public static extern void av_fft_calc(FFTContext *s, FFTComplex *z);
public static extern void av_fft_permute(FFTContext *s, FFTComplex *z);
public static extern void av_fft_calc(FFTContext *s, FFTComplex *z);
public static extern void av_fft_permute(FFTContext *s, FFTComplex *z);