[Speex-dev] Noisy sound quality with Blackfin in WB-mode
bernhard.gerlach at stud.tu-ilmenau.de
Wed Oct 26 03:31:03 PDT 2005
> Can you confirm I'm understanding everything correctly? You encode
> the same encoder and then decode with either A) blackfin assembly and
> fixed-point or B) fixed-point only on Blackfin. Then A) sounds bad and
> B) sounds good. If you do the same in narrowband, it sounds OK. Is
> correct? If that's the case, it's *probably* some kind of bug and/or
Yes, that's right, except one thing: I always use the blackfin
+fixedpoint optimized encoder *and* decoder or the fixedpoint-only
optimized encoder *and* decoder at one time. And I do every encoding/
decoding on the Blackfin.
> invalid assumption in the blackfin assembly. Could you check if that
> happens on all wideband modes (and none of the narrowband modes)?
> testing with 1.1.10 would help (in case I broke something in svn).
I rechecked the issue with the following combinations with the 1.1.11-
Complexity = 1, Quality = 1, 5, 9
Complexity = 5, Quality = 1, 5, 9
Complexity = 9, Quality = 1, 5, 9
I also checked the above combinations for the WB (16 KHz) and UWB-
Mode (32kHz). And I checked everything with 1.1.10 version, too, as
you suggested. I checked by encoding+decoding a test speech sample
for each mode with fixed+blackfin optimizations and by comparing the
resulting file to the fixed-only-optimized encoded+decoded version of
the speech sample.
Results: The strange sound persists in all WB and UWB combinations,
no matter if its the 1.1.11-svn or the 1.1.10 version. No difference
between blackfin+fixed and fixed-only in NB modes. The sound is
getting even worse when comparing WB to UWB modes. Also sound seems
to get worse with raising quality values.
Hope that helps,
Technical University Ilmenau
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