From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- dom/media/webaudio/blink/HRTFKernel.cpp | 109 ++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 dom/media/webaudio/blink/HRTFKernel.cpp (limited to 'dom/media/webaudio/blink/HRTFKernel.cpp') diff --git a/dom/media/webaudio/blink/HRTFKernel.cpp b/dom/media/webaudio/blink/HRTFKernel.cpp new file mode 100644 index 0000000000..ecaa846a66 --- /dev/null +++ b/dom/media/webaudio/blink/HRTFKernel.cpp @@ -0,0 +1,109 @@ +/* + * Copyright (C) 2010 Google Inc. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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. + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of + * its contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS 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 APPLE OR ITS 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. + */ + +#include "HRTFKernel.h" +namespace WebCore { + +// Takes the input audio channel |impulseP| as an input impulse response and +// calculates the average group delay. This represents the initial delay before +// the most energetic part of the impulse response. The sample-frame delay is +// removed from the |impulseP| impulse response, and this value is returned. +// The |length| of the passed in |impulseP| must be must be a power of 2. +static float extractAverageGroupDelay(float* impulseP, size_t length) { + // Check for power-of-2. + MOZ_ASSERT(length && (length & (length - 1)) == 0); + + FFTBlock estimationFrame(length); + estimationFrame.PerformFFT(impulseP); + + float frameDelay = + static_cast(estimationFrame.ExtractAverageGroupDelay()); + estimationFrame.GetInverse(impulseP); + + return frameDelay; +} + +HRTFKernel::HRTFKernel(float* impulseResponse, size_t length, float sampleRate) + : m_frameDelay(0), m_sampleRate(sampleRate) { + AlignedTArray buffer; + // copy to a 32-byte aligned buffer + if (((uintptr_t)impulseResponse & 31) != 0) { + buffer.SetLength(length); + mozilla::PodCopy(buffer.Elements(), impulseResponse, length); + impulseResponse = buffer.Elements(); + } + + // Determine the leading delay (average group delay) for the response. + m_frameDelay = extractAverageGroupDelay(impulseResponse, length); + + // The FFT size (with zero padding) needs to be twice the response length + // in order to do proper convolution. + unsigned fftSize = 2 * length; + + // Quick fade-out (apply window) at truncation point + // because the impulse response has been truncated. + unsigned numberOfFadeOutFrames = static_cast( + sampleRate / 4410); // 10 sample-frames @44.1KHz sample-rate + MOZ_ASSERT(numberOfFadeOutFrames < length); + if (numberOfFadeOutFrames < length) { + for (unsigned i = length - numberOfFadeOutFrames; i < length; ++i) { + float x = + 1.0f - static_cast(i - (length - numberOfFadeOutFrames)) / + numberOfFadeOutFrames; + impulseResponse[i] *= x; + } + } + + m_fftFrame = mozilla::MakeUnique(fftSize); + m_fftFrame->PadAndMakeScaledDFT(impulseResponse, length); +} + +// Interpolates two kernels with x: 0 -> 1 and returns the result. +nsReturnRef HRTFKernel::createInterpolatedKernel( + HRTFKernel* kernel1, HRTFKernel* kernel2, float x) { + MOZ_ASSERT(kernel1 && kernel2); + if (!kernel1 || !kernel2) return nsReturnRef(); + + MOZ_ASSERT(x >= 0.0 && x < 1.0); + x = mozilla::clamped(x, 0.0f, 1.0f); + + float sampleRate1 = kernel1->sampleRate(); + float sampleRate2 = kernel2->sampleRate(); + MOZ_ASSERT(sampleRate1 == sampleRate2); + if (sampleRate1 != sampleRate2) return nsReturnRef(); + + float frameDelay = + (1 - x) * kernel1->frameDelay() + x * kernel2->frameDelay(); + + UniquePtr interpolatedFrame(FFTBlock::CreateInterpolatedBlock( + *kernel1->fftFrame(), *kernel2->fftFrame(), x)); + return HRTFKernel::create(std::move(interpolatedFrame), frameDelay, + sampleRate1); +} + +} // namespace WebCore -- cgit v1.2.3