vorbis/lib/info.c

/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE OggVorbis SOFTWARE 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 SOURCE CODE IS (C) COPYRIGHT 1994-2017             *
 * by the Xiph.Org Foundation http://www.xiph.org/                  *
 *                                                                  *
 ********************************************************************

 function: maintain the info structure, info <-> header packets

 ********************************************************************/

/* general handling of the header and the vorbis_info structure (and
   substructures) */

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <ogg/ogg.h>
#include "vorbis/codec.h"
#include "codec_internal.h"
#include "codebook.h"
#include "registry.h"
#include "window.h"
#include "psy.h"
#include "misc.h"
#include "os.h"

#define GENERAL_VENDOR_STRING "Xiph.Org libVorbis 1.3.5"
#define ENCODE_VENDOR_STRING "Xiph.Org libVorbis I 20150105 (⛄⛄⛄⛄)"

/* helpers */
static void _v_writestring(oggpack_buffer *o,const char *s, int bytes){

  while(bytes--){
    oggpack_write(o,*s++,8);
  }
}

static void _v_readstring(oggpack_buffer *o,char *buf,int bytes){
  while(bytes--){
    *buf++=oggpack_read(o,8);
  }
}

void vorbis_comment_init(vorbis_comment *vc){
  memset(vc,0,sizeof(*vc));
}

void vorbis_comment_add(vorbis_comment *vc,const char *comment){
  vc->user_comments=_ogg_realloc(vc->user_comments,
                            (vc->comments+2)*sizeof(*vc->user_comments));
  vc->comment_lengths=_ogg_realloc(vc->comment_lengths,
                                  (vc->comments+2)*sizeof(*vc->comment_lengths));
  vc->comment_lengths[vc->comments]=strlen(comment);
  vc->user_comments[vc->comments]=_ogg_malloc(vc->comment_lengths[vc->comments]+1);
  strcpy(vc->user_comments[vc->comments], comment);
  vc->comments++;
  vc->user_comments[vc->comments]=NULL;
}

void vorbis_comment_add_tag(vorbis_comment *vc, const char *tag, const char *contents){
  /* Length for key and value +2 for = and \0 */
  char *comment=_ogg_malloc(strlen(tag)+strlen(contents)+2);
  strcpy(comment, tag);
  strcat(comment, "=");
  strcat(comment, contents);
  vorbis_comment_add(vc, comment);
  _ogg_free(comment);
}

/* This is more or less the same as strncasecmp - but that doesn't exist
 * everywhere, and this is a fairly trivial function, so we include it */
static int tagcompare(const char *s1, const char *s2, int n){
  int c=0;
  while(c < n){
    if(toupper(s1[c]) != toupper(s2[c]))
      return !0;
    c++;
  }
  return 0;
}

void vorbis_comment_rm(vorbis_comment *vc, const char *comment){
  long i;
  size_t taglen;
  const char *eq;

  eq = strchr(comment, '=');
  if (eq) {
    eq++; /* Move to what is behind '='. */
    taglen = eq - comment;
  } else {
    taglen = strlen(comment);
  }

  for(i=0;i<vc->comments;i++){
    if (tagcompare(vc->user_comments[i], comment, taglen)) {
      /* Tag name does not match -> try next comment. */
      continue;
    }

    if (eq) {
      /* As we already know that we share the same tag name it is safe to asume
       * the comment is at least taglen long ('\0' not counted). */
      if (strcmp(vc->user_comments[i] + taglen, eq)) {
        /* Tag value does not match -> try next comment. */
        continue;
      }
    }

    /* At this point we found a matching tag. Now let's remove it. */
    _ogg_free(vc->user_comments[i]);
    memmove(&(vc->user_comments[i]), &(vc->user_comments[i+1]),
            sizeof(vc->user_comments[i])*(vc->comments - i - 1));
    vc->comments--;
    return;
  }
}

void vorbis_comment_rm_tag(vorbis_comment *vc, const char *tag, const char *contents){
  long i;
  size_t taglen = strlen(tag);

  for(i=0;i<vc->comments;i++){
    if (tagcompare(vc->user_comments[i], tag, taglen)) {
      /* Tag name does not match -> try next comment. */
      continue;
    }

    /* As we already know that we share the same tag name it is safe to asume
     * the comment is at least taglen long ('\0' not counted). */

    if (vc->user_comments[i][taglen] != '=') {
      /* The tag in our comment does not end at the same position as
       * the provided tag does -> try next comment. */
      continue;
    }

    if (contents) {
      if (strcmp(vc->user_comments[i] + taglen + 1, contents)) {
        /* Tag value does not match -> try next comment. */
        continue;
      }
    }

    /* At this point we found a matching tag. Now let's remove it. */
    _ogg_free(vc->user_comments[i]);
    memmove(&(vc->user_comments[i]), &(vc->user_comments[i+1]),
            sizeof(vc->user_comments[i])*(vc->comments - i - 1));
    vc->comments--;
    return;
  }
}

char *vorbis_comment_query(vorbis_comment *vc, const char *tag, int count){
  long i;
  int found = 0;
  int taglen = strlen(tag)+1; /* +1 for the = we append */
  char *fulltag = _ogg_malloc(taglen+1);

  strcpy(fulltag, tag);
  strcat(fulltag, "=");

  for(i=0;i<vc->comments;i++){
    if(!tagcompare(vc->user_comments[i], fulltag, taglen)){
      if(count == found) {
        /* We return a pointer to the data, not a copy */
        _ogg_free(fulltag);
        return vc->user_comments[i] + taglen;
      } else {
        found++;
      }
    }
  }
  _ogg_free(fulltag);
  return NULL; /* didn't find anything */
}

int vorbis_comment_query_count(vorbis_comment *vc, const char *tag){
  int i,count=0;
  int taglen = strlen(tag)+1; /* +1 for the = we append */
  char *fulltag = _ogg_malloc(taglen+1);
  strcpy(fulltag,tag);
  strcat(fulltag, "=");

  for(i=0;i<vc->comments;i++){
    if(!tagcompare(vc->user_comments[i], fulltag, taglen))
      count++;
  }

  _ogg_free(fulltag);
  return count;
}

void vorbis_comment_clear(vorbis_comment *vc){
  if(vc){
    long i;
    if(vc->user_comments){
      for(i=0;i<vc->comments;i++)
        if(vc->user_comments[i])_ogg_free(vc->user_comments[i]);
      _ogg_free(vc->user_comments);
    }
    if(vc->comment_lengths)_ogg_free(vc->comment_lengths);
    if(vc->vendor)_ogg_free(vc->vendor);
    memset(vc,0,sizeof(*vc));
  }
}

/* blocksize 0 is guaranteed to be short, 1 is guaranteed to be long.
   They may be equal, but short will never ge greater than long */
int vorbis_info_blocksize(vorbis_info *vi,int zo){
  codec_setup_info *ci = vi->codec_setup;
  return ci ? ci->blocksizes[zo] : -1;
}

/* used by synthesis, which has a full, alloced vi */
void vorbis_info_init(vorbis_info *vi){
  memset(vi,0,sizeof(*vi));
  vi->codec_setup=_ogg_calloc(1,sizeof(codec_setup_info));
}

void vorbis_info_clear(vorbis_info *vi){
  codec_setup_info     *ci=vi->codec_setup;
  int i;

  if(ci){

    for(i=0;i<ci->modes;i++)
      if(ci->mode_param[i])_ogg_free(ci->mode_param[i]);

    for(i=0;i<ci->maps;i++) /* unpack does the range checking */
      if(ci->map_param[i]) /* this may be cleaning up an aborted
                              unpack, in which case the below type
                              cannot be trusted */
        _mapping_P[ci->map_type[i]]->free_info(ci->map_param[i]);

    for(i=0;i<ci->floors;i++) /* unpack does the range checking */
      if(ci->floor_param[i]) /* this may be cleaning up an aborted
                                unpack, in which case the below type
                                cannot be trusted */
        _floor_P[ci->floor_type[i]]->free_info(ci->floor_param[i]);

    for(i=0;i<ci->residues;i++) /* unpack does the range checking */
      if(ci->residue_param[i]) /* this may be cleaning up an aborted
                                  unpack, in which case the below type
                                  cannot be trusted */
        _residue_P[ci->residue_type[i]]->free_info(ci->residue_param[i]);

    for(i=0;i<ci->books;i++){
      if(ci->book_param[i]){
        /* knows if the book was not alloced */
        vorbis_staticbook_destroy(ci->book_param[i]);
      }
      if(ci->fullbooks)
        vorbis_book_clear(ci->fullbooks+i);
    }
    if(ci->fullbooks)
        _ogg_free(ci->fullbooks);

    for(i=0;i<ci->psys;i++)
      _vi_psy_free(ci->psy_param[i]);

    _ogg_free(ci);
  }

  memset(vi,0,sizeof(*vi));
}

/* Header packing/unpacking ********************************************/

static int _vorbis_unpack_info(vorbis_info *vi,oggpack_buffer *opb){
  codec_setup_info     *ci=vi->codec_setup;
  if(!ci)return(OV_EFAULT);

  vi->version=oggpack_read(opb,32);
  if(vi->version!=0)return(OV_EVERSION);

  vi->channels=oggpack_read(opb,8);
  vi->rate=oggpack_read(opb,32);

  vi->bitrate_upper=(ogg_int32_t)oggpack_read(opb,32);
  vi->bitrate_nominal=(ogg_int32_t)oggpack_read(opb,32);
  vi->bitrate_lower=(ogg_int32_t)oggpack_read(opb,32);

  ci->blocksizes[0]=1<<oggpack_read(opb,4);
  ci->blocksizes[1]=1<<oggpack_read(opb,4);

  if(vi->rate<1)goto err_out;
  if(vi->channels<1)goto err_out;
  if(ci->blocksizes[0]<64)goto err_out;
  if(ci->blocksizes[1]<ci->blocksizes[0])goto err_out;
  if(ci->blocksizes[1]>8192)goto err_out;

  if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */

  return(0);
 err_out:
  vorbis_info_clear(vi);
  return(OV_EBADHEADER);
}

static int _vorbis_unpack_comment(vorbis_comment *vc,oggpack_buffer *opb){
  int i;
  int vendorlen=oggpack_read(opb,32);
  if(vendorlen<0)goto err_out;
  if(vendorlen>opb->storage-8)goto err_out;
  vc->vendor=_ogg_calloc(vendorlen+1,1);
  _v_readstring(opb,vc->vendor,vendorlen);
  i=oggpack_read(opb,32);
  if(i<0)goto err_out;
  if(i>((opb->storage-oggpack_bytes(opb))>>2))goto err_out;
  vc->comments=i;
  vc->user_comments=_ogg_calloc(vc->comments+1,sizeof(*vc->user_comments));
  vc->comment_lengths=_ogg_calloc(vc->comments+1, sizeof(*vc->comment_lengths));

  for(i=0;i<vc->comments;i++){
    int len=oggpack_read(opb,32);
    if(len<0)goto err_out;
    if(len>opb->storage-oggpack_bytes(opb))goto err_out;
    vc->comment_lengths[i]=len;
    vc->user_comments[i]=_ogg_calloc(len+1,1);
    _v_readstring(opb,vc->user_comments[i],len);
  }
  if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */

  return(0);
 err_out:
  vorbis_comment_clear(vc);
  return(OV_EBADHEADER);
}

/* all of the real encoding details are here.  The modes, books,
   everything */
static int _vorbis_unpack_books(vorbis_info *vi,oggpack_buffer *opb){
  codec_setup_info     *ci=vi->codec_setup;
  int i;

  /* codebooks */
  ci->books=oggpack_read(opb,8)+1;
  if(ci->books<=0)goto err_out;
  for(i=0;i<ci->books;i++){
    ci->book_param[i]=vorbis_staticbook_unpack(opb);
    if(!ci->book_param[i])goto err_out;
  }

  /* time backend settings; hooks are unused */
  {
    int times=oggpack_read(opb,6)+1;
    if(times<=0)goto err_out;
    for(i=0;i<times;i++){
      int test=oggpack_read(opb,16);
      if(test<0 || test>=VI_TIMEB)goto err_out;
    }
  }

  /* floor backend settings */
  ci->floors=oggpack_read(opb,6)+1;
  if(ci->floors<=0)goto err_out;
  for(i=0;i<ci->floors;i++){
    ci->floor_type[i]=oggpack_read(opb,16);
    if(ci->floor_type[i]<0 || ci->floor_type[i]>=VI_FLOORB)goto err_out;
    ci->floor_param[i]=_floor_P[ci->floor_type[i]]->unpack(vi,opb);
    if(!ci->floor_param[i])goto err_out;
  }

  /* residue backend settings */
  ci->residues=oggpack_read(opb,6)+1;
  if(ci->residues<=0)goto err_out;
  for(i=0;i<ci->residues;i++){
    ci->residue_type[i]=oggpack_read(opb,16);
    if(ci->residue_type[i]<0 || ci->residue_type[i]>=VI_RESB)goto err_out;
    ci->residue_param[i]=_residue_P[ci->residue_type[i]]->unpack(vi,opb);
    if(!ci->residue_param[i])goto err_out;
  }

  /* map backend settings */
  ci->maps=oggpack_read(opb,6)+1;
  if(ci->maps<=0)goto err_out;
  for(i=0;i<ci->maps;i++){
    ci->map_type[i]=oggpack_read(opb,16);
    if(ci->map_type[i]<0 || ci->map_type[i]>=VI_MAPB)goto err_out;
    ci->map_param[i]=_mapping_P[ci->map_type[i]]->unpack(vi,opb);
    if(!ci->map_param[i])goto err_out;
  }

  /* mode settings */
  ci->modes=oggpack_read(opb,6)+1;
  if(ci->modes<=0)goto err_out;
  for(i=0;i<ci->modes;i++){
    ci->mode_param[i]=_ogg_calloc(1,sizeof(*ci->mode_param[i]));
    ci->mode_param[i]->blockflag=oggpack_read(opb,1);
    ci->mode_param[i]->windowtype=oggpack_read(opb,16);
    ci->mode_param[i]->transformtype=oggpack_read(opb,16);
    ci->mode_param[i]->mapping=oggpack_read(opb,8);

    if(ci->mode_param[i]->windowtype>=VI_WINDOWB)goto err_out;
    if(ci->mode_param[i]->transformtype>=VI_WINDOWB)goto err_out;
    if(ci->mode_param[i]->mapping>=ci->maps)goto err_out;
    if(ci->mode_param[i]->mapping<0)goto err_out;
  }

  if(oggpack_read(opb,1)!=1)goto err_out; /* top level EOP check */

  return(0);
 err_out:
  vorbis_info_clear(vi);
  return(OV_EBADHEADER);
}

/* Is this packet a vorbis ID header? */
int vorbis_synthesis_idheader(ogg_packet *op){
  oggpack_buffer opb;
  char buffer[6];

  if(op){
    oggpack_readinit(&opb,op->packet,op->bytes);

    if(!op->b_o_s)
      return(0); /* Not the initial packet */

    if(oggpack_read(&opb,8) != 1)
      return 0; /* not an ID header */

    memset(buffer,0,6);
    _v_readstring(&opb,buffer,6);
    if(memcmp(buffer,"vorbis",6))
      return 0; /* not vorbis */

    return 1;
  }

  return 0;
}

/* The Vorbis header is in three packets; the initial small packet in
   the first page that identifies basic parameters, a second packet
   with bitstream comments and a third packet that holds the
   codebook. */

int vorbis_synthesis_headerin(vorbis_info *vi,vorbis_comment *vc,ogg_packet *op){
  oggpack_buffer opb;

  if(op){
    oggpack_readinit(&opb,op->packet,op->bytes);

    /* Which of the three types of header is this? */
    /* Also verify header-ness, vorbis */
    {
      char buffer[6];
      int packtype=oggpack_read(&opb,8);
      memset(buffer,0,6);
      _v_readstring(&opb,buffer,6);
      if(memcmp(buffer,"vorbis",6)){
        /* not a vorbis header */
        return(OV_ENOTVORBIS);
      }
      switch(packtype){
      case 0x01: /* least significant *bit* is read first */
        if(!op->b_o_s){
          /* Not the initial packet */
          return(OV_EBADHEADER);
        }
        if(vi->rate!=0){
          /* previously initialized info header */
          return(OV_EBADHEADER);
        }

        return(_vorbis_unpack_info(vi,&opb));

      case 0x03: /* least significant *bit* is read first */
        if(vi->rate==0){
          /* um... we didn't get the initial header */
          return(OV_EBADHEADER);
        }
        if(vc->vendor!=NULL){
          /* previously initialized comment header */
          return(OV_EBADHEADER);
        }

        return(_vorbis_unpack_comment(vc,&opb));

      case 0x05: /* least significant *bit* is read first */
        if(vi->rate==0 || vc->vendor==NULL){
          /* um... we didn;t get the initial header or comments yet */
          return(OV_EBADHEADER);
        }
        if(vi->codec_setup==NULL){
          /* improperly initialized vorbis_info */
          return(OV_EFAULT);
        }
        if(((codec_setup_info *)vi->codec_setup)->books>0){
          /* previously initialized setup header */
          return(OV_EBADHEADER);
        }

        return(_vorbis_unpack_books(vi,&opb));

      default:
        /* Not a valid vorbis header type */
        return(OV_EBADHEADER);
        break;
      }
    }
  }
  return(OV_EBADHEADER);
}

/* pack side **********************************************************/

static int _vorbis_pack_info(oggpack_buffer *opb,vorbis_info *vi){
  codec_setup_info     *ci=vi->codec_setup;
  if(!ci||
     ci->blocksizes[0]<64||
     ci->blocksizes[1]<ci->blocksizes[0]){
    return(OV_EFAULT);
  }

  /* preamble */
  oggpack_write(opb,0x01,8);
  _v_writestring(opb,"vorbis", 6);

  /* basic information about the stream */
  oggpack_write(opb,0x00,32);
  oggpack_write(opb,vi->channels,8);
  oggpack_write(opb,vi->rate,32);

  oggpack_write(opb,vi->bitrate_upper,32);
  oggpack_write(opb,vi->bitrate_nominal,32);
  oggpack_write(opb,vi->bitrate_lower,32);

  oggpack_write(opb,ov_ilog(ci->blocksizes[0]-1),4);
  oggpack_write(opb,ov_ilog(ci->blocksizes[1]-1),4);
  oggpack_write(opb,1,1);

  return(0);
}

static int _vorbis_pack_comment(oggpack_buffer *opb,vorbis_comment *vc){
  int bytes = strlen(ENCODE_VENDOR_STRING);

  /* preamble */
  oggpack_write(opb,0x03,8);
  _v_writestring(opb,"vorbis", 6);

  /* vendor */
  oggpack_write(opb,bytes,32);
  _v_writestring(opb,ENCODE_VENDOR_STRING, bytes);

  /* comments */

  oggpack_write(opb,vc->comments,32);
  if(vc->comments){
    int i;
    for(i=0;i<vc->comments;i++){
      if(vc->user_comments[i]){
        oggpack_write(opb,vc->comment_lengths[i],32);
        _v_writestring(opb,vc->user_comments[i], vc->comment_lengths[i]);
      }else{
        oggpack_write(opb,0,32);
      }
    }
  }
  oggpack_write(opb,1,1);

  return(0);
}

static int _vorbis_pack_books(oggpack_buffer *opb,vorbis_info *vi){
  codec_setup_info     *ci=vi->codec_setup;
  int i;
  if(!ci)return(OV_EFAULT);

  oggpack_write(opb,0x05,8);
  _v_writestring(opb,"vorbis", 6);

  /* books */
  oggpack_write(opb,ci->books-1,8);
  for(i=0;i<ci->books;i++)
    if(vorbis_staticbook_pack(ci->book_param[i],opb))goto err_out;

  /* times; hook placeholders */
  oggpack_write(opb,0,6);
  oggpack_write(opb,0,16);

  /* floors */
  oggpack_write(opb,ci->floors-1,6);
  for(i=0;i<ci->floors;i++){
    oggpack_write(opb,ci->floor_type[i],16);
    if(_floor_P[ci->floor_type[i]]->pack)
      _floor_P[ci->floor_type[i]]->pack(ci->floor_param[i],opb);
    else
      goto err_out;
  }

  /* residues */
  oggpack_write(opb,ci->residues-1,6);
  for(i=0;i<ci->residues;i++){
    oggpack_write(opb,ci->residue_type[i],16);
    _residue_P[ci->residue_type[i]]->pack(ci->residue_param[i],opb);
  }

  /* maps */
  oggpack_write(opb,ci->maps-1,6);
  for(i=0;i<ci->maps;i++){
    oggpack_write(opb,ci->map_type[i],16);
    _mapping_P[ci->map_type[i]]->pack(vi,ci->map_param[i],opb);
  }

  /* modes */
  oggpack_write(opb,ci->modes-1,6);
  for(i=0;i<ci->modes;i++){
    oggpack_write(opb,ci->mode_param[i]->blockflag,1);
    oggpack_write(opb,ci->mode_param[i]->windowtype,16);
    oggpack_write(opb,ci->mode_param[i]->transformtype,16);
    oggpack_write(opb,ci->mode_param[i]->mapping,8);
  }
  oggpack_write(opb,1,1);

  return(0);
err_out:
  return(-1);
}

int vorbis_commentheader_out(vorbis_comment *vc,
                                          ogg_packet *op){

  oggpack_buffer opb;

  oggpack_writeinit(&opb);
  if(_vorbis_pack_comment(&opb,vc)){
    oggpack_writeclear(&opb);
    return OV_EIMPL;
  }

  op->packet = _ogg_malloc(oggpack_bytes(&opb));
  memcpy(op->packet, opb.buffer, oggpack_bytes(&opb));

  op->bytes=oggpack_bytes(&opb);
  op->b_o_s=0;
  op->e_o_s=0;
  op->granulepos=0;
  op->packetno=1;

  oggpack_writeclear(&opb);
  return 0;
}

int vorbis_analysis_headerout(vorbis_dsp_state *v,
                              vorbis_comment *vc,
                              ogg_packet *op,
                              ogg_packet *op_comm,
                              ogg_packet *op_code){
  int ret=OV_EIMPL;
  vorbis_info *vi=v->vi;
  oggpack_buffer opb;
  private_state *b=v->backend_state;

  if(!b||vi->channels<=0){
    ret=OV_EFAULT;
    goto err_out;
  }

  /* first header packet **********************************************/

  oggpack_writeinit(&opb);
  if(_vorbis_pack_info(&opb,vi))goto err_out;

  /* build the packet */
  if(b->header)_ogg_free(b->header);
  b->header=_ogg_malloc(oggpack_bytes(&opb));
  memcpy(b->header,opb.buffer,oggpack_bytes(&opb));
  op->packet=b->header;
  op->bytes=oggpack_bytes(&opb);
  op->b_o_s=1;
  op->e_o_s=0;
  op->granulepos=0;
  op->packetno=0;

  /* second header packet (comments) **********************************/

  oggpack_reset(&opb);
  if(_vorbis_pack_comment(&opb,vc))goto err_out;

  if(b->header1)_ogg_free(b->header1);
  b->header1=_ogg_malloc(oggpack_bytes(&opb));
  memcpy(b->header1,opb.buffer,oggpack_bytes(&opb));
  op_comm->packet=b->header1;
  op_comm->bytes=oggpack_bytes(&opb);
  op_comm->b_o_s=0;
  op_comm->e_o_s=0;
  op_comm->granulepos=0;
  op_comm->packetno=1;

  /* third header packet (modes/codebooks) ****************************/

  oggpack_reset(&opb);
  if(_vorbis_pack_books(&opb,vi))goto err_out;

  if(b->header2)_ogg_free(b->header2);
  b->header2=_ogg_malloc(oggpack_bytes(&opb));
  memcpy(b->header2,opb.buffer,oggpack_bytes(&opb));
  op_code->packet=b->header2;
  op_code->bytes=oggpack_bytes(&opb);
  op_code->b_o_s=0;
  op_code->e_o_s=0;
  op_code->granulepos=0;
  op_code->packetno=2;

  oggpack_writeclear(&opb);
  return(0);
 err_out:
  memset(op,0,sizeof(*op));
  memset(op_comm,0,sizeof(*op_comm));
  memset(op_code,0,sizeof(*op_code));

  if(b){
    oggpack_writeclear(&opb);
    if(b->header)_ogg_free(b->header);
    if(b->header1)_ogg_free(b->header1);
    if(b->header2)_ogg_free(b->header2);
    b->header=NULL;
    b->header1=NULL;
    b->header2=NULL;
  }
  return(ret);
}

double vorbis_granule_time(vorbis_dsp_state *v,ogg_int64_t granulepos){
  if(granulepos == -1) return -1;

  /* We're not guaranteed a 64 bit unsigned type everywhere, so we
     have to put the unsigned granpo in a signed type. */
  if(granulepos>=0){
    return((double)granulepos/v->vi->rate);
  }else{
    ogg_int64_t granuleoff=0xffffffff;
    granuleoff<<=31;
    granuleoff|=0x7ffffffff;
    return(((double)granulepos+2+granuleoff+granuleoff)/v->vi->rate);
  }
}

const char *vorbis_version_string(void){
  return GENERAL_VENDOR_STRING;
}