15c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)/* 25c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * Copyright (C) 2010, Google Inc. All rights reserved. 35c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 45c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * Redistribution and use in source and binary forms, with or without 55c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * modification, are permitted provided that the following conditions 65c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * are met: 75c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 1. Redistributions of source code must retain the above copyright 85c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * notice, this list of conditions and the following disclaimer. 95c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 2. Redistributions in binary form must reproduce the above copyright 105c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * notice, this list of conditions and the following disclaimer in the 115c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * documentation and/or other materials provided with the distribution. 125c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 135c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY 145c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 155c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 165c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY 175c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 185c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 195c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 205c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 215c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 225c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 235c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) */ 245c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 255c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#include "config.h" 265c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 275c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#if ENABLE(WEB_AUDIO) 285c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 291e202183a5dc46166763171984b285173f8585e5Torne (Richard Coles)#include "platform/audio/AudioResamplerKernel.h" 305c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 315c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#include <algorithm> 321e202183a5dc46166763171984b285173f8585e5Torne (Richard Coles)#include "platform/audio/AudioResampler.h" 335c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 34c1847b1379d12d0e05df27436bf19a9b1bf12deaTorne (Richard Coles)namespace blink { 3502772c6a72f1ee0b226341a4f4439970c29fc861Ben Murdoch 365c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)const size_t AudioResamplerKernel::MaxFramesToProcess = 128; 375c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 385c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)AudioResamplerKernel::AudioResamplerKernel(AudioResampler* resampler) 395c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) : m_resampler(resampler) 405c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // The buffer size must be large enough to hold up to two extra sample frames for the linear interpolation. 415c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) , m_sourceBuffer(2 + static_cast<int>(MaxFramesToProcess * AudioResampler::MaxRate)) 425c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) , m_virtualReadIndex(0.0) 435c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) , m_fillIndex(0) 445c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 455c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_lastValues[0] = 0.0f; 465c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_lastValues[1] = 0.0f; 475c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 485c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 495c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)float* AudioResamplerKernel::getSourcePointer(size_t framesToProcess, size_t* numberOfSourceFramesNeededP) 505c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 515c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) ASSERT(framesToProcess <= MaxFramesToProcess); 5202772c6a72f1ee0b226341a4f4439970c29fc861Ben Murdoch 535c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Calculate the next "virtual" index. After process() is called, m_virtualReadIndex will equal this value. 545c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) double nextFractionalIndex = m_virtualReadIndex + framesToProcess * rate(); 555c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 565c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Because we're linearly interpolating between the previous and next sample we need to round up so we include the next sample. 575c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) int endIndex = static_cast<int>(nextFractionalIndex + 1.0); // round up to next integer index 585c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 595c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Determine how many input frames we'll need. 605c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // We need to fill the buffer up to and including endIndex (so add 1) but we've already buffered m_fillIndex frames from last time. 615c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) size_t framesNeeded = 1 + endIndex - m_fillIndex; 625c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) if (numberOfSourceFramesNeededP) 635c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) *numberOfSourceFramesNeededP = framesNeeded; 645c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 655c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Do bounds checking for the source buffer. 665c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool isGood = m_fillIndex < m_sourceBuffer.size() && m_fillIndex + framesNeeded <= m_sourceBuffer.size(); 675c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) ASSERT(isGood); 685c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) if (!isGood) 695c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return 0; 705c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 715c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return m_sourceBuffer.data() + m_fillIndex; 725c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 735c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 745c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)void AudioResamplerKernel::process(float* destination, size_t framesToProcess) 755c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 765c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) ASSERT(framesToProcess <= MaxFramesToProcess); 775c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 785c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) float* source = m_sourceBuffer.data(); 7902772c6a72f1ee0b226341a4f4439970c29fc861Ben Murdoch 805c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) double rate = this->rate(); 817242dc3dbeb210b5e876a3c42d1ec1a667fc621aPrimiano Tucci rate = std::max(0.0, rate); 827242dc3dbeb210b5e876a3c42d1ec1a667fc621aPrimiano Tucci rate = std::min(AudioResampler::MaxRate, rate); 8302772c6a72f1ee0b226341a4f4439970c29fc861Ben Murdoch 845c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Start out with the previous saved values (if any). 855c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) if (m_fillIndex > 0) { 865c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) source[0] = m_lastValues[0]; 875c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) source[1] = m_lastValues[1]; 885c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) } 895c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 905c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Make a local copy. 915c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) double virtualReadIndex = m_virtualReadIndex; 9202772c6a72f1ee0b226341a4f4439970c29fc861Ben Murdoch 935c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Sanity check source buffer access. 945c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) ASSERT(framesToProcess > 0); 955c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) ASSERT(virtualReadIndex >= 0 && 1 + static_cast<unsigned>(virtualReadIndex + (framesToProcess - 1) * rate) < m_sourceBuffer.size()); 965c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 975c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Do the linear interpolation. 985c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) int n = framesToProcess; 995c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) while (n--) { 1005c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) unsigned readIndex = static_cast<unsigned>(virtualReadIndex); 1015c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) double interpolationFactor = virtualReadIndex - readIndex; 1025c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1035c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) double sample1 = source[readIndex]; 1045c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) double sample2 = source[readIndex + 1]; 1055c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1065c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) double sample = (1.0 - interpolationFactor) * sample1 + interpolationFactor * sample2; 1075c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1085c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) *destination++ = static_cast<float>(sample); 1095c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1105c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) virtualReadIndex += rate; 11102772c6a72f1ee0b226341a4f4439970c29fc861Ben Murdoch } 1125c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1135c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Save the last two sample-frames which will later be used at the beginning of the source buffer the next time around. 1145c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) int readIndex = static_cast<int>(virtualReadIndex); 1155c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_lastValues[0] = source[readIndex]; 1165c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_lastValues[1] = source[readIndex + 1]; 1175c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_fillIndex = 2; 1185c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1195c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Wrap the virtual read index back to the start of the buffer. 1205c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) virtualReadIndex -= readIndex; 1215c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1225c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Put local copy back into member variable. 1235c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_virtualReadIndex = virtualReadIndex; 1245c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 1255c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1265c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)void AudioResamplerKernel::reset() 1275c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 1285c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_virtualReadIndex = 0.0; 1295c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_fillIndex = 0; 1305c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_lastValues[0] = 0.0f; 1315c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) m_lastValues[1] = 0.0f; 1325c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 1335c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1345c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)double AudioResamplerKernel::rate() const 1355c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 1365c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return m_resampler->rate(); 1375c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 1385c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 139c1847b1379d12d0e05df27436bf19a9b1bf12deaTorne (Richard Coles)} // namespace blink 1405c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 1415c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#endif // ENABLE(WEB_AUDIO) 142