ref: 3d78feffcbbc4b2977faf2526d9cc40f8aaca16a
dir: /src/info.c/
/********************************************************************
* *
* THIS FILE IS PART OF THE libopusfile 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 libopusfile SOURCE CODE IS (C) COPYRIGHT 2012 *
* by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
* *
********************************************************************/
#include "internal.h"
#include <limits.h>
#include <string.h>
static unsigned op_parse_uint16le(const unsigned char *_data){
return _data[0]|_data[1]<<8;
}
static int op_parse_int16le(const unsigned char *_data){
int ret;
ret=_data[0]|_data[1]<<8;
return (ret^0x8000)-0x8000;
}
static opus_uint32 op_parse_uint32le(const unsigned char *_data){
return _data[0]|_data[1]<<8|_data[2]<<16|_data[3]<<24;
}
int opus_head_parse(OpusHead *_head,const unsigned char *_data,size_t _len){
OpusHead head;
if(_len<8)return OP_ENOTFORMAT;
if(memcmp(_data,"OpusHead",8)!=0)return OP_ENOTFORMAT;
if(_len<9)return OP_EBADHEADER;
head.version=_data[8];
if(head.version>15)return OP_EVERSION;
if(_len<19)return OP_EBADHEADER;
head.channel_count=_data[9];
head.pre_skip=op_parse_uint16le(_data+10);
head.input_sample_rate=op_parse_uint32le(_data+12);
head.output_gain=op_parse_int16le(_data+16);
head.mapping_family=_data[18];
if(head.mapping_family==0){
if(head.channel_count<1||head.channel_count>2)return OP_EBADHEADER;
if(head.version<=1&&_len>19)return OP_EBADHEADER;
head.stream_count=1;
head.coupled_count=head.channel_count-1;
if(_head!=NULL){
_head->mapping[0]=0;
_head->mapping[1]=1;
}
}
else if(head.mapping_family==1){
size_t size;
int ci;
if(head.channel_count<1||head.channel_count>8)return OP_EBADHEADER;
size=21+head.channel_count;
if(_len<size||head.version<=1&&_len>size)return OP_EBADHEADER;
head.stream_count=_data[19];
if(head.stream_count<1)return OP_EBADHEADER;
head.coupled_count=_data[20];
if(head.coupled_count>head.stream_count)return OP_EBADHEADER;
for(ci=0;ci<head.channel_count;ci++){
if(_data[21+ci]>=head.stream_count+head.coupled_count
&&_data[21+ci]!=255){
return OP_EBADHEADER;
}
}
if(_head!=NULL)memcpy(_head->mapping,_data+21,head.channel_count);
}
/*General purpose players should not attempt to play back content with
channel mapping family 255.*/
else if(head.mapping_family==255)return OP_EIMPL;
/*No other channel mapping families are currently defined.*/
else return OP_EBADHEADER;
if(_head!=NULL)memcpy(_head,&head,head.mapping-(unsigned char *)&head);
return 0;
}
void opus_tags_init(OpusTags *_tags){
memset(_tags,0,sizeof(*_tags));
}
void opus_tags_clear(OpusTags *_tags){
int i;
for(i=_tags->comments;i-->0;)_ogg_free(_tags->user_comments[i]);
_ogg_free(_tags->user_comments);
_ogg_free(_tags->comment_lengths);
_ogg_free(_tags->vendor);
}
/*The actual implementation of opus_tags_parse().
Unlike the public API, this function requires _tags to already be
initialized, modifies its contents before success is guaranteed, and assumes
the caller will clear it on error.*/
int opus_tags_parse_impl(OpusTags *_tags,
const unsigned char *_data,size_t _len){
opus_uint32 count;
size_t size;
size_t len;
int ncomments;
int i;
len=_len;
if(len<8)return OP_ENOTFORMAT;
if(memcmp(_data,"OpusTags",8)!=0)return OP_ENOTFORMAT;
if(len<16)return OP_EBADHEADER;
_data+=8;
len-=8;
count=op_parse_uint32le(_data);
_data+=4;
len-=4;
if(count>len)return OP_EBADHEADER;
if(_tags!=NULL){
char *vendor;
size=count+1;
if(size<count)return OP_EFAULT;
vendor=(char *)_ogg_malloc(size);
if(vendor==NULL)return OP_EFAULT;
memcpy(vendor,_data,count);
vendor[count]='\0';
_tags->vendor=vendor;
}
_data+=count;
len-=count;
if(len<4)return OP_EBADHEADER;
count=op_parse_uint32le(_data);
_data+=4;
len-=4;
/*Check to make sure there's minimally sufficient data left in the packet.*/
if(count>len>>2)return OP_EBADHEADER;
/*Check for overflow (the API limits this to an int).*/
if(count>(opus_uint32)INT_MAX-1)return OP_EFAULT;
if(_tags!=NULL){
size=sizeof(*_tags->comment_lengths)*(count+1);
if(size/sizeof(*_tags->comment_lengths)!=count+1)return OP_EFAULT;
_tags->comment_lengths=(int *)_ogg_malloc(size);
size=sizeof(*_tags->user_comments)*(count+1);
if(size/sizeof(*_tags->user_comments)!=count+1)return OP_EFAULT;
_tags->user_comments=(char **)_ogg_malloc(size);
if(_tags->comment_lengths==NULL||_tags->user_comments==NULL){
return OP_EFAULT;
}
}
ncomments=(int)count;
for(i=0;i<ncomments;i++){
/*Check to make sure there's minimally sufficient data left in the packet.*/
if((size_t)(ncomments-i)>len>>2)return OP_EBADHEADER;
count=op_parse_uint32le(_data);
_data+=4;
len-=4;
if(count>len)return OP_EBADHEADER;
/*Check for overflow (the API limits this to an int).*/
if(count>(opus_uint32)INT_MAX)return OP_EFAULT;
if(_tags!=NULL){
_tags->comment_lengths[i]=(int)count;
size=count+1;
if(size<count)return OP_EFAULT;
_tags->user_comments[i]=(char *)_ogg_malloc(size);
if(_tags->user_comments[i]==NULL)return OP_EFAULT;
_tags->comments=i+1;
memcpy(_tags->user_comments[i],_data,count);
_tags->user_comments[i][count]='\0';
}
_data+=count;
len-=count;
}
if(_tags!=NULL){
_tags->user_comments[ncomments]=NULL;
_tags->comment_lengths[ncomments]=0;
}
return 0;
}
int opus_tags_parse(OpusTags *_tags,const unsigned char *_data,size_t _len){
if(_tags!=NULL){
OpusTags tags;
int ret;
opus_tags_init(&tags);
ret=opus_tags_parse_impl(&tags,_data,_len);
if(ret<0)opus_tags_clear(&tags);
else *_tags=*&tags;
return ret;
}
else return opus_tags_parse_impl(NULL,_data,_len);
}
/*Add room for a new comment.*/
static int op_tags_add_prepare(OpusTags *_tags){
char **user_comments;
int *comment_lengths;
int ncomments;
ncomments=_tags->comments;
user_comments=_ogg_realloc(_tags->user_comments,
sizeof(*_tags->user_comments)*(ncomments+2));
if(OP_UNLIKELY(user_comments==NULL))return OP_EFAULT;
_tags->user_comments=user_comments;
comment_lengths=_ogg_realloc(_tags->comment_lengths,
sizeof(*_tags->comment_lengths)*(ncomments+2));
if(OP_UNLIKELY(comment_lengths==NULL))return OP_EFAULT;
_tags->comment_lengths=comment_lengths;
comment_lengths[ncomments]=comment_lengths[ncomments+1]=0;
/*Our caller will always set user_comments[ncomments].*/
user_comments[ncomments+1]=NULL;
return 0;
}
int opus_tags_add(OpusTags *_tags,const char *_tag,const char *_value){
char *comment;
int tag_len;
int value_len;
int ncomments;
int ret;
ret=op_tags_add_prepare(_tags);
if(OP_UNLIKELY(ret<0))return ret;
tag_len=strlen(_tag);
value_len=strlen(_value);
ncomments=_tags->comments;
/*+2 for '=' and '\0'.*/
_tags->user_comments[ncomments]=comment=
(char *)_ogg_malloc(sizeof(*comment)*(tag_len+value_len+2));
if(OP_UNLIKELY(comment==NULL))return OP_EFAULT;
_tags->comment_lengths[ncomments]=tag_len+value_len+1;
memcpy(comment,_tag,sizeof(*comment)*tag_len);
comment[tag_len]='=';
memcpy(comment+tag_len+1,_value,sizeof(*comment)*(value_len+1));
return 0;
}
int opus_tags_add_comment(OpusTags *_tags,const char *_comment){
char *comment;
int ncomments;
int comment_len;
int ret;
ret=op_tags_add_prepare(_tags);
if(OP_UNLIKELY(ret<0))return ret;
comment_len=strlen(_comment);
ncomments=_tags->comments;
_tags->user_comments[ncomments]=comment=(char *)
_ogg_malloc(sizeof(*_tags->user_comments[ncomments])*(comment_len+1));
if(OP_UNLIKELY(comment==NULL))return OP_EFAULT;
_tags->comment_lengths[ncomments]=comment_len;
memcpy(comment,_comment,sizeof(*comment)*(comment_len+1));
return 0;
}
/*Is _a a "tag=value" comment whose tag matches _b?
0 if it is, a non-zero value otherwise.*/
static int op_tagcompare(const char *_a,const char *_b,int _n){
return op_strncasecmp(_a,_b,_n)||_a[_n]!='=';
}
const char *opus_tags_query(const OpusTags *_tags,const char *_tag,int _count){
char **user_comments;
int tag_len;
int found;
int ncomments;
int ci;
tag_len=strlen(_tag);
ncomments=_tags->comments;
user_comments=_tags->user_comments;
found=0;
for(ci=0;ci<ncomments;ci++){
if(!op_tagcompare(user_comments[ci],_tag,tag_len)){
/*We return a pointer to the data, not a copy.*/
if(_count==found++)return user_comments[ci]+tag_len+1;
}
}
/*Didn't find anything.*/
return NULL;
}
int opus_tags_query_count(const OpusTags *_tags,const char *_tag){
char **user_comments;
int tag_len;
int found;
int ncomments;
int ci;
tag_len=strlen(_tag);
ncomments=_tags->comments;
user_comments=_tags->user_comments;
found=0;
for(ci=0;ci<ncomments;ci++){
if(!op_tagcompare(user_comments[ci],_tag,tag_len))found++;
}
return found;
}