I wrote on android ndk and there is fastpath concept. Thus, I think that
resampling can help me.
Can you recommend me code example ?
Can you give me an example of resampling ? for example from 48Khz to 8Khz
and 8Khz to 48Khz.
I found this:
but it is not enough clear for me,


‫בתאריך יום ד׳, 3 באוק׳ 2018 ב-20:56 מאת ‪Spencer Jackson‬‏ <‪

> On Wed, Oct 3, 2018 at 3:17 AM Alex Dashevski <alexd...@gmail.com> wrote:
>> if I do resampling before and after processing. for example, 48Khz ->
>> 8Khz and then 8Khz -> 48Khz then will it help ?
> Lowering sample rate can help achieve lower latencies by giving you fewer
> samples to process in the same amount of time but just downsampling and
> then upsampling back doesn't really have any effect.
>> I don't understand why I need filter, This is to prevent alias but I
>> can't understand why ?
>> Technically you only need a filter if your signal has information above
> the nyquist frequency of the lowest rate but this is not usually the case.
> I think wikipedia explains aliasing pretty well:
> https://en.wikipedia.org/wiki/Aliasing#Sampling_sinusoidal_functions .
> Once the high frequency information aliases it cannot be recovered by
> resampling back to the higher rate and your lower band information is now
> mixed in with the aliased information. The filter removes this high
> freqency data so that the low band stays clean through the whole process.
> Is there option to decrease latency or delay ?
> The only way to reduce latency in your algorithm (unless there is some
> error in the implementation) is to reduce the block size, so you process
> 128 samples rather than 240. 240 isn't a very large amount of latency for a
> pitch shifter which is typically a CPU intensive process and therefore most
> implementations have relatively high latencies.
> I'm not sure I understand what you mean by the pitch duration requiring a
> buffer-resize or sample-rate decrease. WSOLA creates a signal with more
> samples than the input, you must resample that (usually by a non-integer
> amount) to make it the correct number of samples then output that, and
> reload your buffer with the next block of input data. Please clarify if you
> mean some other issue.
> _Spencer
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