A famous cloud computing file system and developing framework named Hadoop is mainly designed for massive textual data management, such as counting, sorting, indexing, pattern finding, and so on. However, it is merely to seek a multimedia-oriented service via Hadoop. Mohohan is an on-line multimedia transcoding system for video resources, which implemented with Amazon Web Service (AWS) EC2, AWS S3, AWS EMR, Hadoop, and ffmpeg. Its goal is reducing the overall execution time by parallel transcoding via the Hadoop cluster. The concept of Mohohan is simple: 1) to divide the video into several chunk of frames, 2) to transcode the chunks in parallel with multiple nodes (i.e., task tracker) of Hadoop cluster, and 3) to merge the transcoded results into the output. On the homogeneous SaaS comparison, a test report from an impartial third party organization named CloudHarmony has been chosen. Finally, the experiment result shows that Mohohan performs quite better than other on-line video transcoding services mentioned in the test report, such as Encoding, Zencoder, Sorenson, and Panda.