Ratl (Real-time Audio Template Library)

ratl (pronounced rattle) is a C++ header-only library that is designed to help with the processing of real-time audio data. It does this by providing clear and unambiguous types to hold and represent audio data as well as fast and easy ways to convert audio data between these various types.

Features

Support for:

1. 16 bit, 24 bit, and 32 bit integer, and 32 bit floating point samples
2. Host byte order and network byte order samples
3. Interleaved and non-interleaved audio buffers
4. Optional sample dithering

Usage

Converting a 2 channel, 128 frame interleaved buffer of host-order 32-bit floats to network-order 16-bit integers, with dithering:

std::size_t channels = 2;
std::size_t frames = 128;
ratl::interleaved<ratl::float32_t> input = generate_tone(channels, frames);
ratl::network_interleaved<ratl::int16_t> output(channels, frames);
ratl::dither_generator dither_gen;
ratl::transform(input.begin(), input.end(), output.begin(), dither_gen);

Converting a 4 channel, 32 frame externally-allocated interleaved buffer of network-order 24-bit integers to a non-interleaved buffer of host-order 32-bit floats:

std::size_t channels = 4;
std::size_t frames = 32;
const unsigned char* data = read(sizeof(ratl::int24_t) * channels * frames);
ratl::const_network_interleaved_span<ratl::int24_t> input(data, channels, frames);
ratl::noninterleaved<ratl::float32_t> output(channels, frames);
ratl::transform(input.begin(), input.end(), output.begin());

Supported Platforms

Operating Systems

1. Linux
2. MacOS
3. Windows

Compilers

Ratl uses C++14 and is therefore limited to a compiler that has support for this.

1. gcc 5.0+
2. clang 3.4+
3. MSVC 2015+

Getting Started

CMake

You can add ratl as a dependency to your cmake library via the ratl::ratl cmake target.

Tests

To build the ratl tests, set the RATL_BUILD_TESTING option to ON

Benchmarks

To build the ratl benchmarks, set the RATL_BUILD_BENCHMARKS option to ON

Examples

To build the ratl examples, set the RATL_BUILD_EXAMPLES option to ON

SIMD

Ratl has the ability to explicitly use SIMD instructions if it has access to the xsimd library. There are two methods for pulling in xsimd:

1. Via the git submodule in the third_party directory. If this method is used, you will need to set the cmake option RATL_XSIMD_SOURCE to ON.
2. Via a top-level project. If ratl itself is a dependency of a top-level project, xsimd can be added in as a third party dependency alongside ratl. In this case, the xsimd cmake target will automatically be detected and used. The one thing to note is that, due to a large refactor of xsimd that actually removed some required functionality, the xsimd git repository must be on the 7.x branch.