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2014/10/15 ¤U¤È 10:14:01
iphone Programming Glossary: setuprealUsing the apple FFT and accelerate Framework http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework the comments don't actually make life any easier. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and.. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and then reverse to get back to where we started. ip.. So we would pack A with 1024 floats from the mic set log2n 10 2^10 1024 precalculate some bobbins setupReal and vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD Now A will contain n 2 complex numbers. These..
Using the apple FFT and accelerate Framework http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework code is really stupidly obscure it is generously commented but the comments don't actually make life any easier. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and then reverse to get back to where we started. ip stands for.. but the comments don't actually make life any easier. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and then reverse to get back to where we started. ip stands for in place which means A gets overwritten That's the.. is whatever the time duration of 1024 samples is ie 1 44 s. So we would pack A with 1024 floats from the mic set log2n 10 2^10 1024 precalculate some bobbins setupReal and vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD Now A will contain n 2 complex numbers. These represent n 2 frequency bins bin 1 .idealFreq 44Hz ie The lowest..
Using the apple FFT and accelerate Framework http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework commented but the comments don't actually make life any easier. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and then reverse to get.. make life any easier. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and then reverse to get back to where we started. ip stands for in place.. is ie 1 44 s. So we would pack A with 1024 floats from the mic set log2n 10 2^10 1024 precalculate some bobbins setupReal and vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD Now A will contain n 2 complex numbers. These represent n 2 frequency..
iPhone FFT with Accelerate framework vDSP http://stackoverflow.com/questions/6358764/iphone-fft-with-accelerate-framework-vdsp COMPLEX originalReal 2 A 1 nOver2 Set up the required memory for the FFT routines and check its availability. setupReal vDSP_create_fftsetup log2n FFT_RADIX2 if setupReal NULL printf nFFT_Setup failed to allocate enough memory for the real.. required memory for the FFT routines and check its availability. setupReal vDSP_create_fftsetup log2n FFT_RADIX2 if setupReal NULL printf nFFT_Setup failed to allocate enough memory for the real FFT. n exit 0 Carry out a Forward and Inverse FFT transform... to allocate enough memory for the real FFT. n exit 0 Carry out a Forward and Inverse FFT transform. vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE Verify correctness of the results but first..
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