Re: [PATCH] sbc: fix for overflow bug in quantization code

Marcel Holtmann
2008-12-29T10:33:50Z

Hi Siarhei,

> > If we try to use more realistic settings similar to the recommended high
> > quality settings from SBC specification (Table 4.7):
> > ./sbcenc -j -S -b 51 BigBuckBunny-stereo.au >BigBuckBunny-stereo.sbc
> >
> > bluez 16-bit fixed point:
> > stddev: 43.82 PSNR: 63.48 bytes:114491016/114491308
> >
> > bluez 32-bit fixed point:
> > stddev: 43.78 PSNR: 63.49 bytes:114491016/114491308
> >
> > reference encoder:
> > stddev: 43.37 PSNR: 63.57 bytes:114491016/114491308
> [...]
> > PS. I still wonder why there is a loss when compared to reference encoder.
> > 32-bit fixed point version should be even more precise than single
> > precision floating point. Maybe there could be another minor bug in the
> > code, or it is just a random deviation and there could be a win for other
> > audio files.
>
> Found what's the matter. It's a problem in subbands selection criteria for
> joint-stereo. The following patch fixes it.

patch has been applied and pushed upstream. In the future, please leave
the Signed-off-by line out of it. That one is only a requirement for
kernel code and I never required it for BlueZ.

Regards

Marcel