/src/tremor/info.c

Source (jump to first uncovered line)
/********************************************************************
 *                                                                  *
 * 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 <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 = 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 = 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 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=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=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=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=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=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;

  /* 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 */
  ci->times=oggpack_read(opb,6)+1;
  if(ci->times<=0)goto err_out;
  for(i=0;i<ci->times;i++){
    ci->time_type[i]=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=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]=(vorbis_info_mode *)_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);
}


Coverage Report

Created: 2025-07-11 06:15

Line	Count	Source (jump to first uncovered line)
1		/********************************************************************
2		* *
3		* THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. *
4		* *
5		* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
6		* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
7		* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
8		* *
9		* THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003 *
10		* BY THE Xiph.Org FOUNDATION http://www.xiph.org/ *
11		* *
12		********************************************************************
13
14		function: maintain the info structure, info <-> header packets
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 <limits.h>
25		#include <ogg/ogg.h>
26		#include "ivorbiscodec.h"
27		#include "codec_internal.h"
28		#include "codebook.h"
29		#include "registry.h"
30		#include "window.h"
31		#include "misc.h"
32
33		/* helpers */
34	40.9k	static void _v_readstring(oggpack_buffer o,char buf,int bytes){
35	274k	while(bytes--){
36	233k	*buf++=oggpack_read(o,8);
37	233k	}
38	40.9k	}
39
40	8.42k	void vorbis_comment_init(vorbis_comment *vc){
41	8.42k	memset(vc,0,sizeof(*vc));
42	8.42k	}
43
44		/* This is more or less the same as strncasecmp - but that doesn't exist
45		* everywhere, and this is a fairly trivial function, so we include it */
46	0	static int tagcompare(const char s1, const char s2, int n){
47	0	int c=0;
48	0	while(c < n){
49	0	if(toupper(s1[c]) != toupper(s2[c]))
50	0	return !0;
51	0	c++;
52	0	}
53	0	return 0;
54	0	}
55
56	0	char vorbis_comment_query(vorbis_comment vc, char *tag, int count){
57	0	long i;
58	0	int found = 0;
59	0	int taglen = strlen(tag)+1; /* +1 for the = we append */
60	0	char fulltag = (char )alloca(taglen+ 1);
61
62	0	strcpy(fulltag, tag);
63	0	strcat(fulltag, "=");
64
65	0	for(i=0;i<vc->comments;i++){
66	0	if(!tagcompare(vc->user_comments[i], fulltag, taglen)){
67	0	if(count == found)
68		/* We return a pointer to the data, not a copy */
69	0	return vc->user_comments[i] + taglen;
70	0	else
71	0	found++;
72	0	}
73	0	}
74	0	return NULL; /* didn't find anything */
75	0	}
76
77	0	int vorbis_comment_query_count(vorbis_comment vc, char tag){
78	0	int i,count=0;
79	0	int taglen = strlen(tag)+1; /* +1 for the = we append */
80	0	char fulltag = (char )alloca(taglen+1);
81	0	strcpy(fulltag,tag);
82	0	strcat(fulltag, "=");
83
84	0	for(i=0;i<vc->comments;i++){
85	0	if(!tagcompare(vc->user_comments[i], fulltag, taglen))
86	0	count++;
87	0	}
88
89	0	return count;
90	0	}
91
92	10.9k	void vorbis_comment_clear(vorbis_comment *vc){
93	10.9k	if(vc){
94	10.9k	long i;
95	10.9k	if(vc->user_comments){
96	9.54k	for(i=0;i<vc->comments;i++)
97	2.10k	if(vc->user_comments[i])_ogg_free(vc->user_comments[i]);
98	7.44k	_ogg_free(vc->user_comments);
99	7.44k	}
100	10.9k	if(vc->comment_lengths)_ogg_free(vc->comment_lengths);
101	10.9k	if(vc->vendor)_ogg_free(vc->vendor);
102	10.9k	memset(vc,0,sizeof(*vc));
103	10.9k	}
104	10.9k	}
105
106		/* blocksize 0 is guaranteed to be short, 1 is guarantted to be long.
107		They may be equal, but short will never ge greater than long */
108	0	int vorbis_info_blocksize(vorbis_info *vi,int zo){
109	0	codec_setup_info ci = (codec_setup_info )vi->codec_setup;
110	0	return ci ? ci->blocksizes[zo] : -1;
111	0	}
112
113		/* used by synthesis, which has a full, alloced vi */
114	8.42k	void vorbis_info_init(vorbis_info *vi){
115	8.42k	memset(vi,0,sizeof(*vi));
116	8.42k	vi->codec_setup=(codec_setup_info *)_ogg_calloc(1,sizeof(codec_setup_info));
117	8.42k	}
118
119	11.6k	void vorbis_info_clear(vorbis_info *vi){
120	11.6k	codec_setup_info ci=(codec_setup_info )vi->codec_setup;
121	11.6k	int i;
122
123	11.6k	if(ci){
124
125	17.6k	for(i=0;i<ci->modes;i++)
126	9.24k	if(ci->mode_param[i])_ogg_free(ci->mode_param[i]);
127
128	16.5k	for(i=0;i<ci->maps;i++) /* unpack does the range checking */
129	8.11k	if(ci->map_param[i])
130	6.71k	_mapping_P[ci->map_type[i]]->free_info(ci->map_param[i]);
131
132	18.3k	for(i=0;i<ci->floors;i++) /* unpack does the range checking */
133	9.90k	if(ci->floor_param[i])
134	6.82k	_floor_P[ci->floor_type[i]]->free_info(ci->floor_param[i]);
135
136	17.7k	for(i=0;i<ci->residues;i++) /* unpack does the range checking */
137	9.32k	if(ci->residue_param[i])
138	7.79k	_residue_P[ci->residue_type[i]]->free_info(ci->residue_param[i]);
139
140	63.5k	for(i=0;i<ci->books;i++){
141	55.0k	if(ci->book_param[i]){
142		/* knows if the book was not alloced */
143	1.78k	vorbis_staticbook_destroy(ci->book_param[i]);
144	1.78k	}
145	55.0k	if(ci->fullbooks)
146	10.5k	vorbis_book_clear(ci->fullbooks+i);
147	55.0k	}
148	8.42k	if(ci->fullbooks)
149	6.32k	_ogg_free(ci->fullbooks);
150
151	8.42k	_ogg_free(ci);
152	8.42k	}
153
154	11.6k	memset(vi,0,sizeof(*vi));
155	11.6k	}
156
157		/* Header packing/unpacking ********************************************/
158
159	8.05k	static int _vorbis_unpack_info(vorbis_info vi,oggpack_buffer opb){
160	8.05k	codec_setup_info ci=(codec_setup_info )vi->codec_setup;
161	8.05k	if(!ci)return(OV_EFAULT);
162
163	8.05k	vi->version=oggpack_read(opb,32);
164	8.05k	if(vi->version!=0)return(OV_EVERSION);
165
166	8.00k	vi->channels=oggpack_read(opb,8);
167	8.00k	vi->rate=oggpack_read(opb,32);
168
169	8.00k	vi->bitrate_upper=oggpack_read(opb,32);
170	8.00k	vi->bitrate_nominal=oggpack_read(opb,32);
171	8.00k	vi->bitrate_lower=oggpack_read(opb,32);
172
173	8.00k	ci->blocksizes[0]=1<<oggpack_read(opb,4);
174	8.00k	ci->blocksizes[1]=1<<oggpack_read(opb,4);
175
176	8.00k	if(vi->rate<1)goto err_out;
177	8.00k	if(vi->channels<1)goto err_out;
178	7.99k	if(ci->blocksizes[0]<64)goto err_out;
179	7.96k	if(ci->blocksizes[1]<ci->blocksizes[0])goto err_out;
180	7.95k	if(ci->blocksizes[1]>8192)goto err_out;
181
182	7.94k	if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */
183
184	7.94k	return(0);
185	64	err_out:
186	64	vorbis_info_clear(vi);
187	64	return(OV_EBADHEADER);
188	7.94k	}
189
190	7.62k	static int _vorbis_unpack_comment(vorbis_comment vc,oggpack_buffer opb){
191	7.62k	int i;
192	7.62k	int vendorlen;
193	7.62k	vendorlen=oggpack_read(opb,32);
194	7.62k	if(vendorlen<0)goto err_out;
195	7.58k	if(vendorlen>opb->storage-oggpack_bytes(opb))goto err_out;
196	7.54k	vc->vendor=(char *)_ogg_calloc(vendorlen+1,1);
197	7.54k	if(vc->vendor==NULL)goto err_out;
198	7.54k	_v_readstring(opb,vc->vendor,vendorlen);
199	7.54k	i=oggpack_read(opb,32);
200	7.54k	if(i<0\|\|i>=INT_MAX\|\|i>(opb->storage-oggpack_bytes(opb))>>2)goto err_out;
201	7.44k	vc->user_comments=(char *)_ogg_calloc(i+1,sizeof(vc->user_comments));
202	7.44k	vc->comment_lengths=(int )_ogg_calloc(i+1, sizeof(vc->comment_lengths));
203	7.44k	if(vc->user_comments==NULL\|\|vc->comment_lengths==NULL)goto err_out;
204	7.44k	vc->comments=i;
205
206	8.92k	for(i=0;i<vc->comments;i++){
207	1.59k	int len=oggpack_read(opb,32);
208	1.59k	if(len<0\|\|len>opb->storage-oggpack_bytes(opb))goto err_out;
209	1.48k	vc->comment_lengths[i]=len;
210	1.48k	vc->user_comments[i]=(char *)_ogg_calloc(len+1,1);
211	1.48k	if(vc->user_comments[i]==NULL){
212	0	vc->comments=i;
213	0	goto err_out;
214	0	}
215	1.48k	_v_readstring(opb,vc->user_comments[i],len);
216	1.48k	}
217	7.33k	if(oggpack_read(opb,1)!=1)goto err_out; /* EOP check */
218
219	7.32k	return(0);
220	305	err_out:
221	305	vorbis_comment_clear(vc);
222	305	return(OV_EBADHEADER);
223	7.33k	}
224
225		/* all of the real encoding details are here. The modes, books,
226		everything */
227	7.29k	static int _vorbis_unpack_books(vorbis_info vi,oggpack_buffer opb){
228	7.29k	codec_setup_info ci=(codec_setup_info )vi->codec_setup;
229	7.29k	int i;
230
231		/* codebooks */
232	7.29k	ci->books=oggpack_read(opb,8)+1;
233	7.29k	if(ci->books<=0)goto err_out;
234	19.6k	for(i=0;i<ci->books;i++){
235	12.7k	ci->book_param[i]=vorbis_staticbook_unpack(opb);
236	12.7k	if(!ci->book_param[i])goto err_out;
237	12.7k	}
238
239		/* time backend settings */
240	6.93k	ci->times=oggpack_read(opb,6)+1;
241	6.93k	if(ci->times<=0)goto err_out;
242	13.8k	for(i=0;i<ci->times;i++){
243	7.00k	ci->time_type[i]=oggpack_read(opb,16);
244	7.00k	if(ci->time_type[i]<0 \|\| ci->time_type[i]>=VI_TIMEB)goto err_out;
245		/* ci->time_param[i]=_time_P[ci->time_type[i]]->unpack(vi,opb);
246		Vorbis I has no time backend */
247		/if(!ci->time_param[i])goto err_out;/
248	7.00k	}
249
250		/* floor backend settings */
251	6.86k	ci->floors=oggpack_read(opb,6)+1;
252	6.86k	if(ci->floors<=0)goto err_out;
253	13.6k	for(i=0;i<ci->floors;i++){
254	7.02k	ci->floor_type[i]=oggpack_read(opb,16);
255	7.02k	if(ci->floor_type[i]<0 \|\| ci->floor_type[i]>=VI_FLOORB)goto err_out;
256	6.98k	ci->floor_param[i]=_floor_P[ci->floor_type[i]]->unpack(vi,opb);
257	6.98k	if(!ci->floor_param[i])goto err_out;
258	6.98k	}
259
260		/* residue backend settings */
261	6.66k	ci->residues=oggpack_read(opb,6)+1;
262	6.66k	if(ci->residues<=0)goto err_out;
263	14.4k	for(i=0;i<ci->residues;i++){
264	7.92k	ci->residue_type[i]=oggpack_read(opb,16);
265	7.92k	if(ci->residue_type[i]<0 \|\| ci->residue_type[i]>=VI_RESB)goto err_out;
266	7.88k	ci->residue_param[i]=_residue_P[ci->residue_type[i]]->unpack(vi,opb);
267	7.88k	if(!ci->residue_param[i])goto err_out;
268	7.88k	}
269
270		/* map backend settings */
271	6.52k	ci->maps=oggpack_read(opb,6)+1;
272	6.52k	if(ci->maps<=0)goto err_out;
273	13.2k	for(i=0;i<ci->maps;i++){
274	6.85k	ci->map_type[i]=oggpack_read(opb,16);
275	6.85k	if(ci->map_type[i]<0 \|\| ci->map_type[i]>=VI_MAPB)goto err_out;
276	6.82k	ci->map_param[i]=_mapping_P[ci->map_type[i]]->unpack(vi,opb);
277	6.82k	if(!ci->map_param[i])goto err_out;
278	6.82k	}
279
280		/* mode settings */
281	6.37k	ci->modes=oggpack_read(opb,6)+1;
282	6.37k	if(ci->modes<=0)goto err_out;
283	14.9k	for(i=0;i<ci->modes;i++){
284	8.58k	ci->mode_param[i]=(vorbis_info_mode )_ogg_calloc(1,sizeof(ci->mode_param[i]));
285	8.58k	ci->mode_param[i]->blockflag=oggpack_read(opb,1);
286	8.58k	ci->mode_param[i]->windowtype=oggpack_read(opb,16);
287	8.58k	ci->mode_param[i]->transformtype=oggpack_read(opb,16);
288	8.58k	ci->mode_param[i]->mapping=oggpack_read(opb,8);
289
290	8.58k	if(ci->mode_param[i]->windowtype>=VI_WINDOWB)goto err_out;
291	8.57k	if(ci->mode_param[i]->transformtype>=VI_WINDOWB)goto err_out;
292	8.56k	if(ci->mode_param[i]->mapping>=ci->maps)goto err_out;
293	8.55k	if(ci->mode_param[i]->mapping<0)goto err_out;
294	8.55k	}
295
296	6.33k	if(oggpack_read(opb,1)!=1)goto err_out; /* top level EOP check */
297
298	6.32k	return(0);
299	970	err_out:
300	970	vorbis_info_clear(vi);
301	970	return(OV_EBADHEADER);
302	6.33k	}
303
304		/* Is this packet a vorbis ID header? */
305	10.1k	int vorbis_synthesis_idheader(ogg_packet *op){
306	10.1k	oggpack_buffer opb;
307	10.1k	char buffer[6];
308
309	10.1k	if(op){
310	10.1k	oggpack_readinit(&opb,op->packet,op->bytes);
311
312	10.1k	if(!op->b_o_s)
313	272	return(0); /* Not the initial packet */
314
315	9.89k	if(oggpack_read(&opb,8) != 1)
316	1.04k	return 0; /* not an ID header */
317
318	8.84k	memset(buffer,0,6);
319	8.84k	_v_readstring(&opb,buffer,6);
320	8.84k	if(memcmp(buffer,"vorbis",6))
321	791	return 0; /* not vorbis */
322
323	8.05k	return 1;
324	8.84k	}
325
326	0	return 0;
327	10.1k	}
328
329		/* The Vorbis header is in three packets; the initial small packet in
330		the first page that identifies basic parameters, a second packet
331		with bitstream comments and a third packet that holds the
332		codebook. */
333
334	23.0k	int vorbis_synthesis_headerin(vorbis_info vi,vorbis_comment vc,ogg_packet *op){
335	23.0k	oggpack_buffer opb;
336
337	23.0k	if(op){
338	23.0k	oggpack_readinit(&opb,op->packet,op->bytes);
339
340		/* Which of the three types of header is this? */
341		/* Also verify header-ness, vorbis */
342	23.0k	{
343	23.0k	char buffer[6];
344	23.0k	int packtype=oggpack_read(&opb,8);
345	23.0k	memset(buffer,0,6);
346	23.0k	_v_readstring(&opb,buffer,6);
347	23.0k	if(memcmp(buffer,"vorbis",6)){
348		/* not a vorbis header */
349	35	return(OV_ENOTVORBIS);
350	35	}
351	23.0k	switch(packtype){
352	8.07k	case 0x01: /* least significant bit is read first */
353	8.07k	if(!op->b_o_s){
354		/* Not the initial packet */
355	1	return(OV_EBADHEADER);
356	1	}
357	8.07k	if(vi->rate!=0){
358		/* previously initialized info header */
359	23	return(OV_EBADHEADER);
360	23	}
361
362	8.05k	return(_vorbis_unpack_info(vi,&opb));
363
364	7.62k	case 0x03: /* least significant bit is read first */
365	7.62k	if(vi->rate==0){
366		/* um... we didn't get the initial header */
367	0	return(OV_EBADHEADER);
368	0	}
369	7.62k	if(vc->vendor!=NULL){
370		/* previously initialized comment header */
371	1	return(OV_EBADHEADER);
372	1	}
373
374	7.62k	return(_vorbis_unpack_comment(vc,&opb));
375
376	7.32k	case 0x05: /* least significant bit is read first */
377	7.32k	if(vi->rate==0 \|\| vc->vendor==NULL){
378		/* um... we didn;t get the initial header or comments yet */
379	26	return(OV_EBADHEADER);
380	26	}
381	7.29k	if(vi->codec_setup==NULL){
382		/* improperly initialized vorbis_info */
383	0	return(OV_EFAULT);
384	0	}
385	7.29k	if(((codec_setup_info *)vi->codec_setup)->books>0){
386		/* previously initialized setup header */
387	0	return(OV_EBADHEADER);
388	0	}
389
390	7.29k	return(_vorbis_unpack_books(vi,&opb));
391
392	2	default:
393		/* Not a valid vorbis header type */
394	2	return(OV_EBADHEADER);
395	0	break;
396	23.0k	}
397	23.0k	}
398	23.0k	}
399	0	return(OV_EBADHEADER);
400	23.0k	}
401