signal/tensorflow_core/kernels/window_kernel.cc

/* Copyright 2022 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/

#include "signal/src/window.h"
#include "tensorflow/core/framework/op_kernel.h"

namespace tensorflow {
namespace signal {

class WindowOp : public tensorflow::OpKernel {
 public:
  explicit WindowOp(tensorflow::OpKernelConstruction* context)
      : tensorflow::OpKernel(context) {
    OP_REQUIRES_OK(context, context->GetAttr("shift", &shift_));
  }

  void Compute(tensorflow::OpKernelContext* context) override {
    const tensorflow::Tensor& input_tensor = context->input(0);
    const int16_t* input = input_tensor.flat<int16_t>().data();
    const tensorflow::Tensor& weight_tensor = context->input(1);
    const int16_t* weights = weight_tensor.flat<int16_t>().data();
    int weight_size = weight_tensor.flat<int16_t>().size();
    int outer_dims =
        input_tensor.flat_inner_dims<int16_t, 2>().dimensions().at(0);

    tensorflow::Tensor* output_tensor = nullptr;
    OP_REQUIRES_OK(context, context->allocate_output(0, input_tensor.shape(),
                                                     &output_tensor));
    int16_t* output = output_tensor->flat<int16_t>().data();
    for (int i = 0; i < outer_dims; i++) {
      tflm_signal::ApplyWindow(&input[i * weight_size], weights, weight_size,
                               shift_, &output[i * weight_size]);
    }
  }

 private:
  int shift_;
};

// TODO(b/286250473): change back name to "Window" after name clash resolved
REGISTER_KERNEL_BUILDER(Name("SignalWindow").Device(tensorflow::DEVICE_CPU),
                        WindowOp);

}  // namespace signal
}  // namespace tensorflow