Mbone recording playback

This note describes record_session, play_wrtp and view_wrtp, scripts designed for use with Unix sdr and the wrtp record/playback tool

Andrew Daviel, TRIUMF, November 1997

Playing CERN Recordings - Quick Method

On sitka, from CERN's Recorded MBONE Sessions page (csvod1.cern.ch/cgi-bin/nph-MBone-sessions), download the relevant package and untar it, e.g.
 gnutar -zxf ATLAS_97_06_05_1055_1245.tar.gz
which creates files such as
ATLAS_97_06_05_1055_1245.0.a.rtp
Invoke the script view_wrtp with the appropriate prefix, e.g.
play_wrtp ATLAS_97_06_05_1055_1245.0
play_wrtp takes an optional second argument of an offset in seconds. To start playback 10 minutes into the recording, use e.g.
play_wrtp ATLAS_97_06_05_1055_1245.0 600

On a second TRIUMF machine, e.g. indi01, invoke the script view_wrtp. This starts the audio tool rat and the video tool vic.


Vic. To bring up a larger video window, click the thumbnail image. A menu at the bottom of the large window allows small, medium, or large views.


Rat. To bring up the sound, move the volume control slider. The VU meter graphically shows the sound level. If there is no sound, it may be necessary to restart rat. Quit both tools, then re-invoke view_wrtp.

To stop playback, on sitka execute "killall wrtpplay".

This method uses fixed values for the address and port, and a TTL of 1. The session will not be announced in sdr. (The audio tool Rat will not function properly on the same machine as the playback tool.)

Playing CERN Recordings - sdr method

Using sdr, create a new advertised "Site" session (ttl 15) with both audio and video checked. Still in sdr, select the new session then select Record. Enter a suitable file prefix then click Record. The script record_session will be invoked to create a playback script (and a record script). When this script is executed on sitka (taking the same arguments as play_wrtp), the recording will be replayed, and users on other machines may use sdr in the regular way to view the recording.

This is http://andrew.triumf.ca/mbone/wrtp_play.html