Video conferencing over IP networks

摘要

A method for communication includes establishing multiple communication links over a packet network between a server and plurality of client computers that are to participate in a video teleconference. The client computers may also create secondary communication links that function similarly to links between the server and client computers. The server receives from the client computers uplink audio packets and uplink video packets, which respectively contain audio and video data captured by each of the client computers. The server determines the optimal bandwidth for each client computer. The server also mixes the audio data from the uplink audio packets so as to create respective streams of mixed audio data for transmission to the client computers and transmits to the client computers downlink audio packets containing the respective streams of mixed audio data. The server relays the video data to the client computers in downlink video packets. The client computers receive and synchronize the video data with the mixed audio data.

主权项

1. A method for communication, comprising:
establishing a primary communication link over a packet network; establishing at least one secondary communication link over a packet network; receiving uplink audio packets and uplink video packets over at least one communication link, which respectively contain audio and video data, wherein receiving the uplink video packets comprises controlling a quality of the video data by transmitting instructions, wherein controlling a quality of the video data comprises determining a current uplink bandwidth, a current downlink bandwidth, a maximum uplink bandwidth, a minimum uplink bandwidth, a maximum downlink bandwidth, and a minimum downlink bandwidth; mixing the audio data from the uplink audio packets to create respective streams of mixed audio data for transmission; transmitting downlink audio packets containing the respective streams of mixed audio data over at least one communication link; relaying the video data in downlink video packets; analyzing relative time differences between the mixed audio data and each relayed video data stream; generating at least one corresponding synchronization packet based on the analyzed relative time differences between mixed audio data and each relayed video data stream; and, transmitting over at least one communication link the at least one corresponding synchronization packet containing synchronization information for synchronizing the relayed video data in the downlink video packets with the downlink audio packets containing the respective streams of mixed audio data in addition to transmitting the downlink video packets and the downlink audio packets.