librtmp2 0.10.2

Changed

• The server relay no longer copies each relayed frame into every
  player's send buffer. A frame is chunked once, and after the fan-out
  every player gets its own headers plus the shared chunk bodies in one
  vectored sendmsg; only what the socket does not take is buffered.
  With 1000 viewers on one 2.6 Mbps stream the server's memory drops from
  about 59 MiB to 32 MiB at unchanged CPU. TLS players keep the buffered
  path.
• A newly accepted player receives the cached init frames (metadata,
  sequence headers, last keyframe) in the same write as
  NetStream.Play.Start, instead of after every other connection in the
  same poll has been read.

Added

• examples/bench_handshake.rs takes --play to measure connect + play
  latency (up to NetStream.Play.Start) against a live stream.