sig@europa.asd.contel.com.asd.contel.com (Sigurd P. Crossland - Contel WTP 2214N 703-818-4202) (01/25/91)
Has anybody used the audio capabilities of the NeXT on IRC? How difficult would it be to redirect the byte stream from the microphone onto a channel and redirect the corresponding channel output to the D/A converter and the speaker? How would one 'escape' control codes recognized by IRC? Perhaps one could use a shift-in/shift-out sequence with byte stuffing? How about using the space bar as sort of a push-to-talk switch? Any ideas on the performance expected across the network? Anyone interested in discussing the questions mentioned with the goal of eventual implementation? I would like to suggest a dis-key conference on channel +NeXT for Tuesday, January 29th, at 1100 EST (0800 PST & 1600 GMT). Sigurd P. Crossland Contel Federal Systems Principal Engineer FSS/GSY/SWE WTP-2214N Internet: sig@europa.asd.contel.com 15000 Conference Center Dr. Telephone: (703) 818-4202 Chantilly, VA 22021
eps@toaster.SFSU.EDU (Eric P. Scott) (01/29/91)
Here I go, following up my own post. Voice Terminal has just been released for the SPARCstation (only). ISI has expressed interest in developing a fully interoperable NeXT version as well, but was stymied by limitations in 1.0's SoundKit and the performance of '030 cubes. Hopefully NeXT Computer, Inc. has more to offer research in "Interpersonal Computing" than Lip Service(tm). Their direct and immediate support to ISI's efforts would be invaluable. -=EPS=- I am not affiliated with USC/ISI. Attachment ------- Date: Mon, 28 Jan 91 16:27:26 PST From: Annette DeSchon <deschon@venera.isi.edu> Message-Id: <9101290027.AA17261@venera.isi.edu> Subject: VT Source Code Hello, VT source code is available now via anonymous FTP. "vt.100.tar.Z" is located on "venera.isi.edu" in the "pub" directory. The version number, e.g. "100", will be updated as changes and additions are made. Included at the end of this message is an excerpt from the "README" file in the VT package. Please send questions and comments to "deschon@isi.edu". --Annette --------------------------------------------------------------------- Voice Terminal (VT) Program January 28, 1991 Annette DeSchon USC Information Sciences Institute ******************************************************* * * * Please send a message to "deschon@isi.edu" to let * * us know that you have picked up the VT software. * * * ******************************************************* Introduction -------------- The Voice Terminal (VT) program implements the audio portion of ISI's SPARCStation-based Multimedia Conferencing System. Sound is input by a microphone attached to a built-in audio codec. Audio data coming from other conference participants is mixed, and may be played on the built-in speaker. However, to prevent that sound from being picked up by the microphone and echoed back to the other participants, VT provides two options. When the "speakerphone" option is selected, input from the microphone is ignored during the playback of sound from other sites. Alternatively, when the "headphone" option is selected, sound is played through the headphone jack instead of the speaker, for full-duplex communication. The Packet Video Program (PVP), whose function parallels VT's, provides video to each site. PVP uses a prototype HSI/S board from Sun to input data from an external video codec, either the Concept Image30, or the PictureTel C-3000. The HSI/S board is expected to be in production during the summer of 1991. Other applications that make up the Multimedia Conferencing System are as follows. The Multi-Media Conference Controller (MMCC) provides a window-based user interface to ISI's conferencing system. The MMConf is a shared workspace tool developed at BBN. The MBFTPTool is a file transfer tool which distributes files to the various conference sites. VT is currently run interactively in a SPARCStation shell window. Connections are started and stopped using one-letter commands which are typed in at the VT prompt. It is also possible to monitor packet counts and other state information, and to change parameters. In the future VT will be run as a daemon and will be controlled by the MMCC. The purpose of our packet voice and video software is to support research in resource-reservation packet protocols, initially the Stream Protocol (ST). ST is at the same level as IP and makes use of "ST-routers" to do connection setup and resource reservation, in order to provide low delay service. Since there aren't many ST-routers available on the Internet at this point, we use IP encapsulation of the ST packets to get through intermediate IP-routers. However to realize the performance benefits of ST, the use of ST-routers is required. Initially VT should work well over lightly loaded T1 networks and the T3 NSFNET backbone, however we also believe that existing IP networks could easily become overloaded with conferencing traffic. We see this as an opportunity to demonstrate the value of ST and its successors. The current implementation of VT is based on the 1979 specification of ST, and has the ST protocol implemented within the application, in user space. This implementation of ST is only partial, and requires connections to go through an ST-Router in order to connect to more than one other site. No ST-router is required to connect only two SPARCStations. ST packets are encapsulated in IP and sent onto the network using a raw-IP socket. To open the raw-IP socket, VT must be run su'ed to root. Over the next few months, BBN will implement a new version of ST (ST-II, described in RFC 1190) in the SunOS kernel with a BSD socket interface. We will then modify VT to open ST sockets, instead. At that point the raw-IP socket (and the su root) will no longer be required, however VT will require the new kernel with ST added. Other sections of this document include a summary of VT commands, a description of various program components, and detailed instructions for setting up VT. Features to be added in the future are also included. Please direct comments and questions to Annette DeSchon, deschon@isi.edu.