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Diffstat (limited to 'libao2/fir.h')
| -rw-r--r-- | libao2/fir.h | 72 |
1 files changed, 0 insertions, 72 deletions
diff --git a/libao2/fir.h b/libao2/fir.h deleted file mode 100644 index ab508905a5..0000000000 --- a/libao2/fir.h +++ /dev/null @@ -1,72 +0,0 @@ -/*============================================================================= -// -// This software has been released under the terms of the GNU Public -// license. See http://www.gnu.org/copyleft/gpl.html for details. -// -// Copyright 2001 Anders Johansson ajh@atri.curtin.edu.au -// -//============================================================================= -*/ - -#ifndef __FIR_H__ -#define __FIR_H__ - -/* Fixpoint 16 bit FIR filter. The filter is implemented both in C and -MMX assembly. The filter consists of the two inline functions updateq -and firn, update q is used for adding new data to the circular buffer -used by the filter firn. Limitations: max length of n = 16*4 and n -must be multiple of 4 (pad fiter with zeros for other lengths). -Sometimes it works with filters longer than 4*16 (the problem is -overshoot and the acumulated energy in the filter taps). */ - -#ifdef HAVE_MMX -inline int32_t firn(int16_t* x, int16_t* w, int16_t n) -{ - register int32_t y; // Output - // Prologue - asm volatile(" pxor %mm1, %mm1;\n" ); // Clear buffer yt - // Main loop - while((n-=4)>=0){ - asm volatile( - " movq (%1), %%mm0;\n" // Load x(n:n+4) - " pmaddwd (%0), %%mm0;\n" // yt(n:n+1)=sum(x(n:n+4).*w(n:n+4)) - " psrld $16, %%mm0;\n" // yt(n:n+1)=yt(n:n+1)>>16 - " paddd %%mm0, %%mm1;\n" // yt(n:n+1)=yt(n-2:n-1)+yt(n:n+1) - :: "r" (w), "r" (x)); - w+=4; x+=4; - } - // Epilogue - asm volatile( - " movq %%mm1, %%mm0;\n" - " punpckhdq %%mm1, %%mm0;\n" - " paddd %%mm0, %%mm1;\n" //yt(n)=yt(n)+yt(n+1) - " movd %%mm1, %0 ;\n" //y=yt - " emms ;\n" - : "=&r" (y)); - return y; -} - -#else /* HAVE_MMX */ - -// Same thing as above but in C -inline int32_t firn(int16_t* x, int16_t* w, int16_t n) -{ - register int32_t y=0; - while((n-=4) >=0) - y+=w[n]*x[n]+w[n+1]*x[n+1]+w[n+2]*x[n+2]+w[n+3]*x[n+3] >> 16; - return y; -} - -#endif /* HAVE_MMX */ - -/* Add new data to circular queue designed to be used with a FIR - filter. xq is the circular queue, in pointing at the new sample, xi - current index for in xq and l the lenght of the filter */ -inline uint16_t updateq(int16_t* xq, int16_t* in, uint16_t xi, uint16_t l) -{ - xq[xi]=xq[xi+l]=*in; - return (--xi)&(l-1); \ -} - -#endif /* __FIR_H__ */ - |