Crate moq_transfork

An fork of the MoQ Transport protocol.

MoQ Transfork is a pub/sub protocol over QUIC. While originally designed for live media, MoQ Transfork is generic and can be used for other live applications. The specification is a work in progress and will change. See the specification and github for any updates.

The core of this crate is Session, established with Session::connect (client) or Session::accept (server). Once you have a session, you can Session::publish or Session::subscribe.

Producing

There can be only 1 publisher.

• [BroadcastProducer] can create any number of TrackProducers. Each Track is produced independently with a specified order/priority.
• TrackProducer can append any number of GroupProducers, with new subscribers joining at Group boundaries (ex. keyframes).
• GroupProducer can append any number of Frames, either using GroupProducer::write_frame (contiguous) or GroupProducer::create_frame (chunked).
• FrameProducer is thus optional, allowing you to specify an upfront size to write multiple chunks.

All methods are synchronous and will NOT block. If there are no subscribers, then no data will flow over the network but it will remain in cache. If the session is dropped, then any future writes will error.

Consuming

There can be N consumers (via Clone), each getting a copy of any requested data.

• [BroadcastConsumer] can fetch any number of TrackConsumers. Each Track is consumed independently with a specified order/priority.
• TrackConsumer can fetch any number of GroupConsumers, joining at a Group boundary (ex. keyframes).
• GroupConsumer can fetch any number of Frames, either using GroupConsumer::read_frame (contiguous) or GroupConsumer::next_frame (chunked).
• FrameConsumer is thus optional, allowing you to read chunks as they arrive.

All methods are asynchronous and will block until data is available. If the publisher disconnects, then the consumer will error. If the publisher is dropped (clean FIN), then the above methods will return None.

Re-exports

• pub use crate::message::GroupOrder;
• pub use web_transport;

Modules

• coding
  This module contains encoding and decoding helpers.
• message
  Low-level message sent over the wire, as defined in the specification.

Structs

• AnnouncedConsumer
  Consumes announced tracks over the network matching an optional prefix.
• AnnouncedProducer
  Announces tracks to consumers over the network.
• Frame
  A frame of data with an upfront size.
• FrameConsumer
  Used to consume a frame’s worth of data in chunks.
• FrameProducer
  Used to write a frame’s worth of data in chunks.
• Group
  An independent group of frames.
• GroupConsumer
  Consume a group, frame-by-frame.
• GroupProducer
  Create a group, frame-by-frame.
• Path
• Router
  Used to respond to arbitrary track requests.
• RouterConsumer
  Subscribe to abitrary broadcast/tracks.
• RouterProducer
  Receive broadcast/track requests and return if we can fulfill them.
• RouterRequest
  An outstanding request for a path.
• Session
  A MoqTransfork session, used to publish and/or subscribe to broadcasts.
• Track
  A track, a collection of indepedent groups (streams) with a specified order/priority.
• TrackBuilder
  Build a track with optional parameters.
• TrackConsumer
  A consumer for a track, used to read groups.
• TrackProducer
  A producer for a track, used to create new groups.

Enums

• Announced
• Error
  A list of possible errors that can occur during the session.

Constants

• ALPN
  The ALPN used when connecting via QUIC directly.

Type Aliases

• Result