5th International Mobile Multimedia Communications Conference

Research Article

Switching Frames for Constant Bit Rate Video Streams

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  • @INPROCEEDINGS{10.4108/ICST.MOBIMEDIA2009.7590,
        author={M. Altaf and E. Khan and M. Ghanbari},
        title={Switching Frames for Constant Bit Rate Video Streams},
        proceedings={5th International Mobile Multimedia Communications Conference},
        publisher={ICST},
        proceedings_a={MOBIMEDIA},
        year={2010},
        month={5},
        keywords={Constant bit rate H.264/AVC Switching frames Variable bit rate Video Streaming},
        doi={10.4108/ICST.MOBIMEDIA2009.7590}
    }
    
  • M. Altaf
    E. Khan
    M. Ghanbari
    Year: 2010
    Switching Frames for Constant Bit Rate Video Streams
    MOBIMEDIA
    ICST
    DOI: 10.4108/ICST.MOBIMEDIA2009.7590
M. Altaf1,*, E. Khan2,*, M. Ghanbari3,*
  • 1: School of Computer Science and Electronic Engineering, University of Essex, UK. +44 1206-874448
  • 2: Dept. of Electronics Engineering, Aligarh Muslim University, Aligarh, India.
  • 3: School of Computer Science and Electronic Engineering, University of Essex, UK. +44 1206-872826
*Contact email: maltaf@essex.ac.uk, ekhan@lycos.com, ghan@essex.ac.uk

Abstract

To map the data rate to the available channel bandwidth, one method is to switch between video streams of different qualities using either intra (I-) frames or the switching predictive (SP-) frames of H.264. Due to its better coding efficiency SP-frames are preferred over I-frames, but these frames are generally exercised with variable bit rate (VBR) coded videos, therefore limiting their usage. For constant bit rate (CBR) coded videos, in which the quantization parameters (QP) are decided on the fly for every macro block, the design of SP-frames becomes difficult due to the multiple (twice) quantizations used in SP-frames. In this paper we propose to design SP-frames for CBR coded videos, selecting the QPs in such a way that the varying QP nature of CBR coding is preserved. The proposed algorithm is compared with the already implemented SP-frame concept for VBR video coding, showing that both the concepts have similar behavior.