High-resolution sampling about pyroomacoustics

[fakufaku]

Hi @maelp , I think you are referencing the RIR creation method in this paper (ref [1] in the one you linked). Essentially, these guys are rediscovering 60+ years of signal processing on their own. I wouldn't recommend this as a reference for your own implementation.

In their method, they need to generate the RIR at a higher frequency because they use impulses that are rounded to the nearest sample. Pyroomacoustics doesn't have this problem because we generate fractional delays directly. No rounding to the nearest sample is ever done. What comes out of the simulator is better than what you'll get using this upsampling method.

Regarding computations, OLA is a completely standard method. The STFT method of pyroomacoustics lets you do it. Although it is a good point that this is not actually what we use to convolve the RIR in the room simulation. Instead we use scipy.signal.fftconvolve which uses FFT for the convolution (Real FFT filtering in the paper linked, Eq 4). So from their paper, an efficient implementation of OLA might be 2x as fast. The problem for us is that the OLA in stft is done in python, so it might be actually slower than fftconvolve. This should be checked.

[maelp]

Thank you