IP stream tramsmitting/receiving system, IP stream receiving device and receiving process timing synchronization method used for the same

• US 20080049846A1
• Filed: 07/31/2007
• Published: 02/28/2008
• Est. Priority Date: 08/23/2006
• Status: Active Grant

• Current Assignee: IP Wave Pte. Ltd.
• Original Assignee: NEC Corporation
• Inventors: Nagafuji, Nobuyuki
• Granted Patent: US 8,514,945 B2
• Time in Patent Office: Days
• US Class Current: 375/240.28
• CPC Class Codes: H04N 21/4305 Synchronising client clock from received content stream, e.g. locking decoder clock with encoder clock, extraction of the PCR packets arrangements for synchronising receiver with transmitter by comparing receiver clock with transmitter clock H04L7/0012; arrangements for synchronising receiver with transmitter wherein the receiver takes measures against momentary loss of synchronisation H04L7/0083
• CPC Class Codes: H04N 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/64322 IP
• CPC Class Codes: H04N 21/6437 Real-time Transport Protocol [RTP]

Abstract

An IP (Internet Protocol) stream transmitting/receiving system according to an exemplary aspect of the present invention is an IP stream transmitting/receiving system including an IP stream receiving device for performing, at a receiving processing timing of an IP stream, at least FEC (Forward Error Correction) decoding of a received IP stream, wherein the IP stream receiving device includes a circuit for generating the receiving processing timing based on TS (Transport Stream) synchronization that is established in TS time stamp reproducing processing at the latter stage of the FEC decoding processing.

Claims

1. An IP (Internet Protocol) stream transmitting/receiving system comprising an IP stream receiving device for performing, at a receiving processing timing of an IP stream, at least FEC (Forward Error Correction) decoding of a received IP stream, wherein

the IP stream receiving device comprises a circuit for generating the receiving processing timing based on TS (Transport Stream) synchronization that is established in TS time stamp reproducing processing at a latter stage of the FEC decoding processing.

2. The IP stream transmitting/receiving system according to claim 1, wherein

the circuit outputs TS packets at time intervals based on time information added to each TS packet, and generates block synchronization on the basis of the TS synchronization that is established based on the time information in the TS time stamp reproducing processing to provide the FEC decoding processing with the block synchronization.

3. The IP stream transmitting/receiving system according to claim 1, wherein

the receiving processing timing is generated by using at least any of a TS time stamp added to a TS packet, a top of a sequence number of an RTP (Real-time Transport Protocol) header of the received IP stream, and a synchronizing flag of a unique header of the received IP stream.

4. The IP stream transmitting/receiving system according to claim 1, wherein

the IP stream receiving device comprises a circuit for measuring a receiving processing timing of a predetermined number of dummy TS packets, and generating a temporary synchronizing timing based on the measurement to provide the FEC decoding processing with the temporary synchronizing timing;

and

the FEC decoding processing is performed at the temporary synchronizing timing until the TS synchronization is established.

5. The IP stream transmitting/receiving system according to claim 1, wherein

the received IP stream is a UDP (User Datagram Protocol) packet of at least a video and audio stream.

6. The IP stream transmitting/receiving system according to claim 5, wherein

the video and audio stream is coded data and uncompressed data including an MPEG2 (Moving Picture Experts Group-2)-TS (Transport Stream).

7. The IP stream transmitting/receiving system according to claim 1, wherein

the FEC decoding processing is for sequentially performing FEC input processing, FEC correction processing, and FEC output processing;

and

after the FEC output processing is performed, the TS synchronization is established in the TS time stamp reproducing processing.

8. An IP (Internet Protocol) stream receiving device for performing at least FEC (Forward Error Correction) decoding of a received IP stream at a receiving processing timing of the received IP stream, comprising:

a circuit for generating the receiving processing timing based on TS (Transport Stream) synchronization that is established in TS time stamp reproducing processing at a latter stage of the FEC decoding processing.

9. The IP stream receiving device according to claim 8, wherein

the circuit outputs TS packets at time intervals based on time information added to each TS packet, and generates block synchronization on the basis of the TS synchronization that is established based on the time information in the TS time stamp reproducing processing to provide the FEC decoding processing with the block synchronization.

10. The IP stream receiving device according to claim 8, wherein

the receiving processing timing is generated by using at least any of a TS time stamp added to a TS packet, a top of a sequence number of an RTP (Real-time Transport Protocol) header of the received IP stream, and a synchronizing flag of a unique header of the received IP stream.

11. The IP stream receiving device according to claim 8, comprising:

a circuit for measuring a receiving processing timing of a predetermined number of dummy TS packets, and generating a temporary synchronizing timing based on the measurement to provide the FEC decoding processing with the temporary synchronizing timing;

wherein

the FEC decoding processing is performed at the temporary synchronizing timing until the TS synchronization is established.

12. The IP stream receiving device according to claim 8, wherein

the received IP stream is a UDP (User Datagram Protocol) packet of at least a video and audio stream.

13. The IP stream receiving device according to claim 12, wherein

the video and audio stream is coded data and uncompressed data including an MPEG2 (Moving Picture Experts Group-2)-TS (Transport Stream).

14. The IP stream receiving device according to claim 8, wherein

FEC input processing, FEC correction processing, and FEC output processing are sequentially performed in the FEC decoding processing;

and

the TS synchronization is established in the TS time stamp reproducing processing, after the FEC output processing is performed.

15. A receiving processing timing synchronization method used in an IP (Internet Protocol) stream transmitting/receiving system comprising an IP stream receiving device for performing at least an FEC (Forward Error Correction) decoding of a received IP stream at a receiving processing timing of the received IP stream, wherein the method comprising:

at the IP stream receiving device, generating the receiving processing timing based on TS (Transport Stream) synchronization that is established in TS time stamp reproducing processing at a latter stage of the FEC decoding processing.

16. The receiving processing timing synchronization method according to claim 15, wherein

TS packets are output at time intervals based on time information added to each TS packet in the TS time stamp reproducing processing, and block synchronization is generated on the basis of the TS synchronization that is established based on the time information in the TS time stamp reproducing processing to provide the FEC decoding processing with the block synchronization.

17. The receiving processing timing synchronization method according to claim 15, wherein

the receiving processing timing is generated by using at least any of a TS time stamp added to a TS packet, a top of a sequence number of an RTP (Real-time Transport Protocol) header of the received IP stream, and a synchronizing flag of a unique header of the received IP stream.

18. The receiving processing timing synchronization method according to claim 15, comprising:

measuring a receiving processing timing of a predetermined number of dummy TS packets at the IP stream receiving device; and

generating a temporary synchronizing timing based on the measurement at the IP stream receiving device to provide the FEC decoding processing with the temporary synchronizing timing;

wherein

the FEC decoding processing is performed at the temporary synchronizing timing until the TS synchronization is established.

19. The receiving processing timing synchronization method according to claim 15, wherein

the received IP stream is a UDP (User Datagram Protocol) packet of at least a video and audio stream.

20. The receiving processing timing synchronization method according to claim 19, wherein

the video and audio stream is coded data and uncompressed data including an MPEG2 (Moving Picture Experts Group-2)-TS (Transport Stream).

21. The receiving processing timing synchronization method according to claim 15, wherein

FEC input processing, FEC correction processing, and FEC output processing are sequentially performed in the FEC decoding processing;

and

the TS synchronization is established in the TS time stamp reproducing processing, after the FEC output processing is performed.