@misofm/transcoder

Deterministic, storage-neutral AAC-LC fMP4 HLS transcoding for Node 22/24 and Bun 1.4. The Effect v4 library performs local computation only; callers choose how to package, upload, address, or publish its verified loose files.

The public service has three operations: transcode(request), verify(artifact), and cleanup(artifact).

const artifact =
  yield *
  transcoder.transcode({
    inputPath: "/absolute/input.wav",
    workspacePath: "/absolute/workspace",
    ffmpegPath: "/absolute/ffmpeg",
    ffprobePath: "/absolute/ffprobe",
    profile: { maxSegmentsPerRendition: 219 },
  });

The result is the miso-hls/v1 layout defined by @misofm/streaming: aligned 96/160/256 kbps AAC-LC renditions, media playlists, and a master playlist, named as that contract specifies. The transcoder imports the ladder, identifiers, and segment policy from the contract rather than restating them, and verify checks its output against them. artifact.files is stable and contains absolute paths, byte lengths, SHA-256 hashes, and content types. Verification revalidates inventory, hashes, playlists, alignment, and stored-byte bandwidth. Cleanup explicitly removes only the canonical artifact directory.

FFmpeg and FFprobe are caller-supplied and fingerprinted. Workspaces use restrictive modes, locks, durable checkpoints, atomic writes and directory promotion, interruption-safe cleanup, and deterministic transcodeDigest identities. The optional maxSegmentsPerRendition is a generic consumer constraint.

The package never shells out to publication tools and contains no network client, credentials, package index, or provider-specific metadata.