TestingTask Force T021:
Characterization of the New ETSI speech codec on subjective
Test data bases - CNET step 2
Who we are:
STF
Leader:
Joachim
Pomy, Focus Infocom Gesellschaft für
Informatik und Telekommunikation mbH, consultant@joachimpomy.de
STF Experts: Jan
Holub,
Mesaqin.com s.r.o (Ltd.), jan.holub@mesaqin.com
Markus Schnell, Fraunhofer Institut für Integrierte
Schaltungen IIS,
markus.schnell@iis.fraunhofer.de
Maximilian Schlegel, Fraunhofer Institut für Integrierte
Schaltungen IIS,
maximilian.schlegel@iis.fraunhofer.de
What we do
There
are two more topics which had not
been included in TTF T005, because they could only be initiated
after it was
confirmed by TTF T005 that the New ETSI Speech Codec (LC3plus)
fulfils the
requirements set out in TS 103 624. This has now been confirmed by
the
subjective tests conducted by the TTF T005 team.
Therefore,
the proposed activity under
this new TTF consists of the following two topics, which are
required in
context of the New ETSI Speech Codec:
1)
According to TS 103 624
clause 5.5,
the subjective tests shall be followed by a verification with the
objective
method ITU-T P.863.
NOTE: At the time when TS 103
624 was
drafted, there was the expectation that these tests would be
provided by a
specific STQ member at no extra cost. However, that company is no
longer a
member of ETSI and will not provide these tests.
2)
For the purpose of
inclusion of the
New ETSI Speech Codec in transmission planning, ITU-T SG12 is
requesting ETSI
to provide information on the so-called Equipment Impairment
factor(s) (
abbreviation: Ie)
of the New ETSI Speech
Codec for future inclusion in ITU-T G.113.
Ie
-Factors are a characterization of the impact of speech codecs on
the perceived
quality on a psychological scale; their values are available for all
codecs
which are of relevance in modern networks and terminals.
In order to fully establish the New ETSI Speech Codec
internationally, the
knowledge about the
Ie -Factors is required and it
would be
highly promotional for ETSI to provide the international community
with the
Equipment Impairment Factors for transmission planning for the New
ETSI Speech
Codec for all three instances of the Transmission Planning with the
E-model,
namely narrowband (NB), wideband (WB) and fullband (FB).
In order to provide the values for FB, a new methodology will have
to be
established; this can be done based on existing work in the field,
like (1) ,
(2), (3) or (4)
[1] where
the Ie factor
has been derived for the OPUS codec
[2].
Objectives
of the
work to be executed
1)
Objective assessment of the
subjective test result already produced by TTF T005.
This cross check shall verify that the test results on the New ETSI
Speech
Codec (LC3plus) show no statistically significant differences
between
subjective or objective assessment.
2)
Determination of the
Equipment
Impairment Factors for the different bandwidth modes of the codec.
2a)
Test plan definition:
As the exact procedure for FB Ie is currently not standardized, it
is necessary
to design and agree upon the complete test procedure. Also test
plans for the
determination of NB and WB Ie are to be compiled based on ITU-T
P.833, P.833.1
P.834 and P.834.1.
2b)
Preparation
of
test material, recordings:
To derive the Ie parameter, a combination
of subjective and
objective tests is needed. These tests will require a set of test
recordings to
be used as input materials for both test types.
2c)
Subjective
test:
As ITU-T C-208 shows a discrepancy between subjectively (P.833.1)
objectively
(P.834.1) derived
Ie values, Ie
will be derived based on both objective and
subjective tests.
2d)
Objective
assessment
using POLQA (ITU-T P.863)
2e)
Statistical
analysis,
conclusion and derivation of one single
Ie
value per bandwidth mode, if possible.
For more details, see
our
Terms of Reference
Why we do it
The required
knowledge
about the
Ie -Factors for transmission
planning using
the New ETSI Speech Codec (LC3plus) will be available, and the codec
will be
established internationally outside ETSI. This has to be seen in the
context
that for the OPUS codec
Ie - values are already known and
can be used
for network planning purposes.
The LC3plus codec technology is also contributed to
the SIG
Bluetooth providing a significant improvement to previous
technologies. In
order to provide the technical benefits also to groups outside ETSI
this TTF
activity is also performed.
How we do it
The TTF experts are
working
remotely from their locations (Germany, Czech Republic). The
subjective tests
will be performed in MESAQIN.com listening laboratory premises in
Prague using
native English speakers.
Deliverables
The following
detailed
information will be added to TS 103 624:
·
Objective
assessment of
the speech data bases used for the subjective tests using POLQA
(ITU-T P.863):
new Annex to TS 103 624
·
Equipment
Impairment
Factors for the different bandwidth modes of the codec: new Annex to
TS 103 624
After approval by ETSI STQ, the revised version(s) of TS 103 624 will be
available to the general public.
.
Time plan
STQ approval is
scheduled for
end of February 2024.
If additional
information is
needed, please send an email to
consultant@joachimpomy.de
This information is based upon STF/TTF working
assumptions.
The views expressed do not necessarily represent
the
position of ETSI in the context.