text: /*
   *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #ifndef MODULES_AUDIO_PROCESSING_TRANSIENT_FILE_UTILS_H_
  #define MODULES_AUDIO_PROCESSING_TRANSIENT_FILE_UTILS_H_
  
  #include <string.h>
  
  #include "rtc_base/system/file_wrapper.h"
  
  namespace webrtc {
  
  // This is a copy of the cast included in the Chromium codebase here:
  // http://cs.chromium.org/src/third_party/cld/base/casts.h
  template <class Dest, class Source>
  inline Dest bit_cast(const Source& source) {
    // A compile error here means your Dest and Source have different sizes.
    static_assert(sizeof(Dest) == sizeof(Source),
                  "Dest and Source have different sizes");
  
    Dest dest;
    memcpy(&dest, &source, sizeof(dest));
    return dest;
  }
  
  // Converts the byte array with binary float representation to float.
  // Bytes must be in little-endian order.
  // Returns 0 if correct, -1 on error.
  int ConvertByteArrayToFloat(const uint8_t bytes[4], float* out);
  
  // Converts the byte array with binary double representation to double.
  // Bytes must be in little-endian order.
  // Returns 0 if correct, -1 on error.
  int ConvertByteArrayToDouble(const uint8_t bytes[8], double* out);
  
  // Converts a float to a byte array with binary float representation.
  // Bytes will be in little-endian order.
  // Returns 0 if correct, -1 on error.
  int ConvertFloatToByteArray(float value, uint8_t out_bytes[4]);
  
  // Converts a double to a byte array with binary double representation.
  // Bytes will be in little-endian order.
  // Returns 0 if correct, -1 on error.
  int ConvertDoubleToByteArray(double value, uint8_t out_bytes[8]);
  
  // Reads `length` 16-bit integers from `file` to `buffer`.
  // `file` must be previously opened.
  // Returns the number of 16-bit integers read or -1 on error.
  size_t ReadInt16BufferFromFile(FileWrapper* file,
                                 size_t length,
                                 int16_t* buffer);
  
  // Reads `length` 16-bit integers from `file` and stores those values
  // (converting them) in `buffer`.
  // `file` must be previously opened.
  // Returns the number of 16-bit integers read or -1 on error.
  size_t ReadInt16FromFileToFloatBuffer(FileWrapper* file,
                                        size_t length,
                                        float* buffer);
  
  // Reads `length` 16-bit integers from `file` and stores those values
  // (converting them) in `buffer`.
  // `file` must be previously opened.
  // Returns the number of 16-bit integers read or -1 on error.
  size_t ReadInt16FromFileToDoubleBuffer(FileWrapper* file,
                                         size_t length,
                                         double* buffer);
  
  // Reads `length` floats in binary representation (4 bytes) from `file` to
  // `buffer`.
  // `file` must be previously opened.
  // Returns the number of floats read or -1 on error.
  size_t ReadFloatBufferFromFile(FileWrapper* file, size_t length, float* buffer);
  
  // Reads `length` doubles in binary representation (8 bytes) from `file` to
  // `buffer`.
  // `file` must be previously opened.
  // Returns the number of doubles read or -1 on error.
  size_t ReadDoubleBufferFromFile(FileWrapper* file,
                                  size_t length,
                                  double* buffer);
  
  // Writes `length` 16-bit integers from `buffer` in binary representation (2
  // bytes) to `file`. It flushes `file`, so after this call there are no
  // writings pending.
  // `file` must be previously opened.
  // Returns the number of doubles written or -1 on error.
  size_t WriteInt16BufferToFile(FileWrapper* file,
                                size_t length,
                                const int16_t* buffer);
  
  // Writes `length` floats from `buffer` in binary representation (4 bytes) to
  // `file`. It flushes `file`, so after this call there are no writtings pending.
  // `file` must be previously opened.
  // Returns the number of doubles written or -1 on error.
  size_t WriteFloatBufferToFile(FileWrapper* file,
                                size_t length,
                                const float* buffer);
  
  // Writes `length` doubles from `buffer` in binary representation (8 bytes) to
  // `file`. It flushes `file`, so after this call there are no writings pending.
  // `file` must be previously opened.
  // Returns the number of doubles written or -1 on error.
  size_t WriteDoubleBufferToFile(FileWrapper* file,
                                 size_t length,
                                 const double* buffer);
  
  }  // namespace webrtc
  
  #endif  // MODULES_AUDIO_PROCESSING_TRANSIENT_FILE_UTILS_H_
  