Parallelizing Video Transcoding With Load Balancing On Cloud Computing Song Lin, Xinfeng Zhang, Qin Y, Siwei Ma Circuits and Systems, 2013 IEEE

Outline Introduction Related work Problem formulation and system architecture Proposed method Experiment Results Conclusion

Introduction #1 Parallel programming Share memory Pthread – data dependency Message passing MPI – time delay

Introduction #2 Issues Data dependency Cost of data passing Load balance

Introduction #3 Cloud computation Data segmentation Computing capacity

Introduction #4 GOP-based encoding Independence between GOPs

Introduction #5 Paralleling in GOP-based Thread1 Thread2 Thread3

Related work #1 FCFS - First come first server [2] Easy to implement Load balancing problem is still exist

Related work #3 MCT – Minimal complete time [6] Map-Reduce-based

Problem formulation and system architecture #1 Load balance problem on cloud computing Executing time Delay time Data passing C is complexity and P is computing capacity

Problem formulation and system architecture #2 The overall completion time of set S k is. Goal.

Problem formulation and system architecture #3 Optimal solution. n means n task and m means m cores

Problem formulation and system architecture #4 Flow chart of the proposed method

Problem formulation and system architecture #5 For video coding, if the input sequence has instantaneous decoder refresh (IDR) frame, this video coding task can be divided into sub- tasks.[7]

Problem formulation and system architecture #6 For complexity estimation of video transcoding tasks, the existing algorithms [8] [9] can be utilized.

Proposed method #1 The framework includes three modules Task pre-analysis Adaptive threshold segmentation Minimal finish time

Proposed method #2 The threshold of segmentation

Proposed method #3

Proposed method #4 The optical finish time The finish time

Proposed method #5 Assign all the tasks sequentially in descending complexity order For each unassigned task j, the cores are judged in their descending computing capacity order according to the following criterion: assuming the task j is assigned to core k, if Τ κ T thr, the assignment is verified. Otherwise, we will judge the next core.

Proposed method #6 If all the cores are traversed and all the computing time are beyond T thr, the task j will be assigned by MCT algorithm. and T thr is updated to be the new finish time of the received core T k

Proposed method #7

Experiment results #1

Experiment results #2

Experiment results #3

Conclusion Load balancing problem is a NP-hard problem. The proposed algorithm has strong robustness to the task launching delay.