Theorically it's not required at all. These lines "a=rtpmap" are just a textual description. The could appear or not, the only important line is "m=audio...".
Sure it is useless to delete it but i have to ;) Btw it is possible to add a line in the body ? i don't find any functions doing that in Textops. I need to manipulate SDP parameters.
Not sure if it's possible to delet a line. Perhaps you could play with the "s" flag (match newline don't treat it as end of line).
I tried to use "s" flag at the end of subst_body functions but doesn't change anything. I used also replace_body function but it is the same result as subst_body function.
Cheers,
Karhu