/* * Copyright (C) 2011, 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. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. 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 INC. 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 "config.h" #if ENABLE(WEB_AUDIO) #include "WaveShaperDSPKernel.h" #include "WaveShaperProcessor.h" #include <algorithm> using namespace std; namespace WebCore { void WaveShaperDSPKernel::process(const float* source, float* destination, size_t framesToProcess) { ASSERT(source && destination && waveShaperProcessor()); Float32Array* curve = waveShaperProcessor()->curve(); if (!curve) { // Act as "straight wire" pass-through if no curve is set. memcpy(destination, source, sizeof(float) * framesToProcess); return; } float* curveData = curve->data(); int curveLength = curve->length(); ASSERT(curveData); if (!curveData || !curveLength) { memcpy(destination, source, sizeof(float) * framesToProcess); return; } // Apply waveshaping curve. for (unsigned i = 0; i < framesToProcess; ++i) { const float input = source[i]; // Calculate an index based on input -1 -> +1 with 0 being at the center of the curve data. int index = (curveLength * (input + 1)) / 2; // Clip index to the input range of the curve. // This takes care of input outside of nominal range -1 -> +1 index = max(index, 0); index = min(index, curveLength - 1); destination[i] = curveData[index]; } } } // namespace WebCore #endif // ENABLE(WEB_AUDIO)