int opus_tags_get_track_gain(const OpusTags *_tags,int *_gain_q8){
char **comments;
int *comment_lengths;
int ncomments;
int ci;
comments=_tags->user_comments;
comment_lengths=_tags->comment_lengths;
ncomments=_tags->comments;
/*Look for the first valid R128_TRACK_GAIN tag and use that.*/
for(ci=0;ci<ncomments;ci++){
if(comment_lengths[ci]>16
&&op_strncasecmp(comments[ci],"R128_TRACK_GAIN=",16)==0){
char *p;
opus_int32 gain_q8;
int negative;
p=comments[ci]+16;
negative=0;
if(*p=='-'){
negative=-1;
p++;
}
else if(*p=='+')p++;
gain_q8=0;
while(*p>='0'&&*p<='9'){
gain_q8=10*gain_q8+*p-'0';
if(gain_q8>32767-negative)break;
p++;
}
/*This didn't look like a signed 16-bit decimal integer.
Not a valid R128_TRACK_GAIN tag.*/
if(*p!='\0')continue;
*_gain_q8=(int)(gain_q8+negative^negative);
return 0;
}
}
return OP_FALSE;
}
/*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]!='=';
}
int opus_tagncompare(const char *_tag_name,int _tag_len,const char *_comment){
int ret;
OP_ASSERT(_tag_len>=0);
ret=op_strncasecmp(_tag_name,_comment,_tag_len);
return ret?ret:'='-_comment[_tag_len];
}
