Low-delay video encoding method for concealing the effects of packet loss in multi-channel packet switched networks
View Patent ↗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 a number of bits used to encode a frame is a function of an integral distance between the frame and a nearest preceding key frame;
packetizing and transporting the key frame bit sequences over a 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 spacing between key frames in the sequence of key frames is a function of bandwidth available on the high quality network channel.
8. The method of claim 1 , wherein the high quality network channel is a Quality of Service channel.
9. A system for encoding and transporting interactive video, comprising:
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 a number of bits used to encode a frame is a function of an integral distance between the frame and a nearest preceding key frame;
a system packetizer coupled to the system encoder for packetizing the key frame bit sequences and the non-key frame bit sequences;
a high quality network channel coupled to the system packetizer for transporting the packetized key frame bit sequences; and
a lower quality network channel coupled to the system packetizer for transporting the packetized non-key frame bit sequences.
10. The system of claim 9 , wherein the non-key frames exclude bi-directionally predicted frames.
11. The system of claim 9 , wherein the non-key frames include predicted frames.
12. The system of claim 9 , wherein the key frames are inter-frames.
13. The system of claim 9 , wherein the key frames are intra-frames.
14. The system of claim 9 , wherein a number of bits used to encode a frame is a function of bandwidth available on a corresponding channel.
15. The system of claim 9 , wherein spacing between key frames in the sequence of key frames is a function of bandwidth available on the high quality network channel.
16. The system of claim 9 , wherein the high quality network channel is a Quality of Service channel.
17. A system for encoding and transporting interactive video on multiple-network channels, comprising:
a system encoder for encoding a video stream into key frames and non-key frames, spacing between consecutive key frames based on bandwidth available on the multiple-network channels, and a number of bits used to encode any given frame based on an integral distance between the given frame and a nearest preceding key frame and the bandwidth available on the multiple-network channels;
a system packetizer for packetizing key bits representing the key frames and non-key bits representing the non-key frames, coupled to the system encoder;
a high quality network channel for transporting the packetized key bits, coupled to the system packetizer; and
a network channel of the multiple-network channels for transporting the packetized non-key bits, coupled to the system packetizer.
18. A system for encoding and transporting interactive video on multiple-network channels, comprising:
a means for encoding a video stream into key frames and non-key frames, the spacing between consecutive key frames based on bandwidth available on the multiple-network channels, and a number of bits used to encode any given frame based on an integral distance between the given frame and a nearest preceding key frame and the bandwidth available on the multiple-network channels;
a means for packetizing key bits representing the key frames and the non-key bits representing the non-key frames, coupled to the means for encoding;
a first means for providing high quality transportation of the packetized key bits, coupled to the means for packetizing; and
a second means for providing lower quality transportation of the packetized non-key bits, coupled to the means for packetizing.