A simplified motion estimation using an approximation for the MPEG-2 real-time encoder

This paper presents efficient coding and mapping algorithms that lead to a significant speed improvement in low bit rate H.263/H263+ video encoding while maintaining high video reproduction quality. First, by exploiting statistical properties of low resolution and slowly varying video sequences, we reduce significantly the computation times of the most computationally intensive components of video coding, particularly the DCT, the IDCT, quantization, and motion estimation. We also map some of the SIMD (Single Instruction Multiple Data) oriented functions onto Intel's MMX architecture. The developed algorithms are implemented using our public-domain H.263/H.263+ encoder/decoder software [1]. Index Terms-Low bit rate video coding, real-time video coding, H.263, MMX. I. INTRODUCTION The growing interest in digital video applications led academia and industry to work towards developing video compression algorithms. Consequently, several successful standards have emerged, such as the ITU-T H.261, H.263, H.263+, ISO/IEC MPEG-1, and MPEG-2. H.263 and H.263+ are low bit rate video coding standards that are based on H.261. H.263 targets video encoding at rates below 64 kbps (kilo bits per second), providing some major improvements over the H.261 standard and offering four negotiable modes that provide many tradeoffs between compression performance and complexity [2]. H.263+ provides twelve additional negotiable modes that improve compression performance and error resilience, enhance performance over packet-switched networks, allow the use of scalable bit streams, and provide supplemental display and external usage capabilities [3]. While the advanced video coding algorithms, such as those compliant with H.263 and H.263+, provide better compression performance levels than those compliant with H.261 and MPEG-1, they are more complex and more computationally demanding. Until recently, real-time video encoding and decoding were only possible using Application Specific Integrated Circuits (ASICs) or multiple DSP platforms, resulting in coding systems such as the VDSP2 from Matsushita

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“…al. proposed a method for fast half pixel motion estimation in [22] within an MPEG-2 coding framework. Froitzheim et.…”

Section: Efficient Low Bit Rate Video Coding Algorithmsmentioning

confidence: 99%

“…al. [22] proposed a simple approximation technique to remove the need for interpolation and the SAD computations performed for half pixel ME within an MPEG-2 coding framework. They suggest to compute each half pixel SAD from the surrounding integer pixel SADs as illustrated in…”

Section: ) a Simplified Half Pixel Me For Mpeg-2 Encodermentioning

confidence: 99%

Efficient coding and mapping algorithms for software-only real-time video coding at low bit rates

Erol

Kossentini²,

Alnuweiri³

2000

IEEE Trans. Circuits Syst. Video Technol.

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“…Chen et al [14] investigated techniques for reducing the number of search points but needed at least four search points. In this paper, we develop the prediction model, an extension of the works in [12], and [13] to obtain a more precise prediction not only in the horizontal and vertical directions, but also in the diagonal directions. To exploit the potential gain, a novel fast half-pixel search algorithm is proposed to reduce the number of search points from eight to three.…”

Section: Introductionmentioning

confidence: 99%

“…The details of the skipping strategy, however, will not be discussed in this paper. For the latter aspect, [12] and [13] have proposed prediction models for half-pixel matching error to avoid the half-pixel search. However, only horizontal or vertical predictions were proposed there and the prediction accuracy is not satisfied.…”

Section: Introductionmentioning

confidence: 99%

PPHPS: a parabolic prediction-based, fast half-pixel search algorithm for very low bit-rate moving-picture coding

Zheng

2003

IEEE Trans. Circuits Syst. Video Technol.

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In hybrid moving-picture coding schemes, motion estimation is conducted in two stages, one at integer pixel accuracy and the other at subpixel accuracy. In very low bit-rate coding, some fast motion-search algorithms are able to decrease their search points to about ten pixels at the integer pixel search stage. There remains, however, a need to study fast computing for the subpixel motion estimation. A novel, fast-search algorithm using parabolic prediction is proposed in this paper particularly for the half-pixel motion vector estimation. It needs to check only three half-pixels rather than the eight pixels, which are used in the full half-pixel motion search scheme (FHPS). Experimental results show that this algorithm preserves the image quality and has little influence on the bit-rate when compared to that of the referenced FHPS strategy.Index Terms-Fast half-pixel motion estimation, parabolic prediction-based fast half-pixel search algorithm (PPHPS), parabolic prediction, very low bit-rate coding.

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“…However, it requires a plenty of computations not only in the subpixel search process but also in the pixel interpolation. In [134][135][136], some novel algorithms at a fractional pixel basis have been developed, but they may need to be improved further. In our future work, we are going to expand our research from integer pixel to subpixel to further improve the video coding efficiency.…”

Section: Subpixel Motion Estimationmentioning

confidence: 99%

Fast motion estimation for video coding

Qi¹

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First and foremost, I would like to express my earnest appreciation from the bottom of my heart to my supervisor, Dr. Zhu Ce, for his professional guidance, invaluable support and kindly encouragement during my master study as well as his constructive comments on this thesis. It is my pleasure to spend around two years with many talent and kind friends in the Media Lab. I cherish the friendship and thank them for their selfless help. This thesis is dedicated to my parents. Their love and inspiration are always with me.

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A simplified motion estimation using an approximation for the MPEG-2 real-time encoder

Cited by 21 publications

References 5 publications

Efficient coding and mapping algorithms for software-only real-time video coding at low bit rates

Efficient coding and mapping algorithms for software-only real-time video coding at low bit rates

PPHPS: a parabolic prediction-based, fast half-pixel search algorithm for very low bit-rate moving-picture coding

Fast motion estimation for video coding

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