libbw64 – ITU-R BS.2088 Library

Introduction

The libbw64 library is a lightweight C++ header only library to read and write BW64 files. BW64 is standardised as Recommendation ITU-R BS.2088 and the successor of RF64. So it already contains necessary extensions to support files which are bigger than 4 GB. Apart from that a BW64 file is able to contain the ADM metadata and link it with the audio tracks in the file. To do that a BW64 file specifies two new RIFF chunks – the axml chunk and the chna chunk. To parse, create, modify and write the ADM metadata in the axml chunk you may use the libadm library.

Features

• no dependencies (only Boost 1.59 or later for the unit tests)
• support file sizes bigger than 4 GB (ds64 chunk)
• read and write axml and chna chunks
• 16, 24, and 32 bit integer file formats

Installation

Manual

Just copy the content of the include directory to your project or add the repository as a Git submodule to your project.

Alternatively the Git repository can be cloned and the library can be installed system wide using the used CMake build system (version 3.5 or later). See the following instructions for *nix systems.

git clone [email protected]:irt-open-source/libbw64.git
cd libbw64
mkdir build && cd build
cmake ..
make
make install

Basic usage

To use libbw64 simply include the main header file bw64.hpp and use the functions bw64::readFile and bw64::writeFile to create a BW64Reader or BW64Writer object. The functions return a unique_ptr to the object.

Read a BW64 file

#include <iostream>
#include <vector>
#include <bw64/bw64.hpp>

const unsigned int BLOCK_SIZE = 4096;

int main(int argc, char const* argv[]) {
  if (argc != 2) {
    std::cout << "usage: " << argv[0] << " [INFILE]" << std::endl;
    exit(1);
  }
  auto inFile = bw64::readFile(argv[1]);
  auto axmlChunk = inFile->axmlChunk();  // get axml chunk
  auto chnaChunk = inFile->chnaChunk();  // get chna chunk
  std::vector<float> buffer(BLOCK_SIZE * inFile->channels());
  while (!inFile->eof()) {
    auto readFrames = inFile->read(&buffer[0], BLOCK_SIZE);
    // TODO: process samples
  }
  return 0;
}

Write a BW64 file

#include <iostream>
#include <vector>
#include <bw64/bw64.hpp>

const unsigned int BLOCK_SIZE = 4096;

int main(int argc, char const* argv[]) {
  if (argc != 2) {
    std::cout << "usage: " << argv[0] << " [OUTFILE]" << std::endl;
    exit(1);
  }
  auto outFile = bw64::writeFile(argv[1]);
  std::vector<float> buffer(BLOCK_SIZE);
  for (int i = 0; i < 100; ++i) {
    // TODO: fill vector with data
    outFile->write(&buffer.front(), BLOCK_SIZE);
  }
  return 0;
}

More examples

See the examples folder in the repository for more examples.

Acknowledgement

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 687645.

License

Copyright 2018 Institut fuer Rundfunktechnik GmbH (IRT)

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.