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Diffstat (limited to 'dom/media/webaudio/blink/HRTFElevation.cpp')
| -rw-r--r-- | dom/media/webaudio/blink/HRTFElevation.cpp | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/dom/media/webaudio/blink/HRTFElevation.cpp b/dom/media/webaudio/blink/HRTFElevation.cpp new file mode 100644 index 0000000000..af4e520384 --- /dev/null +++ b/dom/media/webaudio/blink/HRTFElevation.cpp @@ -0,0 +1,338 @@ +/* + * 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 "HRTFElevation.h" + +#include <speex/speex_resampler.h> +#include "mozilla/PodOperations.h" +#include "AudioSampleFormat.h" + +#include "IRC_Composite_C_R0195-incl.cpp" + +using namespace mozilla; + +namespace WebCore { + +const int elevationSpacing = irc_composite_c_r0195_elevation_interval; +const int firstElevation = irc_composite_c_r0195_first_elevation; +const int numberOfElevations = MOZ_ARRAY_LENGTH(irc_composite_c_r0195); + +const unsigned HRTFElevation::NumberOfTotalAzimuths = 360 / 15 * 8; + +const int rawSampleRate = irc_composite_c_r0195_sample_rate; + +// Number of frames in an individual impulse response. +const size_t ResponseFrameSize = 256; + +size_t HRTFElevation::sizeOfIncludingThis( + mozilla::MallocSizeOf aMallocSizeOf) const { + size_t amount = aMallocSizeOf(this); + + amount += m_kernelListL.ShallowSizeOfExcludingThis(aMallocSizeOf); + for (size_t i = 0; i < m_kernelListL.Length(); i++) { + amount += m_kernelListL[i]->sizeOfIncludingThis(aMallocSizeOf); + } + + return amount; +} + +size_t HRTFElevation::fftSizeForSampleRate(float sampleRate) { + // The IRCAM HRTF impulse responses were 512 sample-frames @44.1KHz, + // but these have been truncated to 256 samples. + // An FFT-size of twice impulse response size is used (for convolution). + // So for sample rates of 44.1KHz an FFT size of 512 is good. + // We double the FFT-size only for sample rates at least double this. + // If the FFT size is too large then the impulse response will be padded + // with zeros without the fade-out provided by HRTFKernel. + MOZ_ASSERT(sampleRate > 1.0 && sampleRate < 1048576.0); + + // This is the size if we were to use all raw response samples. + unsigned resampledLength = + floorf(ResponseFrameSize * sampleRate / rawSampleRate); + // Keep things semi-sane, with max FFT size of 1024. + unsigned size = std::min(resampledLength, 1023U); + // Ensure a minimum of 2 * WEBAUDIO_BLOCK_SIZE (with the size++ below) for + // FFTConvolver and set the 8 least significant bits for rounding up to + // the next power of 2 below. + size |= 2 * WEBAUDIO_BLOCK_SIZE - 1; + // Round up to the next power of 2, making the FFT size no more than twice + // the impulse response length. This doubles size for values that are + // already powers of 2. This works by filling in alls bit to right of the + // most significant bit. The most significant bit is no greater than + // 1 << 9, and the least significant 8 bits were already set above, so + // there is at most one bit to add. + size |= (size >> 1); + size++; + MOZ_ASSERT((size & (size - 1)) == 0); + + return size; +} + +nsReturnRef<HRTFKernel> HRTFElevation::calculateKernelForAzimuthElevation( + int azimuth, int elevation, SpeexResamplerState* resampler, + float sampleRate) { + int elevationIndex = (elevation - firstElevation) / elevationSpacing; + MOZ_ASSERT(elevationIndex >= 0 && elevationIndex <= numberOfElevations); + + int numberOfAzimuths = irc_composite_c_r0195[elevationIndex].count; + int azimuthSpacing = 360 / numberOfAzimuths; + MOZ_ASSERT(numberOfAzimuths * azimuthSpacing == 360); + + int azimuthIndex = azimuth / azimuthSpacing; + MOZ_ASSERT(azimuthIndex * azimuthSpacing == azimuth); + + const int16_t(&impulse_response_data)[ResponseFrameSize] = + irc_composite_c_r0195[elevationIndex].azimuths[azimuthIndex]; + + // When libspeex_resampler is compiled with FIXED_POINT, samples in + // speex_resampler_process_float are rounded directly to int16_t, which + // only works well if the floats are in the range +/-32767. On such + // platforms it's better to resample before converting to float anyway. +#ifdef MOZ_SAMPLE_TYPE_S16 +# define RESAMPLER_PROCESS speex_resampler_process_int + const int16_t* response = impulse_response_data; + const int16_t* resampledResponse; +#else +# define RESAMPLER_PROCESS speex_resampler_process_float + float response[ResponseFrameSize]; + ConvertAudioSamples(impulse_response_data, response, ResponseFrameSize); + float* resampledResponse; +#endif + + // Note that depending on the fftSize returned by the panner, we may be + // truncating the impulse response. + const size_t resampledResponseLength = fftSizeForSampleRate(sampleRate) / 2; + + AutoTArray<AudioDataValue, 2 * ResponseFrameSize> resampled; + if (sampleRate == rawSampleRate) { + resampledResponse = response; + MOZ_ASSERT(resampledResponseLength == ResponseFrameSize); + } else { + resampled.SetLength(resampledResponseLength); + resampledResponse = resampled.Elements(); + speex_resampler_skip_zeros(resampler); + + // Feed the input buffer into the resampler. + spx_uint32_t in_len = ResponseFrameSize; + spx_uint32_t out_len = resampled.Length(); + RESAMPLER_PROCESS(resampler, 0, response, &in_len, resampled.Elements(), + &out_len); + + if (out_len < resampled.Length()) { + // The input should have all been processed. + MOZ_ASSERT(in_len == ResponseFrameSize); + // Feed in zeros get the data remaining in the resampler. + spx_uint32_t out_index = out_len; + in_len = speex_resampler_get_input_latency(resampler); + out_len = resampled.Length() - out_index; + RESAMPLER_PROCESS(resampler, 0, nullptr, &in_len, + resampled.Elements() + out_index, &out_len); + out_index += out_len; + // There may be some uninitialized samples remaining for very low + // sample rates. + PodZero(resampled.Elements() + out_index, resampled.Length() - out_index); + } + + speex_resampler_reset_mem(resampler); + } + +#ifdef MOZ_SAMPLE_TYPE_S16 + AutoTArray<float, 2 * ResponseFrameSize> floatArray; + floatArray.SetLength(resampledResponseLength); + float* floatResponse = floatArray.Elements(); + ConvertAudioSamples(resampledResponse, floatResponse, + resampledResponseLength); +#else + float* floatResponse = resampledResponse; +#endif +#undef RESAMPLER_PROCESS + + return HRTFKernel::create(floatResponse, resampledResponseLength, sampleRate); +} + +// The range of elevations for the IRCAM impulse responses varies depending on +// azimuth, but the minimum elevation appears to always be -45. +// +// Here's how it goes: +static int maxElevations[] = { + // Azimuth + // + 90, // 0 + 45, // 15 + 60, // 30 + 45, // 45 + 75, // 60 + 45, // 75 + 60, // 90 + 45, // 105 + 75, // 120 + 45, // 135 + 60, // 150 + 45, // 165 + 75, // 180 + 45, // 195 + 60, // 210 + 45, // 225 + 75, // 240 + 45, // 255 + 60, // 270 + 45, // 285 + 75, // 300 + 45, // 315 + 60, // 330 + 45 // 345 +}; + +nsReturnRef<HRTFElevation> HRTFElevation::createBuiltin(int elevation, + float sampleRate) { + if (elevation < firstElevation || + elevation > firstElevation + numberOfElevations * elevationSpacing || + (elevation / elevationSpacing) * elevationSpacing != elevation) + return nsReturnRef<HRTFElevation>(); + + // Spacing, in degrees, between every azimuth loaded from resource. + // Some elevations do not have data for all these intervals. + // See maxElevations. + static const unsigned AzimuthSpacing = 15; + static const unsigned NumberOfRawAzimuths = 360 / AzimuthSpacing; + static_assert(AzimuthSpacing * NumberOfRawAzimuths == 360, "Not a multiple"); + static const unsigned InterpolationFactor = + NumberOfTotalAzimuths / NumberOfRawAzimuths; + static_assert( + NumberOfTotalAzimuths == NumberOfRawAzimuths * InterpolationFactor, + "Not a multiple"); + + HRTFKernelList kernelListL; + kernelListL.SetLength(NumberOfTotalAzimuths); + + SpeexResamplerState* resampler = + sampleRate == rawSampleRate + ? nullptr + : speex_resampler_init(1, rawSampleRate, sampleRate, + SPEEX_RESAMPLER_QUALITY_MIN, nullptr); + + // Load convolution kernels from HRTF files. + int interpolatedIndex = 0; + for (unsigned rawIndex = 0; rawIndex < NumberOfRawAzimuths; ++rawIndex) { + // Don't let elevation exceed maximum for this azimuth. + int maxElevation = maxElevations[rawIndex]; + int actualElevation = std::min(elevation, maxElevation); + + kernelListL[interpolatedIndex] = calculateKernelForAzimuthElevation( + rawIndex * AzimuthSpacing, actualElevation, resampler, sampleRate); + + interpolatedIndex += InterpolationFactor; + } + + if (resampler) speex_resampler_destroy(resampler); + + // Now go back and interpolate intermediate azimuth values. + for (unsigned i = 0; i < NumberOfTotalAzimuths; i += InterpolationFactor) { + int j = (i + InterpolationFactor) % NumberOfTotalAzimuths; + + // Create the interpolated convolution kernels and delays. + for (unsigned jj = 1; jj < InterpolationFactor; ++jj) { + float x = + float(jj) / float(InterpolationFactor); // interpolate from 0 -> 1 + + kernelListL[i + jj] = HRTFKernel::createInterpolatedKernel( + kernelListL[i], kernelListL[j], x); + } + } + + return nsReturnRef<HRTFElevation>( + new HRTFElevation(std::move(kernelListL), elevation, sampleRate)); +} + +nsReturnRef<HRTFElevation> HRTFElevation::createByInterpolatingSlices( + HRTFElevation* hrtfElevation1, HRTFElevation* hrtfElevation2, float x, + float sampleRate) { + MOZ_ASSERT(hrtfElevation1 && hrtfElevation2); + if (!hrtfElevation1 || !hrtfElevation2) return nsReturnRef<HRTFElevation>(); + + MOZ_ASSERT(x >= 0.0 && x < 1.0); + + HRTFKernelList kernelListL; + kernelListL.SetLength(NumberOfTotalAzimuths); + + const HRTFKernelList& kernelListL1 = hrtfElevation1->kernelListL(); + const HRTFKernelList& kernelListL2 = hrtfElevation2->kernelListL(); + + // Interpolate kernels of corresponding azimuths of the two elevations. + for (unsigned i = 0; i < NumberOfTotalAzimuths; ++i) { + kernelListL[i] = HRTFKernel::createInterpolatedKernel(kernelListL1[i], + kernelListL2[i], x); + } + + // Interpolate elevation angle. + double angle = (1.0 - x) * hrtfElevation1->elevationAngle() + + x * hrtfElevation2->elevationAngle(); + + return nsReturnRef<HRTFElevation>(new HRTFElevation( + std::move(kernelListL), static_cast<int>(angle), sampleRate)); +} + +void HRTFElevation::getKernelsFromAzimuth( + double azimuthBlend, unsigned azimuthIndex, HRTFKernel*& kernelL, + HRTFKernel*& kernelR, double& frameDelayL, double& frameDelayR) { + bool checkAzimuthBlend = azimuthBlend >= 0.0 && azimuthBlend < 1.0; + MOZ_ASSERT(checkAzimuthBlend); + if (!checkAzimuthBlend) azimuthBlend = 0.0; + + unsigned numKernels = m_kernelListL.Length(); + + bool isIndexGood = azimuthIndex < numKernels; + MOZ_ASSERT(isIndexGood); + if (!isIndexGood) { + kernelL = 0; + kernelR = 0; + return; + } + + // Return the left and right kernels, + // using symmetry to produce the right kernel. + kernelL = m_kernelListL[azimuthIndex]; + int azimuthIndexR = (numKernels - azimuthIndex) % numKernels; + kernelR = m_kernelListL[azimuthIndexR]; + + frameDelayL = kernelL->frameDelay(); + frameDelayR = kernelR->frameDelay(); + + int azimuthIndex2L = (azimuthIndex + 1) % numKernels; + double frameDelay2L = m_kernelListL[azimuthIndex2L]->frameDelay(); + int azimuthIndex2R = (numKernels - azimuthIndex2L) % numKernels; + double frameDelay2R = m_kernelListL[azimuthIndex2R]->frameDelay(); + + // Linearly interpolate delays. + frameDelayL = + (1.0 - azimuthBlend) * frameDelayL + azimuthBlend * frameDelay2L; + frameDelayR = + (1.0 - azimuthBlend) * frameDelayR + azimuthBlend * frameDelay2R; +} + +} // namespace WebCore |