Design And Realization Of H.264 And AVS-M Video Transcoder

With the development of wireless network and audio and video technology, the application of mobile multimedia codec plays an important role more and more in social life. For supporting the communication between different sets with different code standard, it is necessary for transforming the coded bit-stream into another style. This process is called video transcode. As a digital audio and video codec standard established and owned by China, AVS, Audio and Video Standard, includes a video standard called AVS-M as its seventh part; H.264-Baseline, the base level of H.264/AVC(Advanced Video Coding), is the mainstream standard of international mobile multimedia communication. The essay's work is the transformation between them:(1) Introducing the principle of H.264-Baseline and AVS-M, comparing with each other and taking the keys about realizing the transcoder.(2) After comparing the part of integer transform between H.264-Baseline and AVS-M, the essay presents a transcoding fast algorithm about transform coefficient in the transform field, which transforming the transform coefficient matrix between them by using butterfly-type algorithms, realizes the remnant data 's fast transcoding.(3) After analyzing and finding difference between the part of intra predication, the essay presents a fast algorithm for mapping the intra prediction modes. Using the way of cutting the 16×16 luminance macro block and mapping its prediction mode, it is nice for reusing the results about intra mode prediction, advancing the speed of getting the best prediction mode.(4) After comparing the part of inter predication, the essay proposes a tree-type inter prediction transcoding algorithm, which using the motion vector correction and the regain of insert-value, advances the efficiency of inter prediction transcoding and keeps the quality of image.(5) At last, the essay builds a transcoder by using such three algorithms, tests the quality and efficiency of transcoding. This architecture can realize the transcoding between H.264-Baseline and AVS-M, and advance the efficiency of transcoding that kept the quality of image.