The
VoiceAge Open AMR Implementation
This free offer is a single-port, Win32 implementation
that allows for experimentation with the AMR
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 right
by licensing the intellectual property. An indemnified
Win32 version — and other implementations —
are available through sales@voiceage.com.
For information
on how to license AMR intellectual property,
see Licensing
AMR.
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
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
The AMR (Adaptive Multi-Rate) standard is a
speech coding algorithm that operates at variable
bit rates in the range of 4.75 to 12.2 Kbps
in its narrowband configuration. This technology
was initially developed for the GSM system,
the single most deployed 2G mobile telecommunication
system worldwide, used mostly in Europe and
Asia. It was later adapted by the 3GPP as the
mandatory codec for 3G wireless systems based
on the evolved GSM core network (WCDMA, EDGE,
GPRS). The AMR narrowband codec was standardized
by the European Telecommunications Standards
Institute (ETSI) in 1999.
AMR is the only
narrowband speech codec offering eight different
bit rates that can be adapted according to network
congestion, thus enabling significant enhancement
of QoS. The codec also provides these advantages:
- Voice Activity Detector
(VAD)
- Comfort Noise Generation
(CNG)
- Discontinuous Transmission
(DTX)
- Proven speech coding technology
tested in various operating conditions in
the selection and characterization phases
of ETSI and 3GPP standardization
- Bridge between packet network
and wireless applications, eliminating the
need for transcoding and its associated
quality degradation
For more information
about AMR, see our Technologies
section.
