Dynamic packet size control for MPEG-4 data partition mode

Abstract

A dynamic AC prediction technique is implemented in a data partition mode which automatically disables AC prediction for encoding the current macroblock in the next packet when packet overflow occurs. Otherwise, when there is no overflow, AC prediction remains enabled to maintain compression efficiency. More particularly, in the preferred embodiment, a determination is first made whether a macroblock causes a packet overflow if it is encoded in the current packet. If so, a new packet is initiated into which the macroblock is encoded without AC prediction as the first macroblock. Otherwise, the macroblock with AC prediction remains in the current packet and a new macroblock is encoded.

Description

RELATED APPLICATIONS[0001]The present application is a divisional of and claims the benefit of U.S. patent application Ser. No. 10 / 721,709, filed Nov. 25, 2003, entitled “DYNAMIC PACKET SIZE CONTROL FOR MPEG-4 DATA PARTITION MODE,” naming Ram Prabhakar, Harikrishna M. Reddy, Lefan Zhong, Wei Sun, Leonardo Vainsencher, and Visalakshi Vaduganathan as inventors, assigned to the assignee of the present invention, and having attorney docket number NVID-P000899. That application is incorporated herein by reference in its entirety and for all purposes.[0002]The present application is related to U.S. patent application Ser. No. ______,filed Dec. ______, 2007, entitled “DYNAMIC PACKET SIZE CONTROL FOR MPEG-4 DATA PARTITION MODE,” naming Ram Prabhakar, Harikrishna M. Reddy, Lefan Zhong, Wei Sun, Leonardo Vainsencher, and Visalakshi Vaduganathan as inventors, assigned to the assignee of the present invention, and having attorney docket number NVID-P000899.D2. That application is incorporated h...

AI Technical Summary

Benefits of technology

[0013]Accordingly, the present invention provides a method and apparatus to prevent video packet overflow in a MPEG data partition mode while minimizing the compression efficiency impact and maintaining video quality.

Problems solved by technology

As such, a significant part of the video information in an image is predictable and therefore redundant.

On the other hand, irrelevant video image information is information that cannot be seen by the human eye under certain reasonable viewing conditions.

Compressed video data is vulnerable to transmission errors.

As a result of the strict packet sizes in data partition mode, there are inherent concerns about packet data overflow during the encoding of a macroblock.

However, if the AC prediction is always turned on during data partition mode, such re-encoding may cause a change in the AC prediction direction and predicted differences which in turn effects the ZigZag run length of the bitstream.

Conversely, if the AC prediction is turned off completely during data partition mode, the compression efficiency is negatively impacted.

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