CounterPath Bria Android Edition 1.1.9 User Guide - Manual (Page 34)

CounterPath Corporation
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Audio Codecs Selection
Codecs are programs in Bria involved in transmitting audio; each codec has different characteristics and
therefore each works better in some situations than in others.
Novice and Non-technical Users
We recommend you enable all codecs and let Bria select the best codec to use in a given situation.
Technically Savvy Users
You may choose to enable one, some or all codecs. If only one codec is enabled, all calls will be made with that
codec. If more than one is enabled, Bria negotiates the codec to use (from among the enabled codecs) with the
other person. If no codecs are enabled, Bria uses G.711u.
G.722 and SILK-HD are wideband codecs. All other codecs are narrowband. When a wideband codec is used,
data usage will be higher and audio quality will generally be better. When a narrowband codec is used, data
usage may be lower but audio quality may be affected.
Data usage for the codecs with a fixed bit rate, from high to low usage, is: G.722, G.711, iLBC, GSM, G.729a.
SILK-HD and SILK-NB have a variable bit rate; the data usage will fluctuate depending on the network
conditions. The optional G.729a codec will provide you the best performance (audio quality and bandwidth
usage/cost) when using cellular (3G) for phone calls.
If you turn on the Higher Priority field, then when a narrowband codec is available, it will be given a higher
priority in the media negotiation with the other person, which may result in that codec being used. If you leave
this field off, a narrowband codec will not be given a higher priority in the negotiation.