shithub: opus

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Changed ordering of real FFT freq data to something more aligned (it's not
used anywhere yet).

--- a/libcelt/kiss_fftr.c

+++ b/libcelt/kiss_fftr.c

@@ -92,7 +92,7 @@

    ncfft = st->substate->nfft;

    /*perform the parallel fft of two real signals packed in real,imag*/

-   kiss_fft( st->substate , (const kiss_fft_cpx*)timedata, st->tmpbuf );

+   kiss_fft( st->substate , (const kiss_fft_cpx*)timedata, (kiss_fft_cpx *)freqdata );

     /* The real part of the DC element of the frequency spectrum in st->tmpbuf

    * contains the sum of the even-numbered elements of the input time sequence

    * The imag part is the sum of the odd-numbered elements

@@ -103,35 +103,35 @@

    *      yielding Nyquist bin of input time sequence

     */

-   tdc.r = st->tmpbuf[0].r;

-   tdc.i = st->tmpbuf[0].i;

+   tdc.r = freqdata[0];

+   tdc.i = freqdata[1];

    C_FIXDIV(tdc,2);

    CHECK_OVERFLOW_OP(tdc.r ,+, tdc.i);

    CHECK_OVERFLOW_OP(tdc.r ,-, tdc.i);

    freqdata[0] = tdc.r + tdc.i;

-   freqdata[2*ncfft-1] = tdc.r - tdc.i;

+   freqdata[1] = tdc.r - tdc.i;

    for ( k=1;k <= ncfft/2 ; ++k )

    {

-      f2k.r = SHR32(SUB32(EXTEND32(st->tmpbuf[k].r), EXTEND32(st->tmpbuf[ncfft-k].r)),1);

-      f2k.i = PSHR32(ADD32(EXTEND32(st->tmpbuf[k].i), EXTEND32(st->tmpbuf[ncfft-k].i)),1);

+      f2k.r = SHR32(SUB32(EXTEND32(freqdata[2*k]), EXTEND32(freqdata[2*(ncfft-k)])),1);

+      f2k.i = PSHR32(ADD32(EXTEND32(freqdata[2*k+1]), EXTEND32(freqdata[2*(ncfft-k)+1])),1);

-      f1kr = SHL32(ADD32(EXTEND32(st->tmpbuf[k].r), EXTEND32(st->tmpbuf[ncfft-k].r)),13);

-      f1ki = SHL32(SUB32(EXTEND32(st->tmpbuf[k].i), EXTEND32(st->tmpbuf[ncfft-k].i)),13);

+      f1kr = SHL32(ADD32(EXTEND32(freqdata[2*k]), EXTEND32(freqdata[2*(ncfft-k)])),13);

+      f1ki = SHL32(SUB32(EXTEND32(freqdata[2*k+1]), EXTEND32(freqdata[2*(ncfft-k)+1])),13);

       twr = SHR32(ADD32(MULT16_16(f2k.r,st->super_twiddles[k].r),MULT16_16(f2k.i,st->super_twiddles[k].i)), 1);

       twi = SHR32(SUB32(MULT16_16(f2k.i,st->super_twiddles[k].r),MULT16_16(f2k.r,st->super_twiddles[k].i)), 1);

 #ifdef FIXED_POINT

-      freqdata[2*k-1] = PSHR32(f1kr + twr, 15);

-      freqdata[2*k] = PSHR32(f1ki + twi, 15);

-      freqdata[2*(ncfft-k)-1] = PSHR32(f1kr - twr, 15);

-      freqdata[2*(ncfft-k)] = PSHR32(twi - f1ki, 15);

+      freqdata[2*k] = PSHR32(f1kr + twr, 15);

+      freqdata[2*k+1] = PSHR32(f1ki + twi, 15);

+      freqdata[2*(ncfft-k)] = PSHR32(f1kr - twr, 15);

+      freqdata[2*(ncfft-k)+1] = PSHR32(twi - f1ki, 15);

 #else

-      freqdata[2*k-1] = .5f*(f1kr + twr);

-      freqdata[2*k] = .5f*(f1ki + twi);

-      freqdata[2*(ncfft-k)-1] = .5f*(f1kr - twr);

-      freqdata[2*(ncfft-k)] = .5f*(twi - f1ki);

+      freqdata[2*k] = .5f*(f1kr + twr);

+      freqdata[2*k+1] = .5f*(f1ki + twi);

+      freqdata[2*(ncfft-k)] = .5f*(f1kr - twr);

+      freqdata[2*(ncfft-k)+1] = .5f*(twi - f1ki);

 #endif

    }

@@ -148,15 +148,15 @@

    ncfft = st->substate->nfft;

-   st->tmpbuf[0].r = freqdata[0] + freqdata[2*ncfft-1];

-   st->tmpbuf[0].i = freqdata[0] - freqdata[2*ncfft-1];

+   st->tmpbuf[0].r = freqdata[0] + freqdata[1];

+   st->tmpbuf[0].i = freqdata[0] - freqdata[1];

    for (k = 1; k <= ncfft / 2; ++k) {

       kiss_fft_cpx fk, fnkc, fek, fok, tmp;

-      fk.r = freqdata[2*k-1];

-      fk.i = freqdata[2*k];

-      fnkc.r = freqdata[2*(ncfft - k)-1];

-      fnkc.i = -freqdata[2*(ncfft - k)];

+      fk.r = freqdata[2*k];

+      fk.i = freqdata[2*k+1];

+      fnkc.r = freqdata[2*(ncfft - k)];

+      fnkc.i = -freqdata[2*(ncfft - k)+1];

       C_ADD (fek, fk, fnkc);

       C_SUB (tmp, fk, fnkc);

--- a/tests/real-fft-test.c

+++ b/tests/real-fft-test.c

@@ -33,9 +33,9 @@

     for (k=1;k<n;++k) {

         sigpow += (double)vec1[k].r * (double)vec1[k].r + 

                   (double)vec1[k].i * (double)vec1[k].i;

-        err = (double)vec1[k].r - (double)vec2[2*k-1];

+        err = (double)vec1[k].r - (double)vec2[2*k];

         noisepow += err * err;

-        err = (double)vec1[k].i - (double)vec2[2*k];

+        err = (double)vec1[k].i - (double)vec2[2*k+1];

         noisepow += err * err;

     }

@@ -146,11 +146,11 @@

     }

     fin[0] = cin[0].r;

-    fin[NFFT-1] = cin[NFFT/2].r;

+    fin[1] = cin[NFFT/2].r;

     for (i=1;i< NFFT/2;++i)

     {

-       fin[2*i-1] = cin[i].r;

-       fin[2*i]   = cin[i].i;

+       fin[2*i] = cin[i].r;

+       fin[2*i+1] = cin[i].i;

     }

     kiss_fft(kiss_fft_state,cin,cout);