redlux

AAC decoder for MPEG-4 (MP4, M4A etc) and AAC files, with rodio support

Reads MPEG-4 containers using rust-mp4, and then constructs ADTS headers for it. Decodes AAC to PCM using fdk-aac c-bindings. Check the examples for usage with rodio.

Supports AAC-LC, HE-AAC v1 (SBR) and HE-AAC v2 (PS).

Caveats

1. It only decodes the first AAC track it finds in an MPEG-4 container.
2. Not sure if MPEG files with CRC are supported.
3. According to this MultimediaWiki page, 13 bits of the ADTS header is for specifying the frame length, and this number must include the ADTS header itself. For 8 channel audio, I would assume the frame length could be 8192 bytes, and if we add the header bytes on top of that, it would exceed what 13 bits can carry. Is this a potential issue? No idea.

Dev instructions

Get started

Install Rust.

Run tests:

cargo test

Build:

cargo build

Releasing a new version

1. Update CHANGELOG.md
2. Bump the version number in Cargo.toml
3. Run cargo test
4. Commit and tag in format v#.#.#
5. Publish on crates.io:
   1. Login by running cargo login and following the instructions
   2. Test publish to ensure there are no errors/warnings

      cargo publish --dry-run
      

   3. Publish

      cargo publish
      

6. Create GitHub release with release notes