In MP3 stereo processing,"is_ratio" value is calculated by the following equation
is_ratio = tan((double)is_pos * (PI / 12));
And it is used as
1/1+is_ratio and is_ratio/1+is_ratio.
Is there a case where is_ration becomes -1 and the second equation becomes infinity?
Is is guarenteed that is_pos will never have a value which makes the tan value -1?
Can some one please give some insight and thanks in advance.
Tony