Function writeWavHeader

plugins/wasi_nn/wasinn_piper.cpp:32–66

Helper function to write the WAV header.

// Helper function to write the WAV header.
void writeWavHeader(int SampleRate, int16_t NumChannels, int32_t NumSamples,
                    std::vector<uint8_t> &OutputBuffer) {
  int32_t const ByteRate = SampleRate * NumChannels * sizeof(int16_t);
  int32_t const DataSize = NumSamples * NumChannels * sizeof(int16_t);
  int32_t const RiffSize = 36 + DataSize;

  auto PushU32 = [&](int32_t Val) {
    OutputBuffer.push_back(Val & 0xFF);
    OutputBuffer.push_back((Val >> 8) & 0xFF);
    OutputBuffer.push_back((Val >> 16) & 0xFF);
    OutputBuffer.push_back((Val >> 24) & 0xFF);
  };
  auto PushU16 = [&](int16_t Val) {
    OutputBuffer.push_back(Val & 0xFF);
    OutputBuffer.push_back((Val >> 8) & 0xFF);
  };
  auto PushStr = [&](const char *Str) {
    for (int I = 0; I < 4; I++)
      OutputBuffer.push_back(Str[I]);
  };

  PushStr("RIFF");
  PushU32(RiffSize);
  PushStr("WAVE");
  PushStr("fmt ");
  PushU32(16);
  PushU16(1);
  PushU16(NumChannels);
  PushU32(SampleRate);
  PushU32(ByteRate);
  PushU16(NumChannels * sizeof(int16_t));
  PushU16(16);
  PushStr("data");
  PushU32(DataSize);
}

} // namespace
template <typename T>