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Diffstat (limited to 'drivers/opus/celt/mdct.c')
-rw-r--r-- | drivers/opus/celt/mdct.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/opus/celt/mdct.c b/drivers/opus/celt/mdct.c new file mode 100644 index 0000000000..d08d026fac --- /dev/null +++ b/drivers/opus/celt/mdct.c @@ -0,0 +1,311 @@ + /* 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 OPUS_HAVE_CONFIG_H +#include "opus_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" + +#ifdef CUSTOM_MODES + +int clt_mdct_init(celt_mdct_lookup *l,int N, int maxshift) +{ + int i; + int N4; + kiss_twiddle_scalar *trig; +#if defined(OPUS_FIXED_POINT) + int N2=N>>1; +#endif + l->n = N; + N4 = N>>2; + l->maxshift = maxshift; + for (i=0;i<=maxshift;i++) + { + if (i==0) + l->kfft[i] = opus_fft_alloc(N>>2>>i, 0, 0); + else + l->kfft[i] = opus_fft_alloc_twiddles(N>>2>>i, 0, 0, l->kfft[0]); +#ifndef ENABLE_TI_DSPLIB55 + if (l->kfft[i]==NULL) + return 0; +#endif + } + l->trig = trig = (kiss_twiddle_scalar*)opus_alloc((N4+1)*sizeof(kiss_twiddle_scalar)); + if (l->trig==NULL) + return 0; + /* We have enough points that sine isn't necessary */ +#if defined(OPUS_FIXED_POINT) + for (i=0;i<=N4;i++) + trig[i] = TRIG_UPSCALE*celt_cos_norm(DIV32(ADD32(SHL32(EXTEND32(i),17),N2),N)); +#else + for (i=0;i<=N4;i++) + trig[i] = (kiss_twiddle_scalar)cos(2*PI*i/N); +#endif + return 1; +} + +void clt_mdct_clear(celt_mdct_lookup *l) +{ + int i; + for (i=0;i<=l->maxshift;i++) + opus_fft_free(l->kfft[i]); + opus_free((kiss_twiddle_scalar*)l->trig); +} + +#endif /* CUSTOM_MODES */ + +/* Forward MDCT trashes the input array */ +void clt_mdct_forward(const celt_mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out, + const opus_val16 *window, int overlap, int shift, int stride) +{ + int i; + int N, N2, N4; + kiss_twiddle_scalar sine; + VARDECL(kiss_fft_scalar, f); + VARDECL(kiss_fft_scalar, f2); + SAVE_STACK; + N = l->n; + N >>= shift; + N2 = N>>1; + N4 = N>>2; + ALLOC(f, N2, kiss_fft_scalar); + ALLOC(f2, N2, kiss_fft_scalar); + /* sin(x) ~= x here */ +#ifdef OPUS_FIXED_POINT + sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N; +#else + sine = (kiss_twiddle_scalar)2*PI*(.125f)/N; +#endif + + /* 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 = &l->trig[0]; + for(i=0;i<N4;i++) + { + kiss_fft_scalar re, im, yr, yi; + re = yp[0]; + im = yp[1]; + 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 */ + *yp++ = yr + S_MUL(yi,sine); + *yp++ = yi - S_MUL(yr,sine); + } + } + + /* N/4 complex FFT, down-scales by 4/N */ + opus_fft(l->kfft[shift], (kiss_fft_cpx *)f, (kiss_fft_cpx *)f2); + + /* Post-rotate */ + { + /* Temp pointers to make it really clear to the compiler what we're doing */ + const kiss_fft_scalar * 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 = &l->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[1],t[(N4-i)<<shift]) + S_MUL(fp[0],t[i<<shift]); + yi = S_MUL(fp[0],t[(N4-i)<<shift]) - S_MUL(fp[1],t[i<<shift]); + /* works because the cos is nearly one */ + *yp1 = yr - S_MUL(yi,sine); + *yp2 = yi + S_MUL(yr,sine);; + fp += 2; + yp1 += 2*stride; + yp2 -= 2*stride; + } + } + RESTORE_STACK; +} + +void clt_mdct_backward(const celt_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 i; + int N, N2, N4; + kiss_twiddle_scalar sine; + VARDECL(kiss_fft_scalar, f2); + SAVE_STACK; + N = l->n; + N >>= shift; + N2 = N>>1; + N4 = N>>2; + ALLOC(f2, N2, kiss_fft_scalar); + /* sin(x) ~= x here */ +#ifdef OPUS_FIXED_POINT + sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N; +#else + sine = (kiss_twiddle_scalar)2*PI*(.125f)/N; +#endif + + /* 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 = 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; + } + } + + /* Inverse N/4 complex FFT. This one should *not* downscale even in fixed-point */ + opus_ifft(l->kfft[shift], (kiss_fft_cpx *)f2, (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 * OPUS_RESTRICT yp0 = out+(overlap>>1); + kiss_fft_scalar * OPUS_RESTRICT yp1 = out+(overlap>>1)+N2-2; + const kiss_twiddle_scalar *t = &l->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; + re = yp0[0]; + im = yp0[1]; + t0 = t[i<<shift]; + t1 = t[(N4-i)<<shift]; + /* We'd scale up by 2 here, but instead it's done when mixing the windows */ + yr = S_MUL(re,t0) - S_MUL(im,t1); + yi = S_MUL(im,t0) + S_MUL(re,t1); + re = yp1[0]; + im = yp1[1]; + /* works because the cos is nearly one */ + yp0[0] = -(yr - S_MUL(yi,sine)); + yp1[1] = yi + S_MUL(yr,sine); + + t0 = t[(N4-i-1)<<shift]; + t1 = t[(i+1)<<shift]; + /* We'd scale up by 2 here, but instead it's done when mixing the windows */ + yr = S_MUL(re,t0) - S_MUL(im,t1); + yi = S_MUL(im,t0) + S_MUL(re,t1); + /* works because the cos is nearly one */ + yp1[0] = -(yr - S_MUL(yi,sine)); + yp0[1] = yi + S_MUL(yr,sine); + 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++ = MULT16_32_Q15(*wp2, x2) - MULT16_32_Q15(*wp1, x1); + *xp1-- = MULT16_32_Q15(*wp1, x2) + MULT16_32_Q15(*wp2, x1); + wp1++; + wp2--; + } + } + RESTORE_STACK; +} |