Thank you to anyone who has already donated - your generous donations helped make three months of treatment possible.
My brother Nate continues to fight stage IV Hodgkin's lymphoma. He's just 31, with a wife and baby girl. They have no active income (since he's been unable to return to work), no insurance, and cannot afford the treatment he needs. Nate and his family need your help. Please consider a donation, every dollar helps. Thanks.
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diff --git a/lib/rbcodec/codecs/libopus/celt/mdct.c b/lib/rbcodec/codecs/libopus/celt/mdct.c index 0f9af9e..8754337 100644 --- a/lib/rbcodec/codecs/libopus/celt/mdct.c +++ b/lib/rbcodec/codecs/libopus/celt/mdct.c @@ -238,7 +238,7 @@ void clt_mdct_backward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scala /* sin(x) ~= x here */ #ifdef FIXED_POINT - sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N; + sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N; /* 0.78... = 2*PI*0.125 */ #else sine = (kiss_twiddle_scalar)2*PI*(.125f)/N; #endif @@ -249,18 +249,38 @@ void clt_mdct_backward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scala const kiss_fft_scalar * OPUS_RESTRICT xp1 = in; const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+stride*(N2-1); kiss_fft_scalar * OPUS_RESTRICT yp = f2; - const kiss_twiddle_scalar *t = &l->trig[0]; - for(i=0;i<N4;i++) - { - kiss_fft_scalar yr, yi; - yr = -S_MUL(*xp2, t[i<<shift]) + S_MUL(*xp1,t[(N4-i)<<shift]); - yi = -S_MUL(*xp2, t[(N4-i)<<shift]) - S_MUL(*xp1,t[i<<shift]); - /* works because the cos is nearly one */ - *yp++ = yr - S_MUL(yi,sine); - *yp++ = yi + S_MUL(yr,sine); - xp1+=2*stride; - xp2-=2*stride; - } + const kiss_twiddle_scalar *t0 = &l->trig[0]; + const kiss_twiddle_scalar *t1 = &l->trig[N4<<shift]; + + /* stride = 1<<shift */ + if (stride != 1) + for(i=0;i<N4;i++) + { + kiss_fft_scalar yr, yi; + yr = -S_MUL(*xp2,*t0) + S_MUL(*xp1,*t1); + yi = S_MUL(*xp2,*t1) + S_MUL(*xp1,*t0); + /* works because the cos is nearly one (yr*cos - yi*sin and yi*cos + yr*sin) */ + *yp++ = yr + S_MUL(yi,sine); + *yp++ = S_MUL(yr,sine) - yi; + xp1+=2*stride; + xp2-=2*stride; + t0 +=stride; + t1 -=stride; + } + else + for(i=0;i<N4;i++) + { + kiss_fft_scalar yr, yi; + yr = -S_MUL(*xp2,*t0) + S_MUL(*xp1,*t1); + yi = S_MUL(*xp2,*t1) + S_MUL(*xp1,*t0); + /* works because the cos is nearly one (yr*cos - yi*sin and yi*cos + yr*sin) */ + *yp++ = yr + S_MUL(yi,sine); + *yp++ = S_MUL(yr,sine) - yi; + xp1+=2; + xp2-=2; + t0 +=1; + t1 -=1; + } } /* Inverse N/4 complex FFT. This one should *not* downscale even in fixed-point */ @@ -268,20 +288,25 @@ void clt_mdct_backward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scala /* Post-rotate */ { + const kiss_fft_scalar * OPUS_RESTRICT fp1 = f; + const kiss_fft_scalar * OPUS_RESTRICT fp2 = f+1; kiss_fft_scalar * OPUS_RESTRICT fp = f; - const kiss_twiddle_scalar *t = &l->trig[0]; + const kiss_twiddle_scalar *t0 = &l->trig[0]; + const kiss_twiddle_scalar *t1 = &l->trig[N4<<shift]; for(i=0;i<N4;i++) { - kiss_fft_scalar re, im, yr, yi; - re = fp[0]; - im = fp[1]; + kiss_fft_scalar yr, yi; /* We'd scale up by 2 here, but instead it's done when mixing the windows */ - yr = S_MUL(re,t[i<<shift]) - S_MUL(im,t[(N4-i)<<shift]); - yi = S_MUL(im,t[i<<shift]) + S_MUL(re,t[(N4-i)<<shift]); - /* works because the cos is nearly one */ + yr = S_MUL(*fp1,*t0) - S_MUL(*fp2,*t1); + yi = S_MUL(*fp2,*t0) + S_MUL(*fp1,*t1); + /* works because the cos is nearly one (yr*cos - yi*sin and yi*cos + yr*sin) */ *fp++ = yr - S_MUL(yi,sine); *fp++ = yi + S_MUL(yr,sine); + fp1+=2; + fp2+=2; + t0 +=stride; + t1 -=stride; } } /* De-shuffle the components for the middle of the window only */ |
