1 files changed, 1592 insertions, 0 deletions

diff --git a/core/multimedia/opieplayer/vorbis/tremor/vorbisfile.c b/core/multimedia/opieplayer/vorbis/tremor/vorbisfile.c
new file mode 100644
index 0000000..7448b1e
--- a/dev/null
+++ b/core/multimedia/opieplayer/vorbis/tremor/vorbisfile.c
@@ -0,0 +1,1592 @@
+/********************************************************************
+ *                                                                  *
+ * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
+ *                                                                  *
+ * 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 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003    *
+ * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
+ *                                                                  *
+ ********************************************************************
+
+ function: stdio-based convenience library for opening/seeking/decoding
+ last mod: $Id$
+
+ ********************************************************************/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <math.h>
+
+#include "ivorbiscodec.h"
+#include "ivorbisfile.h"
+
+#include "os.h"
+#include "misc.h"
+
+/* A 'chained bitstream' is a Vorbis bitstream that contains more than
+   one logical bitstream arranged end to end (the only form of Ogg
+   multiplexing allowed in a Vorbis bitstream; grouping [parallel
+   multiplexing] is not allowed in Vorbis) */
+
+/* A Vorbis file can be played beginning to end (streamed) without
+   worrying ahead of time about chaining (see decoder_example.c).  If
+   we have the whole file, however, and want random access
+   (seeking/scrubbing) or desire to know the total length/time of a
+   file, we need to account for the possibility of chaining. */
+
+/* We can handle things a number of ways; we can determine the entire
+   bitstream structure right off the bat, or find pieces on demand.
+   This example determines and caches structure for the entire
+   bitstream, but builds a virtual decoder on the fly when moving
+   between links in the chain. */
+
+/* There are also different ways to implement seeking.  Enough
+   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 coarse navigation through the stream. */
+
+/*************************************************************************
+ * Many, many internal helpers.  The intention is not to be confusing; 
+ * rampant duplication and monolithic function implementation would be 
+ * harder to understand anyway.  The high level functions are last.  Begin
+ * grokking near the end of the file */
+
+
+/* read a little more data from the file/pipe into the ogg_sync framer */
+static long _get_data(OggVorbis_File *vf){
+  errno=0;
+  if(vf->datasource){
+    char *buffer=ogg_sync_bufferin(vf->oy,CHUNKSIZE);
+    long bytes=(vf->callbacks.read_func)(buffer,1,CHUNKSIZE,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 */
+static void _seek_helper(OggVorbis_File *vf,ogg_int64_t offset){
+  if(vf->datasource){ 
+    (vf->callbacks.seek_func)(vf->datasource, offset, SEEK_SET);
+    vf->offset=offset;
+    ogg_sync_reset(vf->oy);
+  }else{
+    /* shouldn't happen unless someone writes a broken callback */
+    return;
+  }
+}
+
+/* The read/seek functions track absolute position within the stream */
+
+/* from the head of the stream, get the next page.  boundary specifies
+   if the function is allowed to fetch more data from the stream (and
+   how much) or only use internally buffered data.
+
+   boundary: -1) unbounded search
+              0) read no additional data; use cached only
+              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 
+
+              produces a refcounted page */
+
+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(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);
+        }
+      }else{
+        /* got a page.  Return the offset at the page beginning,
+           advance the internal offset past the page end */
+        ogg_int64_t ret=vf->offset;
+        vf->offset+=more;
+        return(ret);
+        
+      }
+    }
+  }
+}
+
+/* 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. */
+/* returns offset or OV_EREAD, OV_FAULT and produces a refcounted page */
+
+static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_page *og){
+  ogg_int64_t begin=vf->offset;
+  ogg_int64_t end=begin;
+  ogg_int64_t ret;
+  ogg_int64_t offset=-1;
+
+  while(offset==-1){
+    begin-=CHUNKSIZE;
+    if(begin<0)
+      begin=0;
+    _seek_helper(vf,begin);
+    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{
+        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);
+
+  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,
+                                    ogg_int64_t begin,
+                                    ogg_int64_t searched,
+                                    ogg_int64_t end,
+                                    ogg_uint32_t currentno,
+                                    long m){
+  ogg_int64_t endsearched=end;
+  ogg_int64_t next=end;
+  ogg_page og={0,0,0,0};
+  ogg_int64_t ret;
+  
+  /* 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{
+      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;
+    }
+    ogg_page_release(&og);
+  }
+
+  _seek_helper(vf,next);
+  ret=_get_next_page(vf,&og,-1);
+  if(ret==OV_EREAD)return(OV_EREAD);
+  
+  if(searched>=end || ret<0){
+    ogg_page_release(&og);
+    vf->links=m+1;
+    vf->offsets=_ogg_malloc((vf->links+1)*sizeof(*vf->offsets));
+    vf->serialnos=_ogg_malloc(vf->links*sizeof(*vf->serialnos));
+    vf->offsets[m+1]=searched;
+  }else{
+    ret=_bisect_forward_serialno(vf,next,vf->offset,
+                                 end,ogg_page_serialno(&og),m+1);
+    ogg_page_release(&og);
+    if(ret==OV_EREAD)return(OV_EREAD);
+  }
+  
+  vf->offsets[m]=begin;
+  vf->serialnos[m]=currentno;
+  return(0);
+}
+
+/* uses the local ogg_stream storage in vf; this is important for
+   non-streaming input sources */
+/* consumes the page that's passed in (if any) */
+
+static int _fetch_headers(OggVorbis_File *vf,
+                          vorbis_info *vi,
+                          vorbis_comment *vc,
+                          ogg_uint32_t *serialno,
+                          ogg_page *og_ptr){
+  ogg_page og={0,0,0,0};
+  ogg_packet op={0,0,0,0,0,0};
+  int i,ret;
+  
+  if(!og_ptr){
+    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;
+  }
+
+  ogg_stream_reset_serialno(vf->os,ogg_page_serialno(og_ptr));
+  if(serialno)*serialno=vf->os->serialno;
+  vf->ready_state=STREAMSET;
+  
+  /* 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);
+  
+  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;
+      }
+      if((ret=vorbis_synthesis_headerin(vi,vc,&op))){
+        goto bail_header;
+      }
+      i++;
+    }
+    if(i<3)
+      if(_get_next_page(vf,og_ptr,CHUNKSIZE)<0){
+        ret=OV_EBADHEADER;
+        goto bail_header;
+      }
+  }
+
+  ogg_packet_release(&op);
+  ogg_page_release(&og);
+  return 0; 
+
+ bail_header:
+  ogg_packet_release(&op);
+  ogg_page_release(&og);
+  vorbis_info_clear(vi);
+  vorbis_comment_clear(vc);
+  vf->ready_state=OPENED;
+
+  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, ogg_int64_t dataoffset){
+  ogg_page og={0,0,0,0};
+  int i;
+  ogg_int64_t ret;
+  
+  vf->vi=_ogg_realloc(vf->vi,vf->links*sizeof(*vf->vi));
+  vf->vc=_ogg_realloc(vf->vc,vf->links*sizeof(*vf->vc));
+  vf->dataoffsets=_ogg_malloc(vf->links*sizeof(*vf->dataoffsets));
+  vf->pcmlengths=_ogg_malloc(vf->links*2*sizeof(*vf->pcmlengths));
+  
+  for(i=0;i<vf->links;i++){
+    if(i==0){
+      /* we already grabbed the initial header earlier.  Just set the offset */
+      vf->dataoffsets[i]=dataoffset;
+      _seek_helper(vf,dataoffset);
+
+    }else{
+
+      /* seek to the location of the initial header */
+
+      _seek_helper(vf,vf->offsets[i]);
+      if(_fetch_headers(vf,vf->vi+i,vf->vc+i,NULL,NULL)<0){
+            vf->dataoffsets[i]=-1;
+      }else{
+        vf->dataoffsets[i]=vf->offset;
+      }
+    }
+
+    /* fetch beginning PCM offset */
+
+    if(vf->dataoffsets[i]!=-1){
+      ogg_int64_t accumulated=0,pos;
+      long        lastblock=-1;
+      int         result;
+
+      ogg_stream_reset_serialno(vf->os,vf->serialnos[i]);
+
+      while(1){
+        ogg_packet op={0,0,0,0,0,0};
+
+        ret=_get_next_page(vf,&og,-1);
+        if(ret<0)
+          /* this should not be possible unless the file is
+             truncated/mangled */
+          break;
+       
+        if(ogg_page_serialno(&og)!=vf->serialnos[i])
+          break;
+        
+        pos=ogg_page_granulepos(&og);
+
+        /* 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(vf->vi+i,&op);
+            if(lastblock!=-1)
+              accumulated+=(lastblock+thisblock)>>2;
+            lastblock=thisblock;
+          }
+        }
+        ogg_packet_release(&op);
+
+        if(pos!=-1){
+          /* pcm offset of last packet on the first audio page */
+          accumulated= pos-accumulated;
+          break;
+        }
+      }
+
+      /* less than zero?  This is a stream with samples trimmed off
+         the beginning, a normal occurrence; set the offset to zero */
+      if(accumulated<0)accumulated=0;
+
+      vf->pcmlengths[i*2]=accumulated;
+    }
+
+    /* get the PCM length of this link. To do this,
+       get the last page of the stream */
+    {
+      ogg_int64_t end=vf->offsets[i+1];
+      _seek_helper(vf,end);
+
+      while(1){
+        ret=_get_prev_page(vf,&og);
+        if(ret<0){
+          /* this should not be possible */
+          vorbis_info_clear(vf->vi+i);
+          vorbis_comment_clear(vf->vc+i);
+          break;
+        }
+        if(ogg_page_granulepos(&og)!=-1){
+          vf->pcmlengths[i*2+1]=ogg_page_granulepos(&og)-vf->pcmlengths[i*2];
+          break;
+        }
+        vf->offset=ret;
+      }
+    }
+  }
+  ogg_page_release(&og);
+}
+
+static void _make_decode_ready(OggVorbis_File *vf){
+  if(vf->ready_state!=STREAMSET)return;
+  if(vf->seekable){
+    vorbis_synthesis_init(&vf->vd,vf->vi+vf->current_link);
+  }else{
+    vorbis_synthesis_init(&vf->vd,vf->vi);
+  }    
+  vorbis_block_init(&vf->vd,&vf->vb);
+  vf->ready_state=INITSET;
+  vf->bittrack=0;
+  vf->samptrack=0;
+  return;
+}
+
+static int _open_seekable2(OggVorbis_File *vf){
+  ogg_uint32_t serialno=vf->current_serialno;
+  ogg_uint32_t tempserialno;
+  ogg_int64_t dataoffset=vf->offset, end;
+  ogg_page og={0,0,0,0};
+
+  /* we're partially open and have a first link header state in
+     storage in vf */
+  /* we can seek, so set out learning all about this file */
+  (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)return(end);
+
+  /* more than one logical bitstream? */
+  tempserialno=ogg_page_serialno(&og);
+  ogg_page_release(&og);
+
+  if(tempserialno!=serialno){
+
+    /* 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)return(OV_EREAD);
+
+  }else{
+
+    /* Only one logical bitstream */
+    if(_bisect_forward_serialno(vf,0,end,end+1,serialno,0))return(OV_EREAD);
+
+  }
+
+  /* the initial header memory is referenced by vf after; don't free it */
+  _prefetch_all_headers(vf,dataoffset);
+  return(ov_raw_seek(vf,0));
+}
+
+/* clear out the current logical bitstream decoder */ 
+static void _decode_clear(OggVorbis_File *vf){
+  vorbis_dsp_clear(&vf->vd);
+  vorbis_block_clear(&vf->vb);
+  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
+   readp). 
+
+   return: <0) error, OV_HOLE (lost packet) or OV_EOF
+            0) need more data (only if readp==0)
+            1) got a packet 
+*/
+
+static int _fetch_and_process_packet(OggVorbis_File *vf,
+                                     int readp,
+                                     int spanp){
+  ogg_page og={0,0,0,0};
+  ogg_packet op={0,0,0,0,0,0};
+  int ret=0;
+
+  /* handle one packet.  Try to fetch it from current stream state */
+  /* extract packets from page */
+  while(1){
+    
+    /* process a packet if we can.  If the machine isn't loaded,
+       neither is a page */
+    if(vf->ready_state==INITSET){
+      while(1) {
+        int result=ogg_stream_packetout(vf->os,&op);
+        ogg_int64_t granulepos;
+
+        if(result<0){
+          ret=OV_HOLE; /* hole in the data. */
+          goto cleanup;
+        }
+        if(result>0){
+          /* got a packet.  process it */
+          granulepos=op.granulepos;
+          if(!vorbis_synthesis(&vf->vb,&op,1)){ /* 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){
+                ret=OV_EFAULT;
+                goto cleanup;
+              }
+
+              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 */
+
+              if(vf->seekable && link>0)
+                granulepos-=vf->pcmlengths[link*2];
+              if(granulepos<0)granulepos=0; /* actually, this
+                                               shouldn't be possible
+                                               here unless the stream
+                                               is very broken */
+
+              samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+            
+              granulepos-=samples;
+              for(i=0;i<link;i++)
+                granulepos+=vf->pcmlengths[i*2+1];
+              vf->pcm_offset=granulepos;
+            }
+            ret=1;
+            goto cleanup;
+          }
+        }
+        else 
+          break;
+      }
+    }
+
+    if(vf->ready_state>=OPENED){
+      int ret;
+      if(!readp){
+        ret=0;
+        goto cleanup;
+      }
+      if((ret=_get_next_page(vf,&og,-1))<0){
+        ret=OV_EOF; /* eof. leave unitialized */
+        goto cleanup;
+      }
+
+        /* bitrate tracking; add the header's bytes here, the body bytes
+           are done by packet above */
+      vf->bittrack+=og.header_len*8;
+      
+      /* has our decoding just traversed a bitstream boundary? */
+      if(vf->ready_state==INITSET){
+        if(vf->current_serialno!=ogg_page_serialno(&og)){
+          if(!spanp){
+            ret=OV_EOF;
+            goto cleanup;
+          }
+
+          _decode_clear(vf);
+          
+          if(!vf->seekable){
+            vorbis_info_clear(vf->vi);
+            vorbis_comment_clear(vf->vc);
+          }
+        }
+      }
+    }
+
+    /* Do we need to load a new machine before submitting the page? */
+    /* 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
+       with it and continue on our merry way.
+
+       In the non-seekable (streaming) case, we'll only be at a
+       boundary if we just left the previous logical bitstream and
+       we're now nominally at the header of the next bitstream
+    */
+
+    if(vf->ready_state!=INITSET){ 
+      int link;
+
+      if(vf->ready_state<STREAMSET){
+        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){
+            ret=OV_EBADLINK; /* sign of a bogus stream.  error out,
+                                leave machine uninitialized */
+            goto cleanup;
+          }
+          
+          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,&vf->current_serialno,&og);
+          if(ret) goto cleanup;
+          vf->current_link++;
+          link=0;
+        }
+      }
+      
+      _make_decode_ready(vf);
+    }
+    ogg_stream_pagein(vf->os,&og);
+  }
+ cleanup:
+  ogg_packet_release(&op);
+  ogg_page_release(&og);
+  return ret;
+}
+
+/* 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,char *initial,
+                     long ibytes, ov_callbacks callbacks){
+  int offsettest=(f?callbacks.seek_func(f,0,SEEK_CUR):-1);
+  int ret;
+
+  memset(vf,0,sizeof(*vf));
+  vf->datasource=f;
+  vf->callbacks = callbacks;
+
+  /* init the framing state */
+  vf->oy=ogg_sync_create();
+
+  /* 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_bufferin(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));
+  vf->os=ogg_stream_create(-1); /* fill in the serialno later */
+
+  /* Try to fetch the headers, maintaining all the storage */
+  if((ret=_fetch_headers(vf,vf->vi,vf->vc,&vf->current_serialno,NULL))<0){
+    vf->datasource=NULL;
+    ov_clear(vf);
+  }else if(vf->ready_state < PARTOPEN)
+    vf->ready_state=PARTOPEN;
+  return(ret);
+}
+
+static int _ov_open2(OggVorbis_File *vf){
+  if(vf->ready_state < OPENED)
+    vf->ready_state=OPENED;
+  if(vf->seekable){
+    int ret=_open_seekable2(vf);
+    if(ret){
+      vf->datasource=NULL;
+      ov_clear(vf);
+    }
+    return(ret);
+  }
+  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_destroy(vf->os);
+    
+    if(vf->vi && vf->links){
+      int i;
+      for(i=0;i<vf->links;i++){
+        vorbis_info_clear(vf->vi+i);
+        vorbis_comment_clear(vf->vc+i);
+      }
+      _ogg_free(vf->vi);
+      _ogg_free(vf->vc);
+    }
+    if(vf->dataoffsets)_ogg_free(vf->dataoffsets);
+    if(vf->pcmlengths)_ogg_free(vf->pcmlengths);
+    if(vf->serialnos)_ogg_free(vf->serialnos);
+    if(vf->offsets)_ogg_free(vf->offsets);
+    ogg_sync_destroy(vf->oy);
+
+    if(vf->datasource)(vf->callbacks.close_func)(vf->datasource);
+    memset(vf,0,sizeof(*vf));
+  }
+#ifdef DEBUG_LEAKS
+  _VDBG_dump();
+#endif
+  return(0);
+}
+
+/* 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. 
+
+   return: -1) error
+            0) OK
+*/
+
+int ov_open_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
+    ov_callbacks callbacks){
+  int ret=_ov_open1(f,vf,initial,ibytes,callbacks);
+  if(ret)return ret;
+  return _ov_open2(vf);
+}
+
+int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
+  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_open_callbacks((void *)f, vf, initial, ibytes, callbacks);
+}
+  
+/* 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. */
+
+int ov_test_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
+    ov_callbacks callbacks)
+{
+  return _ov_open1(f,vf,initial,ibytes,callbacks);
+}
+
+int ov_test(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
+  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? */
+long ov_streams(OggVorbis_File *vf){
+  return vf->links;
+}
+
+/* Is the FILE * associated with vf seekable? */
+long ov_seekable(OggVorbis_File *vf){
+  return vf->seekable;
+}
+
+/* returns the bitrate for a given logical bitstream or the entire
+   physical bitstream.  If the file is open for random access, it will
+   find the *actual* average bitrate.  If the file is streaming, it
+   returns the nominal bitrate (if set) else the average of the
+   upper/lower bounds (if set) else -1 (unset).
+
+   If you want the actual bitrate field settings, get them from the
+   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;
+    for(i=0;i<vf->links;i++)
+      bits+=(vf->offsets[i+1]-vf->dataoffsets[i])*8;
+    /* 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.
+     */
+    return(bits*1000/ov_time_total(vf,-1));
+  }else{
+    if(vf->seekable){
+      /* return the actual bitrate */
+      return((vf->offsets[i+1]-vf->dataoffsets[i])*8000/ov_time_total(vf,i));
+    }else{
+      /* return nominal if set */
+      if(vf->vi[i].bitrate_nominal>0){
+        return vf->vi[i].bitrate_nominal;
+      }else{
+        if(vf->vi[i].bitrate_upper>0){
+          if(vf->vi[i].bitrate_lower>0){
+            return (vf->vi[i].bitrate_upper+vf->vi[i].bitrate_lower)/2;
+          }else{
+            return vf->vi[i].bitrate_upper;
+          }
+        }
+        return(OV_FALSE);
+      }
+    }
+  }
+}
+
+/* returns the actual bitrate since last call.  returns -1 if no
+   additional data to offer since last call (or at beginning of stream),
+   EINVAL if stream is only partially open 
+*/
+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;
+  vf->bittrack=0;
+  vf->samptrack=0;
+  return(ret);
+}
+
+/* Guess */
+long ov_serialnumber(OggVorbis_File *vf,int i){
+  if(i>=vf->links)return(ov_serialnumber(vf,vf->links-1));
+  if(!vf->seekable && i>=0)return(ov_serialnumber(vf,-1));
+  if(i<0){
+    return(vf->current_serialno);
+  }else{
+    return(vf->serialnos[i]);
+  }
+}
+
+/* returns: total raw (compressed) length of content if i==-1
+            raw (compressed) length of that logical bitstream for i==0 to n
+            OV_EINVAL if the stream is not seekable (we can't know the length)
+            or if stream is only partially open
+*/
+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){
+    ogg_int64_t acc=0;
+    int i;
+    for(i=0;i<vf->links;i++)
+      acc+=ov_raw_total(vf,i);
+    return(acc);
+  }else{
+    return(vf->offsets[i+1]-vf->offsets[i]);
+  }
+}
+
+/* returns: total PCM length (samples) of content if i==-1 PCM length
+            (samples) of that logical bitstream for i==0 to n
+            OV_EINVAL if the stream is not seekable (we can't know the
+            length) or only partially open 
+*/
+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;
+    int i;
+    for(i=0;i<vf->links;i++)
+      acc+=ov_pcm_total(vf,i);
+    return(acc);
+  }else{
+    return(vf->pcmlengths[i*2+1]);
+  }
+}
+
+/* returns: total milliseconds of content if i==-1
+            milliseconds in that logical bitstream for i==0 to n
+            OV_EINVAL if the stream is not seekable (we can't know the
+            length) or only partially open 
+*/
+ogg_int64_t 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){
+    ogg_int64_t acc=0;
+    int i;
+    for(i=0;i<vf->links;i++)
+      acc+=ov_time_total(vf,i);
+    return(acc);
+  }else{
+    return(((ogg_int64_t)vf->pcmlengths[i*2+1])*1000/vf->vi[i].rate);
+  }
+}
+
+/* seek to an offset relative to the *compressed* data. This also
+   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 */
+
+int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
+  ogg_stream_state *work_os=NULL;
+  ogg_page og={0,0,0,0};
+  ogg_packet op={0,0,0,0,0,0};
+  
+  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);
+
+  /* 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);
+    
+  _seek_helper(vf,pos);
+
+  /* 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. 
+  */
+
+  {
+    int lastblock=0;
+    int accblock=0;
+    int thisblock;
+    int eosflag;
+
+    work_os=ogg_stream_create(vf->current_serialno); /* get the memory ready */
+    while(1){
+      if(vf->ready_state>=STREAMSET){
+        /* snarf/scan a packet if we can */
+        int result=ogg_stream_packetout(work_os,&op);
+      
+        if(result>0){
+
+          if(vf->vi[vf->current_link].codec_setup){
+            thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
+            if(thisblock<0){
+              ogg_stream_packetout(vf->os,NULL);
+              thisblock=0;
+            }else{
+              
+              if(eosflag)
+                ogg_stream_packetout(vf->os,NULL);
+              else
+                if(lastblock)accblock+=(lastblock+thisblock)>>2;
+                    }    
+
+            if(op.granulepos!=-1){
+              int i,link=vf->current_link;
+              ogg_int64_t granulepos=op.granulepos-vf->pcmlengths[link*2];
+              if(granulepos<0)granulepos=0;
+              
+              for(i=0;i<link;i++)
+                granulepos+=vf->pcmlengths[i*2+1];
+              vf->pcm_offset=granulepos-accblock;
+              break;
+            }
+            lastblock=thisblock;
+            continue;
+          }else
+            ogg_stream_packetout(vf->os,NULL);
+        }
+      }
+      
+      if(!lastblock){
+        if(_get_next_page(vf,&og,-1)<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)){
+          _decode_clear(vf); /* clear out stream state */
+          ogg_stream_destroy(work_os);
+        }
+
+      if(vf->ready_state<STREAMSET){
+        int link;
+        
+        vf->current_serialno=ogg_page_serialno(&og);
+        for(link=0;link<vf->links;link++)
+          if(vf->serialnos[link]==vf->current_serialno)break;
+        if(link==vf->links)
+          goto seek_error; /* sign of a bogus stream.  error out,
+                              leave machine uninitialized */
+ 
+        vf->current_link=link;
+        
+        ogg_stream_reset_serialno(vf->os,vf->current_serialno);
+        ogg_stream_reset_serialno(work_os,vf->current_serialno); 
+        vf->ready_state=STREAMSET;
+        
+      }
+    
+      {
+        ogg_page dup;
+        ogg_page_dup(&dup,&og);
+        eosflag=ogg_page_eos(&og);
+        ogg_stream_pagein(vf->os,&og);
+        ogg_stream_pagein(work_os,&dup);
+      }
+    }
+  }
+
+  ogg_packet_release(&op);
+  ogg_page_release(&og);
+  ogg_stream_destroy(work_os);
+  vf->bittrack=0;
+  vf->samptrack=0;
+  return(0);
+
+ seek_error:
+  ogg_packet_release(&op);
+  ogg_page_release(&og);
+
+  /* dump the machine so we're in a known state */
+  vf->pcm_offset=-1;
+  ogg_stream_destroy(work_os);
+  _decode_clear(vf);
+  return OV_EBADLINK;
+}
+
+/* Page granularity seek (faster than sample granularity because we
+   don't do the last bit of decode to find a specific sample).
+
+   Seek to the last [granule marked] page preceeding the specified pos
+   location, such that decoding past the returned point will quickly
+   arrive at the requested position. */
+int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
+  int link=-1;
+  ogg_int64_t result=0;
+  ogg_int64_t total=ov_pcm_total(vf,-1);
+  ogg_page og={0,0,0,0};
+  ogg_packet op={0,0,0,0,0,0};
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  if(!vf->seekable)return(OV_ENOSEEK);
+  if(pos<0 || pos>total)return(OV_EINVAL);
+ 
+  /* which bitstream section does this pcm offset occur in? */
+  for(link=vf->links-1;link>=0;link--){
+    total-=vf->pcmlengths[link*2+1];
+    if(pos>=total)break;
+  }
+
+  /* search within the logical bitstream for the page with the highest
+     pcm_pos preceeding (or equal to) pos.  There is a danger here;
+     missing pages or incorrect frame number information in the
+     bitstream could make our task impossible.  Account for that (it
+     would be an error condition) */
+
+  /* new search algorithm by HB (Nicholas Vinen) */
+  {
+    ogg_int64_t end=vf->offsets[link+1];
+    ogg_int64_t begin=vf->offsets[link];
+    ogg_int64_t begintime = vf->pcmlengths[link*2];
+    ogg_int64_t endtime = vf->pcmlengths[link*2+1]+begintime;
+    ogg_int64_t target=pos-total+begintime;
+    ogg_int64_t best=begin;
+    
+    while(begin<end){
+      ogg_int64_t bisect;
+      
+      if(end-begin<CHUNKSIZE){
+        bisect=begin;
+      }else{
+        /* take a (pretty decent) guess. */
+        bisect=begin + 
+          (target-begintime)*(end-begin)/(endtime-begintime) - CHUNKSIZE;
+        if(bisect<=begin)
+          bisect=begin+1;
+      }
+      
+      _seek_helper(vf,bisect);
+    
+      while(begin<end){
+        result=_get_next_page(vf,&og,end-vf->offset);
+        if(result==OV_EREAD) goto seek_error;
+        if(result<0){
+          if(bisect<=begin+1)
+            end=begin; /* found it */
+          else{
+            if(bisect==0) goto seek_error;
+            bisect-=CHUNKSIZE;
+            if(bisect<=begin)bisect=begin+1;
+            _seek_helper(vf,bisect);
+          }
+        }else{
+          ogg_int64_t granulepos=ogg_page_granulepos(&og);
+          if(granulepos==-1)continue;
+          if(granulepos<target){
+            best=result;  /* raw offset of packet with granulepos */ 
+            begin=vf->offset; /* raw offset of next page */
+            begintime=granulepos;
+            
+            if(target-begintime>44100)break;
+            bisect=begin; /* *not* begin + 1 */
+          }else{
+            if(bisect<=begin+1)
+              end=begin;  /* found it */
+            else{
+              if(end==vf->offset){ /* we're pretty close - we'd be stuck in */
+                end=result;
+                bisect-=CHUNKSIZE; /* an endless loop otherwise. */
+                if(bisect<=begin)bisect=begin+1;
+                _seek_helper(vf,bisect);
+              }else{
+                end=result;
+                endtime=granulepos;
+                break;
+              }
+            }
+          }
+        }
+      }
+    }
+
+    /* found our page. seek to it, update pcm offset. Easier case than
+       raw_seek, don't keep packets preceeding granulepos. */
+    {
+      
+      /* seek */
+      _seek_helper(vf,best);
+      vf->pcm_offset=-1;
+      
+      if(_get_next_page(vf,&og,-1)<0){
+        ogg_page_release(&og);
+        return(OV_EOF); /* shouldn't happen */
+      }
+
+      if(link!=vf->current_link){
+        /* Different link; dump entire decode machine */
+        _decode_clear(vf);  
+        
+        vf->current_link=link;
+        vf->current_serialno=ogg_page_serialno(&og);
+        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){
+          /* !!! the packet finishing this page originated on a
+             preceeding page. Keep fetching previous pages until we
+             get one with a granulepos or without the 'continued' flag
+             set.  Then just use raw_seek for simplicity. */
+          
+          _seek_helper(vf,best);
+          
+          while(1){
+            result=_get_prev_page(vf,&og);
+            if(result<0) goto seek_error;
+            if(ogg_page_granulepos(&og)>-1 ||
+               !ogg_page_continued(&og)){
+              return ov_raw_seek(vf,result);
+            }
+            vf->offset=result;
+          }
+        }
+        if(result<0){
+          result = OV_EBADPACKET; 
+          goto seek_error;
+        }
+        if(op.granulepos!=-1){
+          vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
+          if(vf->pcm_offset<0)vf->pcm_offset=0;
+          vf->pcm_offset+=total;
+          break;
+        }else
+          result=ogg_stream_packetout(vf->os,NULL);
+      }
+    }
+  }
+  
+  /* verify result */
+  if(vf->pcm_offset>pos || pos>ov_pcm_total(vf,-1)){
+    result=OV_EFAULT;
+    goto seek_error;
+  }
+  vf->bittrack=0;
+  vf->samptrack=0;
+
+  ogg_page_release(&og);
+  ogg_packet_release(&op);
+  return(0);
+  
+ seek_error:
+
+  ogg_page_release(&og);
+  ogg_packet_release(&op);
+
+  /* dump machine so we're in a known state */
+  vf->pcm_offset=-1;
+  _decode_clear(vf);
+  return (int)result;
+}
+
+/* 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){
+  ogg_packet op={0,0,0,0,0,0};
+  ogg_page og={0,0,0,0};
+  int thisblock,lastblock=0;
+  int ret=ov_pcm_seek_page(vf,pos);
+  if(ret<0)return(ret);
+  _make_decode_ready(vf);
+
+  /* discard leading packets we don't need for the lapping of the
+     position we want; don't decode them */
+
+  while(1){
+
+    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(&vf->vb,&op,0);  /* 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(vf->current_serialno!=ogg_page_serialno(&og))_decode_clear(vf);
+      
+      if(vf->ready_state<STREAMSET){
+        int link;
+        
+        vf->current_serialno=ogg_page_serialno(&og);
+        for(link=0;link<vf->links;link++)
+          if(vf->serialnos[link]==vf->current_serialno)break;
+        if(link==vf->links){
+          ogg_page_release(&og);
+          ogg_packet_release(&op);
+          return(OV_EBADLINK);
+        }
+        vf->current_link=link;
+        
+        ogg_stream_reset_serialno(vf->os,vf->current_serialno); 
+        vf->ready_state=STREAMSET;      
+        _make_decode_ready(vf);
+        lastblock=0;
+      }
+
+      ogg_stream_pagein(vf->os,&og);
+    }
+  }
+
+  vf->bittrack=0;
+  vf->samptrack=0;
+  /* discard samples until we reach the desired position. Crossing a
+     logical bitstream boundary with abandon is OK. */
+  while(vf->pcm_offset<pos){
+    ogg_int64_t target=pos-vf->pcm_offset;
+    long samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+
+    if(samples>target)samples=target;
+    vorbis_synthesis_read(&vf->vd,samples);
+    vf->pcm_offset+=samples;
+    
+    if(samples<target)
+      if(_fetch_and_process_packet(vf,1,1)<=0)
+        vf->pcm_offset=ov_pcm_total(vf,-1); /* eof */
+  }
+
+  ogg_page_release(&og);
+  ogg_packet_release(&op);
+  return 0;
+}
+
+/* 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,ogg_int64_t milliseconds){
+  /* translate time to PCM position and call ov_pcm_seek */
+
+  int link=-1;
+  ogg_int64_t pcm_total=ov_pcm_total(vf,-1);
+  ogg_int64_t time_total=ov_time_total(vf,-1);
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  if(!vf->seekable)return(OV_ENOSEEK);
+  if(milliseconds<0 || milliseconds>time_total)return(OV_EINVAL);
+  
+  /* which bitstream section does this time offset occur in? */
+  for(link=vf->links-1;link>=0;link--){
+    pcm_total-=vf->pcmlengths[link*2+1];
+    time_total-=ov_time_total(vf,link);
+    if(milliseconds>=time_total)break;
+  }
+
+  /* enough information to convert time offset to pcm offset */
+  {
+    ogg_int64_t target=pcm_total+(milliseconds-time_total)*vf->vi[link].rate/1000;
+    return(ov_pcm_seek(vf,target));
+  }
+}
+
+/* page-granularity version of ov_time_seek 
+   returns zero on success, nonzero on failure */
+int ov_time_seek_page(OggVorbis_File *vf,ogg_int64_t milliseconds){
+  /* translate time to PCM position and call ov_pcm_seek */
+
+  int link=-1;
+  ogg_int64_t pcm_total=ov_pcm_total(vf,-1);
+  ogg_int64_t time_total=ov_time_total(vf,-1);
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  if(!vf->seekable)return(OV_ENOSEEK);
+  if(milliseconds<0 || milliseconds>time_total)return(OV_EINVAL);
+  
+  /* which bitstream section does this time offset occur in? */
+  for(link=vf->links-1;link>=0;link--){
+    pcm_total-=vf->pcmlengths[link*2+1];
+    time_total-=ov_time_total(vf,link);
+    if(milliseconds>=time_total)break;
+  }
+
+  /* enough information to convert time offset to pcm offset */
+  {
+    ogg_int64_t target=pcm_total+(milliseconds-time_total)*vf->vi[link].rate/1000;
+    return(ov_pcm_seek_page(vf,target));
+  }
+}
+
+/* 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){
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  return(vf->pcm_offset);
+}
+
+/* return time offset (milliseconds) of next PCM sample to be read */
+ogg_int64_t ov_time_tell(OggVorbis_File *vf){
+  int link=0;
+  ogg_int64_t pcm_total=0;
+  ogg_int64_t time_total=0;
+  
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+  if(vf->seekable){
+    pcm_total=ov_pcm_total(vf,-1);
+    time_total=ov_time_total(vf,-1);
+  
+    /* which bitstream section does this time offset occur in? */
+    for(link=vf->links-1;link>=0;link--){
+      pcm_total-=vf->pcmlengths[link*2+1];
+      time_total-=ov_time_total(vf,link);
+      if(vf->pcm_offset>=pcm_total)break;
+    }
+  }
+
+  return(time_total+(1000*vf->pcm_offset-pcm_total)/vf->vi[link].rate);
+}
+
+/*  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 */
+
+vorbis_info *ov_info(OggVorbis_File *vf,int link){
+  if(vf->seekable){
+    if(link<0)
+      if(vf->ready_state>=STREAMSET)
+        return vf->vi+vf->current_link;
+      else
+      return vf->vi;
+    else
+      if(link>=vf->links)
+        return NULL;
+      else
+        return vf->vi+link;
+  }else{
+    return vf->vi;
+  }
+}
+
+/* grr, strong typing, grr, no templates/inheritence, grr */
+vorbis_comment *ov_comment(OggVorbis_File *vf,int link){
+  if(vf->seekable){
+    if(link<0)
+      if(vf->ready_state>=STREAMSET)
+        return vf->vc+vf->current_link;
+      else
+        return vf->vc;
+    else
+      if(link>=vf->links)
+        return NULL;
+      else
+        return vf->vc+link;
+  }else{
+    return vf->vc;
+  }
+}
+
+/* up to this point, everything could more or less hide the multiple
+   logical bitstream nature of chaining from the toplevel application
+   if the toplevel application didn't particularly care.  However, at
+   the point that we actually read audio back, the multiple-section
+   nature must surface: Multiple bitstream sections do not necessarily
+   have to have the same number of channels or sampling rate.
+
+   ov_read returns the sequential logical bitstream number currently
+   being decoded along with the PCM data in order that the toplevel
+   application can take action on channel/sample rate changes.  This
+   number will be incremented even for streamed (non-seekable) streams
+   (for seekable streams, it represents the actual logical bitstream
+   index within the physical bitstream.  Note that the accessor
+   functions above are aware of this dichotomy).
+
+   input values: buffer) a buffer to hold packed PCM data for return
+                 length) the byte length requested to be placed into buffer
+
+   return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL)
+                   0) EOF
+                   n) number of bytes of PCM actually returned.  The
+                   below works on a packet-by-packet basis, so the
+                   return length is not related to the 'length' passed
+                   in, just guaranteed to fit.
+
+            *section) set to the logical bitstream number */
+
+long ov_read(OggVorbis_File *vf,char *buffer,int bytes_req,int *bitstream){
+  int i,j;
+
+  ogg_int32_t **pcm;
+  long samples;
+
+  if(vf->ready_state<OPENED)return(OV_EINVAL);
+
+  while(1){
+    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,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;
+
+    if(channels==1){
+      if(samples>(bytes_req/2))
+        samples=bytes_req/2;      
+    }else{
+      if(samples>(bytes_req/4))
+        samples=bytes_req/4;
+    }
+    
+    for(i=0;i<channels;i++) { /* It's faster in this order */
+      ogg_int32_t *src=pcm[i];
+      short *dest=((short *)buffer)+i;
+      for(j=0;j<samples;j++) {
+        *dest=CLIP_TO_15(src[j]>>9);
+        dest+=channels;
+      }
+    }
+    
+    vorbis_synthesis_read(&vf->vd,samples);
+    vf->pcm_offset+=samples;
+    if(bitstream)*bitstream=vf->current_link;
+    return(samples*2*channels);
+  }else{
+    return(samples);
+  }
+}