#srt #livestream

srt-c

API compatabile libsrt reimplementation using srt-tokio

3 unstable releases

0.4.3 Sep 25, 2023
0.4.0 Mar 11, 2023
0.3.0 Jan 14, 2022

#120 in Video

46 downloads per month

Apache-2.0

730KB
16K SLoC

srt-rs

codecov Rust

NOTE: THIS IS NOT PRODUCTION READY.

Pure rust implementation of SRT (Secure Reliable Transport), without unsafe code.

Reference implementation is available at https://github.com/haivision/srt

Features

  • Fast (heap allocations are rare, uses async IO)
  • Full safety guarantees of rust

What works

  • Listen server connecting
  • Client (connect) connecting
  • Rendezvous connecting
  • Receiving
  • Sending
  • Special SRT packets (partial)
  • Actual SRT (TSBPD)
  • Timestamp drift recovery (not throughly tested)
  • Congestion control
  • Encryption
  • Bidirectional

Thread Efficiency

The reference implementation of SRT requires 3 threads per sender and 5 threads per receiver.

With srt-rs, you can assign as many connections to exactly as many threads as you want (usually as many as you have cores) using tokio's futures scheduling. This should allow for handing of many more connections.

Examples

Generate and send SRT packets

cargo run --example sender

Receive SRT packets

cargo run --example receiver

Structure

This repository is structured into 5 crates:

  • srt-protocol: State machines for the SRT protocol, with no dependencies on futures or tokio. Someday, I would like this to be a no-std crate. I expect this to have frequent breaking changes.
  • srt-tokio: Tokio elements written on top of the protocol, expected to be a relatively stable API.
  • srt-transmit: A srt-live-tranmsit replacement written ontop of srt-tokio
  • srt-c: Experimental C bindings to this crate, intended to be both API and ABI compatiable with the reference implementation
  • srt-c-unittests: The unit tests from the reference implementation that are ran against srt-c. Many of these do not pass yet.

Dependencies

~11–26MB
~369K SLoC