I have an international i9505, rooted, but my s4 seems to be affected with some kind of mic defect that makes one of the audio channels present a lot of pops and cracking sounds. This seems to be a hardware issue that affects some s4,specially the first ones sold in Europe.
The best workaround I found so far is to record stereo and discard the audio from the defective channel afterwards, in a painful process that includes transferring the files to a pc for processing...
I found some 3rd party camera apps that have this option (mono audio ), like "camera jb+" and "snap camera hdr". I bought both, but they generate 15fps files that are much worse than the 30fps files from the s4 default camera app.
So.. What I am wondering is if I could somehow change the way the camera app records audio (maybe changing some xml,... I don't know).
Or... Maybe someone could point me some nice 3rd party app that could solve my issue.