[opus] fixed point version for celt_pitch_xcorr on aarch64

Viswanath Puttagunta viswanath.puttagunta at linaro.org
Mon Feb 2 09:31:21 PST 2015

On 1 February 2015 at 16:26, Timothy B. Terriberry <tterribe at xiph.org>

> Viswanath Puttagunta wrote:
>> Could you please elaborate on "It would be nice to have"? Specifically:
>> - Are there use cases where fixed point is preferred when AAarch64 has
>> mandatory support for floating point both in regular CPU as well as
>> NEON?
> Even on x86, when the complexity setting is below the maximum, then for
> medium-low bitrate speech the fixed-point encoder will generally be faster,
> because much of the SILK processing uses exact integer math, and this
> avoids several float->int->float round trips. That's why the x86 intrinsics
> code Cisco contributed focused on fixed-point, for example.
> I have not tested on aarch64, but I expect similar properties to hold.
> It also depends on the rest of your pipeline. If your whole audio pipeline
> is fixed-point (which is common in real-time stacks), then you'd have to
> pay additional conversion penalties to use the floating-point API.
   Thanks.. I will add adding neon capabilities to fixed point to by todo
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