Hi,

I don't understand your answer.
I have already audio echo application on Android. Buffer size and Frequency
sample infuence on latency.
Could you explain me how implement WSOLA on Real-time ?  It is a bit more
difficult .

Thanks,
Alex

2018-05-27 21:41 GMT+03:00 Phil Burk <philb...@mobileer.com>:

> Hello Alex,
>
> The period is 1 / frequency. I think what was confusing is you said that
> the pitch was 5 milliseconds. Pitch is normally described either in Hertz
> or in semitones.
>
> Also the buffer size that you are referring to is a single buffer used for
> reading or writing the audio data. That is not the total size of the
> sample. The buffer size use for reading and writing should not affect the
> signal processing algorithm because you are basically processing one sample
> at a time anyway. You can collect the samples into blocks of data if you
> need to. but that is independent of the input output buffer size.
>
> Most smart phones including Android should be fast enough to implement
> this algorithm. It should be possible. You might want to start with just
> reading a WAV file in, processing the data, then writing a WAV file out.
> Separate the reading and writing of the file from the processing algorithm.
> Then when you have it working you can just port it to Android.
>
> If you have Android specific questions about the Android APIs then please
> use the Android mailing list. If you have mathematical questions about DSP
> then this is a better mailing list.
>
> Phil Burk
>
> On Sun, May 27, 2018, 6:27 AM Alex Dashevski <alexd...@gmail.com> wrote:
>
>> Hi,
>> I mean that fundamental frequency is between 50Hz and 4"50Hz.  Right?
>> Why period of pitct isn't equal to 1/fundamental frequency?
>>
>> what is about of subsampling?  That means that proccessing will be done
>> with 8Kh.
>>
>> what is about pitch shifting?
>>
>> How can I prove to my instractor that I can't implementation wsola?
>>
>> I have already asked this question on  ndk android group but they refer
>> me to this forum.
>>
>> Thanks,
>> Alex
>>
>>
>> On Sun, May 27, 2018, 02:51 robert bristow-johnson <
>> r...@audioimagination.com> wrote:
>>
>>> On 5/25/18 2:06 PM, Alex Dashevski wrote:
>>> >
>>> > I want to implement WSOLA on Real Time.
>>> > The pitch is between 5ms and 20ms.
>>> do you mean the *period* is between 5 ms and 20 ms?  or that the
>>> fundamental frequency is between 50 Hz and 200 Hz?  this appears to be a
>>> bass instrument
>>>
>>> > Frequency samples of the system is 48Khz
>>> > Buffer size has 240 sample.
>>>
>>> that's not long enough.  you will never be able to even do the necessary
>>> pitch detection with a buffer that small.  (unless you mean the
>>> input/output buffer of the android, then that is plenty long.)
>>>
>>> > I want to implement it on android.
>>>
>>> then you should have no problem securing a megabyte of memory.
>>>
>>> > My issue is that my buffer is smaller than pitch,
>>>
>>> it's the *period*.  pitch is not measured in ms.
>>>
>>> > I can't understand how I can implement WSOLA.
>>>
>>> you can't unless you can allocate more memory.  that's a programming
>>> issue with the android.
>>>
>>>
>>>
>>> --
>>>
>>> r b-j                  r...@audioimagination.com
>>>
>>> "Imagination is more important than knowledge."
>>>
>>>
>>>
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