I am using Polyphase resampling function of IPP libraries ( https://software.intel.com/content/www/us/en/develop/documentation/ipp-dev-reference/top/volume-1-signal-and-data-processing/filtering-functions/filtering-functions-1/polyphase-resampling-functions.html ).
For the moment I am just testing for upsampling a signal by a factor of 2. I am using the Fixed_32f family of functions and specifically the GetFilter and SetFilter functions. SetFilter allows to set a precomputed FIR filter to the resampling object.
I have a problem when I am resampling using a filter imported with the SetFilter: I see a bad value for the first sample of the impulse response. When I check the impulse response, I see that its first sample is the coefficient of the filter created with the Init function instead of the first sample that corresponds to the filter set with SetFilter method.
Has anyone been able to make it working properly with these GetFilter and SetFilter functions? The IPP documentation is not of great help with this since it sets the same filter as the one set by default with the init method ( see https://software.intel.com/content/www/us/en/develop/documentation/ipp-dev-reference/top/volume-1-signal-and-data-processing/filtering-functions/filtering-functions-1/polyphase-resampling-functions/resamplepolyphasegetfixedfilter.html ).
It's also not detailed in the documentation how one has to organise the coefficients when using the SetFilter method, so i had to to deduce this by getting the filter coefficients created upon calling the Init function (but i think i get this right). Anyone had a similar problem?
Thanks in advance for your feedback,
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