System for protecting the transmission of live data streams, and upon reception, for reconstructing the live data streams and recording them into files

• US 20030009718A1
• Filed: 04/19/2002
• Published: 01/09/2003
• Est. Priority Date: 04/20/2001
• Status: Active Grant

• Current Assignee: KenCast Inc.
• Original Assignee: KenCast Inc.
• Inventors: Fang, Weimin, Wolfgang, H. Lewis
• Granted Patent: US 7,024,609 B2
• Time in Patent Office: Days
• US Class Current: 714/751
• CPC Class Codes: G11B 20/10 Digital recording or reproducing
• CPC Class Codes: G11B 20/18 Error detection or correction; Testing , e.g. of drop-outs
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 2001/0096 Channel splitting in point-to-point links

Abstract

The present invention relates to a system for (1) protecting the transmission of packet streams between a host computer and one or more client computers, and (2) upon reception, (a) reconstructing any outage damage caused during the transmission to the packet streams, and (b) digitally recording the reconstructed packet streams to a file. The present invention also relates to a method for dynamically generating a file index table as the packet stream is being digitally recorded.

Claims

1. A system comprising a client computer, said client computer comprising:

means for receiving a packet stream transmitted by a host computer over a first communication channel;

means for digitally recording the received packet stream to a file;

means for reconstructing the digitally-recorded file by retrieving one or more packets lost during transmission from the host computer, said reconstruction means using a second communication channel different from the first communication channel.

2. A system according to claim 1, said client computer further comprising means for on-the-fly packet-level FEC decoding the received packet stream, prior to digital recording, when the transmitted packet stream had been on-the-fly packet-level FEC encoded by the host computer.

3. A system according to claim 2, said client computer further comprising means for deinterleaving the received packet stream, when the transmitted packet stream had been interleaved by the host computer.

4. A system according to claim 1, said client computer further comprising means for outputting the received packet stream.

5. A system according to claim 1, said client computer further comprising means for rebroadcasting the reconstructed file.

6. A system according to claim 1, said client computer further comprising means for dynamically generating a plurality of file indices as the received packet stream is digitally recorded into the file.

7. A system according to claim 1, wherein said digital recording means records independently of the packet stream protocol.

8. A system according to claim 1, further comprising said host computer, which includes means for storing the transmitted packet stream into a file, from which file said reconstructing means of said client computer retrieves the one or more lost packets.

9. A system comprising a client computer, said client computer comprising:

means for receiving a packet stream transmitted over a one-way communication channel by a host computer, the transmitted packet stream generated by the host computer by on-the-fly packet-level FEC encoding a plurality of original packets;

means for on-the-fly packet-level FEC decoding the received packet stream to obtain the plurality of original packets; and

means for digitally recording the plurality of original packets to a file.

10. A system according to claim 9, said client computer further comprising means, communicatively connected to the host computer, for reconstructing the plurality of original packets by retrieving one or more packets lost during transmission over the one-way communication channel, in the event the original packets cannot be obtained by said on-the-fly packet-level FEC decoding means.

11. A system according to claim 10, further comprising said host computer, which includes means for storing the transmitted packet stream into a file, from which file said reconstructing means of said client computer retrieves the one or more lost packets.

12. A system according to claim 9, said client computer further comprising means for deinterleaving the received packet stream, when the transmitted packet stream had been interleaved by the host computer.

13. A system according to claim 9, said client computer further comprising means for outputting the original packets.

14. A system according to claim 9, said client computer further comprising means for rebroadcasting the reconstructed file.

15. A system according to claim 9, said client computer further comprising means for dynamically generating a plurality of file indices as the received packet stream is digitally recorded into the file.

16. A system according to claim 9, wherein said digital recording means records independently of the packet stream protocol.

17. A method for iteratively generating a plurality of file indices as a packet stream is digitally recorded into a file, said method comprising the steps of:

at start of recording, selecting an upper bound for the total number of indices, and a gap between consecutive indices; and

for each iteration, generating one of the file indices, wherein the total number of indices remains between half of the selected upper bound and the selected upper bound, and the gap between consecutive indices increases.

18. A method for generating an index table containing a plurality of file indices as a packet stream is digitally recorded into a file, said method comprising the steps of:

for each packet of the packet stream, determining whether a position value is greater than or equal to a target value;

if not, increasing the position value by the length of the packet, and if so, storing the position value in the index table;

determining whether the target value is a maximal target value for a current gap value, and if so, doubling the current gap value; and

increasing the target value by the current gap value.