Combining bit reverse and time reverse of a sequence in asm
Posted: Thu Jul 21, 2022 9:30 am
I am using dsp_fft_bit_reverse before dsp_fft_forward.
In order to do cross-correlation as [1], as one alternative, I would need to also time reverse one of the sequences before doing the dsp_fft_forward. I guess this is faster than the alternative, to do the complex conjugate after the fft.
I am using lib_dsp(6.2.1) and X2, which seems to do dsp_fft_bit_reverse in asm in dsp_fft_bit_reverse.S.
Is there anybody out there who'd like to rewrite or even would have that code doing a built-in time reverse? This is for a hobby project. I don't know xCore asm at all.
Øyvind
[1] How do I implement cross-correlation to prove two audio files are similar?
In order to do cross-correlation as [1], as one alternative, I would need to also time reverse one of the sequences before doing the dsp_fft_forward. I guess this is faster than the alternative, to do the complex conjugate after the fft.
I am using lib_dsp(6.2.1) and X2, which seems to do dsp_fft_bit_reverse in asm in dsp_fft_bit_reverse.S.
Is there anybody out there who'd like to rewrite or even would have that code doing a built-in time reverse? This is for a hobby project. I don't know xCore asm at all.
Øyvind
[1] How do I implement cross-correlation to prove two audio files are similar?