 ogg_int64_t ov_pcm_tell(OggVorbis_File *vf){
   return(vf->offset);
 }
 
 /* return PCM offset (sample) of next PCM sample to be read */
 ogg_int64_t ov_pcm_tell(OggVorbis_File *vf){

+  if(vf->ready_state<OPENED)return(OV_EINVAL);

   return(vf->pcm_offset);
 }
 
 /* return time offset (seconds) of next PCM sample to be read */
 double ov_time_tell(OggVorbis_File *vf){
   return(vf->pcm_offset);
 }
 
 /* return time offset (seconds) of next PCM sample to be read */
 double ov_time_tell(OggVorbis_File *vf){

-  /* translate time to PCM position and call ov_pcm_seek */
-
-  int link=-1;
+  int link=0;

   ogg_int64_t pcm_total=0;
   ogg_int64_t pcm_total=0;

-  double time_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);
   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--){
     /* which bitstream section does this time offset occur in? */
     for(link=vf->links-1;link>=0;link--){

-      pcm_total-=vf->pcmlengths[link];
+      pcm_total-=vf->pcmlengths[link*2+1];

       time_total-=ov_time_total(vf,link);
       if(vf->pcm_offset>=pcm_total)break;
     }
       time_total-=ov_time_total(vf,link);
       if(vf->pcm_offset>=pcm_total)break;
     }


@@ -1031,7 +1870,7 @@ 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
 /*  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 */
     In the case of a non-seekable bitstream, any call returns the
     current bitstream.  NULL in the case that the machine is not
     initialized */


@@ -1039,20 +1878,17 @@ double ov_time_tell(OggVorbis_File *vf){
 vorbis_info *ov_info(OggVorbis_File *vf,int link){
   if(vf->seekable){
     if(link<0)
 vorbis_info *ov_info(OggVorbis_File *vf,int link){
   if(vf->seekable){
     if(link<0)

-      if(vf->decode_ready)
-       return vf->vi+vf->current_link;
+      if(vf->ready_state>=STREAMSET)
+        return vf->vi+vf->current_link;

       else
       else

-       return NULL;
+      return vf->vi;

     else
       if(link>=vf->links)
     else
       if(link>=vf->links)

-       return NULL;
+        return NULL;

       else
       else

-       return vf->vi+link;
+        return vf->vi+link;

   }else{
   }else{

-    if(vf->decode_ready)
-      return vf->vi;
-    else
-      return NULL;
+    return vf->vi;

   }
 }
 
   }
 }
 


@@ -1060,24 +1896,21 @@ vorbis_info *ov_info(OggVorbis_File *vf,int link){
 vorbis_comment *ov_comment(OggVorbis_File *vf,int link){
   if(vf->seekable){
     if(link<0)
 vorbis_comment *ov_comment(OggVorbis_File *vf,int link){
   if(vf->seekable){
     if(link<0)

-      if(vf->decode_ready)
-       return vf->vc+vf->current_link;
+      if(vf->ready_state>=STREAMSET)
+        return vf->vc+vf->current_link;

       else
       else

-       return NULL;
+        return vf->vc;

     else
       if(link>=vf->links)
     else
       if(link>=vf->links)

-       return NULL;
+        return NULL;

       else
       else

-       return vf->vc+link;
+        return vf->vc+link;

   }else{
   }else{

-    if(vf->decode_ready)
-      return vf->vc;
-    else
-      return NULL;
+    return vf->vc;

   }
 }
 
   }
 }
 

-int host_is_big_endian() {
+static int host_is_big_endian() {

   ogg_int32_t pattern = 0xfeedface; /* deadbeef */
   unsigned char *bytewise = (unsigned char *)&pattern;
   if (bytewise[0] == 0xfe) return 1;
   ogg_int32_t pattern = 0xfeedface; /* deadbeef */
   unsigned char *bytewise = (unsigned char *)&pattern;
   if (bytewise[0] == 0xfe) return 1;


@@ -1099,141 +1932,493 @@ int host_is_big_endian() {
    index within the physical bitstream.  Note that the accessor
    functions above are aware of this dichotomy).
 
    index within the physical bitstream.  Note that the accessor
    functions above are aware of this dichotomy).
 

+   ov_read_filter is exactly the same as ov_read except that it processes
+   the decoded audio data through a filter before packing it into the
+   requested format. This gives greater accuracy than applying a filter
+   after the audio has been converted into integral PCM.
+

    input values: buffer) a buffer to hold packed PCM data for return
    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: -1) error/hole in data (OV_HOLE)
+   return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL)

                    0) EOF
                    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(OggVorbis_File *vf,char *buffer,int length,
-                   int bigendianp,int word,int sgned,int *bitstream){
+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 i,j;
   int host_endian = host_is_big_endian();
   int i,j;
   int host_endian = host_is_big_endian();

+  int hs;
+
+  float **pcm;
+  long samples;
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);

 
   while(1){
 
   while(1){

-    if(vf->decode_ready){
+    if(vf->ready_state==INITSET){
+      samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
+      if(samples)break;
+    }
+
+    /* suck in another packet */
+    {
+      int ret=_fetch_and_process_packet(vf,NULL,1,1);
+      if(ret==OV_EOF)
+        return(0);
+      if(ret<=0)
+        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;
+    if(samples>length/bytespersample)samples=length/bytespersample;
+
+    if(samples <= 0)
+      return OV_EINVAL;
+
+    /* Here. */
+    if(filter)
+      filter(pcm,channels,samples,filter_param);
+
+    /* a tight loop to pack each size */
+    {
+      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);
+      }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);
+
+        }
+      }
+    }
+
+    vorbis_synthesis_read(&vf->vd,samples);
+    hs=vorbis_synthesis_halfrate_p(vf->vi);
+    vf->pcm_offset+=(samples<<hs);
+    if(bitstream)*bitstream=vf->current_link;
+    return(samples*bytespersample);
+  }else{
+    return(samples);
+  }
+}
+
+long ov_read(OggVorbis_File *vf,char *buffer,int length,
+             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
+
+   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.
+
+            *section) set to the logical bitstream number */
+
+
+
+long ov_read_float(OggVorbis_File *vf,float ***pcm_channels,int length,
+                   int *bitstream){
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+
+  while(1){
+    if(vf->ready_state==INITSET){

       float **pcm;
       long samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
       if(samples){
       float **pcm;
       long samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
       if(samples){

-       /* yay! proceed to pack data into the byte buffer */
-
-       long channels=ov_info(vf,-1)->channels;
-       long bytespersample=word * channels;
-       vorbis_fpu_control fpu;
-       if(samples>length/bytespersample)samples=length/bytespersample;
-       
-       /* a tight loop to pack each size */
-       {
-         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.);
-               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.);
-                   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.);
-                   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.);
-                 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.);
-                 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;
-       if(bitstream)*bitstream=vf->current_link;
-       return(samples*bytespersample);
+        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;
+

       }
     }
 
     /* suck in another packet */
       }
     }
 
     /* suck in another packet */

-    switch(_process_packet(vf,1)){
-    case 0:case OV_EOF:
-      return(0);
-    case OV_HOLE:
-      return(OV_HOLE);
-    case OV_EBADLINK:
-      return(OV_EBADLINK);
+    {
+      int ret=_fetch_and_process_packet(vf,NULL,1,1);
+      if(ret==OV_EOF)return(0);
+      if(ret<=0)return(ret);
+    }
+
+  }
+}
+
+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,
+                       const float *w1, const float *w2){
+  int i,j;
+  const float *w=w1;
+  int n=n1;
+
+  if(n1>n2){
+    n=n2;
+    w=w2;
+  }
+
+  /* splice */
+  for(j=0;j<ch1 && j<ch2;j++){
+    float *s=lappcm[j];
+    float *d=pcm[j];
+
+    for(i=0;i<n;i++){
+      float wd=w[i]*w[i];
+      float ws=1.-wd;
+      d[i]=d[i]*wd + s[i]*ws;
+    }
+  }
+  /* window from zero */
+  for(;j<ch2;j++){
+    float *d=pcm[j];
+    for(i=0;i<n;i++){
+      float wd=w[i]*w[i];
+      d[i]=d[i]*wd;
+    }
+  }
+
+}
+
+/* make sure vf is INITSET */
+static int _ov_initset(OggVorbis_File *vf){
+  while(1){
+    if(vf->ready_state==INITSET)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;

 }
 
 }
 

+/* make sure vf is INITSET and that we have a primed buffer; if
+   we're crosslapping at a stream section boundary, this also makes
+   sure we're sanity checking against the right stream information */
+static int _ov_initprime(OggVorbis_File *vf){
+  vorbis_dsp_state *vd=&vf->vd;
+  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;
+}

 
 

+/* grab enough data for lapping from vf; this may be in the form of
+   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){
+  int lapcount=0,i;
+  float **pcm;
+
+  /* try first to decode the lapping data */
+  while(lapcount<lapsize){
+    int samples=vorbis_synthesis_pcmout(vd,&pcm);
+    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);
+      lapcount+=samples;
+      vorbis_synthesis_read(vd,samples);
+    }else{
+    /* suck in another packet */
+      int ret=_fetch_and_process_packet(vf,NULL,1,0); /* do *not* span */
+      if(ret==OV_EOF)break;
+    }
+  }
+  if(lapcount<lapsize){
+    /* failed to get lapping data from normal decode; pry it from the
+       postextrapolation buffering, or the second half of the MDCT
+       from the last packet */
+    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);
+      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);
+      lapcount+=samples;
+    }
+  }
+}
+
+/* this sets up crosslapping of a sample by using trailing data from
+   sample 1 and lapping it into the windowing buffer of sample 2 */
+int ov_crosslap(OggVorbis_File *vf1, OggVorbis_File *vf2){
+  vorbis_info *vi1,*vi2;
+  float **lappcm;
+  float **pcm;
+  const float *w1,*w2;
+  int n1,n2,i,ret,hs1,hs2;
+
+  if(vf1==vf2)return(0); /* degenerate case */
+  if(vf1->ready_state<OPENED)return(OV_EINVAL);
+  if(vf2->ready_state<OPENED)return(OV_EINVAL);
+
+  /* the relevant overlap buffers must be pre-checked and pre-primed
+     before looking at settings in the event that priming would cross
+     a bitstream boundary.  So, do it now */
+
+  ret=_ov_initset(vf1);
+  if(ret)return(ret);
+  ret=_ov_initprime(vf2);
+  if(ret)return(ret);
+
+  vi1=ov_info(vf1,-1);
+  vi2=ov_info(vf2,-1);
+  hs1=ov_halfrate_p(vf1);
+  hs2=ov_halfrate_p(vf2);
+
+  lappcm=alloca(sizeof(*lappcm)*vi1->channels);
+  n1=vorbis_info_blocksize(vi1,0)>>(1+hs1);
+  n2=vorbis_info_blocksize(vi2,0)>>(1+hs2);
+  w1=vorbis_window(&vf1->vd,0);
+  w2=vorbis_window(&vf2->vd,0);
+
+  for(i=0;i<vi1->channels;i++)
+    lappcm[i]=alloca(sizeof(**lappcm)*n1);
+
+  _ov_getlap(vf1,vi1,&vf1->vd,lappcm,n1);
+
+  /* have a lapping buffer from vf1; now to splice it into the lapping
+     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)){
+  vorbis_info *vi;
+  float **lappcm;
+  float **pcm;
+  const float *w1,*w2;
+  int n1,n2,ch1,ch2,hs;
+  int i,ret;
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  ret=_ov_initset(vf);
+  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 */
+
+  lappcm=alloca(sizeof(*lappcm)*ch1);
+  for(i=0;i<ch1;i++)
+    lappcm[i]=alloca(sizeof(**lappcm)*n1);
+  _ov_getlap(vf,vi,&vf->vd,lappcm,n1);
+
+  /* have lapping data; seek and prime the buffer */
+  ret=localseek(vf,pos);
+  if(ret)return ret;
+  ret=_ov_initprime(vf);
+  if(ret)return(ret);
+
+ /* Guard against cross-link changes; they're perfectly legal */
+  vi=ov_info(vf,-1);
+  ch2=vi->channels;
+  n2=vorbis_info_blocksize(vi,0)>>(1+hs);
+  w2=vorbis_window(&vf->vd,0);
+
+  /* consolidate and expose the buffer. */
+  vorbis_synthesis_lapout(&vf->vd,&pcm);
+
+  /* splice */
+  _ov_splice(pcm,lappcm,n1,n2,ch1,ch2,w1,w2);
+
+  /* done */
+  return(0);
+}

 
 

+int ov_raw_seek_lap(OggVorbis_File *vf,ogg_int64_t pos){
+  return _ov_64_seek_lap(vf,pos,ov_raw_seek);
+}
+
+int ov_pcm_seek_lap(OggVorbis_File *vf,ogg_int64_t pos){
+  return _ov_64_seek_lap(vf,pos,ov_pcm_seek);
+}
+
+int ov_pcm_seek_page_lap(OggVorbis_File *vf,ogg_int64_t pos){
+  return _ov_64_seek_lap(vf,pos,ov_pcm_seek_page);
+}
+
+static int _ov_d_seek_lap(OggVorbis_File *vf,double pos,
+                           int (*localseek)(OggVorbis_File *,double)){
+  vorbis_info *vi;
+  float **lappcm;
+  float **pcm;
+  const float *w1,*w2;
+  int n1,n2,ch1,ch2,hs;
+  int i,ret;
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  ret=_ov_initset(vf);
+  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 */
+
+  lappcm=alloca(sizeof(*lappcm)*ch1);
+  for(i=0;i<ch1;i++)
+    lappcm[i]=alloca(sizeof(**lappcm)*n1);
+  _ov_getlap(vf,vi,&vf->vd,lappcm,n1);
+
+  /* have lapping data; seek and prime the buffer */
+  ret=localseek(vf,pos);
+  if(ret)return ret;
+  ret=_ov_initprime(vf);
+  if(ret)return(ret);
+
+ /* Guard against cross-link changes; they're perfectly legal */
+  vi=ov_info(vf,-1);
+  ch2=vi->channels;
+  n2=vorbis_info_blocksize(vi,0)>>(1+hs);
+  w2=vorbis_window(&vf->vd,0);
+
+  /* consolidate and expose the buffer. */
+  vorbis_synthesis_lapout(&vf->vd,&pcm);
+
+  /* splice */
+  _ov_splice(pcm,lappcm,n1,n2,ch1,ch2,w1,w2);
+
+  /* done */
+  return(0);
+}
+
+int ov_time_seek_lap(OggVorbis_File *vf,double pos){
+  return _ov_d_seek_lap(vf,pos,ov_time_seek);
+}
+
+int ov_time_seek_page_lap(OggVorbis_File *vf,double pos){
+  return _ov_d_seek_lap(vf,pos,ov_time_seek_page);
+}