reg. speex Ie Values

Hi,

I'm using the ITU-T P.834 methodology to derive the Ie parameter for
Speex. According to the E-model, Ie indicates the degradation in
quality of a codec at 0% packet loss. It is a non-negative value: the
higher, the worst. Details in ITU-T G.107.

Because Speex is multi-rate, we are deriving one Ie parameter for each
Speex rate. In our preliminary experiments, we've got a value of Ie=0
for [email protected], which is the same value for the G.711 (64kbps).
All other codecs has generally Ie above 0, because of lossy
compression. Thus, I'm amazed that [email protected] is giving us a very
good value of Ie=0. Looking at the PESQ x bitrate graph presented at
Speex home page (http://www.speex.org/comparison/), I saw that the
last red cross point of Speex is very close to the pink square point
of G.711, which corroborates to our findings. We've also used PESQ in
our experiments, so I'm afraid that our results can be only another
way of reading this graph.

So, I would like to hear from you guys if this result of Ie=0 for
[email protected] does make any sense?  There are any human-based
evaluation study of Speex that can be used for comparison?

Regards,

Leandro Galvao


From jean-marc.valin at usherbrooke.ca  Mon Sep 17 07:57:43 2007
From: jean-marc.valin at usherbrooke.ca (Jean-Marc Valin)
Date: Mon Sep 17 08:01:55 2007
Subject: [Speex-dev] reg. speex Ie Values
In-Reply-To: <[email protected]>
References: <[email protected]>
	<[email protected]>
Message-ID: <[email protected]>

I've honestly no idea what that Ie value is and whether it's applicable
to Speex in the first place. As for G.107 not mentioning Speex, it's
just normal since Speex isn't an ITU codec.

	Jean-Marc

Supriya Kher wrote:
>  Hi ,
>
>
>  We would like to know as to what is the impairment caused by the Speex
> codec
>  I mean what is the value of equipment impairment factor Ie ( as defined in
> G.107 Emodel Standardization )
>  for speex codec ?
>  The standard G.107 does not talk about the Ie values of this codec type.
>  Would greatly help if I could get to know the same,
>
>
> Awaiting your response,
>  thanks
>  supriya
>
>
>
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