CounterPath Bria iPhone Edition 2.5 User Guide - Manual (Page 63)

Bria iPhone Edition User Guide
59
Audio Codecs Selection
Mobile Audio Codecs Wi-Fi Audio Codecs
These two screens list the audio codecs that can be used during a Wi-Fi call or mobile data call. 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 iPhone 4S/iPod 5th generation, and
newer 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.
You can prioritize codecs by dragging them up or down 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 (16kHz), 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.
You can only enable these codecs
if you have purchased them; see
page 61.
Drag the codec up or down to
change its priority in the list. See
below.