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HIGHLY PARALLEL FRAMEWORK FOR HEVC MOTION ESTIMATION ON MANY-

CORE PLATFORM

Data Compression Conference 2013

Chenggang Yan, Yongdong Zhang, Feng Dai and Liang Li

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Outline Introduction Related Work Proposed Method Experimental Results Conclusion

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Introduction(1/2)

HEVC coding tree unit (CTU)

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Introduction(2/2)

Local parallel method (LPM) Maximum parallelism of LMP is equal or less than 8. independent Pus (IPUs)

Directed acyclic graph (DAG)

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Related Work(1/2)

Local parallel method (LPM) [16] Motion estimate region (MER)

[16] Minhua Zhou, “AHG10: Configurable and CU-group level parallel merge/skip,” JCTVC-H0082, Feb. 2012

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Related Work(2/2)

Local parallel method (LPM)

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M = 16 or 8

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Proposed Method A. Data Dependency Analysis

B. DAG for CTUs

C. Highly Parallel Framework

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Proposed Method.A(1/3)

Independent PUs (IPUs) The IPU’s left boundary and MER’s left boundary do not

overlap. The IPU’s upper boundary and MER’s upper boundary do not

overlap.

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Proposed Method.A(2/3)

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Proposed Method.A(3/3)

Neighboring CTUs left upper upper-left upper-right

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Proposed Method A. Data Dependency Analysis

B. DAG for CTUs

C. Highly Parallel Framework

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Proposed Method.B(1/4)

Generate a DAG to capture the dependency relationships of CTUs.

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Proposed Method.B(2/4)

DAG consists of a set of vertices V and edges E. data dependency <=> an edge. Processed <=> remove

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Proposed Method.B(3/4)

Condition matrix (CM)

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Proposed Method.B(4/4)

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Proposed Method A. Data Dependency Analysis

B. DAG for CTUs

C. Highly Parallel Framework

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Proposed Method.C(1/5)

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Proposed Method.C(2/5)

Step1 : Initialize DQ and CM. DQ is a waiting queue. CM is

designed to record the number of related CTUs for each CTU. Step2 :

When some values in the CM become zero, get the corresponding coordinates and push them into DQ.

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Proposed Method.C(3/5)

Step3 :Get coordinates from DQ and process corresponding

CTUs in parallel on many-core platform. Step4 :

Update CM. When a CTU with coordinate (i, j) in CM is processed, the values of coordinates (i+1, j), (i+1, j-1), (i,j+1) and (i+1,j+1) in CM will minus one operation.

Step5 :Repeat above steps 2~4 until each frame is over.

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Proposed Method.C(4/5)

Maximum parallelism of CTU

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Maximum parallelism of highly parallel framework

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Average parallelism of highly parallel framework

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Proposed Method.C(5/5)

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Experimental Results(1/5)

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Experimental Results(2/5)

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Experimental Results(3/5)

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Experimental Results(4/5)

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Experimental Results(5/5)

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Conclusion(1/1)

Highly parallel framework provide sufficient parallelism for many-core platforms.

Use the DAG-based order to parallelize CTUs.