The
VoiceAge AMR-WB Implementation
This free offer is a single-port, Win32 implementation
that allows for experimentation with the AMR-WB
standard. You can take it from one desktop computer
to another without constraints. It is important
to note that this version is not indemnified,
which means that this code can not be used for
commercial purposes — it is restricted to research
and prototype development. If commercial deployment
is planned, you must obtain the legal rights
through licensing (see the link on the left).
An indemnified Win32 version — and other implementations
— are available through sales@voiceage.com.
For information on how to license
AMR-WB intellectual property, see Licensing
AMR-WB.
Please note that this free
codec implementation is provided to you for
integration into your respective product solutions
under the terms of the End-User Licensing
Agreement specified during their download
process. Consequently, you are responsible
for obtaining the appropriate intellectual
property rights for this technology corresponding
to your target application. Please contact
VoiceAge
Corporation, the authorized Intellectual
Property Licensing Administrator, for AMR
technology for additional information.
This VoiceAge AMR-WB implementation
is a derivative work that exists in the form
of object code: a set of native computer instructions
readily executable by a specific processor.
The effort required to create the implementation
involved a combination of manual and automatic
translation of reference source code into
highly optimized native code.
About AMR-WB
The adoption of AMR-WB by ETSI/3GPP and ITU-T
(where it is referred to as G.722.2) is of significant
importance because, for the first time, the
same codec has been adopted for wireless as
well as wireline services. This eliminates the
need for transcoding and facilitates the implementation
of wideband voice applications and services
across a wide range of communication systems
and platforms.
Wideband speech
coding results in major subjective improvements
in speech quality. Compared to narrowband telephone
speech (limited to about 200-3400 Hz and sampled
at a rate of 8 kHz), low-frequency enhancement
in AMR-WB from 50 to 200 Hz contributes to increased
naturalness, presence, and comfort. The high-frequency
extension from 3400 to 7000 Hz provides better
fricative differentiation (for example, between
words like fin and thin), and therefore higher
intelligibility. Not only does AMR-WB provide
superior voice quality over the existing narrowband
standards, but it is also very robust against
transmission errors due to multi-rate operation
and adaptation.
The AMR-WB standard
is the only wideband technology offering a comprehensive
range of built-in features. In addition to the
codec, the package comprises VAD, CNG, DTX,
payload and storage formats, and hooks to media
file formats.
For more information
about AMR-WB, see our Technologies
section.
