cannam@154: /* Copyright (c) 2007-2008 CSIRO
cannam@154:    Copyright (c) 2007-2008 Xiph.Org Foundation
cannam@154:    Written by Jean-Marc Valin */
cannam@154: /*
cannam@154:    Redistribution and use in source and binary forms, with or without
cannam@154:    modification, are permitted provided that the following conditions
cannam@154:    are met:
cannam@154: 
cannam@154:    - Redistributions of source code must retain the above copyright
cannam@154:    notice, this list of conditions and the following disclaimer.
cannam@154: 
cannam@154:    - Redistributions in binary form must reproduce the above copyright
cannam@154:    notice, this list of conditions and the following disclaimer in the
cannam@154:    documentation and/or other materials provided with the distribution.
cannam@154: 
cannam@154:    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
cannam@154:    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
cannam@154:    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
cannam@154:    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
cannam@154:    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
cannam@154:    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
cannam@154:    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
cannam@154:    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
cannam@154:    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
cannam@154:    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
cannam@154:    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
cannam@154: */
cannam@154: 
cannam@154: /* This is a simple MDCT implementation that uses a N/4 complex FFT
cannam@154:    to do most of the work. It should be relatively straightforward to
cannam@154:    plug in pretty much and FFT here.
cannam@154: 
cannam@154:    This replaces the Vorbis FFT (and uses the exact same API), which
cannam@154:    was a bit too messy and that was ending up duplicating code
cannam@154:    (might as well use the same FFT everywhere).
cannam@154: 
cannam@154:    The algorithm is similar to (and inspired from) Fabrice Bellard's
cannam@154:    MDCT implementation in FFMPEG, but has differences in signs, ordering
cannam@154:    and scaling in many places.
cannam@154: */
cannam@154: 
cannam@154: #ifndef MDCT_H
cannam@154: #define MDCT_H
cannam@154: 
cannam@154: #include "opus_defines.h"
cannam@154: #include "kiss_fft.h"
cannam@154: #include "arch.h"
cannam@154: 
cannam@154: typedef struct {
cannam@154:    int n;
cannam@154:    int maxshift;
cannam@154:    const kiss_fft_state *kfft[4];
cannam@154:    const kiss_twiddle_scalar * OPUS_RESTRICT trig;
cannam@154: } mdct_lookup;
cannam@154: 
cannam@154: #if defined(HAVE_ARM_NE10)
cannam@154: #include "arm/mdct_arm.h"
cannam@154: #endif
cannam@154: 
cannam@154: 
cannam@154: int clt_mdct_init(mdct_lookup *l,int N, int maxshift, int arch);
cannam@154: void clt_mdct_clear(mdct_lookup *l, int arch);
cannam@154: 
cannam@154: /** Compute a forward MDCT and scale by 4/N, trashes the input array */
cannam@154: void clt_mdct_forward_c(const mdct_lookup *l, kiss_fft_scalar *in,
cannam@154:                         kiss_fft_scalar * OPUS_RESTRICT out,
cannam@154:                         const opus_val16 *window, int overlap,
cannam@154:                         int shift, int stride, int arch);
cannam@154: 
cannam@154: /** Compute a backward MDCT (no scaling) and performs weighted overlap-add
cannam@154:     (scales implicitly by 1/2) */
cannam@154: void clt_mdct_backward_c(const mdct_lookup *l, kiss_fft_scalar *in,
cannam@154:       kiss_fft_scalar * OPUS_RESTRICT out,
cannam@154:       const opus_val16 * OPUS_RESTRICT window,
cannam@154:       int overlap, int shift, int stride, int arch);
cannam@154: 
cannam@154: #if !defined(OVERRIDE_OPUS_MDCT)
cannam@154: /* Is run-time CPU detection enabled on this platform? */
cannam@154: #if defined(OPUS_HAVE_RTCD) && defined(HAVE_ARM_NE10)
cannam@154: 
cannam@154: extern void (*const CLT_MDCT_FORWARD_IMPL[OPUS_ARCHMASK+1])(
cannam@154:       const mdct_lookup *l, kiss_fft_scalar *in,
cannam@154:       kiss_fft_scalar * OPUS_RESTRICT out, const opus_val16 *window,
cannam@154:       int overlap, int shift, int stride, int arch);
cannam@154: 
cannam@154: #define clt_mdct_forward(_l, _in, _out, _window, _overlap, _shift, _stride, _arch) \
cannam@154:    ((*CLT_MDCT_FORWARD_IMPL[(arch)&OPUS_ARCHMASK])(_l, _in, _out, \
cannam@154:                                                    _window, _overlap, _shift, \
cannam@154:                                                    _stride, _arch))
cannam@154: 
cannam@154: extern void (*const CLT_MDCT_BACKWARD_IMPL[OPUS_ARCHMASK+1])(
cannam@154:       const mdct_lookup *l, kiss_fft_scalar *in,
cannam@154:       kiss_fft_scalar * OPUS_RESTRICT out, const opus_val16 *window,
cannam@154:       int overlap, int shift, int stride, int arch);
cannam@154: 
cannam@154: #define clt_mdct_backward(_l, _in, _out, _window, _overlap, _shift, _stride, _arch) \
cannam@154:    (*CLT_MDCT_BACKWARD_IMPL[(arch)&OPUS_ARCHMASK])(_l, _in, _out, \
cannam@154:                                                    _window, _overlap, _shift, \
cannam@154:                                                    _stride, _arch)
cannam@154: 
cannam@154: #else /* if defined(OPUS_HAVE_RTCD) && defined(HAVE_ARM_NE10) */
cannam@154: 
cannam@154: #define clt_mdct_forward(_l, _in, _out, _window, _overlap, _shift, _stride, _arch) \
cannam@154:    clt_mdct_forward_c(_l, _in, _out, _window, _overlap, _shift, _stride, _arch)
cannam@154: 
cannam@154: #define clt_mdct_backward(_l, _in, _out, _window, _overlap, _shift, _stride, _arch) \
cannam@154:    clt_mdct_backward_c(_l, _in, _out, _window, _overlap, _shift, _stride, _arch)
cannam@154: 
cannam@154: #endif /* end if defined(OPUS_HAVE_RTCD) && defined(HAVE_ARM_NE10) && !defined(FIXED_POINT) */
cannam@154: #endif /* end if !defined(OVERRIDE_OPUS_MDCT) */
cannam@154: 
cannam@154: #endif