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8a838fd207
Bug: webrtc:8366 Change-Id: I741a381fe1cf18909baefd89743b2ff4fe0a6bae Reviewed-on: https://webrtc-review.googlesource.com/86822 Reviewed-by: Niklas Enbom <niklas.enbom@webrtc.org> Reviewed-by: Oskar Sundbom <ossu@webrtc.org> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Commit-Queue: Artem Titov <titovartem@webrtc.org> Cr-Commit-Position: refs/heads/master@{#24091}
126 lines
4.2 KiB
C
126 lines
4.2 KiB
C
/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include <math.h>
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#include "modules/audio_coding/codecs/isac/main/source/settings.h"
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#include "modules/audio_coding/codecs/isac/main/source/codec.h"
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#include "modules/audio_coding/codecs/isac/main/source/os_specific_inline.h"
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#include "modules/third_party/fft/fft.h"
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void WebRtcIsac_InitTransform(TransformTables* tables) {
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int k;
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double fact, phase;
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fact = PI / (FRAMESAMPLES_HALF);
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phase = 0.0;
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for (k = 0; k < FRAMESAMPLES_HALF; k++) {
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tables->costab1[k] = cos(phase);
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tables->sintab1[k] = sin(phase);
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phase += fact;
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}
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fact = PI * ((double) (FRAMESAMPLES_HALF - 1)) / ((double) FRAMESAMPLES_HALF);
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phase = 0.5 * fact;
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for (k = 0; k < FRAMESAMPLES_QUARTER; k++) {
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tables->costab2[k] = cos(phase);
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tables->sintab2[k] = sin(phase);
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phase += fact;
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}
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}
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void WebRtcIsac_Time2Spec(const TransformTables* tables,
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double* inre1,
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double* inre2,
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int16_t* outreQ7,
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int16_t* outimQ7,
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FFTstr* fftstr_obj) {
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int k;
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int dims[1];
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double tmp1r, tmp1i, xr, xi, yr, yi, fact;
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double tmpre[FRAMESAMPLES_HALF], tmpim[FRAMESAMPLES_HALF];
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dims[0] = FRAMESAMPLES_HALF;
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/* Multiply with complex exponentials and combine into one complex vector */
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fact = 0.5 / sqrt(FRAMESAMPLES_HALF);
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for (k = 0; k < FRAMESAMPLES_HALF; k++) {
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tmp1r = tables->costab1[k];
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tmp1i = tables->sintab1[k];
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tmpre[k] = (inre1[k] * tmp1r + inre2[k] * tmp1i) * fact;
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tmpim[k] = (inre2[k] * tmp1r - inre1[k] * tmp1i) * fact;
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}
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/* Get DFT */
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WebRtcIsac_Fftns(1, dims, tmpre, tmpim, -1, 1.0, fftstr_obj);
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/* Use symmetry to separate into two complex vectors and center frames in time around zero */
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for (k = 0; k < FRAMESAMPLES_QUARTER; k++) {
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xr = tmpre[k] + tmpre[FRAMESAMPLES_HALF - 1 - k];
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yi = -tmpre[k] + tmpre[FRAMESAMPLES_HALF - 1 - k];
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xi = tmpim[k] - tmpim[FRAMESAMPLES_HALF - 1 - k];
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yr = tmpim[k] + tmpim[FRAMESAMPLES_HALF - 1 - k];
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tmp1r = tables->costab2[k];
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tmp1i = tables->sintab2[k];
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outreQ7[k] = (int16_t)WebRtcIsac_lrint((xr * tmp1r - xi * tmp1i) * 128.0);
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outimQ7[k] = (int16_t)WebRtcIsac_lrint((xr * tmp1i + xi * tmp1r) * 128.0);
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outreQ7[FRAMESAMPLES_HALF - 1 - k] = (int16_t)WebRtcIsac_lrint((-yr * tmp1i - yi * tmp1r) * 128.0);
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outimQ7[FRAMESAMPLES_HALF - 1 - k] = (int16_t)WebRtcIsac_lrint((-yr * tmp1r + yi * tmp1i) * 128.0);
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}
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}
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void WebRtcIsac_Spec2time(const TransformTables* tables,
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double* inre,
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double* inim,
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double* outre1,
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double* outre2,
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FFTstr* fftstr_obj) {
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int k;
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double tmp1r, tmp1i, xr, xi, yr, yi, fact;
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int dims;
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dims = FRAMESAMPLES_HALF;
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for (k = 0; k < FRAMESAMPLES_QUARTER; k++) {
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/* Move zero in time to beginning of frames */
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tmp1r = tables->costab2[k];
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tmp1i = tables->sintab2[k];
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xr = inre[k] * tmp1r + inim[k] * tmp1i;
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xi = inim[k] * tmp1r - inre[k] * tmp1i;
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yr = -inim[FRAMESAMPLES_HALF - 1 - k] * tmp1r - inre[FRAMESAMPLES_HALF - 1 - k] * tmp1i;
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yi = -inre[FRAMESAMPLES_HALF - 1 - k] * tmp1r + inim[FRAMESAMPLES_HALF - 1 - k] * tmp1i;
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/* Combine into one vector, z = x + j * y */
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outre1[k] = xr - yi;
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outre1[FRAMESAMPLES_HALF - 1 - k] = xr + yi;
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outre2[k] = xi + yr;
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outre2[FRAMESAMPLES_HALF - 1 - k] = -xi + yr;
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}
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/* Get IDFT */
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WebRtcIsac_Fftns(1, &dims, outre1, outre2, 1, FRAMESAMPLES_HALF, fftstr_obj);
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/* Demodulate and separate */
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fact = sqrt(FRAMESAMPLES_HALF);
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for (k = 0; k < FRAMESAMPLES_HALF; k++) {
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tmp1r = tables->costab1[k];
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tmp1i = tables->sintab1[k];
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xr = (outre1[k] * tmp1r - outre2[k] * tmp1i) * fact;
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outre2[k] = (outre2[k] * tmp1r + outre1[k] * tmp1i) * fact;
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outre1[k] = xr;
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}
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}
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