Author: Willem Hengeveld itsme@xs4all.nl
Date: Tue Dec 4 01:26:56 CET 2001

streaming ascii tv

this package takes the output of 'aatv' http://n00n.free.fr/aatv/ and stream compressed ascii-tv signal to its clients.

aatv in turn uses v4l (in the linux kernel) and aalib http://aa-project.sourceforge.net/aalib/

software that does something related to multicasting/multiplexing of data streams.

but none of these could take the output of one program and stream it compressed to various independent clients.

so I started out with this project

how to use

first start the server: "perl mcast.pl"
connect using netcat and pipe output through "compress -d"
example: nc asciitv.someserver.test 2000 | compress -d

configuration is currently done by modifying the source.

files in package: (download here)

readme.txt: text version of this file.
Compress/Compress.pm: wrapper for /usr/bin/compress
this gives a better realtime streaming performance than gzip or zlib * maybe if I do per-frame compression, and use 'flush' it will work with zlib too.
TVData.pm: wrapper for aatv command
mcast.pl: main program
tvclient.pm: wrapper for client socket, handles compression
tvstream: v0.0 version, does not support multiple clients
aatv.patch: changes I made to aatv-0.2
[patch generated using 'diff -wurN origversion newversion']

first version (20011204) can be found here

see comments in mcast.pl

various tech details of instability caused by unhandled exceptions
need to send data to client one frame at a time.
disconnects are not handled well: all clients get disconnected.
need to figure out how much data is still in the xmit buffer of a socket. ( you can get it from /proc/net/tcp, but a more direct way would be appreciated )