RTP payload format for VC-1

• US 7,720,096 B2
• Filed: 12/30/2005
• Issued: 05/18/2010
• Est. Priority Date: 10/13/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Klemets, Anders E.
• Primary Examiner(s): Duong; Frank
• Assistant Examiner(s): RIYAMI, ABDULLAH A
• Application Number:
  US11/275,426
• Publication Number:
  US 20070086481A1
• Time in Patent Office: 1,600 Days
• Field of Search: 370/216, 370/229, 370/230, 370/230.1, 370/231, 370/232, 370/233, 370/234, 370/235, 370/261, 370/263, 370/264, 370/265, 370/352, 370/389, 370/400, 370/466, 370/260, 370/390, 370/329, 348/14.1, 348/14.08, 348/14.12, 348/14, 348/15, 348/16, 348/17, 348/14.9, 348/462, 375/240.02, 375/240.05, 375/240.07, 725/31, 725/135, 725/105, 725/136, 725/138, 725/139, 725/143, 725/151, 725/38, 725/78, 725/27, 380/46, 380/277, 380/200, 380/255, 709/204, 709/205, 709/231
• US Class Current: 370/466
• CPC Class Codes: H04N 21/2381 Adapting the multiplex stream to a specific network, e.g. an Internet Protocol [IP] network transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 21/6437 Real-time Transport Protocol [RTP]

Abstract

An RTP payload format for VC-1 is described. The RTP payload format accommodates an RTP payload that can include one or more Access Units (AUs). An Access Unit can provide a complete frame of VC-1 information. Alternatively, a frame of VC-1 information can be fragmented among multiple Access Units. Each Access Unit includes an Access Unit header and an Access Unit payload. The RTP payload format incorporates various provisions for improving the efficiency and robustness in the processing of the VC-1 information, enabled, in part, by control information conveyed by the respective Access Unit headers of the Access Units.

Claims

1. A computer implemented method for encapsulating VC-1 (Video Codec 1) information in an RTP (Real-Time Transport Protocol) packet, comprising:

arranging by a computing device, the VC-1 information into a at least one Access Unit, collectively forming an RTP payload; and

appending by the computing device, an RTP header onto the RTP payload to form the RTP packet, the VC-1 information being arranged in a variable length RTP payload in accordance to a size of the RTP packet compared to a maximum transmission unit (MTU) size to at least avoid IP-level fragmentation, the length of the RTP payload being determined during the encapsulation of the VC-1 information, wherein at least a portion of the method is implemented in a computer,

wherein a frame of VC-1 information is fragmented over plural Access Units in response to the size of the RTP packet being greater than the MTU size, each of the plural Access Units being assigned to a separate RTP packet, and an RTP payload of one of the separate RTP packets includes a last of the plural Access Units and does not include any other Access Units of other frames of VC-1 information based on a rule preventing the inclusion of portions of two or more frames of VC-1 information in a same RTP payload.

2. The method of claim 1, wherein an Access Unit contains a complete frame of VC-1 information in response to the size of the RTP packet being not greater than the MTU size.

3. The method of claim 1, further comprising setting control information in a header of an Access Unit to indicate that the Access Unit includes a fragment of a frame.

4. The method of claim 1, further comprising, after receipt of the plural Access Units, reassembling the frame of VC-1 information from the plural Access Units, prior to decoding the VC-1 information.

5. The method of claim 1, further comprising, after receipt of the plural Access Units, reassembling fragments of the frame of VC-1 information into at least one encapsulated bit-stream data unit (EBDU).

6. The method of claim 1, further comprising providing control information to indicate that the VC-1 information contains no pictures that require reordering.

7. The method of claim 1, further comprising incrementing a counter in a header of an Access Unit to detect the occurrence of a random access point.

8. The method of claim 1, further comprising setting control information in a header of an Access Unit to indicate that the Access Unit contains a random access point.

9. The method of claim 1, further comprising:

determining an actual peak transmission rate; and

reducing a number of parameters expressed in Access Units to remove superfluous parameter information that does not pertain to the actual peak transmission rate.

10. The method of claim 1, further comprising redundantly repeating a sequence layer header within a bitstream defined by a sequence of RTP packets to make the bitstream more resilient to loss of information.

11. The method of claim 1, further comprising including control information in a header of an Access Unit to indicate that a sequence layer header has been transmitted which differs from an immediately preceding sequence layer header.

12. The method of claim 1, further comprising providing control information to indicate that a sequence layer header does not vary within a bitstream defined by a sequence of RTP packets.

13. The method of claim 12, further comprising omitting the sequence layer headers that do not vary from the bitstream.

14. The method of claim 1, further comprising providing control information to indicate that an entry point header does not vary within a bitstream defined by a sequence to of RTP packets.

15. The method of claim 14, further comprising:

omitting the entry point headers that do not vary from the bitstream; and

reinserting the entry point headers in the bitstream prior to decoding the bitstream.

16. An RTP (Real-Time Transport Protocol) data structure for encapsulating VC-1 (Video Codec 1) information in an RTP packet, as stored on one or more non-transitory computer readable media, comprising:

an RTP packet including an RTP header and a variable length RTP payload,

wherein the RTP payload includes at least one Access Unit,

wherein said at least one Access Unit comprises an Access Unit header and an Access Unit payload,

wherein said at least one Access Unit comprises a fragment of a VC-1 frame, the VC-1 frame being fragmented over plural Access Units in response to the size of the RTP packet being greater than a maximum transmission unit (MTU) size, each of the plural Access Units being assigned to a separate RTP packet, and the length of the RTP payload being determined during the encapsulation of the VC-1 information, and

wherein an RTP payload of one of the separate RTP packets includes a last of the plural Access Units and does not include any other Access Units of other frames of VC-1 information based on a rule preventing the inclusion of portions of two or more frames of VC-1 information in a same RTP payload.

17. A source module configured to encapsulate VC-1 (Video Codec 1) information in an RTP (Real-Time Transport Protocol) packet, comprising:

logic configured to be operated by a processor to arrange the VC-1 information into a at least one Access Unit, collectively forming a variable length RTP payload; and

logic configured to be operated by the processor to append an RTP header onto the RTP payload to form the RTP packet in accordance to a size of the RTP packet compared to a maximum transmission unit (MTU) size to at least avoid IP-level fragmentation, the length of the RTP payload being determined during the formation of the RTP packet,

wherein a frame of VC-1 information is fragmented over plural Access Units in response to the size of the RTP packet being greater than the MTU size, each of the plural Access Units being assigned to a separate RTP packet, and an RTP payload of one of the separate RTP packets includes a last of the plural Access Units and does not include any other Access Units of other frames of VC-1 information based on a rule preventing the inclusion of portions of two or more frames of VC-1 information in a same RTP payload.