Systems methods for adjusting targeted bit allocation based on an occupancy level of a VBV buffer model

Abstract

The invention is related to methods and apparatus that advantageously improve bit rate control in a video encoder, such as an MPEG video encoder. One embodiment of the invention advantageously varies the targeted bit allocation for a picture to be encoded based on an occupancy level of a buffer model, such as a video buffer verifier (VBV) buffer model.

Description

RELATED APPLICATION[0001]This application is a Continuation patent application of co-pending application Ser. No. 10 / 452,769, filed on 30 May 2003.APPENDIX A[0002]Appendix A, which forms a part of this disclosure, is a list of commonly owned copending U.S. patent applications. Each one of the applications listed in Appendix A is hereby incorporated herein in its entirety by reference thereto.BACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The invention generally relates to video encoding techniques. In particular, the invention relates to adjusting a target number of bits to encode a picture based in part to achieve bit rate control and maintain buffer occupancy.[0005]2. Description of the Related Art[0006]A variety of digital video compression techniques have arisen to transmit or to store a video signal with a lower data rate or with less storage space. Such video compression techniques include international standards, such as H.261, H.263, H.263+, H.263++, H.264, ...

AI Technical Summary

Benefits of technology

[0010]The invention is related to methods and apparatus that advantageously improve bit rate control in a video encoder, such as an MPEG video encoder. One embodiment of the inv...

Problems solved by technology

For relatively high image quality, video encoding can consume a relatively large amount of data.

However, the communication networks that carry the video data can limit the data rate that is available for encoding.

As a result, a video encoding process often trades off image quality against the number of bits used to compress the images.

Moreover, video encoding can be relatively complex.

For example, where implemented in software, the video encoding process can consume relatively many CPU cycles.

Further, the time constraints applied to an encoding process when video is encoded in real time can limit the complexity with which encoding is performed, thereby limiting the picture quality that can be attained.

An example of such a shortcoming is that TM5 does not guarantee compliance with Video Buffer Verifier (VBV) requirement.

As a result, overrunning and underrunning of a decoder buffer can occur, which undesirably results in the freezing of a sequence of pictures and the loss of data.

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