Hello,
Does FreePBX have support HD Voice?
If yes, how can i upload to FreePBX audio files with HD Voice quality?
Yes, it is a phone and carrier dependent codec called g722.
If everything supports it you can add it to the codec your phones and lines appropriately.
Ok, how can i upload to FreePBX audio files with HD Voice quality?
I would use rsync the files need to be g722 and have an extension .g722
If you have the file already, asterisk can do the conversion, but of course it only upconverts so doesn’t sound any better
http://fetzig.org/2010/07/24/converting-audio-files-to-g-722-for-use-with-asterisk/
has the necessary intermediate step if you have sox on your box.
It is possible in FreePBX to use sample rate >16kHz?
Or 16kHz is upper limit for any codec?