SCREAM(1) SCREAM(1)
NAME
screamsend, screamrecv, screamenc, screamdec - multicast
audio protocol
SYNOPSIS
audio/screamsend [ interfaceip ]...
audio/screamrecv [ interfaceip ]...
audio/screamenc
audio/screamdec
DESCRIPTION
Scream is a simple network protocol for transmitting PCM
audio on a local network. It sends UDP packets at a con-
stant rate to the multicast address 239.255.77.77 on port
4010. Each packet starts with a small 5-byte header that
contains information about the sample-rate and data format
followed raw PCM data payload (maximum 1157 bytes).
Screamsend reads PCM audio from /dev/audio and sends scream
packets to the local network on the interface given by
interfaceip. When interfaceip is omitted, it uses first IPv4
interface ip address from /net/ipselftab as a default.
Screamrecv listens for packets from the local network on the
interfaces selected by interfaceip and writes PCM audio to
/dev/audio. When no interfaceip addresses where given, it
will listen on all interfaces with an IPv4 address.
Both screamsend and screamrecv are usually run after
audio/mixfs (see audio(1)) to provide loopback audio source
as well as mixing for multiple senders.
Screamenc reads PCM audio from standard-input and writes
scream packets to standard-output.
Screamdec reads scream packets from standard-input, and
writes PCM audio to standard-output. It spawns
audio/pcmconv (see audio(1)) to convert the audio in case
the scream packet format is not the default of 16-bit
little-endian stereo samples at 44100 Hz. It exits when no
packets have arrived for 500 milliseconds.
SOURCE
/sys/src/cmd/audio/scream
SEE ALSO
audio(1).
https://github.com/duncanthrax/scream