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      1 /********************************************************************
      2  *                                                                  *
      3  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
      4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
      5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
      6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
      7  *                                                                  *
      8  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2010             *
      9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
     10  *                                                                  *
     11  ********************************************************************
     12 
     13  function: maintain the info structure, info <-> header packets
     14  last mod: $Id: info.c 17080 2010-03-26 06:59:58Z xiphmont $
     15 
     16  ********************************************************************/
     17 
     18 /* general handling of the header and the vorbis_info structure (and
     19    substructures) */
     20 
     21 #include <stdlib.h>
     22 #include <string.h>
     23 #include <ctype.h>
     24 #include <ogg/ogg.h>
     25 #include "vorbis/codec.h"
     26 #include "codec_internal.h"
     27 #include "codebook.h"
     28 #include "registry.h"
     29 #include "window.h"
     30 #include "psy.h"
     31 #include "misc.h"
     32 #include "os.h"
     33 
     34 #define GENERAL_VENDOR_STRING "Xiph.Org libVorbis 1.3.1"
     35 #define ENCODE_VENDOR_STRING "Xiph.Org libVorbis I 20100325 (Everywhere)"
     36 
     37 /* helpers */
     38 static int ilog2(unsigned int v){
     39   int ret=0;
     40   if(v)--v;
     41   while(v){
     42     ret++;
     43     v>>=1;
     44   }
     45   return(ret);
     46 }
     47 
     48 static void _v_writestring(oggpack_buffer *o,const char *s, int bytes){
     49 
     50   while(bytes--){
     51     oggpack_write(o,*s++,8);
     52   }
     53 }
     54 
     55 static void _v_readstring(oggpack_buffer *o,char *buf,int bytes){
     56   while(bytes--){
     57     *buf++=oggpack_read(o,8);
     58   }
     59 }
     60 
     61 void vorbis_comment_init(vorbis_comment *vc){
     62   memset(vc,0,sizeof(*vc));
     63 }
     64 
     65 void vorbis_comment_add(vorbis_comment *vc,const char *comment){
     66   vc->user_comments=_ogg_realloc(vc->user_comments,
     67                             (vc->comments+2)*sizeof(*vc->user_comments));
     68   vc->comment_lengths=_ogg_realloc(vc->comment_lengths,
     69                                   (vc->comments+2)*sizeof(*vc->comment_lengths));
     70   vc->comment_lengths[vc->comments]=strlen(comment);
     71   vc->user_comments[vc->comments]=_ogg_malloc(vc->comment_lengths[vc->comments]+1);
     72   strcpy(vc->user_comments[vc->comments], comment);
     73   vc->comments++;
     74   vc->user_comments[vc->comments]=NULL;
     75 }
     76 
     77 void vorbis_comment_add_tag(vorbis_comment *vc, const char *tag, const char *contents){
     78   char *comment=alloca(strlen(tag)+strlen(contents)+2); /* +2 for = and \0 */
     79   strcpy(comment, tag);
     80   strcat(comment, "=");
     81   strcat(comment, contents);
     82   vorbis_comment_add(vc, comment);
     83 }
     84 
     85 /* This is more or less the same as strncasecmp - but that doesn't exist
     86  * everywhere, and this is a fairly trivial function, so we include it */
     87 static int tagcompare(const char *s1, const char *s2, int n){
     88   int c=0;
     89   while(c < n){
     90     if(toupper(s1[c]) != toupper(s2[c]))
     91       return !0;
     92     c++;
     93   }
     94   return 0;
     95 }
     96 
     97 char *vorbis_comment_query(vorbis_comment *vc, const char *tag, int count){
     98   long i;
     99   int found = 0;
    100   int taglen = strlen(tag)+1; /* +1 for the = we append */
    101   char *fulltag = alloca(taglen+ 1);
    102 
    103   strcpy(fulltag, tag);
    104   strcat(fulltag, "=");
    105 
    106   for(i=0;i<vc->comments;i++){
    107     if(!tagcompare(vc->user_comments[i], fulltag, taglen)){
    108       if(count == found)
    109         /* We return a pointer to the data, not a copy */
    110               return vc->user_comments[i] + taglen;
    111       else
    112         found++;
    113     }
    114   }
    115   return NULL; /* didn't find anything */
    116 }
    117 
    118 int vorbis_comment_query_count(vorbis_comment *vc, const char *tag){
    119   int i,count=0;
    120   int taglen = strlen(tag)+1; /* +1 for the = we append */
    121   char *fulltag = alloca(taglen+1);
    122   strcpy(fulltag,tag);
    123   strcat(fulltag, "=");
    124 
    125   for(i=0;i<vc->comments;i++){
    126     if(!tagcompare(vc->user_comments[i], fulltag, taglen))
    127       count++;
    128   }
    129 
    130   return count;
    131 }
    132 
    133 void vorbis_comment_clear(vorbis_comment *vc){
    134   if(vc){
    135     long i;
    136     if(vc->user_comments){
    137       for(i=0;i<vc->comments;i++)
    138         if(vc->user_comments[i])_ogg_free(vc->user_comments[i]);
    139       _ogg_free(vc->user_comments);
    140     }
    141     if(vc->comment_lengths)_ogg_free(vc->comment_lengths);
    142     if(vc->vendor)_ogg_free(vc->vendor);
    143     memset(vc,0,sizeof(*vc));
    144   }
    145 }
    146 
    147 /* blocksize 0 is guaranteed to be short, 1 is guaranteed to be long.
    148    They may be equal, but short will never ge greater than long */
    149 int vorbis_info_blocksize(vorbis_info *vi,int zo){
    150   codec_setup_info *ci = vi->codec_setup;
    151   return ci ? ci->blocksizes[zo] : -1;
    152 }
    153 
    154 /* used by synthesis, which has a full, alloced vi */
    155 void vorbis_info_init(vorbis_info *vi){
    156   memset(vi,0,sizeof(*vi));
    157   vi->codec_setup=_ogg_calloc(1,sizeof(codec_setup_info));
    158 }
    159 
    160 void vorbis_info_clear(vorbis_info *vi){
    161   codec_setup_info     *ci=vi->codec_setup;
    162   int i;
    163 
    164   if(ci){
    165 
    166     for(i=0;i<ci->modes;i++)
    167       if(ci->mode_param[i])_ogg_free(ci->mode_param[i]);
    168 
    169     for(i=0;i<ci->maps;i++) /* unpack does the range checking */
    170       if(ci->map_param[i]) /* this may be cleaning up an aborted
    171                               unpack, in which case the below type
    172                               cannot be trusted */
    173         _mapping_P[ci->map_type[i]]->free_info(ci->map_param[i]);
    174 
    175     for(i=0;i<ci->floors;i++) /* unpack does the range checking */
    176       if(ci->floor_param[i]) /* this may be cleaning up an aborted
    177                                 unpack, in which case the below type
    178                                 cannot be trusted */
    179         _floor_P[ci->floor_type[i]]->free_info(ci->floor_param[i]);
    180 
    181     for(i=0;i<ci->residues;i++) /* unpack does the range checking */
    182       if(ci->residue_param[i]) /* this may be cleaning up an aborted
    183                                   unpack, in which case the below type
    184                                   cannot be trusted */
    185         _residue_P[ci->residue_type[i]]->free_info(ci->residue_param[i]);
    186 
    187     for(i=0;i<ci->books;i++){
    188       if(ci->book_param[i]){
    189         /* knows if the book was not alloced */
    190         vorbis_staticbook_destroy(ci->book_param[i]);
    191       }
    192       if(ci->fullbooks)
    193         vorbis_book_clear(ci->fullbooks+i);
    194     }
    195     if(ci->fullbooks)
    196         _ogg_free(ci->fullbooks);
    197 
    198     for(i=0;i<ci->psys;i++)
    199       _vi_psy_free(ci->psy_param[i]);
    200 
    201     _ogg_free(ci);
    202   }
    203 
    204   memset(vi,0,sizeof(*vi));
    205 }
    206 
    207 /* Header packing/unpacking ********************************************/
    208 
    209 static int _vorbis_unpack_info(vorbis_info *vi,oggpack_buffer *opb){
    210   codec_setup_info     *ci=vi->codec_setup;
    211   if(!ci)return(OV_EFAULT);
    212 
    213   vi->version=oggpack_read(opb,32);
    214   if(vi->version!=0)return(OV_EVERSION);
    215 
    216   vi->channels=oggpack_read(opb,8);
    217   vi->rate=oggpack_read(opb,32);
    218 
    219   vi->bitrate_upper=oggpack_read(opb,32);
    220   vi->bitrate_nominal=oggpack_read(opb,32);
    221   vi->bitrate_lower=oggpack_read(opb,32);
    222 
    223   ci->blocksizes[0]=1<<oggpack_read(opb,4);
    224   ci->blocksizes[1]=1<<oggpack_read(opb,4);
    225 
    226   if(vi->rate<1)goto err_out;
    227   if(vi->channels<1)goto err_out;
    228   if(ci->blocksizes[0]<64)goto err_out;
    229   if(ci->blocksizes[1]<ci->blocksizes[0])goto err_out;
    230   if(ci->blocksizes[1]>8192)goto err_out;
    231 
    232   if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */
    233 
    234   return(0);
    235  err_out:
    236   vorbis_info_clear(vi);
    237   return(OV_EBADHEADER);
    238 }
    239 
    240 static int _vorbis_unpack_comment(vorbis_comment *vc,oggpack_buffer *opb){
    241   int i;
    242   int vendorlen=oggpack_read(opb,32);
    243   if(vendorlen<0)goto err_out;
    244   if(vendorlen>opb->storage-8)goto err_out;
    245   vc->vendor=_ogg_calloc(vendorlen+1,1);
    246   _v_readstring(opb,vc->vendor,vendorlen);
    247   i=oggpack_read(opb,32);
    248   if(i<0)goto err_out;
    249   if(i>((opb->storage-oggpack_bytes(opb))>>2))goto err_out;
    250   vc->comments=i;
    251   vc->user_comments=_ogg_calloc(vc->comments+1,sizeof(*vc->user_comments));
    252   vc->comment_lengths=_ogg_calloc(vc->comments+1, sizeof(*vc->comment_lengths));
    253 
    254   for(i=0;i<vc->comments;i++){
    255     int len=oggpack_read(opb,32);
    256     if(len<0)goto err_out;
    257     if(len>opb->storage-oggpack_bytes(opb))goto err_out;
    258     vc->comment_lengths[i]=len;
    259     vc->user_comments[i]=_ogg_calloc(len+1,1);
    260     _v_readstring(opb,vc->user_comments[i],len);
    261   }
    262   if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */
    263 
    264   return(0);
    265  err_out:
    266   vorbis_comment_clear(vc);
    267   return(OV_EBADHEADER);
    268 }
    269 
    270 /* all of the real encoding details are here.  The modes, books,
    271    everything */
    272 static int _vorbis_unpack_books(vorbis_info *vi,oggpack_buffer *opb){
    273   codec_setup_info     *ci=vi->codec_setup;
    274   int i;
    275   if(!ci)return(OV_EFAULT);
    276 
    277   /* codebooks */
    278   ci->books=oggpack_read(opb,8)+1;
    279   if(ci->books<=0)goto err_out;
    280   for(i=0;i<ci->books;i++){
    281     ci->book_param[i]=vorbis_staticbook_unpack(opb);
    282     if(!ci->book_param[i])goto err_out;
    283   }
    284 
    285   /* time backend settings; hooks are unused */
    286   {
    287     int times=oggpack_read(opb,6)+1;
    288     if(times<=0)goto err_out;
    289     for(i=0;i<times;i++){
    290       int test=oggpack_read(opb,16);
    291       if(test<0 || test>=VI_TIMEB)goto err_out;
    292     }
    293   }
    294 
    295   /* floor backend settings */
    296   ci->floors=oggpack_read(opb,6)+1;
    297   if(ci->floors<=0)goto err_out;
    298   for(i=0;i<ci->floors;i++){
    299     ci->floor_type[i]=oggpack_read(opb,16);
    300     if(ci->floor_type[i]<0 || ci->floor_type[i]>=VI_FLOORB)goto err_out;
    301     ci->floor_param[i]=_floor_P[ci->floor_type[i]]->unpack(vi,opb);
    302     if(!ci->floor_param[i])goto err_out;
    303   }
    304 
    305   /* residue backend settings */
    306   ci->residues=oggpack_read(opb,6)+1;
    307   if(ci->residues<=0)goto err_out;
    308   for(i=0;i<ci->residues;i++){
    309     ci->residue_type[i]=oggpack_read(opb,16);
    310     if(ci->residue_type[i]<0 || ci->residue_type[i]>=VI_RESB)goto err_out;
    311     ci->residue_param[i]=_residue_P[ci->residue_type[i]]->unpack(vi,opb);
    312     if(!ci->residue_param[i])goto err_out;
    313   }
    314 
    315   /* map backend settings */
    316   ci->maps=oggpack_read(opb,6)+1;
    317   if(ci->maps<=0)goto err_out;
    318   for(i=0;i<ci->maps;i++){
    319     ci->map_type[i]=oggpack_read(opb,16);
    320     if(ci->map_type[i]<0 || ci->map_type[i]>=VI_MAPB)goto err_out;
    321     ci->map_param[i]=_mapping_P[ci->map_type[i]]->unpack(vi,opb);
    322     if(!ci->map_param[i])goto err_out;
    323   }
    324 
    325   /* mode settings */
    326   ci->modes=oggpack_read(opb,6)+1;
    327   if(ci->modes<=0)goto err_out;
    328   for(i=0;i<ci->modes;i++){
    329     ci->mode_param[i]=_ogg_calloc(1,sizeof(*ci->mode_param[i]));
    330     ci->mode_param[i]->blockflag=oggpack_read(opb,1);
    331     ci->mode_param[i]->windowtype=oggpack_read(opb,16);
    332     ci->mode_param[i]->transformtype=oggpack_read(opb,16);
    333     ci->mode_param[i]->mapping=oggpack_read(opb,8);
    334 
    335     if(ci->mode_param[i]->windowtype>=VI_WINDOWB)goto err_out;
    336     if(ci->mode_param[i]->transformtype>=VI_WINDOWB)goto err_out;
    337     if(ci->mode_param[i]->mapping>=ci->maps)goto err_out;
    338     if(ci->mode_param[i]->mapping<0)goto err_out;
    339   }
    340 
    341   if(oggpack_read(opb,1)!=1)goto err_out; /* top level EOP check */
    342 
    343   return(0);
    344  err_out:
    345   vorbis_info_clear(vi);
    346   return(OV_EBADHEADER);
    347 }
    348 
    349 /* Is this packet a vorbis ID header? */
    350 int vorbis_synthesis_idheader(ogg_packet *op){
    351   oggpack_buffer opb;
    352   char buffer[6];
    353 
    354   if(op){
    355     oggpack_readinit(&opb,op->packet,op->bytes);
    356 
    357     if(!op->b_o_s)
    358       return(0); /* Not the initial packet */
    359 
    360     if(oggpack_read(&opb,8) != 1)
    361       return 0; /* not an ID header */
    362 
    363     memset(buffer,0,6);
    364     _v_readstring(&opb,buffer,6);
    365     if(memcmp(buffer,"vorbis",6))
    366       return 0; /* not vorbis */
    367 
    368     return 1;
    369   }
    370 
    371   return 0;
    372 }
    373 
    374 /* The Vorbis header is in three packets; the initial small packet in
    375    the first page that identifies basic parameters, a second packet
    376    with bitstream comments and a third packet that holds the
    377    codebook. */
    378 
    379 int vorbis_synthesis_headerin(vorbis_info *vi,vorbis_comment *vc,ogg_packet *op){
    380   oggpack_buffer opb;
    381 
    382   if(op){
    383     oggpack_readinit(&opb,op->packet,op->bytes);
    384 
    385     /* Which of the three types of header is this? */
    386     /* Also verify header-ness, vorbis */
    387     {
    388       char buffer[6];
    389       int packtype=oggpack_read(&opb,8);
    390       memset(buffer,0,6);
    391       _v_readstring(&opb,buffer,6);
    392       if(memcmp(buffer,"vorbis",6)){
    393         /* not a vorbis header */
    394         return(OV_ENOTVORBIS);
    395       }
    396       switch(packtype){
    397       case 0x01: /* least significant *bit* is read first */
    398         if(!op->b_o_s){
    399           /* Not the initial packet */
    400           return(OV_EBADHEADER);
    401         }
    402         if(vi->rate!=0){
    403           /* previously initialized info header */
    404           return(OV_EBADHEADER);
    405         }
    406 
    407         return(_vorbis_unpack_info(vi,&opb));
    408 
    409       case 0x03: /* least significant *bit* is read first */
    410         if(vi->rate==0){
    411           /* um... we didn't get the initial header */
    412           return(OV_EBADHEADER);
    413         }
    414 
    415         return(_vorbis_unpack_comment(vc,&opb));
    416 
    417       case 0x05: /* least significant *bit* is read first */
    418         if(vi->rate==0 || vc->vendor==NULL){
    419           /* um... we didn;t get the initial header or comments yet */
    420           return(OV_EBADHEADER);
    421         }
    422 
    423         return(_vorbis_unpack_books(vi,&opb));
    424 
    425       default:
    426         /* Not a valid vorbis header type */
    427         return(OV_EBADHEADER);
    428         break;
    429       }
    430     }
    431   }
    432   return(OV_EBADHEADER);
    433 }
    434 
    435 /* pack side **********************************************************/
    436 
    437 static int _vorbis_pack_info(oggpack_buffer *opb,vorbis_info *vi){
    438   codec_setup_info     *ci=vi->codec_setup;
    439   if(!ci)return(OV_EFAULT);
    440 
    441   /* preamble */
    442   oggpack_write(opb,0x01,8);
    443   _v_writestring(opb,"vorbis", 6);
    444 
    445   /* basic information about the stream */
    446   oggpack_write(opb,0x00,32);
    447   oggpack_write(opb,vi->channels,8);
    448   oggpack_write(opb,vi->rate,32);
    449 
    450   oggpack_write(opb,vi->bitrate_upper,32);
    451   oggpack_write(opb,vi->bitrate_nominal,32);
    452   oggpack_write(opb,vi->bitrate_lower,32);
    453 
    454   oggpack_write(opb,ilog2(ci->blocksizes[0]),4);
    455   oggpack_write(opb,ilog2(ci->blocksizes[1]),4);
    456   oggpack_write(opb,1,1);
    457 
    458   return(0);
    459 }
    460 
    461 static int _vorbis_pack_comment(oggpack_buffer *opb,vorbis_comment *vc){
    462   int bytes = strlen(ENCODE_VENDOR_STRING);
    463 
    464   /* preamble */
    465   oggpack_write(opb,0x03,8);
    466   _v_writestring(opb,"vorbis", 6);
    467 
    468   /* vendor */
    469   oggpack_write(opb,bytes,32);
    470   _v_writestring(opb,ENCODE_VENDOR_STRING, bytes);
    471 
    472   /* comments */
    473 
    474   oggpack_write(opb,vc->comments,32);
    475   if(vc->comments){
    476     int i;
    477     for(i=0;i<vc->comments;i++){
    478       if(vc->user_comments[i]){
    479         oggpack_write(opb,vc->comment_lengths[i],32);
    480         _v_writestring(opb,vc->user_comments[i], vc->comment_lengths[i]);
    481       }else{
    482         oggpack_write(opb,0,32);
    483       }
    484     }
    485   }
    486   oggpack_write(opb,1,1);
    487 
    488   return(0);
    489 }
    490 
    491 static int _vorbis_pack_books(oggpack_buffer *opb,vorbis_info *vi){
    492   codec_setup_info     *ci=vi->codec_setup;
    493   int i;
    494   if(!ci)return(OV_EFAULT);
    495 
    496   oggpack_write(opb,0x05,8);
    497   _v_writestring(opb,"vorbis", 6);
    498 
    499   /* books */
    500   oggpack_write(opb,ci->books-1,8);
    501   for(i=0;i<ci->books;i++)
    502     if(vorbis_staticbook_pack(ci->book_param[i],opb))goto err_out;
    503 
    504   /* times; hook placeholders */
    505   oggpack_write(opb,0,6);
    506   oggpack_write(opb,0,16);
    507 
    508   /* floors */
    509   oggpack_write(opb,ci->floors-1,6);
    510   for(i=0;i<ci->floors;i++){
    511     oggpack_write(opb,ci->floor_type[i],16);
    512     if(_floor_P[ci->floor_type[i]]->pack)
    513       _floor_P[ci->floor_type[i]]->pack(ci->floor_param[i],opb);
    514     else
    515       goto err_out;
    516   }
    517 
    518   /* residues */
    519   oggpack_write(opb,ci->residues-1,6);
    520   for(i=0;i<ci->residues;i++){
    521     oggpack_write(opb,ci->residue_type[i],16);
    522     _residue_P[ci->residue_type[i]]->pack(ci->residue_param[i],opb);
    523   }
    524 
    525   /* maps */
    526   oggpack_write(opb,ci->maps-1,6);
    527   for(i=0;i<ci->maps;i++){
    528     oggpack_write(opb,ci->map_type[i],16);
    529     _mapping_P[ci->map_type[i]]->pack(vi,ci->map_param[i],opb);
    530   }
    531 
    532   /* modes */
    533   oggpack_write(opb,ci->modes-1,6);
    534   for(i=0;i<ci->modes;i++){
    535     oggpack_write(opb,ci->mode_param[i]->blockflag,1);
    536     oggpack_write(opb,ci->mode_param[i]->windowtype,16);
    537     oggpack_write(opb,ci->mode_param[i]->transformtype,16);
    538     oggpack_write(opb,ci->mode_param[i]->mapping,8);
    539   }
    540   oggpack_write(opb,1,1);
    541 
    542   return(0);
    543 err_out:
    544   return(-1);
    545 }
    546 
    547 int vorbis_commentheader_out(vorbis_comment *vc,
    548                                           ogg_packet *op){
    549 
    550   oggpack_buffer opb;
    551 
    552   oggpack_writeinit(&opb);
    553   if(_vorbis_pack_comment(&opb,vc)) return OV_EIMPL;
    554 
    555   op->packet = _ogg_malloc(oggpack_bytes(&opb));
    556   memcpy(op->packet, opb.buffer, oggpack_bytes(&opb));
    557 
    558   op->bytes=oggpack_bytes(&opb);
    559   op->b_o_s=0;
    560   op->e_o_s=0;
    561   op->granulepos=0;
    562   op->packetno=1;
    563 
    564   return 0;
    565 }
    566 
    567 int vorbis_analysis_headerout(vorbis_dsp_state *v,
    568                               vorbis_comment *vc,
    569                               ogg_packet *op,
    570                               ogg_packet *op_comm,
    571                               ogg_packet *op_code){
    572   int ret=OV_EIMPL;
    573   vorbis_info *vi=v->vi;
    574   oggpack_buffer opb;
    575   private_state *b=v->backend_state;
    576 
    577   if(!b){
    578     ret=OV_EFAULT;
    579     goto err_out;
    580   }
    581 
    582   /* first header packet **********************************************/
    583 
    584   oggpack_writeinit(&opb);
    585   if(_vorbis_pack_info(&opb,vi))goto err_out;
    586 
    587   /* build the packet */
    588   if(b->header)_ogg_free(b->header);
    589   b->header=_ogg_malloc(oggpack_bytes(&opb));
    590   memcpy(b->header,opb.buffer,oggpack_bytes(&opb));
    591   op->packet=b->header;
    592   op->bytes=oggpack_bytes(&opb);
    593   op->b_o_s=1;
    594   op->e_o_s=0;
    595   op->granulepos=0;
    596   op->packetno=0;
    597 
    598   /* second header packet (comments) **********************************/
    599 
    600   oggpack_reset(&opb);
    601   if(_vorbis_pack_comment(&opb,vc))goto err_out;
    602 
    603   if(b->header1)_ogg_free(b->header1);
    604   b->header1=_ogg_malloc(oggpack_bytes(&opb));
    605   memcpy(b->header1,opb.buffer,oggpack_bytes(&opb));
    606   op_comm->packet=b->header1;
    607   op_comm->bytes=oggpack_bytes(&opb);
    608   op_comm->b_o_s=0;
    609   op_comm->e_o_s=0;
    610   op_comm->granulepos=0;
    611   op_comm->packetno=1;
    612 
    613   /* third header packet (modes/codebooks) ****************************/
    614 
    615   oggpack_reset(&opb);
    616   if(_vorbis_pack_books(&opb,vi))goto err_out;
    617 
    618   if(b->header2)_ogg_free(b->header2);
    619   b->header2=_ogg_malloc(oggpack_bytes(&opb));
    620   memcpy(b->header2,opb.buffer,oggpack_bytes(&opb));
    621   op_code->packet=b->header2;
    622   op_code->bytes=oggpack_bytes(&opb);
    623   op_code->b_o_s=0;
    624   op_code->e_o_s=0;
    625   op_code->granulepos=0;
    626   op_code->packetno=2;
    627 
    628   oggpack_writeclear(&opb);
    629   return(0);
    630  err_out:
    631   memset(op,0,sizeof(*op));
    632   memset(op_comm,0,sizeof(*op_comm));
    633   memset(op_code,0,sizeof(*op_code));
    634 
    635   if(b){
    636     oggpack_writeclear(&opb);
    637     if(b->header)_ogg_free(b->header);
    638     if(b->header1)_ogg_free(b->header1);
    639     if(b->header2)_ogg_free(b->header2);
    640     b->header=NULL;
    641     b->header1=NULL;
    642     b->header2=NULL;
    643   }
    644   return(ret);
    645 }
    646 
    647 double vorbis_granule_time(vorbis_dsp_state *v,ogg_int64_t granulepos){
    648   if(granulepos>=0)
    649     return((double)granulepos/v->vi->rate);
    650   return(-1);
    651 }
    652 
    653 const char *vorbis_version_string(void){
    654   return GENERAL_VENDOR_STRING;
    655 }
    656