| /* Copyright (c) 2007-2008 CSIRO |
| Copyright (c) 2007-2008 Xiph.Org Foundation |
| Written by Jean-Marc Valin */ |
| /* |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| |
| - Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| |
| - Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER |
| OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /* This is a simple MDCT implementation that uses a N/4 complex FFT |
| to do most of the work. It should be relatively straightforward to |
| plug in pretty much and FFT here. |
| |
| This replaces the Vorbis FFT (and uses the exact same API), which |
| was a bit too messy and that was ending up duplicating code |
| (might as well use the same FFT everywhere). |
| |
| The algorithm is similar to (and inspired from) Fabrice Bellard's |
| MDCT implementation in FFMPEG, but has differences in signs, ordering |
| and scaling in many places. |
| */ |
| |
| #ifndef SKIP_CONFIG_H |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| #endif |
| |
| #include "mdct.h" |
| #include "kiss_fft.h" |
| #include "_kiss_fft_guts.h" |
| #include <math.h> |
| #include "os_support.h" |
| #include "mathops.h" |
| #include "stack_alloc.h" |
| |
| #if defined(MIPSr1_ASM) |
| #include "mips/mdct_mipsr1.h" |
| #endif |
| |
| |
| #ifdef CUSTOM_MODES |
| |
| int clt_mdct_init(mdct_lookup *l,int N, int maxshift, int arch) |
| { |
| int i; |
| kiss_twiddle_scalar *trig; |
| int shift; |
| int N2=N>>1; |
| l->n = N; |
| l->maxshift = maxshift; |
| for (i=0;i<=maxshift;i++) |
| { |
| if (i==0) |
| l->kfft[i] = opus_fft_alloc(N>>2>>i, 0, 0, arch); |
| else |
| l->kfft[i] = opus_fft_alloc_twiddles(N>>2>>i, 0, 0, l->kfft[0], arch); |
| #ifndef ENABLE_TI_DSPLIB55 |
| if (l->kfft[i]==NULL) |
| return 0; |
| #endif |
| } |
| l->trig = trig = (kiss_twiddle_scalar*)opus_alloc((N-(N2>>maxshift))*sizeof(kiss_twiddle_scalar)); |
| if (l->trig==NULL) |
| return 0; |
| for (shift=0;shift<=maxshift;shift++) |
| { |
| /* We have enough points that sine isn't necessary */ |
| #if defined(FIXED_POINT) |
| #if 1 |
| for (i=0;i<N2;i++) |
| trig[i] = TRIG_UPSCALE*celt_cos_norm(DIV32(ADD32(SHL32(EXTEND32(i),17),N2+16384),N)); |
| #else |
| for (i=0;i<N2;i++) |
| trig[i] = (kiss_twiddle_scalar)MAX32(-32767,MIN32(32767,floor(.5+32768*cos(2*M_PI*(i+.125)/N)))); |
| #endif |
| #else |
| for (i=0;i<N2;i++) |
| trig[i] = (kiss_twiddle_scalar)cos(2*PI*(i+.125)/N); |
| #endif |
| trig += N2; |
| N2 >>= 1; |
| N >>= 1; |
| } |
| return 1; |
| } |
| |
| void clt_mdct_clear(mdct_lookup *l, int arch) |
| { |
| int i; |
| for (i=0;i<=l->maxshift;i++) |
| opus_fft_free(l->kfft[i], arch); |
| opus_free((kiss_twiddle_scalar*)l->trig); |
| } |
| |
| #endif /* CUSTOM_MODES */ |
| |
| /* Forward MDCT trashes the input array */ |
| #ifndef OVERRIDE_clt_mdct_forward |
| void clt_mdct_forward_c(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out, |
| const opus_val16 *window, int overlap, int shift, int stride, int arch) |
| { |
| int i; |
| int N, N2, N4; |
| VARDECL(kiss_fft_scalar, f); |
| VARDECL(kiss_fft_cpx, f2); |
| const kiss_fft_state *st = l->kfft[shift]; |
| const kiss_twiddle_scalar *trig; |
| opus_val16 scale; |
| #ifdef FIXED_POINT |
| /* Allows us to scale with MULT16_32_Q16(), which is faster than |
| MULT16_32_Q15() on ARM. */ |
| int scale_shift = st->scale_shift-1; |
| #endif |
| SAVE_STACK; |
| (void)arch; |
| scale = st->scale; |
| |
| N = l->n; |
| trig = l->trig; |
| for (i=0;i<shift;i++) |
| { |
| N >>= 1; |
| trig += N; |
| } |
| N2 = N>>1; |
| N4 = N>>2; |
| |
| ALLOC(f, N2, kiss_fft_scalar); |
| ALLOC(f2, N4, kiss_fft_cpx); |
| |
| /* Consider the input to be composed of four blocks: [a, b, c, d] */ |
| /* Window, shuffle, fold */ |
| { |
| /* Temp pointers to make it really clear to the compiler what we're doing */ |
| const kiss_fft_scalar * OPUS_RESTRICT xp1 = in+(overlap>>1); |
| const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+N2-1+(overlap>>1); |
| kiss_fft_scalar * OPUS_RESTRICT yp = f; |
| const opus_val16 * OPUS_RESTRICT wp1 = window+(overlap>>1); |
| const opus_val16 * OPUS_RESTRICT wp2 = window+(overlap>>1)-1; |
| for(i=0;i<((overlap+3)>>2);i++) |
| { |
| /* Real part arranged as -d-cR, Imag part arranged as -b+aR*/ |
| *yp++ = MULT16_32_Q15(*wp2, xp1[N2]) + MULT16_32_Q15(*wp1,*xp2); |
| *yp++ = MULT16_32_Q15(*wp1, *xp1) - MULT16_32_Q15(*wp2, xp2[-N2]); |
| xp1+=2; |
| xp2-=2; |
| wp1+=2; |
| wp2-=2; |
| } |
| wp1 = window; |
| wp2 = window+overlap-1; |
| for(;i<N4-((overlap+3)>>2);i++) |
| { |
| /* Real part arranged as a-bR, Imag part arranged as -c-dR */ |
| *yp++ = *xp2; |
| *yp++ = *xp1; |
| xp1+=2; |
| xp2-=2; |
| } |
| for(;i<N4;i++) |
| { |
| /* Real part arranged as a-bR, Imag part arranged as -c-dR */ |
| *yp++ = -MULT16_32_Q15(*wp1, xp1[-N2]) + MULT16_32_Q15(*wp2, *xp2); |
| *yp++ = MULT16_32_Q15(*wp2, *xp1) + MULT16_32_Q15(*wp1, xp2[N2]); |
| xp1+=2; |
| xp2-=2; |
| wp1+=2; |
| wp2-=2; |
| } |
| } |
| /* Pre-rotation */ |
| { |
| kiss_fft_scalar * OPUS_RESTRICT yp = f; |
| const kiss_twiddle_scalar *t = &trig[0]; |
| for(i=0;i<N4;i++) |
| { |
| kiss_fft_cpx yc; |
| kiss_twiddle_scalar t0, t1; |
| kiss_fft_scalar re, im, yr, yi; |
| t0 = t[i]; |
| t1 = t[N4+i]; |
| re = *yp++; |
| im = *yp++; |
| yr = S_MUL(re,t0) - S_MUL(im,t1); |
| yi = S_MUL(im,t0) + S_MUL(re,t1); |
| yc.r = yr; |
| yc.i = yi; |
| yc.r = PSHR32(MULT16_32_Q16(scale, yc.r), scale_shift); |
| yc.i = PSHR32(MULT16_32_Q16(scale, yc.i), scale_shift); |
| f2[st->bitrev[i]] = yc; |
| } |
| } |
| |
| /* N/4 complex FFT, does not downscale anymore */ |
| opus_fft_impl(st, f2); |
| |
| /* Post-rotate */ |
| { |
| /* Temp pointers to make it really clear to the compiler what we're doing */ |
| const kiss_fft_cpx * OPUS_RESTRICT fp = f2; |
| kiss_fft_scalar * OPUS_RESTRICT yp1 = out; |
| kiss_fft_scalar * OPUS_RESTRICT yp2 = out+stride*(N2-1); |
| const kiss_twiddle_scalar *t = &trig[0]; |
| /* Temp pointers to make it really clear to the compiler what we're doing */ |
| for(i=0;i<N4;i++) |
| { |
| kiss_fft_scalar yr, yi; |
| yr = S_MUL(fp->i,t[N4+i]) - S_MUL(fp->r,t[i]); |
| yi = S_MUL(fp->r,t[N4+i]) + S_MUL(fp->i,t[i]); |
| *yp1 = yr; |
| *yp2 = yi; |
| fp++; |
| yp1 += 2*stride; |
| yp2 -= 2*stride; |
| } |
| } |
| RESTORE_STACK; |
| } |
| #endif /* OVERRIDE_clt_mdct_forward */ |
| |
| #ifndef OVERRIDE_clt_mdct_backward |
| void clt_mdct_backward_c(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out, |
| const opus_val16 * OPUS_RESTRICT window, int overlap, int shift, int stride, int arch) |
| { |
| int i; |
| int N, N2, N4; |
| const kiss_twiddle_scalar *trig; |
| (void) arch; |
| |
| N = l->n; |
| trig = l->trig; |
| for (i=0;i<shift;i++) |
| { |
| N >>= 1; |
| trig += N; |
| } |
| N2 = N>>1; |
| N4 = N>>2; |
| |
| /* Pre-rotate */ |
| { |
| /* Temp pointers to make it really clear to the compiler what we're doing */ |
| 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 = out+(overlap>>1); |
| const kiss_twiddle_scalar * OPUS_RESTRICT t = &trig[0]; |
| const opus_int16 * OPUS_RESTRICT bitrev = l->kfft[shift]->bitrev; |
| for(i=0;i<N4;i++) |
| { |
| int rev; |
| kiss_fft_scalar yr, yi; |
| rev = *bitrev++; |
| yr = ADD32_ovflw(S_MUL(*xp2, t[i]), S_MUL(*xp1, t[N4+i])); |
| yi = SUB32_ovflw(S_MUL(*xp1, t[i]), S_MUL(*xp2, t[N4+i])); |
| /* We swap real and imag because we use an FFT instead of an IFFT. */ |
| yp[2*rev+1] = yr; |
| yp[2*rev] = yi; |
| /* Storing the pre-rotation directly in the bitrev order. */ |
| xp1+=2*stride; |
| xp2-=2*stride; |
| } |
| } |
| |
| opus_fft_impl(l->kfft[shift], (kiss_fft_cpx*)(out+(overlap>>1))); |
| |
| /* Post-rotate and de-shuffle from both ends of the buffer at once to make |
| it in-place. */ |
| { |
| kiss_fft_scalar * yp0 = out+(overlap>>1); |
| kiss_fft_scalar * yp1 = out+(overlap>>1)+N2-2; |
| const kiss_twiddle_scalar *t = &trig[0]; |
| /* Loop to (N4+1)>>1 to handle odd N4. When N4 is odd, the |
| middle pair will be computed twice. */ |
| for(i=0;i<(N4+1)>>1;i++) |
| { |
| kiss_fft_scalar re, im, yr, yi; |
| kiss_twiddle_scalar t0, t1; |
| /* We swap real and imag because we're using an FFT instead of an IFFT. */ |
| re = yp0[1]; |
| im = yp0[0]; |
| t0 = t[i]; |
| t1 = t[N4+i]; |
| /* We'd scale up by 2 here, but instead it's done when mixing the windows */ |
| yr = ADD32_ovflw(S_MUL(re,t0), S_MUL(im,t1)); |
| yi = SUB32_ovflw(S_MUL(re,t1), S_MUL(im,t0)); |
| /* We swap real and imag because we're using an FFT instead of an IFFT. */ |
| re = yp1[1]; |
| im = yp1[0]; |
| yp0[0] = yr; |
| yp1[1] = yi; |
| |
| t0 = t[(N4-i-1)]; |
| t1 = t[(N2-i-1)]; |
| /* We'd scale up by 2 here, but instead it's done when mixing the windows */ |
| yr = ADD32_ovflw(S_MUL(re,t0), S_MUL(im,t1)); |
| yi = SUB32_ovflw(S_MUL(re,t1), S_MUL(im,t0)); |
| yp1[0] = yr; |
| yp0[1] = yi; |
| yp0 += 2; |
| yp1 -= 2; |
| } |
| } |
| |
| /* Mirror on both sides for TDAC */ |
| { |
| kiss_fft_scalar * OPUS_RESTRICT xp1 = out+overlap-1; |
| kiss_fft_scalar * OPUS_RESTRICT yp1 = out; |
| const opus_val16 * OPUS_RESTRICT wp1 = window; |
| const opus_val16 * OPUS_RESTRICT wp2 = window+overlap-1; |
| |
| for(i = 0; i < overlap/2; i++) |
| { |
| kiss_fft_scalar x1, x2; |
| x1 = *xp1; |
| x2 = *yp1; |
| *yp1++ = SUB32_ovflw(MULT16_32_Q15(*wp2, x2), MULT16_32_Q15(*wp1, x1)); |
| *xp1-- = ADD32_ovflw(MULT16_32_Q15(*wp1, x2), MULT16_32_Q15(*wp2, x1)); |
| wp1++; |
| wp2--; |
| } |
| } |
| } |
| #endif /* OVERRIDE_clt_mdct_backward */ |
