| 2 | 1 README version 22jun2005 | 
|  | 2 | 
|  | 3 Welcome to intercom, a Voice over IP speaker-phone conference | 
|  | 4 application. The application can: | 
|  | 5 - dial a intercom partner via short-dial buttons | 
|  | 6 - make a RTP connection to transport your voice over IPv4 | 
|  | 7 - make a telephone conference | 
|  | 8 - support wideband codec (16kHz sample frequency) | 
|  | 9 | 
|  | 10 Intercom is still very limited. But the things it can do, it does | 
|  | 11 very well! | 
|  | 12 | 
|  | 13 | 
|  | 14 Modify file ~/.intercom.conf for your short-dial labels | 
|  | 15 and your IP-addresses. | 
|  | 16 | 
|  | 17 To start the application enter | 
|  | 18 | 
|  | 19   intercom | 
|  | 20 | 
|  | 21 Read shell script /usr/local/bin/intercom to get an idea of what is | 
|  | 22 going on. For better echo cancellation start intercom with the -m or | 
|  | 23 -l option. | 
|  | 24 | 
|  | 25 For a first test talk to yourself by clicking the button for your own | 
|  | 26 IP-address, e.g. EDDF TEC2 if your computer is 192.168.1.2. | 
|  | 27 The button should become green. | 
|  | 28 Attention: A short click (less then 300ms) toggles on/off, a long | 
|  | 29 click works as push-to-talk. | 
|  | 30 | 
|  | 31 ATTENTION: The intercom application needs PCM out for playback. This | 
|  | 32 hardware device is used also by other sound programs like MP3 players | 
|  | 33 (e.g. xmms) or WAV record/playback programs like sweep and audacity. The | 
|  | 34 intercom application blocks (freezes) as long as another program uses | 
|  | 35 PCM out. There are ways around this like using sound daemons aRTs or | 
|  | 36 esound. But this is outside of the intercom application. | 
|  | 37 | 
|  | 38 If you dial another intercom station, you get an one-way connection from | 
|  | 39 your microphone to the loudspeaker of your intercom partner. If your | 
|  | 40 partner clicks on the correct button (the magenta one), both of you have | 
|  | 41 a two-way communication. Now you or your partner can dial more intercom | 
|  | 42 stations to make a conference with maximum 6 stations. | 
|  | 43 Note: Start intercom with the -t option to get "everybody can talk and | 
|  | 44 listen with everybody else". | 
|  | 45 | 
|  | 46 | 
|  | 47 Read the file | 
|  | 48 http://home.arcor.de/andreadrian/intercom/draft-conference-01.txt | 
|  | 49 for more information. | 
|  | 50 | 
|  | 51 | 
|  | 52 Supported royalty free Codecs: | 
|  | 53 For License see ITU-T G.191 or IETF RFC3951 | 
|  | 54 | 
|  | 55 Narrowband (8kHz sample frequency): | 
|  | 56 ----------------------------------- | 
|  | 57 IETF iLBC           15.2kBit/s  Global IP Sound iLBC Public License | 
|  | 58 ITU-T G.711 A-law   64kBit/s    ITU-T SOFTWARE TOOLS' GENERAL PUBLIC LICENSE | 
|  | 59 ITU-T G.711 u-law   64kBit/s    ITU-T SOFTWARE TOOLS' GENERAL PUBLIC LICENSE | 
|  | 60 ITU-T G.726 32kbs   32kBit/s    ITU-T SOFTWARE TOOLS' GENERAL PUBLIC LICENSE | 
|  | 61 3GPP GSM            13.2kBit/s  ITU-T SOFTWARE TOOLS' GENERAL PUBLIC LICENSE | 
|  | 62 | 
|  | 63 Wideband (16kHz sample frequency): | 
|  | 64 ---------------------------------- | 
|  | 65 Speex               27.8kBit/s  Xiph.org license (BSD license variant) | 
|  | 66 | 
|  | 67 Author: Andre Adrian | 
|  | 68 E-Mail: Andre dot Adrian at dfs dot de | 
|  | 69 Postal: DFS Tower Frankfurt | 
|  | 70         Mr. Andre Adrian | 
|  | 71         Flughafen Gebaeude 501 | 
|  | 72         60549 Frankfurt, Germany |