every-channel/every.channel
1
0
Fork 0
Code Releases Activity Actions 2
every.channel/docs/ARCHITECTURE.md

3.6 KiB
Raw Blame History

Architecture

Layers

  1. Capture
  • Hardware: ATSC antennas -> HDHomeRun or Linux IPTV capture devices.
  • Output: MPEG-TS or ATSC 3.0 streams.
  1. Normalize
  • Demux and normalize timestamps.
  • Select program IDs and identify audio/video tracks.
  1. Deterministic transcode
  • Encode with a fixed profile (codec, GOP, bitrate, keyframe cadence).
  • Emit fixed-duration chunks with stable ordering.
  • Hash chunks to produce content identifiers.
  1. MoQ publish
  • Map each channel to a track namespace.
  • Each chunk becomes a MoQ object in a group.
  • Objects are named and addressed deterministically.
  1. Settlement rails
  • Ethereum-compatible commitments mirror stream identity, manifests, and transport announcements.
  • Observation consensus is a separate rail on top of those commitments: a reality-derived ObservationHeader is hashed, witnessed, and finalized per (stream, epoch) slot.
  • The chain stores compact commitment pointers only; media bytes and full manifests remain on iroh, relays, and archive storage.
  • OP Stack is the current private-chain operator target, with ecp-forge as the head node for the first Sepolia-anchored testnet tranche.
  • Private-chain operation is a protocol extension, not a replacement for transport.
  1. Relay mesh
  • Relays cache objects and announce tracks.
  • iroh provides programmable topology and peer routing.
  • Multiple relays can serve identical objects.
  1. Playback
  • Desktop: Tauri app that subscribes to tracks.
  • CLI: debugging, inspection, and headless clients.
  • Web: static site that connects to a relay gateway.

Roles

  • Runner: owns capture + transcode + publish.
  • Chopper: executes deterministic chunking profiles.
  • Relay: stores and forwards MoQ objects.
  • Manager: configures nodes and applies policy.
  • Provisioner: bootstraps nodes and manages deployment.
  • Witness: attests to a reality-derived observation hash for a stream epoch.

Determinism

  • The same input with the same profile should yield identical chunks.
  • Chunk hashes are the primitive for availability and de-duplication.
  • Deterministic names allow relays to converge without coordination.
  • Observation consensus derives a second deterministic summary from the archive/manifests layer: streamHash, epochHash, dataRoot, and locatorHash become the on-chain observation header.
  • Local manifests keep BLAKE3 manifest_ids and merkle+blake3 proofs, while the Ethereum rail adds Keccak ABI/data commitments and optional secp256k1 EIP-712 body signatures for settlement.
  • Discovery identity should prefer broadcast-scoped channel identity when available and only fall back to source-scoped IDs when the ingest path cannot yet prove a usable broadcast identity.
  • PAT-derived identity is accepted only when the stream exposes a single non-zero program; ambiguous multi-program TS inputs remain source-scoped to avoid accidental convergence on the wrong channel.
  • ec-ts parses ATSC PSIP at the table layer (MGT, TVCT/CVCT, STT, RRT, EIT, ETT), including EIT / ETT on the PIDs advertised by MGT.
  • Current discovery promotion uses PAT plus VCT fields; the rest of PSIP is parsed and preserved for inspection, validation, and future policy rather than guessed into the stream key.

Time synchronization

  • Chunk boundaries are derived from PCR and, when available, broadcast UTC (ATSC STT / DVB TDT/TOT).
  • ATSC STT is interpreted as GPS time plus offset correction, then converted to Unix time for chunk anchoring and diagnostics.
  • Unsynced sources remain source-scoped until broadcast time is present.
  • Discontinuities force a new chunk group boundary.