first, sorry to my English is poor..
I make call recorder with Galaxy S2 and S4 now. so i used Voice_downlink.
But it is not working.
I found that. but i can't find solution.
I find downlink is sometimes sealed by manufacturer because of hardware chipset.
if seal is true, i want to unseal by editing kernel source or S2 or etc...
my S2 is rooted.
please give me solution who knows. I'll very thanks to you and pleased.
Thanks to read my thread!