Playloop plays and loops Ogg Vorbis audio files that have loop metadata in them. It expects Vorbis comments LOOPSTART and LOOPEND to be set to sample positions.
This project is written in Rust and uses Lewton for Vorbis decoding and SDL for sound output. It was primarily developed for fun, to learn Rust and to brush up on my audio programming skills. The program decodes and seeks on-the-fly, and uses minimal allocations (at least in the code I wrote; can't speak for the dependencies).
The looping is perfectly accurate. This was tricky to get right with Lewton/Vorbis due to the lack of precision seeking. For example, playloop will seek to an earlier Vorbis "granule" then skip N samples forward to reach the correct sample to play. There are automated tests to prove this works correctly. The tests decode an entire file into memory and compare the on-the-fly looped output against it.
This project can be built using Rust's cargo build tool. You'll also need SDL2 development libraries.
apt install libsdl2-dev
cargo build --releaseAfter building, the executable will live at target/release/playloop.
brew install sdl2
cargo build --releaseAfter building, the executable will live at target/release/playloop.
On Windows, building takes a little more effort. As a convenience, you can find a build for Windows in the releases area.
To build from source, see the rust-sdl2 setup docs.
playloop file.oggcargo testNote: the tests can take a long time since they decode a bunch of Vorbis data.