diff -r 04bbe344b8d3 -r 9bd2d6b1ba52 misc/libtremor/framing.c
--- a/misc/libtremor/framing.c	Sun Oct 09 15:15:45 2011 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1126 +0,0 @@
-/********************************************************************
- *                                                                  *
- * 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: decode Ogg streams back into raw packets
-
- note: The CRC code is directly derived from public domain code by
- Ross Williams (ross@guest.adelaide.edu.au).  See docs/framing.html
- for details.
-
- ********************************************************************/
-
-#include <stdlib.h>
-#include <string.h>
-#include "ogg.h"
-#include "misc.h"
-
-
-/* A complete description of Ogg framing exists in docs/framing.html */
-
-/* basic, centralized Ogg memory management based on linked lists of
-   references to refcounted memory buffers.  References and buffers
-   are both recycled.  Buffers are passed around and consumed in
-   reference form. */
-
-static ogg_buffer_state *ogg_buffer_create(void){
-  ogg_buffer_state *bs=_ogg_calloc(1,sizeof(*bs));
-  return bs;
-}
-
-/* destruction is 'lazy'; there may be memory references outstanding,
-   and yanking the buffer state out from underneath would be
-   antisocial.  Dealloc what is currently unused and have
-   _release_one watch for the stragglers to come in.  When they do,
-   finish destruction. */
-
-/* call the helper while holding lock */
-static void _ogg_buffer_destroy(ogg_buffer_state *bs){
-  ogg_buffer *bt;
-  ogg_reference *rt;
-
-  if(bs->shutdown){
-
-    bt=bs->unused_buffers;
-    rt=bs->unused_references;
-
-    while(bt){
-      ogg_buffer *b=bt;
-      bt=b->ptr.next;
-      if(b->data)_ogg_free(b->data);
-      _ogg_free(b);
-    }
-    bs->unused_buffers=0;
-    while(rt){
-      ogg_reference *r=rt;
-      rt=r->next;
-      _ogg_free(r);
-    }
-    bs->unused_references=0;
-
-    if(!bs->outstanding)
-      _ogg_free(bs);
-
-  }
-}
-
-static void ogg_buffer_destroy(ogg_buffer_state *bs){
-  bs->shutdown=1;
-  _ogg_buffer_destroy(bs);
-}
-
-static ogg_buffer *_fetch_buffer(ogg_buffer_state *bs,long bytes){
-  ogg_buffer    *ob;
-  bs->outstanding++;
-
-  /* do we have an unused buffer sitting in the pool? */
-  if(bs->unused_buffers){
-    ob=bs->unused_buffers;
-    bs->unused_buffers=ob->ptr.next;
-
-    /* if the unused buffer is too small, grow it */
-    if(ob->size<bytes){
-      ob->data=_ogg_realloc(ob->data,bytes);
-      ob->size=bytes;
-    }
-  }else{
-    /* allocate a new buffer */
-    ob=_ogg_malloc(sizeof(*ob));
-    ob->data=_ogg_malloc(bytes<16?16:bytes);
-    ob->size=bytes;
-  }
-
-  ob->refcount=1;
-  ob->ptr.owner=bs;
-  return ob;
-}
-
-static ogg_reference *_fetch_ref(ogg_buffer_state *bs){
-  ogg_reference *or;
-  bs->outstanding++;
-
-  /* do we have an unused reference sitting in the pool? */
-  if(bs->unused_references){
-    or=bs->unused_references;
-    bs->unused_references=or->next;
-  }else{
-    /* allocate a new reference */
-    or=_ogg_malloc(sizeof(*or));
-  }
-
-  or->begin=0;
-  or->length=0;
-  or->next=0;
-  return or;
-}
-
-/* fetch a reference pointing to a fresh, initially continguous buffer
-   of at least [bytes] length */
-static ogg_reference *ogg_buffer_alloc(ogg_buffer_state *bs,long bytes){
-  ogg_buffer    *ob=_fetch_buffer(bs,bytes);
-  ogg_reference *or=_fetch_ref(bs);
-  or->buffer=ob;
-  return or;
-}
-
-/* enlarge the data buffer in the current link */
-static void ogg_buffer_realloc(ogg_reference *or,long bytes){
-  ogg_buffer    *ob=or->buffer;
-  
-  /* if the unused buffer is too small, grow it */
-  if(ob->size<bytes){
-    ob->data=_ogg_realloc(ob->data,bytes);
-    ob->size=bytes;
-  }
-}
-
-static void _ogg_buffer_mark_one(ogg_reference *or){
-  or->buffer->refcount++;
-}
-
-/* increase the refcount of the buffers to which the reference points */
-static void ogg_buffer_mark(ogg_reference *or){
-  while(or){
-    _ogg_buffer_mark_one(or);
-    or=or->next;
-  }
-}
-
-/* duplicate a reference (pointing to the same actual buffer memory)
-   and increment buffer refcount.  If the desired segment begins out
-   of range, NULL is returned; if the desired segment is simply zero
-   length, a zero length ref is returned.  Partial range overlap
-   returns the overlap of the ranges */
-static ogg_reference *ogg_buffer_sub(ogg_reference *or,long begin,long length){
-  ogg_reference *ret=0,*head=0;
-
-  /* walk past any preceeding fragments we don't want */
-  while(or && begin>=or->length){
-    begin-=or->length;
-    or=or->next;
-  }
-
-  /* duplicate the reference chain; increment refcounts */
-  while(or && length){
-    ogg_reference *temp=_fetch_ref(or->buffer->ptr.owner);
-    if(head)
-      head->next=temp;
-    else
-      ret=temp;
-    head=temp;
-    head->buffer=or->buffer;    
-    head->begin=or->begin+begin;
-    head->length=length;
-    if(head->length>or->length-begin)
-      head->length=or->length-begin;
-    
-    begin=0;
-    length-=head->length;
-    or=or->next;
-  }
-
-  ogg_buffer_mark(ret);
-  return ret;
-}
-
-ogg_reference *ogg_buffer_dup(ogg_reference *or){
-  ogg_reference *ret=0,*head=0;
-  /* duplicate the reference chain; increment refcounts */
-  while(or){
-    ogg_reference *temp=_fetch_ref(or->buffer->ptr.owner);
-    if(head)
-      head->next=temp;
-    else
-      ret=temp;
-    head=temp;
-    head->buffer=or->buffer;    
-    head->begin=or->begin;
-    head->length=or->length;
-    or=or->next;
-  }
-
-  ogg_buffer_mark(ret);
-  return ret;
-}
-
-/* split a reference into two references; 'return' is a reference to
-   the buffer preceeding pos and 'head'/'tail' are the buffer past the
-   split.  If pos is at or past the end of the passed in segment,
-   'head/tail' are NULL */
-static ogg_reference *ogg_buffer_split(ogg_reference **tail,
-                                ogg_reference **head,long pos){
-
-  /* walk past any preceeding fragments to one of:
-     a) the exact boundary that seps two fragments
-     b) the fragment that needs split somewhere in the middle */
-  ogg_reference *ret=*tail;
-  ogg_reference *or=*tail;
-
-  while(or && pos>or->length){
-    pos-=or->length;
-    or=or->next;
-  }
-
-  if(!or || pos==0){
-
-    return 0;
-    
-  }else{
-    
-    if(pos>=or->length){
-      /* exact split, or off the end? */
-      if(or->next){
-        
-        /* a split */
-        *tail=or->next;
-        or->next=0;
-        
-      }else{
-        
-        /* off or at the end */
-        *tail=*head=0;
-        
-      }
-    }else{
-      
-      /* split within a fragment */
-      long lengthA=pos;
-      long beginB=or->begin+pos;
-      long lengthB=or->length-pos;
-      
-      /* make a new reference to tail the second piece */
-      *tail=_fetch_ref(or->buffer->ptr.owner);
-      
-      (*tail)->buffer=or->buffer;
-      (*tail)->begin=beginB;
-      (*tail)->length=lengthB;
-      (*tail)->next=or->next;
-      _ogg_buffer_mark_one(*tail);
-      if(head && or==*head)*head=*tail;    
-      
-      /* update the first piece */
-      or->next=0;
-      or->length=lengthA;
-      
-    }
-  }
-  return ret;
-}
-
-static void ogg_buffer_release_one(ogg_reference *or){
-  ogg_buffer *ob=or->buffer;
-  ogg_buffer_state *bs=ob->ptr.owner;
-
-  ob->refcount--;
-  if(ob->refcount==0){
-    bs->outstanding--; /* for the returned buffer */
-    ob->ptr.next=bs->unused_buffers;
-    bs->unused_buffers=ob;
-  }
-  
-  bs->outstanding--; /* for the returned reference */
-  or->next=bs->unused_references;
-  bs->unused_references=or;
-
-  _ogg_buffer_destroy(bs); /* lazy cleanup (if needed) */
-
-}
-
-/* release the references, decrease the refcounts of buffers to which
-   they point, release any buffers with a refcount that drops to zero */
-static void ogg_buffer_release(ogg_reference *or){
-  while(or){
-    ogg_reference *next=or->next;
-    ogg_buffer_release_one(or);
-    or=next;
-  }
-}
-
-static ogg_reference *ogg_buffer_pretruncate(ogg_reference *or,long pos){
-  /* release preceeding fragments we don't want */
-  while(or && pos>=or->length){
-    ogg_reference *next=or->next;
-    pos-=or->length;
-    ogg_buffer_release_one(or);
-    or=next;
-  }
-  if (or) {
-    or->begin+=pos;
-    or->length-=pos;
-  }
-  return or;
-}
-
-static ogg_reference *ogg_buffer_walk(ogg_reference *or){
-  if(!or)return NULL;
-  while(or->next){
-    or=or->next;
-  }
-  return(or);
-}
-
-/* *head is appended to the front end (head) of *tail; both continue to
-   be valid pointers, with *tail at the tail and *head at the head */
-static ogg_reference *ogg_buffer_cat(ogg_reference *tail, ogg_reference *head){
-  if(!tail)return head;
-
-  while(tail->next){
-    tail=tail->next;
-  }
-  tail->next=head;
-  return ogg_buffer_walk(head);
-}
-
-static void _positionB(oggbyte_buffer *b,int pos){
-  if(pos<b->pos){
-    /* start at beginning, scan forward */
-    b->ref=b->baseref;
-    b->pos=0;
-    b->end=b->pos+b->ref->length;
-    b->ptr=b->ref->buffer->data+b->ref->begin;
-  }
-}
-
-static void _positionF(oggbyte_buffer *b,int pos){
-  /* scan forward for position */
-  while(pos>=b->end){
-    /* just seek forward */
-    b->pos+=b->ref->length;
-    b->ref=b->ref->next;
-    b->end=b->ref->length+b->pos;
-    b->ptr=b->ref->buffer->data+b->ref->begin;
-  }
-}
-
-static int oggbyte_init(oggbyte_buffer *b,ogg_reference *or){
-  memset(b,0,sizeof(*b));
-  if(or){
-    b->ref=b->baseref=or;
-    b->pos=0;
-    b->end=b->ref->length;
-    b->ptr=b->ref->buffer->data+b->ref->begin;  
-    return 0;
-  }else
-    return -1;
-}
-
-static void oggbyte_set4(oggbyte_buffer *b,ogg_uint32_t val,int pos){
-  int i;
-  _positionB(b,pos);
-  for(i=0;i<4;i++){
-    _positionF(b,pos);
-    b->ptr[pos-b->pos]=val;
-    val>>=8;
-    ++pos;
-  }
-}
- 
-static unsigned char oggbyte_read1(oggbyte_buffer *b,int pos){
-  _positionB(b,pos);
-  _positionF(b,pos);
-  return b->ptr[pos-b->pos];
-}
-
-static ogg_uint32_t oggbyte_read4(oggbyte_buffer *b,int pos){
-  ogg_uint32_t ret;
-  _positionB(b,pos);
-  _positionF(b,pos);
-  ret=b->ptr[pos-b->pos];
-  _positionF(b,++pos);
-  ret|=b->ptr[pos-b->pos]<<8;
-  _positionF(b,++pos);
-  ret|=b->ptr[pos-b->pos]<<16;
-  _positionF(b,++pos);
-  ret|=b->ptr[pos-b->pos]<<24;
-  return ret;
-}
-
-static ogg_int64_t oggbyte_read8(oggbyte_buffer *b,int pos){
-  ogg_int64_t ret;
-  unsigned char t[7];
-  int i;
-  _positionB(b,pos);
-  for(i=0;i<7;i++){
-    _positionF(b,pos);
-    t[i]=b->ptr[pos++ -b->pos];
-  }
-
-  _positionF(b,pos);
-  ret=b->ptr[pos-b->pos];
-
-  for(i=6;i>=0;--i)
-    ret= ret<<8 | t[i];
-
-  return ret;
-}
-
-/* Now we get to the actual framing code */
-
-int ogg_page_version(ogg_page *og){
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-  return oggbyte_read1(&ob,4);
-}
-
-int ogg_page_continued(ogg_page *og){
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-  return oggbyte_read1(&ob,5)&0x01;
-}
-
-int ogg_page_bos(ogg_page *og){
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-  return oggbyte_read1(&ob,5)&0x02;
-}
-
-int ogg_page_eos(ogg_page *og){
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-  return oggbyte_read1(&ob,5)&0x04;
-}
-
-ogg_int64_t ogg_page_granulepos(ogg_page *og){
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-  return oggbyte_read8(&ob,6);
-}
-
-ogg_uint32_t ogg_page_serialno(ogg_page *og){
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-  return oggbyte_read4(&ob,14);
-}
- 
-ogg_uint32_t ogg_page_pageno(ogg_page *og){
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-  return oggbyte_read4(&ob,18);
-}
-
-/* returns the number of packets that are completed on this page (if
-   the leading packet is begun on a previous page, but ends on this
-   page, it's counted */
-
-/* NOTE:
-If a page consists of a packet begun on a previous page, and a new
-packet begun (but not completed) on this page, the return will be:
-  ogg_page_packets(page)   ==1, 
-  ogg_page_continued(page) !=0
-
-If a page happens to be a single packet that was begun on a
-previous page, and spans to the next page (in the case of a three or
-more page packet), the return will be: 
-  ogg_page_packets(page)   ==0, 
-  ogg_page_continued(page) !=0
-*/
-
-int ogg_page_packets(ogg_page *og){
-  int i;
-  int n;
-  int count=0;
-  oggbyte_buffer ob;
-  oggbyte_init(&ob,og->header);
-
-  n=oggbyte_read1(&ob,26);
-  for(i=0;i<n;i++)
-    if(oggbyte_read1(&ob,27+i)<255)count++;
-  return(count);
-}
-
-/* Static CRC calculation table.  See older code in CVS for dead
-   run-time initialization code. */
-
-static ogg_uint32_t crc_lookup[256]={
-  0x00000000,0x04c11db7,0x09823b6e,0x0d4326d9,
-  0x130476dc,0x17c56b6b,0x1a864db2,0x1e475005,
-  0x2608edb8,0x22c9f00f,0x2f8ad6d6,0x2b4bcb61,
-  0x350c9b64,0x31cd86d3,0x3c8ea00a,0x384fbdbd,
-  0x4c11db70,0x48d0c6c7,0x4593e01e,0x4152fda9,
-  0x5f15adac,0x5bd4b01b,0x569796c2,0x52568b75,
-  0x6a1936c8,0x6ed82b7f,0x639b0da6,0x675a1011,
-  0x791d4014,0x7ddc5da3,0x709f7b7a,0x745e66cd,
-  0x9823b6e0,0x9ce2ab57,0x91a18d8e,0x95609039,
-  0x8b27c03c,0x8fe6dd8b,0x82a5fb52,0x8664e6e5,
-  0xbe2b5b58,0xbaea46ef,0xb7a96036,0xb3687d81,
-  0xad2f2d84,0xa9ee3033,0xa4ad16ea,0xa06c0b5d,
-  0xd4326d90,0xd0f37027,0xddb056fe,0xd9714b49,
-  0xc7361b4c,0xc3f706fb,0xceb42022,0xca753d95,
-  0xf23a8028,0xf6fb9d9f,0xfbb8bb46,0xff79a6f1,
-  0xe13ef6f4,0xe5ffeb43,0xe8bccd9a,0xec7dd02d,
-  0x34867077,0x30476dc0,0x3d044b19,0x39c556ae,
-  0x278206ab,0x23431b1c,0x2e003dc5,0x2ac12072,
-  0x128e9dcf,0x164f8078,0x1b0ca6a1,0x1fcdbb16,
-  0x018aeb13,0x054bf6a4,0x0808d07d,0x0cc9cdca,
-  0x7897ab07,0x7c56b6b0,0x71159069,0x75d48dde,
-  0x6b93dddb,0x6f52c06c,0x6211e6b5,0x66d0fb02,
-  0x5e9f46bf,0x5a5e5b08,0x571d7dd1,0x53dc6066,
-  0x4d9b3063,0x495a2dd4,0x44190b0d,0x40d816ba,
-  0xaca5c697,0xa864db20,0xa527fdf9,0xa1e6e04e,
-  0xbfa1b04b,0xbb60adfc,0xb6238b25,0xb2e29692,
-  0x8aad2b2f,0x8e6c3698,0x832f1041,0x87ee0df6,
-  0x99a95df3,0x9d684044,0x902b669d,0x94ea7b2a,
-  0xe0b41de7,0xe4750050,0xe9362689,0xedf73b3e,
-  0xf3b06b3b,0xf771768c,0xfa325055,0xfef34de2,
-  0xc6bcf05f,0xc27dede8,0xcf3ecb31,0xcbffd686,
-  0xd5b88683,0xd1799b34,0xdc3abded,0xd8fba05a,
-  0x690ce0ee,0x6dcdfd59,0x608edb80,0x644fc637,
-  0x7a089632,0x7ec98b85,0x738aad5c,0x774bb0eb,
-  0x4f040d56,0x4bc510e1,0x46863638,0x42472b8f,
-  0x5c007b8a,0x58c1663d,0x558240e4,0x51435d53,
-  0x251d3b9e,0x21dc2629,0x2c9f00f0,0x285e1d47,
-  0x36194d42,0x32d850f5,0x3f9b762c,0x3b5a6b9b,
-  0x0315d626,0x07d4cb91,0x0a97ed48,0x0e56f0ff,
-  0x1011a0fa,0x14d0bd4d,0x19939b94,0x1d528623,
-  0xf12f560e,0xf5ee4bb9,0xf8ad6d60,0xfc6c70d7,
-  0xe22b20d2,0xe6ea3d65,0xeba91bbc,0xef68060b,
-  0xd727bbb6,0xd3e6a601,0xdea580d8,0xda649d6f,
-  0xc423cd6a,0xc0e2d0dd,0xcda1f604,0xc960ebb3,
-  0xbd3e8d7e,0xb9ff90c9,0xb4bcb610,0xb07daba7,
-  0xae3afba2,0xaafbe615,0xa7b8c0cc,0xa379dd7b,
-  0x9b3660c6,0x9ff77d71,0x92b45ba8,0x9675461f,
-  0x8832161a,0x8cf30bad,0x81b02d74,0x857130c3,
-  0x5d8a9099,0x594b8d2e,0x5408abf7,0x50c9b640,
-  0x4e8ee645,0x4a4ffbf2,0x470cdd2b,0x43cdc09c,
-  0x7b827d21,0x7f436096,0x7200464f,0x76c15bf8,
-  0x68860bfd,0x6c47164a,0x61043093,0x65c52d24,
-  0x119b4be9,0x155a565e,0x18197087,0x1cd86d30,
-  0x029f3d35,0x065e2082,0x0b1d065b,0x0fdc1bec,
-  0x3793a651,0x3352bbe6,0x3e119d3f,0x3ad08088,
-  0x2497d08d,0x2056cd3a,0x2d15ebe3,0x29d4f654,
-  0xc5a92679,0xc1683bce,0xcc2b1d17,0xc8ea00a0,
-  0xd6ad50a5,0xd26c4d12,0xdf2f6bcb,0xdbee767c,
-  0xe3a1cbc1,0xe760d676,0xea23f0af,0xeee2ed18,
-  0xf0a5bd1d,0xf464a0aa,0xf9278673,0xfde69bc4,
-  0x89b8fd09,0x8d79e0be,0x803ac667,0x84fbdbd0,
-  0x9abc8bd5,0x9e7d9662,0x933eb0bb,0x97ffad0c,
-  0xafb010b1,0xab710d06,0xa6322bdf,0xa2f33668,
-  0xbcb4666d,0xb8757bda,0xb5365d03,0xb1f740b4};
-
-ogg_sync_state *ogg_sync_create(void){
-  ogg_sync_state *oy=_ogg_calloc(1,sizeof(*oy));
-  memset(oy,0,sizeof(*oy));
-  oy->bufferpool=ogg_buffer_create();
-  return oy;
-}
-
-int ogg_sync_destroy(ogg_sync_state *oy){
-  if(oy){
-    ogg_sync_reset(oy);
-    ogg_buffer_destroy(oy->bufferpool);
-    memset(oy,0,sizeof(*oy));
-    _ogg_free(oy);
-  }
-  return OGG_SUCCESS;
-}
-
-unsigned char *ogg_sync_bufferin(ogg_sync_state *oy, long bytes){
-
-  /* [allocate and] expose a buffer for data submission.
-
-     If there is no head fragment
-       allocate one and expose it
-     else
-       if the current head fragment has sufficient unused space
-         expose it
-       else
-         if the current head fragment is unused
-           resize and expose it
-         else
-           allocate new fragment and expose it
-  */
-
-  /* base case; fifo uninitialized */
-  if(!oy->fifo_head){
-    oy->fifo_head=oy->fifo_tail=ogg_buffer_alloc(oy->bufferpool,bytes);
-    return oy->fifo_head->buffer->data;
-  }
-  
-  /* space left in current fragment case */
-  if(oy->fifo_head->buffer->size-
-     oy->fifo_head->length-
-     oy->fifo_head->begin >= bytes)
-    return oy->fifo_head->buffer->data+
-      oy->fifo_head->length+oy->fifo_head->begin;
-
-  /* current fragment is unused, but too small */
-  if(!oy->fifo_head->length){
-    ogg_buffer_realloc(oy->fifo_head,bytes);
-    return oy->fifo_head->buffer->data+oy->fifo_head->begin;
-  }
-  
-  /* current fragment used/full; get new fragment */
-  {
-    ogg_reference *new=ogg_buffer_alloc(oy->bufferpool,bytes);
-    oy->fifo_head->next=new;
-    oy->fifo_head=new;
-  }
-  return oy->fifo_head->buffer->data;
-}
-
-int ogg_sync_wrote(ogg_sync_state *oy, long bytes){ 
-  if(!oy->fifo_head)return OGG_EINVAL;
-  if(oy->fifo_head->buffer->size-oy->fifo_head->length-oy->fifo_head->begin < 
-     bytes)return OGG_EINVAL;
-  oy->fifo_head->length+=bytes;
-  oy->fifo_fill+=bytes;
-  return OGG_SUCCESS;
-}
-
-static ogg_uint32_t _checksum(ogg_reference *or, int bytes){
-  ogg_uint32_t crc_reg=0;
-  int j,post;
-
-  while(or){
-    unsigned char *data=or->buffer->data+or->begin;
-    post=(bytes<or->length?bytes:or->length);
-    for(j=0;j<post;++j)
-      crc_reg=(crc_reg<<8)^crc_lookup[((crc_reg >> 24)&0xff)^data[j]];
-    bytes-=j;
-    or=or->next;
-  }
-
-  return crc_reg;
-}
-
-
-/* sync the stream.  This is meant to be useful for finding page
-   boundaries.
-
-   return values for this:
-  -n) skipped n bytes
-   0) page not ready; more data (no bytes skipped)
-   n) page synced at current location; page length n bytes
-   
-*/
-
-long ogg_sync_pageseek(ogg_sync_state *oy,ogg_page *og){
-  oggbyte_buffer page;
-  long           bytes,ret=0;
-
-  ogg_page_release(og);
-
-  bytes=oy->fifo_fill;
-  oggbyte_init(&page,oy->fifo_tail);
-
-  if(oy->headerbytes==0){
-    if(bytes<27)goto sync_out; /* not enough for even a minimal header */
-    
-    /* verify capture pattern */
-    if(oggbyte_read1(&page,0)!=(int)'O' ||
-       oggbyte_read1(&page,1)!=(int)'g' ||
-       oggbyte_read1(&page,2)!=(int)'g' ||
-       oggbyte_read1(&page,3)!=(int)'S'    ) goto sync_fail;
-
-    oy->headerbytes=oggbyte_read1(&page,26)+27;
-  }
-  if(bytes<oy->headerbytes)goto sync_out; /* not enough for header +
-                                             seg table */
-  if(oy->bodybytes==0){
-    int i;
-    /* count up body length in the segment table */
-    for(i=0;i<oy->headerbytes-27;i++)
-      oy->bodybytes+=oggbyte_read1(&page,27+i);
-  }
-  
-  if(oy->bodybytes+oy->headerbytes>bytes)goto sync_out;
-
-  /* we have what appears to be a complete page; last test: verify
-     checksum */
-  {
-    ogg_uint32_t chksum=oggbyte_read4(&page,22);
-    oggbyte_set4(&page,0,22);
-
-    /* Compare checksums; memory continues to be common access */
-    if(chksum!=_checksum(oy->fifo_tail,oy->bodybytes+oy->headerbytes)){
-      
-      /* D'oh.  Mismatch! Corrupt page (or miscapture and not a page
-         at all). replace the computed checksum with the one actually
-         read in; remember all the memory is common access */
-      
-      oggbyte_set4(&page,chksum,22);
-      goto sync_fail;
-    }
-    oggbyte_set4(&page,chksum,22);
-  }
-
-  /* We have a page.  Set up page return. */
-  if(og){
-    /* set up page output */
-    og->header=ogg_buffer_split(&oy->fifo_tail,&oy->fifo_head,oy->headerbytes);
-    og->header_len=oy->headerbytes;
-    og->body=ogg_buffer_split(&oy->fifo_tail,&oy->fifo_head,oy->bodybytes);
-    og->body_len=oy->bodybytes;
-  }else{
-    /* simply advance */
-    oy->fifo_tail=
-      ogg_buffer_pretruncate(oy->fifo_tail,oy->headerbytes+oy->bodybytes);
-    if(!oy->fifo_tail)oy->fifo_head=0;
-  }
-  
-  ret=oy->headerbytes+oy->bodybytes;
-  oy->unsynced=0;
-  oy->headerbytes=0;
-  oy->bodybytes=0;
-  oy->fifo_fill-=ret;
-
-  return ret;
-  
- sync_fail:
-
-  oy->headerbytes=0;
-  oy->bodybytes=0;
-  oy->fifo_tail=ogg_buffer_pretruncate(oy->fifo_tail,1);
-  ret--;
-  
-  /* search forward through fragments for possible capture */
-  while(oy->fifo_tail){
-    /* invariant: fifo_cursor points to a position in fifo_tail */
-    unsigned char *now=oy->fifo_tail->buffer->data+oy->fifo_tail->begin;
-    unsigned char *next=memchr(now, 'O', oy->fifo_tail->length);
-      
-    if(next){
-      /* possible capture in this segment */
-      long bytes=next-now;
-      oy->fifo_tail=ogg_buffer_pretruncate(oy->fifo_tail,bytes);
-      ret-=bytes;
-      break;
-    }else{
-      /* no capture.  advance to next segment */
-      long bytes=oy->fifo_tail->length;
-      ret-=bytes;
-      oy->fifo_tail=ogg_buffer_pretruncate(oy->fifo_tail,bytes);
-    }
-  }
-  if(!oy->fifo_tail)oy->fifo_head=0;
-  oy->fifo_fill+=ret;
-
- sync_out:
-  return ret;
-}
-
-/* sync the stream and get a page.  Keep trying until we find a page.
-   Supress 'sync errors' after reporting the first.
-
-   return values:
-   OGG_HOLE) recapture (hole in data)
-          0) need more data
-          1) page returned
-
-   Returns pointers into buffered data; invalidated by next call to
-   _stream, _clear, _init, or _buffer */
-
-int ogg_sync_pageout(ogg_sync_state *oy, ogg_page *og){
-
-  /* all we need to do is verify a page at the head of the stream
-     buffer.  If it doesn't verify, we look for the next potential
-     frame */
-
-  while(1){
-    long ret=ogg_sync_pageseek(oy,og);
-    if(ret>0){
-      /* have a page */
-      return 1;
-    }
-    if(ret==0){
-      /* need more data */
-      return 0;
-    }
-    
-    /* head did not start a synced page... skipped some bytes */
-    if(!oy->unsynced){
-      oy->unsynced=1;
-      return OGG_HOLE;
-    }
-
-    /* loop. keep looking */
-
-  }
-}
-
-/* clear things to an initial state.  Good to call, eg, before seeking */
-int ogg_sync_reset(ogg_sync_state *oy){
-
-  ogg_buffer_release(oy->fifo_tail);
-  oy->fifo_tail=0;
-  oy->fifo_head=0;
-  oy->fifo_fill=0;
-
-  oy->unsynced=0;
-  oy->headerbytes=0;
-  oy->bodybytes=0;
-  return OGG_SUCCESS;
-}
-
-ogg_stream_state *ogg_stream_create(int serialno){
-  ogg_stream_state *os=_ogg_calloc(1,sizeof(*os));
-  os->serialno=serialno;
-  os->pageno=-1;
-  return os;
-} 
-
-int ogg_stream_destroy(ogg_stream_state *os){
-  if(os){
-    ogg_buffer_release(os->header_tail);
-    ogg_buffer_release(os->body_tail);
-    memset(os,0,sizeof(*os));    
-    _ogg_free(os);
-  }
-  return OGG_SUCCESS;
-} 
-
-
-#define FINFLAG 0x80000000UL
-#define FINMASK 0x7fffffffUL
-
-static void _next_lace(oggbyte_buffer *ob,ogg_stream_state *os){
-  /* search ahead one lace */
-  os->body_fill_next=0;
-  while(os->laceptr<os->lacing_fill){
-    int val=oggbyte_read1(ob,27+os->laceptr++);
-    os->body_fill_next+=val;
-    if(val<255){
-      os->body_fill_next|=FINFLAG;
-      os->clearflag=1;
-      break;
-    }
-  }
-}
-
-static void _span_queued_page(ogg_stream_state *os){ 
-  while( !(os->body_fill&FINFLAG) ){
-    
-    if(!os->header_tail)break;
-
-    /* first flush out preceeding page header (if any).  Body is
-       flushed as it's consumed, so that's not done here. */
-
-    if(os->lacing_fill>=0)
-      os->header_tail=ogg_buffer_pretruncate(os->header_tail,
-                                             os->lacing_fill+27);
-    os->lacing_fill=0;
-    os->laceptr=0;
-    os->clearflag=0;
-
-    if(!os->header_tail){
-      os->header_head=0;
-      break;
-    }else{
-      
-      /* process/prepare next page, if any */
-
-      long pageno;
-      oggbyte_buffer ob;
-      ogg_page og;               /* only for parsing header values */
-      og.header=os->header_tail; /* only for parsing header values */
-      pageno=ogg_page_pageno(&og);
-
-      oggbyte_init(&ob,os->header_tail);
-      os->lacing_fill=oggbyte_read1(&ob,26);
-      
-      /* are we in sequence? */
-      if(pageno!=os->pageno){
-        if(os->pageno==-1) /* indicates seek or reset */
-          os->holeflag=1;  /* set for internal use */
-        else
-          os->holeflag=2;  /* set for external reporting */
-
-        os->body_tail=ogg_buffer_pretruncate(os->body_tail,
-                                             os->body_fill);
-        if(os->body_tail==0)os->body_head=0;
-        os->body_fill=0;
-
-      }
-    
-      if(ogg_page_continued(&og)){
-        if(os->body_fill==0){
-          /* continued packet, but no preceeding data to continue */
-          /* dump the first partial packet on the page */
-          _next_lace(&ob,os);   
-          os->body_tail=
-            ogg_buffer_pretruncate(os->body_tail,os->body_fill_next&FINMASK);
-          if(os->body_tail==0)os->body_head=0;
-          /* set span flag */
-          if(!os->spanflag && !os->holeflag)os->spanflag=2;
-        }
-      }else{
-        if(os->body_fill>0){
-          /* preceeding data to continue, but not a continued page */
-          /* dump body_fill */
-          os->body_tail=ogg_buffer_pretruncate(os->body_tail,
-                                               os->body_fill);
-          if(os->body_tail==0)os->body_head=0;
-          os->body_fill=0;
-
-          /* set espan flag */
-          if(!os->spanflag && !os->holeflag)os->spanflag=2;
-        }
-      }
-
-      if(os->laceptr<os->lacing_fill){
-        os->granulepos=ogg_page_granulepos(&og);
-
-        /* get current packet size & flag */
-        _next_lace(&ob,os);
-        os->body_fill+=os->body_fill_next; /* addition handles the flag fine;
-                                             unsigned on purpose */
-        /* ...and next packet size & flag */
-        _next_lace(&ob,os);
-
-      }
-      
-      os->pageno=pageno+1;
-      os->e_o_s=ogg_page_eos(&og);
-      os->b_o_s=ogg_page_bos(&og);
-    
-    }
-  }
-}
-
-/* add the incoming page to the stream state; we decompose the page
-   into packet segments here as well. */
-
-int ogg_stream_pagein(ogg_stream_state *os, ogg_page *og){
-
-  int serialno=ogg_page_serialno(og);
-  int version=ogg_page_version(og);
-
-  /* check the serial number */
-  if(serialno!=os->serialno){
-    ogg_page_release(og);
-    return OGG_ESERIAL;
-  }
-  if(version>0){
-    ogg_page_release(og);
-    return OGG_EVERSION;
-  }
-
-  /* add to fifos */
-  if(!os->body_tail){
-    os->body_tail=og->body;
-    os->body_head=ogg_buffer_walk(og->body);
-  }else{
-    os->body_head=ogg_buffer_cat(os->body_head,og->body);
-  }
-  if(!os->header_tail){
-    os->header_tail=og->header;
-    os->header_head=ogg_buffer_walk(og->header);
-    os->lacing_fill=-27;
-  }else{
-    os->header_head=ogg_buffer_cat(os->header_head,og->header);
-  }
-
-  memset(og,0,sizeof(*og));
-  return OGG_SUCCESS;
-}
-
-int ogg_stream_reset(ogg_stream_state *os){
-
-  ogg_buffer_release(os->header_tail);
-  ogg_buffer_release(os->body_tail);
-  os->header_tail=os->header_head=0;
-  os->body_tail=os->body_head=0;
-
-  os->e_o_s=0;
-  os->b_o_s=0;
-  os->pageno=-1;
-  os->packetno=0;
-  os->granulepos=0;
-
-  os->body_fill=0;
-  os->lacing_fill=0;
-
-  os->holeflag=0;
-  os->spanflag=0;
-  os->clearflag=0;
-  os->laceptr=0;
-  os->body_fill_next=0;
-
-  return OGG_SUCCESS;
-}
-
-int ogg_stream_reset_serialno(ogg_stream_state *os,int serialno){
-  ogg_stream_reset(os);
-  os->serialno=serialno;
-  return OGG_SUCCESS;
-}
-
-static int _packetout(ogg_stream_state *os,ogg_packet *op,int adv){
-
-  ogg_packet_release(op);
-  _span_queued_page(os);
-
-  if(os->holeflag){
-    int temp=os->holeflag;
-    if(os->clearflag)
-      os->holeflag=0;
-    else
-      os->holeflag=1;
-    if(temp==2){
-      os->packetno++;
-      return OGG_HOLE;
-    }
-  }
-  if(os->spanflag){
-    int temp=os->spanflag;
-    if(os->clearflag)
-      os->spanflag=0;
-    else
-      os->spanflag=1;
-    if(temp==2){
-      os->packetno++;
-      return OGG_SPAN;
-    }
-  }
-
-  if(!(os->body_fill&FINFLAG)) return 0;
-  if(!op && !adv)return 1; /* just using peek as an inexpensive way
-                               to ask if there's a whole packet
-                               waiting */
-  if(op){
-    op->b_o_s=os->b_o_s;
-    if(os->e_o_s && os->body_fill_next==0)
-      op->e_o_s=os->e_o_s;
-    else
-      op->e_o_s=0;
-    if( (os->body_fill&FINFLAG) && !(os->body_fill_next&FINFLAG) )
-      op->granulepos=os->granulepos;
-    else
-      op->granulepos=-1;
-    op->packetno=os->packetno;
-  }
-
-  if(adv){
-    oggbyte_buffer ob;
-    oggbyte_init(&ob,os->header_tail);
-
-    /* split the body contents off */
-    if(op){
-      op->packet=ogg_buffer_split(&os->body_tail,&os->body_head,
-				  os->body_fill&FINMASK);
-      op->bytes=os->body_fill&FINMASK;
-    }else{
-      os->body_tail=ogg_buffer_pretruncate(os->body_tail,
-					   os->body_fill&FINMASK);
-      if(os->body_tail==0)os->body_head=0;
-    }
-
-    /* update lacing pointers */
-    os->body_fill=os->body_fill_next;
-    _next_lace(&ob,os);
-  }else{
-    if(op){
-      op->packet=ogg_buffer_sub(os->body_tail,0,os->body_fill&FINMASK);
-      op->bytes=os->body_fill&FINMASK;
-    }
-  }
-  
-  if(adv){
-    os->packetno++;
-    os->b_o_s=0;
-  }
-
-  return 1;
-}
-
-int ogg_stream_packetout(ogg_stream_state *os,ogg_packet *op){
-  return _packetout(os,op,1);
-}
-
-int ogg_stream_packetpeek(ogg_stream_state *os,ogg_packet *op){
-  return _packetout(os,op,0);
-}
-
-int ogg_packet_release(ogg_packet *op) {
-  if(op){
-    ogg_buffer_release(op->packet);
-    memset(op, 0, sizeof(*op));
-  }
-  return OGG_SUCCESS;
-}
-
-int ogg_page_release(ogg_page *og) {
-  if(og){
-    ogg_buffer_release(og->header);
-    ogg_buffer_release(og->body);
-    memset(og, 0, sizeof(*og));
-  }
-  return OGG_SUCCESS;
-}
-
-void ogg_page_dup(ogg_page *dup,ogg_page *orig){
-  dup->header_len=orig->header_len;
-  dup->body_len=orig->body_len;
-  dup->header=ogg_buffer_dup(orig->header);
-  dup->body=ogg_buffer_dup(orig->body);
-}
-