Low-delay video encoding method for concealing the effects of packet loss in multi-channel packet switched networks

Abstract

A method for encoding digital video with low delay for transport on a multi-channel QoS packet-switched network using multiple reference pictures with specially designated “key frames” to minimize the undesired effects of packet loss on video quality.

1 . A method of encoding and transporting interactive video, comprising the steps of: 
 receiving a video sequence;    encoding the video sequence into key frames represented by key frame bit sequences and non-key frames represented by non-key frame bit sequences, wherein spacing between key frames in the sequence of key frames is a function of bandwidth available on a high quality network channel;    packetizing and transporting the key frame bit sequences over the high quality network channel; and    packetizing and transporting the non-key frame bit sequences over a lower quality network channel.    
   
   
       2 . The method of  claim 1 , wherein the non-key frames exclude bi-directionally predicted frames.  
   
   
       3 . The method of  claim 1 , wherein the non-key frames include predicted frames.  
   
   
       4 . The method of  claim 1 , wherein the key frames are inter-frames.  
   
   
       5 . The method of  claim 1 , wherein the key frames are intra-frames.  
   
   
       6 . The method of  claim 1 , wherein a number of bits used to encode a frame is a function of bandwidth available on a corresponding channel.  
   
   
       7 . The method of  claim 1 , wherein the high quality network channel is a Quality of Service channel.  
   
   
       8 . A system for encoding and transporting interactive video, comprising: 
 a high quality network channel;    a lower quality network channel;    a system encoder for encoding a video stream into key frames represented by key frame bit sequences and non-key frames represented by non-key frame bit sequences, wherein spacing between key frames in the key frame bit sequences is a function of bandwidth available on the high quality network channel;    a system packetizer coupled to the system encoder for packetizing the key frame bit sequences and the non-key frame bit sequences, coupled to the high quality network channel for transporting the packetized key frame bit sequences, and coupled to the lower quality network channel for transporting the packetized non-key frame bit sequences.    
   
   
       9 . The system of  claim 8 , wherein the non-key frames exclude bi-directionally predicted frames.  
   
   
       10 . The system of  claim 8 , wherein the non-key frames include predicted frames.  
   
   
       11 . The system of  claim 8 , wherein the key frames are inter-frames.  
   
   
       12 . The system of  claim 8 , wherein the key frames are intra-frames.  
   
   
       13 . The system of  claim 8 , wherein a number of bits used to encode a frame is a function of bandwidth available on a corresponding channel.  
   
   
       14 . The system of  claim 8 , wherein the high quality network channel is a Quality of Service channel.