text: /********************************************************************
   *                                                                  *
   * 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: 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 <limits.h>
  #include <yip-imports/ogg/ogg.h>
  #include "ivorbiscodec.h"
  #include "codec_internal.h"
  #include "codebook.h"
  #include "registry.h"
  #include "window.h"
  #include "misc.h"
  
  /* helpers */
  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));
  }
  
  /* 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;
  }
  
  char *vorbis_comment_query(vorbis_comment *vc, char *tag, int count){
    long i;
    int found = 0;
    int taglen = (int)strlen(tag)+1; /* +1 for the = we append */
    char *fulltag = (char *)alloca(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 */
        	return vc->user_comments[i] + taglen;
        else
  	found++;
      }
    }
    return NULL; /* didn't find anything */
  }
  
  int vorbis_comment_query_count(vorbis_comment *vc, char *tag){
    int i,count=0;
    int taglen = (int)strlen(tag)+1; /* +1 for the = we append */
    char *fulltag = (char *)alloca(taglen+1);
    strcpy(fulltag,tag);
    strcat(fulltag, "=");
  
    for(i=0;i<vc->comments;i++){
      if(!tagcompare(vc->user_comments[i], fulltag, taglen))
        count++;
    }
  
    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 guarantted 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 = (codec_setup_info *)vi->codec_setup;
    return (int)(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=(codec_setup_info *)_ogg_calloc(1,sizeof(codec_setup_info));
  }
  
  void vorbis_info_clear(vorbis_info *vi){
    codec_setup_info     *ci=(codec_setup_info *)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])
  	_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])
  	_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])
  	_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);
      
      _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=(codec_setup_info *)vi->codec_setup;
    if(!ci)return(OV_EFAULT);
  
    vi->version=(int)oggpack_read(opb,32);
    if(vi->version!=0)return(OV_EVERSION);
  
    vi->channels=(int)oggpack_read(opb,8);
    vi->rate=oggpack_read(opb,32);
  
    vi->bitrate_upper=oggpack_read(opb,32);
    vi->bitrate_nominal=oggpack_read(opb,32);
    vi->bitrate_lower=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;
    vendorlen=(int)oggpack_read(opb,32);
    if(vendorlen<0)goto err_out;
    if(vendorlen>opb->storage-oggpack_bytes(opb))goto err_out;
    vc->vendor=(char *)_ogg_calloc(vendorlen+1,1);
    if(vc->vendor==NULL)goto err_out;
    _v_readstring(opb,vc->vendor,vendorlen);
    i=(int)oggpack_read(opb,32);
    if(i<0||i>=INT_MAX||i>(opb->storage-oggpack_bytes(opb))>>2)goto err_out;
    vc->user_comments=(char **)_ogg_calloc(i+1,sizeof(*vc->user_comments));
    vc->comment_lengths=(int *)_ogg_calloc(i+1, sizeof(*vc->comment_lengths));
    if(vc->user_comments==NULL||vc->comment_lengths==NULL)goto err_out;
    vc->comments=i;
  
    for(i=0;i<vc->comments;i++){
      int len=(int)oggpack_read(opb,32);
      if(len<0||len>opb->storage-oggpack_bytes(opb))goto err_out;
      vc->comment_lengths[i]=len;
      vc->user_comments[i]=(char *)_ogg_calloc(len+1,1);
      if(vc->user_comments[i]==NULL){
        vc->comments=i;
        goto err_out;
      }
      _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=(codec_setup_info *)vi->codec_setup;
    int i;
    if(!ci)return(OV_EFAULT);
  
    /* codebooks */
    ci->books=(int)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 */
    ci->times=(int)oggpack_read(opb,6)+1;
    if(ci->times<=0)goto err_out;
    for(i=0;i<ci->times;i++){
      ci->time_type[i]=(int)oggpack_read(opb,16);
      if(ci->time_type[i]<0 || ci->time_type[i]>=VI_TIMEB)goto err_out;
      /* ci->time_param[i]=_time_P[ci->time_type[i]]->unpack(vi,opb);
         Vorbis I has no time backend */
      /*if(!ci->time_param[i])goto err_out;*/
    }
  
    /* floor backend settings */
    ci->floors=(int)oggpack_read(opb,6)+1;
    if(ci->floors<=0)goto err_out;
    for(i=0;i<ci->floors;i++){
      ci->floor_type[i]=(int)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=(int)oggpack_read(opb,6)+1;
    if(ci->residues<=0)goto err_out;
    for(i=0;i<ci->residues;i++){
      ci->residue_type[i]=(int)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=(int)oggpack_read(opb,6)+1;
    if(ci->maps<=0)goto err_out;
    for(i=0;i<ci->maps;i++){
      ci->map_type[i]=(int)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=(int)oggpack_read(opb,6)+1;
    if(ci->modes<=0)goto err_out;
    for(i=0;i<ci->modes;i++){
      ci->mode_param[i]=(vorbis_info_mode *)_ogg_calloc(1,sizeof(*ci->mode_param[i]));
      ci->mode_param[i]->blockflag=(int)oggpack_read(opb,1);
      ci->mode_param[i]->windowtype=(int)oggpack_read(opb,16);
      ci->mode_param[i]->transformtype=(int)oggpack_read(opb,16);
      ci->mode_param[i]->mapping=(int)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,(int)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,(int)op->bytes);
  
      /* Which of the three types of header is this? */
      /* Also verify header-ness, vorbis */
      {
        char buffer[6];
        int packtype=(int)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);
  	}
  
  	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);
  	}
  
  	return(_vorbis_unpack_books(vi,&opb));
  
        default:
  	/* Not a valid vorbis header type */
  	return(OV_EBADHEADER);
  	break;
        }
      }
    }
    return(OV_EBADHEADER);
  }
  
  