Interactive video distribution systems – Video distribution system components
Reexamination Certificate
1998-12-17
2001-07-31
Grant, Chris (Department: 2611)
Interactive video distribution systems
Video distribution system components
C348S014120
Reexamination Certificate
active
06269483
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of audio-visual telecommunications. In particular, the invention relates to video telecommunications between a plurality of conferees, each producing an output video stream and an output audio stream. A particular video stream and audio stream may be rendered dormant based on the audio level of an audio stream.
BACKGROUND OF THE INVENTION
With the recent proliferation of inexpensive, powerful computer technology, methods of communication have progressed significantly. The ordinary voice telephone call, an efficient communication technique, is now accompanied by efficient and widely used alternatives such as electronic mail and on-line chat rooms which allow participants to convey text, images and other data to each other over computer networks.
Video conferencing is another technique for communication which allows participants to convey both sound and video in real time to each other over computer networks. Video conferencing has been cost prohibitive for individuals and corporations to put into wide-spread use. Recently, however, technology has progressed such that video conferencing technology is available, at a reasonable cost, for implementation at terminals such as a desktop or portable computer or hand-held communications device.
Video-conferencing terminals are typically equipped with a video camera and a microphone for respectively capturing, in real-time, video images and sound from participants of the video-conference. The terminals also typically include a display and a speaker for playing the video images and sound in real time to the participants. When a video conference has two participants, it is called a point-to-point conference. Typically, in this arrangement, each terminal will capture video and sound from the participant stationed at the terminal and will transmit the captured video and audio streams to the other terminal. Each terminal will also play the video and audio streams received from the other terminal on the display and speakers respectively of the terminal.
When a video conference has more than two participants, it is called a multi-point videoconference. Typically, in this arrangement, each terminal will capture video and sound from the participant stationed at the terminal. Subsequently, the captured video and audio streams will be transmitted either directly or indirectly to the other terminals. Each terminal will then display one or more video streams and play the audio streams from the other participants.
A problem to confront in multi-point video-conferences concerns the large volume of video and sound data which must be processed and transmitted between the terminals. Terminals are typically coupled together over packet switched networks, such as a local area network (LAN), a wide area network (WAN) or the Internet. Packet switched networks have limited amounts of bandwidth available. The available bandwidth may quickly be exceeded by the video and audio stream data produced by participants in a multi-point video conference.
Moreover, once the video and audio streams arrive at a terminal, the terminal must process the data prior to playing it on the display and speaker. Processing multiple video streams is demanding of the terminal's processing capability. The processing capability of a terminal may quickly be exceeded by having to process more than one video stream for display. In this event, the video and audio streams may become distorted or cease to be played by the terminal.
There is a need for an automatic mechanism to control the transmission of videoconferencing data from a terminal that is participating in a video-conference. Specifically, there is a need for an automatic mechanism to reduce the transmission of high-bandwidth data when a participant at the terminal is not speaking anymore. A conventional video-conferencing program, CU-SeeMe provides a manual mechanism for starting and stopping the transmission of video data from a terminal involved in a videoconference. CU-SeeMe provides a key on the keyboard which must be depressed when a participant desires his video and audio streams to be transmitted. The participant must release the key when the participant stops speaking. During the period when key is depressed, that participant's video stream is transmitted over a network to other terminals participating in the video conference.
SUMMARY OF THE INVENTION
According to the present invention, a method automatically limits the transmission of a video stream from a terminal to a network. The method includes a capturing step which captures a video and audio stream from a camera and microphone at a terminal participating in a video-conference. A transmitting step transmits the audio and video streams to the network and a varying step varies the amount of video stream data transmitted in the transmitting step to the network based on an audio level of the audio stream.
In one embodiment, the varying step results in reducing the amount of video stream data transmitted to the network when the audio level of the audio stream has a value which falls below a predetermined threshold. In another embodiment, the varying step results in increasing the amount of video stream data transmitted to the network when the audio level of the audio stream has a value which rises above a predetermined threshold. The method results in a saving of network bandwidth because video streams of video conference participants who are not contributing to the video conference are throttled back, restoring bandwidth to the network for allocation to other uses.
An apparatus according to the present invention automatically limits the transmission of a video stream from a terminal to a network. The apparatus includes a microphone, a camera, a network interface and a processor. The microphone and camera respectively capture audio and video stream data from a participant in a video conference. The network interface is coupled to a network, for transmitting the audio and video stream data to the network. The processor is coupled to the microphone, the camera and the network interface. In operation, the processor reads the video and audio stream data and varying the amount of video stream data sent to the network interface for transmission to the network based on an audio level of the audio stream. The apparatus is typically a desktop or portable computer or hand-held communications device.
REFERENCES:
patent: 5392223 (1995-02-01), Caci
patent: 5500673 (1996-03-01), Zhou
patent: 5548346 (1996-08-01), Mimura et al.
patent: 5594494 (1997-01-01), Okada et al.
patent: 5684527 (1997-11-01), Terui et al.
patent: 5760825 (1998-06-01), Grenier
patent: 5963246 (1999-10-01), Kato
Grant Chris
International Business Machines Corp.
Morgan & Finnegan L.L.P.
LandOfFree
Method and apparatus for using audio level to make a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for using audio level to make a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for using audio level to make a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2533746