Development

This is a normal sbt project. You can compile code with sbt compile, run it with sbt run, and sbt console will start a Scala 3 REPL.

Beholder requires that ffmpeg 7.1 or newer, including ffprobe, is installed to function correctly. Both ship in the same package on Homebrew and Debian/Ubuntu. Without ffprobe captures still succeed, but H.264/HEVC frames keep their codec padding rows.

The docker build includes ffmpeg: the base image is pinned to an Ubuntu release so the ffmpeg major version cannot drift, and the build fails if ffmpeg is older than the required major or if either binary is missing. See the Docker section of CLAUDE.md.

Useful Commands

1. stage - Build runnable project in target/universal
2. universal:packageBin - Build zip files of runnable project in target/universal
3. laikaSite - Build documentation, including API docs to target/docs/site
4. compile then scalafmtAll - Will convert all syntax to new-style, indent based Scala 3.

Libraries

• circe for JSON handling
• Methanol with Java's HttpClient for HTTP client
• munit for testing
• picocli for command line arg parsing
• slf4j with logback for logging. Use java.lang.System.Logger
• ZIO for effects