[speex-dev] delay issues in speex, integer API

Christian Buchner Christian.Buchner1 at epost.de
Sun Jun 22 16:42:19 PDT 2003

Hmm, the delay caused by the filters in the speex UWB mode seems to be 509
I used the GoldWave editor to determine the offset. I have always been
confused by
the SNR output in the testenc source code. It did not make sense because it
uses a
640 (=FRAME_SIZE) offset for its SNR calculations. After changing the
method, the SNR readings are much better.

I may decide to adjust my ACM codec to compensate for this delay. I'll
scrap the initial x samples in the decoding process where x would be 509 for
the UWB mode (x is yet to be determined for all the other modes).

In the integer Speex version, I changed all public API function names in
to begin with "sphinx_" instead of "speex_". I also prepended every table,
or function name with an underscore. That allows me to link against libspeex
libsphinx at the same time without conflict and compare the SNR values of

Regarding the ACM, I received a bug report indicating that the beta ACM
crashes when used in VirtualDub. I will also look into this. And I got some
correspondence regarding someone trying to use the ACM codec with Microsoft
Netmeeting. It appears they will be checking this out for us.


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