Server Setup - Audio Codecs
You can select default Start-up Codec settings. A codec is a device or software capable of encoding or decoding a digital data stream or signal ("coder-decoder"). However, the first remote user connecting to the audio server can choose his own codec settings if you allow by checking the Remote user may change Code checkbox. The second conneced remote user will have the same codec settings as the first connected remote user.
Two codecs can be used. The uncompressed PCM Codec (PCM = Pulse-code modulation) is a method used to digitally represent sampled analog signals. PCM streams have two basic properties that determine their fidelity to the original analog signal: the sampling rate, which is the number of times per second that samples are taken; and the bit depth, which determines the number of possible digital values that each sample can take. A sample rate of 8 kHz and bit depth of 8 or 16 bit are usually sufficient for a very high radio audio quality.
GSM 6.10 is a compressed mono channel codec with a very low transfer rate of about 1.6 kB/s at 8 kHz but the audio quality is much lower.
Note: GSM 6.10 with a sample rate of 22 kHz and PCM with 22 or 44.1 kHz might not necessarily be supported by your system and might not work.