From owner-freebsd-multimedia Sat Dec 13 23:05:08 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id XAA16231 for multimedia-outgoing; Sat, 13 Dec 1997 23:05:08 -0800 (PST) (envelope-from owner-freebsd-multimedia) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id XAA16217 for ; Sat, 13 Dec 1997 23:05:01 -0800 (PST) (envelope-from luigi@labinfo.iet.unipi.it) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id GAA01124; Sun, 14 Dec 1997 06:38:09 +0100 From: Luigi Rizzo Message-Id: <199712140538.GAA01124@labinfo.iet.unipi.it> Subject: RTP tools (was: Re: Remote and Voice control) To: hasty@rah.star-gate.com (Amancio Hasty) Date: Sun, 14 Dec 1997 06:38:09 +0100 (MET) Cc: multimedia@FreeBSD.ORG, don@partsnow.com In-Reply-To: <199712132104.NAA06292@rah.star-gate.com> from "Amancio Hasty" at Dec 13, 97 01:04:02 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-multimedia@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > controller and helping Petri for an rtp to mtv glue logic. this is a very interesting project. On the same subject, recently I have wrapped up a small "transcoder" program which can forward bidirectional RTP traffic (both data and control) between two sockets, doing some data conversion in the middle. Code (a bit rought perhaps, I haven't had time to check it carefully) is at http://www.iet.unipi.it/~luigi/tcoder971214.tgz Main use (for me) was to be able to listen the audio of last week's IETF while at home, where I don't have multicast routing, and the bandwidth is too limited to allow PCM or DVI data to come in. In the above case I run the transcoder on a mbone-connected host, as follows: rizzo% tcoder -m multicast.group/portm -u my.home.machine/portu and it converts incoming audio packets to GSM (or LPC, as I like) as they come in. The backend at home is vat (or my tel program for which I am the only user...) listening to rizzo/portu . Worked very well, and it took about one day to put the program together (borrowing a lot of code from "tel"). Another possible use is to run multiple tcoder's to send data from multiple conferences to one vat, or forward from one multicast group to another one (must be careful to loops in this case... the thing works much like an ethernet bridge). In the future I plan to add more format conversions also for video, so if someone wants to join in and help I'd be quite glad. tcoder provides all the glue (user interface, open sockets, handle multiple network connections) so you can concentrate on the real work (decoding/encoding the payload). These things are good if they run on multiple platforms. Currently my tcoder has many FreeBSD dependencies, but I have also a port to SunOS which I will merge in during the holidays. Cheers Luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________