shithub: aubio

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ref: 53457f6d09d07320bf8b2ddb94f757e35f396402
parent: 03df4dcfd8dec47de94f34239855b56da2e33266
author: Paul Brossier <piem@piem.org>
date: Wed Oct 4 10:58:53 EDT 2017 

src/spectral/dct_accelerate.c: add vdsp dct


--- /dev/null
+++ b/src/spectral/dct_accelerate.c
@@ -1,0 +1,99 @@
+/*
+  Copyright (C) 2017 Paul Brossier <piem@aubio.org>
+
+  This file is part of aubio.
+
+  aubio is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  aubio is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#include "aubio_priv.h"
+#include "fvec.h"
+#include "cvec.h"
+#include "spectral/dct.h"
+
+#if defined(HAVE_ACCELERATE)
+
+#if HAVE_AUBIO_DOUBLE
+#warning "no double-precision dct with accelerate"
+#endif
+
+struct _aubio_dct_t {
+  uint_t size;
+  fvec_t *tmp;
+  vDSP_DFT_Setup setup;
+  vDSP_DFT_Setup setupInv;
+};
+
+aubio_dct_t * new_aubio_dct (uint_t size) {
+  aubio_dct_t * s = AUBIO_NEW(aubio_dct_t);
+
+  if ((sint_t)size < 16 || !aubio_is_power_of_two(size)) {
+    AUBIO_ERR("dct: can only create with sizes greater than 16 and"
+        "that are powers of two, requested %d\n", size);
+    goto beach;
+  }
+
+  s->setup = vDSP_DCT_CreateSetup(NULL, (vDSP_Length)size, vDSP_DCT_II);
+  s->setupInv = vDSP_DCT_CreateSetup(NULL, (vDSP_Length)size, vDSP_DCT_III);
+  if (s->setup == NULL || s->setupInv == NULL) {
+    goto beach;
+  }
+
+  s->size = size;
+
+  return s;
+
+beach:
+  del_aubio_dct(s);
+  return NULL;
+}
+
+void del_aubio_dct(aubio_dct_t *s) {
+  if (s->setup) vDSP_DFT_DestroySetup(s->setup);
+  if (s->setupInv) vDSP_DFT_DestroySetup(s->setupInv);
+  AUBIO_FREE(s);
+}
+
+void aubio_dct_do(aubio_dct_t *s, const fvec_t *input, fvec_t *output) {
+
+  vDSP_DCT_Execute(s->setup, (const float *)input->data, (float *)output->data);
+
+  // apply orthonormal scaling
+  output->data[0] *= SQRT(1./s->size);
+  smpl_t scaler = SQRT(2./s->size);
+
+  aubio_vDSP_vsmul(output->data + 1, 1, &scaler, output->data + 1, 1,
+      output->length - 1);
+
+}
+
+void aubio_dct_rdo(aubio_dct_t *s, const fvec_t *input, fvec_t *output) {
+
+  output->data[0] = input->data[0] / SQRT(1./s->size);
+  smpl_t scaler = 1./SQRT(2./s->size);
+
+  aubio_vDSP_vsmul(input->data + 1, 1, &scaler, output->data + 1, 1,
+      output->length - 1);
+
+  vDSP_DCT_Execute(s->setupInv, (const float *)output->data,
+      (float *)output->data);
+
+  scaler = 2./s->size;
+
+  aubio_vDSP_vsmul(output->data, 1, &scaler, output->data, 1, output->length);
+
+}
+
+#endif //defined(HAVE_ACCELERATE)