michael@0: /*
michael@0:  * Copyright (C) 2010 Google Inc. All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  *
michael@0:  * 1.  Redistributions of source code must retain the above copyright
michael@0:  *     notice, this list of conditions and the following disclaimer.
michael@0:  * 2.  Redistributions in binary form must reproduce the above copyright
michael@0:  *     notice, this list of conditions and the following disclaimer in the
michael@0:  *     documentation and/or other materials provided with the distribution.
michael@0:  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
michael@0:  *     its contributors may be used to endorse or promote products derived
michael@0:  *     from this software without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
michael@0:  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
michael@0:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
michael@0:  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
michael@0:  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
michael@0:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
michael@0:  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
michael@0:  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
michael@0:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: 
michael@0: #include "HRTFElevation.h"
michael@0: 
michael@0: #include "speex/speex_resampler.h"
michael@0: #include "mozilla/PodOperations.h"
michael@0: #include "AudioSampleFormat.h"
michael@0: 
michael@0: #include "IRC_Composite_C_R0195-incl.cpp"
michael@0: 
michael@0: using namespace std;
michael@0: using namespace mozilla;
michael@0:  
michael@0: namespace WebCore {
michael@0: 
michael@0: const int elevationSpacing = irc_composite_c_r0195_elevation_interval;
michael@0: const int firstElevation = irc_composite_c_r0195_first_elevation;
michael@0: const int numberOfElevations = MOZ_ARRAY_LENGTH(irc_composite_c_r0195);
michael@0: 
michael@0: const unsigned HRTFElevation::NumberOfTotalAzimuths = 360 / 15 * 8;
michael@0: 
michael@0: const int rawSampleRate = irc_composite_c_r0195_sample_rate;
michael@0: 
michael@0: // Number of frames in an individual impulse response.
michael@0: const size_t ResponseFrameSize = 256;
michael@0: 
michael@0: size_t HRTFElevation::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
michael@0: {
michael@0:     size_t amount = aMallocSizeOf(this);
michael@0: 
michael@0:     amount += m_kernelListL.SizeOfExcludingThis(aMallocSizeOf);
michael@0:     for (size_t i = 0; i < m_kernelListL.Length(); i++) {
michael@0:         amount += m_kernelListL[i]->sizeOfIncludingThis(aMallocSizeOf);
michael@0:     }
michael@0: 
michael@0:     return amount;
michael@0: }
michael@0: 
michael@0: size_t HRTFElevation::fftSizeForSampleRate(float sampleRate)
michael@0: {
michael@0:     // The IRCAM HRTF impulse responses were 512 sample-frames @44.1KHz,
michael@0:     // but these have been truncated to 256 samples.
michael@0:     // An FFT-size of twice impulse response size is used (for convolution).
michael@0:     // So for sample rates of 44.1KHz an FFT size of 512 is good.
michael@0:     // We double the FFT-size only for sample rates at least double this.
michael@0:     // If the FFT size is too large then the impulse response will be padded
michael@0:     // with zeros without the fade-out provided by HRTFKernel.
michael@0:     MOZ_ASSERT(sampleRate > 1.0 && sampleRate < 1048576.0);
michael@0: 
michael@0:     // This is the size if we were to use all raw response samples.
michael@0:     unsigned resampledLength =
michael@0:         floorf(ResponseFrameSize * sampleRate / rawSampleRate);
michael@0:     // Keep things semi-sane, with max FFT size of 1024 and minimum of 4.
michael@0:     // "size |= 3" ensures a minimum of 4 (with the size++ below) and sets the
michael@0:     // 2 least significant bits for rounding up to the next power of 2 below.
michael@0:     unsigned size = min(resampledLength, 1023U);
michael@0:     size |= 3;
michael@0:     // Round up to the next power of 2, making the FFT size no more than twice
michael@0:     // the impulse response length.  This doubles size for values that are
michael@0:     // already powers of 2.  This works by filling in 7 bits to right of the
michael@0:     // most significant bit.  The most significant bit is no greater than
michael@0:     // 1 << 9, and the least significant 2 bits were already set above.
michael@0:     size |= (size >> 1);
michael@0:     size |= (size >> 2);
michael@0:     size |= (size >> 4);
michael@0:     size++;
michael@0:     MOZ_ASSERT((size & (size - 1)) == 0);
michael@0: 
michael@0:     return size;
michael@0: }
michael@0: 
michael@0: nsReturnRef<HRTFKernel> HRTFElevation::calculateKernelForAzimuthElevation(int azimuth, int elevation, SpeexResamplerState* resampler, float sampleRate)
michael@0: {
michael@0:     int elevationIndex = (elevation - firstElevation) / elevationSpacing;
michael@0:     MOZ_ASSERT(elevationIndex >= 0 && elevationIndex <= numberOfElevations);
michael@0: 
michael@0:     int numberOfAzimuths = irc_composite_c_r0195[elevationIndex].count;
michael@0:     int azimuthSpacing = 360 / numberOfAzimuths;
michael@0:     MOZ_ASSERT(numberOfAzimuths * azimuthSpacing == 360);
michael@0: 
michael@0:     int azimuthIndex = azimuth / azimuthSpacing;
michael@0:     MOZ_ASSERT(azimuthIndex * azimuthSpacing == azimuth);
michael@0: 
michael@0:     const int16_t (&impulse_response_data)[ResponseFrameSize] =
michael@0:         irc_composite_c_r0195[elevationIndex].azimuths[azimuthIndex];
michael@0: 
michael@0:     // When libspeex_resampler is compiled with FIXED_POINT, samples in
michael@0:     // speex_resampler_process_float are rounded directly to int16_t, which
michael@0:     // only works well if the floats are in the range +/-32767.  On such
michael@0:     // platforms it's better to resample before converting to float anyway.
michael@0: #ifdef MOZ_SAMPLE_TYPE_S16
michael@0: #  define RESAMPLER_PROCESS speex_resampler_process_int
michael@0:     const int16_t* response = impulse_response_data;
michael@0:     const int16_t* resampledResponse;
michael@0: #else
michael@0: #  define RESAMPLER_PROCESS speex_resampler_process_float
michael@0:     float response[ResponseFrameSize];
michael@0:     ConvertAudioSamples(impulse_response_data, response, ResponseFrameSize);
michael@0:     float* resampledResponse;
michael@0: #endif
michael@0: 
michael@0:     // Note that depending on the fftSize returned by the panner, we may be truncating the impulse response.
michael@0:     const size_t resampledResponseLength = fftSizeForSampleRate(sampleRate) / 2;
michael@0: 
michael@0:     nsAutoTArray<AudioDataValue, 2 * ResponseFrameSize> resampled;
michael@0:     if (sampleRate == rawSampleRate) {
michael@0:         resampledResponse = response;
michael@0:         MOZ_ASSERT(resampledResponseLength == ResponseFrameSize);
michael@0:     } else {
michael@0:         resampled.SetLength(resampledResponseLength);
michael@0:         resampledResponse = resampled.Elements();
michael@0:         speex_resampler_skip_zeros(resampler);
michael@0: 
michael@0:         // Feed the input buffer into the resampler.
michael@0:         spx_uint32_t in_len = ResponseFrameSize;
michael@0:         spx_uint32_t out_len = resampled.Length();
michael@0:         RESAMPLER_PROCESS(resampler, 0, response, &in_len,
michael@0:                           resampled.Elements(), &out_len);
michael@0: 
michael@0:         if (out_len < resampled.Length()) {
michael@0:             // The input should have all been processed.
michael@0:             MOZ_ASSERT(in_len == ResponseFrameSize);
michael@0:             // Feed in zeros get the data remaining in the resampler.
michael@0:             spx_uint32_t out_index = out_len;
michael@0:             in_len = speex_resampler_get_input_latency(resampler);
michael@0:             out_len = resampled.Length() - out_index;
michael@0:             RESAMPLER_PROCESS(resampler, 0, nullptr, &in_len,
michael@0:                               resampled.Elements() + out_index, &out_len);
michael@0:             out_index += out_len;
michael@0:             // There may be some uninitialized samples remaining for very low
michael@0:             // sample rates.
michael@0:             PodZero(resampled.Elements() + out_index,
michael@0:                     resampled.Length() - out_index);
michael@0:         }
michael@0: 
michael@0:         speex_resampler_reset_mem(resampler);
michael@0:     }
michael@0: 
michael@0: #ifdef MOZ_SAMPLE_TYPE_S16
michael@0:     nsAutoTArray<float, 2 * ResponseFrameSize> floatArray;
michael@0:     floatArray.SetLength(resampledResponseLength);
michael@0:     float *floatResponse = floatArray.Elements();
michael@0:     ConvertAudioSamples(resampledResponse,
michael@0:                         floatResponse, resampledResponseLength);
michael@0: #else
michael@0:     float *floatResponse = resampledResponse;
michael@0: #endif
michael@0: #undef RESAMPLER_PROCESS
michael@0: 
michael@0:     return HRTFKernel::create(floatResponse, resampledResponseLength, sampleRate);
michael@0: }
michael@0: 
michael@0: // The range of elevations for the IRCAM impulse responses varies depending on azimuth, but the minimum elevation appears to always be -45.
michael@0: //
michael@0: // Here's how it goes:
michael@0: static int maxElevations[] = {
michael@0:         //  Azimuth
michael@0:         //
michael@0:     90, // 0  
michael@0:     45, // 15 
michael@0:     60, // 30 
michael@0:     45, // 45 
michael@0:     75, // 60 
michael@0:     45, // 75 
michael@0:     60, // 90 
michael@0:     45, // 105 
michael@0:     75, // 120 
michael@0:     45, // 135 
michael@0:     60, // 150 
michael@0:     45, // 165 
michael@0:     75, // 180 
michael@0:     45, // 195 
michael@0:     60, // 210 
michael@0:     45, // 225 
michael@0:     75, // 240 
michael@0:     45, // 255 
michael@0:     60, // 270 
michael@0:     45, // 285 
michael@0:     75, // 300 
michael@0:     45, // 315 
michael@0:     60, // 330 
michael@0:     45 //  345 
michael@0: };
michael@0: 
michael@0: nsReturnRef<HRTFElevation> HRTFElevation::createBuiltin(int elevation, float sampleRate)
michael@0: {
michael@0:     if (elevation < firstElevation ||
michael@0:         elevation > firstElevation + numberOfElevations * elevationSpacing ||
michael@0:         (elevation / elevationSpacing) * elevationSpacing != elevation)
michael@0:         return nsReturnRef<HRTFElevation>();
michael@0:         
michael@0:     // Spacing, in degrees, between every azimuth loaded from resource.
michael@0:     // Some elevations do not have data for all these intervals.
michael@0:     // See maxElevations.
michael@0:     static const unsigned AzimuthSpacing = 15;
michael@0:     static const unsigned NumberOfRawAzimuths = 360 / AzimuthSpacing;
michael@0:     static_assert(AzimuthSpacing * NumberOfRawAzimuths == 360,
michael@0:                   "Not a multiple");
michael@0:     static const unsigned InterpolationFactor =
michael@0:         NumberOfTotalAzimuths / NumberOfRawAzimuths;
michael@0:     static_assert(NumberOfTotalAzimuths ==
michael@0:                   NumberOfRawAzimuths * InterpolationFactor, "Not a multiple");
michael@0: 
michael@0:     HRTFKernelList kernelListL;
michael@0:     kernelListL.SetLength(NumberOfTotalAzimuths);
michael@0: 
michael@0:     SpeexResamplerState* resampler = sampleRate == rawSampleRate ? nullptr :
michael@0:         speex_resampler_init(1, rawSampleRate, sampleRate,
michael@0:                              SPEEX_RESAMPLER_QUALITY_DEFAULT, nullptr);
michael@0: 
michael@0:     // Load convolution kernels from HRTF files.
michael@0:     int interpolatedIndex = 0;
michael@0:     for (unsigned rawIndex = 0; rawIndex < NumberOfRawAzimuths; ++rawIndex) {
michael@0:         // Don't let elevation exceed maximum for this azimuth.
michael@0:         int maxElevation = maxElevations[rawIndex];
michael@0:         int actualElevation = min(elevation, maxElevation);
michael@0: 
michael@0:         kernelListL[interpolatedIndex] = calculateKernelForAzimuthElevation(rawIndex * AzimuthSpacing, actualElevation, resampler, sampleRate);
michael@0:             
michael@0:         interpolatedIndex += InterpolationFactor;
michael@0:     }
michael@0: 
michael@0:     if (resampler)
michael@0:         speex_resampler_destroy(resampler);
michael@0: 
michael@0:     // Now go back and interpolate intermediate azimuth values.
michael@0:     for (unsigned i = 0; i < NumberOfTotalAzimuths; i += InterpolationFactor) {
michael@0:         int j = (i + InterpolationFactor) % NumberOfTotalAzimuths;
michael@0: 
michael@0:         // Create the interpolated convolution kernels and delays.
michael@0:         for (unsigned jj = 1; jj < InterpolationFactor; ++jj) {
michael@0:             float x = float(jj) / float(InterpolationFactor); // interpolate from 0 -> 1
michael@0: 
michael@0:             kernelListL[i + jj] = HRTFKernel::createInterpolatedKernel(kernelListL[i], kernelListL[j], x);
michael@0:         }
michael@0:     }
michael@0:     
michael@0:     return nsReturnRef<HRTFElevation>(new HRTFElevation(&kernelListL, elevation, sampleRate));
michael@0: }
michael@0: 
michael@0: nsReturnRef<HRTFElevation> HRTFElevation::createByInterpolatingSlices(HRTFElevation* hrtfElevation1, HRTFElevation* hrtfElevation2, float x, float sampleRate)
michael@0: {
michael@0:     MOZ_ASSERT(hrtfElevation1 && hrtfElevation2);
michael@0:     if (!hrtfElevation1 || !hrtfElevation2)
michael@0:         return nsReturnRef<HRTFElevation>();
michael@0:         
michael@0:     MOZ_ASSERT(x >= 0.0 && x < 1.0);
michael@0:     
michael@0:     HRTFKernelList kernelListL;
michael@0:     kernelListL.SetLength(NumberOfTotalAzimuths);
michael@0: 
michael@0:     const HRTFKernelList& kernelListL1 = hrtfElevation1->kernelListL();
michael@0:     const HRTFKernelList& kernelListL2 = hrtfElevation2->kernelListL();
michael@0:     
michael@0:     // Interpolate kernels of corresponding azimuths of the two elevations.
michael@0:     for (unsigned i = 0; i < NumberOfTotalAzimuths; ++i) {
michael@0:         kernelListL[i] = HRTFKernel::createInterpolatedKernel(kernelListL1[i], kernelListL2[i], x);
michael@0:     }
michael@0: 
michael@0:     // Interpolate elevation angle.
michael@0:     double angle = (1.0 - x) * hrtfElevation1->elevationAngle() + x * hrtfElevation2->elevationAngle();
michael@0:     
michael@0:     return nsReturnRef<HRTFElevation>(new HRTFElevation(&kernelListL, static_cast<int>(angle), sampleRate));
michael@0: }
michael@0: 
michael@0: void HRTFElevation::getKernelsFromAzimuth(double azimuthBlend, unsigned azimuthIndex, HRTFKernel* &kernelL, HRTFKernel* &kernelR, double& frameDelayL, double& frameDelayR)
michael@0: {
michael@0:     bool checkAzimuthBlend = azimuthBlend >= 0.0 && azimuthBlend < 1.0;
michael@0:     MOZ_ASSERT(checkAzimuthBlend);
michael@0:     if (!checkAzimuthBlend)
michael@0:         azimuthBlend = 0.0;
michael@0:     
michael@0:     unsigned numKernels = m_kernelListL.Length();
michael@0: 
michael@0:     bool isIndexGood = azimuthIndex < numKernels;
michael@0:     MOZ_ASSERT(isIndexGood);
michael@0:     if (!isIndexGood) {
michael@0:         kernelL = 0;
michael@0:         kernelR = 0;
michael@0:         return;
michael@0:     }
michael@0:     
michael@0:     // Return the left and right kernels,
michael@0:     // using symmetry to produce the right kernel.
michael@0:     kernelL = m_kernelListL[azimuthIndex];
michael@0:     int azimuthIndexR = (numKernels - azimuthIndex) % numKernels;
michael@0:     kernelR = m_kernelListL[azimuthIndexR];
michael@0: 
michael@0:     frameDelayL = kernelL->frameDelay();
michael@0:     frameDelayR = kernelR->frameDelay();
michael@0: 
michael@0:     int azimuthIndex2L = (azimuthIndex + 1) % numKernels;
michael@0:     double frameDelay2L = m_kernelListL[azimuthIndex2L]->frameDelay();
michael@0:     int azimuthIndex2R = (numKernels - azimuthIndex2L) % numKernels;
michael@0:     double frameDelay2R = m_kernelListL[azimuthIndex2R]->frameDelay();
michael@0: 
michael@0:     // Linearly interpolate delays.
michael@0:     frameDelayL = (1.0 - azimuthBlend) * frameDelayL + azimuthBlend * frameDelay2L;
michael@0:     frameDelayR = (1.0 - azimuthBlend) * frameDelayR + azimuthBlend * frameDelay2R;
michael@0: }
michael@0: 
michael@0: } // namespace WebCore