Jean-Marc,
I hate to say such things about Speex, especially when I've been
unable to make such problems consistently reproducible. It takes
a great deal of patience and effort to track down a rarely
occurring problem like this in a production VOIP system. I ended
up solving my problems by being more careful with the input to the
encoder and switching to an SVN version of Speex. This was a long
time ago, though.
So, I don't have any examples of how current Speex can enter a
bad state. But here's one from the past:
http://lists.xiph.org/pipermail/speex-dev/2005-December/004010.html
Tom
Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
wrote:>
> Tom Grandgent a ?crit :
> > You might not be doing anything wrong. Speex is stateful and can
> > get into a bad state sometimes. It's happened to me too, but not
> > recently. And I've seen such bugs reported on this list and
fixed.
> > I suggest several approaches to solving the problem:
>
> Tom, can you give an example of how Speex can enter a "bad
state"? I
> don't see how that could happen, but if you have an example, I can
> probably fix it.
>
> > 2) Try to make the problem trivially reproducible for others so that
> > the bug (if it exists) can be tracked down and fixed. You must
> > identify exactly which version of Speex you're using and provide
> > sample data, code, and instructions so that someone else can
> > reproduce the problem with minimal effort.
>
> I'd like to add something for everyone: *please* try and reproduce the
> problem with speexenc/speexdec instead of your own code. It's less
> likely to be buggy and a bug that can be reproduced from those will get
> my attention *much* more quickly.
>
> > 3) Try to be nice to Speex. Don't feed the decoder corrupted
data,
> > out of order data, data with gaps, etc. Put extra checks in your
> > code/protocol to make sure you're decoding exactly the data that
> > the encoder produced. You might be surprised at the result. Also
> > keep in mind that the nature of the audio data itself may be
> > triggering the problem, especially if it is unusual in some way.
>
> Again, do you have examples of that happening.
>
> Cheers,
>
> Jean-Marc
>
> > Good luck,
> >
> > Tom
> >
> > jesus <jmorion@toomeeting.com> wrote:
> >> thank you, i will explain it more detailed:
> >>
> >> I use libspeex in an activeX project compiled on Visual C++ 2003
> >> (Windows XP).
> >>
> >> I have one array of SpeexBits and other of decoder states. The
first
> >> time a user speaks, i create and initialize the elements of those
arrays
> >> who correspond to his user_id. Next packets of this user are
decoded
> >> using those elements. The decoder instance is always the same for
every
> >> user packets.
> >>
> >> It works fine most time, but sometimes one user begins to sound
like
> >> voice hits and the others still sounds ok. At that point, if i
destroy
> >> his elements of the two arrays and re-create and initialize, it
solves.
> >>
> >> OK, I will read speechenc/dec just one more time.
> >>
> >> Thank you.
> >>
> >> Jonas T?rnstr?m wrote:
> >>> You're doing something wrong.
> >>> Read the documentation and check speechenc/dec just one more
time.
> >>>
> >>> If that wouldn't help I'd suggest posting samples of
your source code
> >>> and describe what platform/compiler/os you're using.
> >>>
> >>> //JT
> >>>
> >>>
> >>> -----Ursprungligt meddelande-----
> >>> Fr?n: speex-dev-bounces@xiph.org
[mailto:speex-dev-bounces@xiph.org] F?r
> >>> jesus
> >>> Skickat: den 22 januari 2007 19:43
> >>> Till: speex-dev@xiph.org
> >>> ?mne: [Speex-dev] How to detect SpeexBits corruption
> >>>
> >>> Hello,
> >>>
> >>> im using speex library on my vo ip project, but some times,
after it
> >>> works ok, it begins to play noises (like voice hits) decoding
the
> >>> packets of one source (the others sound ok).
> >>>
> >>> I finally found that reseting SpeexBits and decoder state it
solves.
> >>>
> >>> If i cant avoid this problem, i wish to solve when it occours,
but ?how
> >>> to detect this?
> >>>
> >>> Please, if anyone has experiment this issue i will thank any
help.
> >>>
> >>> by MJM.
> >>> _______________________________________________
> >>> Speex-dev mailing list
> >>> Speex-dev@xiph.org
> >>> http://lists.xiph.org/mailman/listinfo/speex-dev
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >> _______________________________________________
> >> Speex-dev mailing list
> >> Speex-dev@xiph.org
> >> http://lists.xiph.org/mailman/listinfo/speex-dev
> > _______________________________________________
> > Speex-dev mailing list
> > Speex-dev@xiph.org
> > http://lists.xiph.org/mailman/listinfo/speex-dev
> >
> >
