blob: 6b7220fb7f703006af170de82ccd896f2ef51017 [file] [log] [blame]
// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <memory>
#include "base/macros.h"
#include "third_party/blink/renderer/platform/audio/audio_array.h"
#include "third_party/blink/renderer/platform/audio/fft_frame.h"
#include "third_party/blink/renderer/platform/wtf/allocator.h"
namespace blink {
// The SimpleFFTConvolver does an FFT convolution. It differs from
// the FFTConvolver in that it restricts the maximum size of
// |convolution_kernel| to |input_block_size|. This restriction allows it to do
// an FFT on every Process call. Therefore, the processing delay of
// the SimpleFFTConvolver is the same as that of the DirectConvolver and thus
// smaller than that of the FFTConvolver.
class PLATFORM_EXPORT SimpleFFTConvolver {
size_t input_block_size,
const std::unique_ptr<AudioFloatArray>& convolution_kernel);
void Process(const float* source_p,
float* dest_p,
uint32_t frames_to_process);
void Reset();
size_t ConvolutionKernelSize() const { return convolution_kernel_size_; }
size_t FftSize() const { return frame_.FftSize(); }
size_t convolution_kernel_size_;
FFTFrame fft_kernel_;
FFTFrame frame_;
// Buffer input until we get fftSize / 2 samples then do an FFT
AudioFloatArray input_buffer_;
// Stores output which we read a little at a time
AudioFloatArray output_buffer_;
// Saves the 2nd half of the FFT buffer, so we can do an overlap-add with the
// 1st half of the next one
AudioFloatArray last_overlap_buffer_;
} // namespace blink