CounterPath Bria Android Tablet Edition 3.0 User Guide - Manual (Page 63)

Bria Android Tablet Edition User Guide
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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.
In general, it is desirable to have several codecs enabled. Make sure that there are common codecs between you
and the remote peer, otherwise your call will fail with a 488 error.
SILK-SuperWideband (24k) and Opus-Fullband (48k) are available only in devices with 1.2 GHz dual core
CPU or higher. These codecs will be disabled on any slower devices.
Novice and Non-technical Users
We recommend you use the default setting/priority 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.
You can prioritize codecs by tapping the Up or Down icon in the list. Codecs higher in the list are given a higher
priority in the offer, when negotiating codecs with the other party. Therefore, moving a codec higher should
improve its chances of being chosen.
G.722, AMR-WB, SILK-WB, SILK-SWB (24kHz), and Opus-Full HD (48kHz) 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.
AMR-WB, SILK and OPUS 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 mobile network for phone calls.