MPEG-2 (Moving Pictures Experts Group-2) to H.264 fast video transcoding method

Abstract

The invention discloses an MPEG-2 (Moving Pictures Experts Group-2) to H.264 fast video transcoding method, comprising the following steps of: firstly saving coding macro block modes of macro blocks in a P frame, coding block modes of the macro blocks and four 8*8 direct current coefficients in the macro blocks in MPEG-2 original video decoding process; secondly dividing all macro blocks in the P frame into five different types of macro blocks according to the saved coding macro types and the coding block modes; thirdly, only self-adaptively selecting the optimal coding mode from the coding modes having larger relativity with the performances of the macro blocks to code the macro blocks in the H.264 coding process. The method largely reduces the number of candidate coding modes for coding the macro blocks in the P frame in the premise of ensuring that the reduction of the video quality is a little and the increment of the code rate is not much, thereby effectively reducing the time complexity of macro code coding mode selection in the H.264 coding process, and reducing the MPEG-2 to H.264 video transcoding time, i.e. improving the MPEG-2 to H.264 video transcoding efficiency.

Description

technical field [0001] The invention relates to a digital video information transcoding technology, in particular to a fast video transcoding method from MPEG-2 to H.264. Background technique [0002] At present, MPEG-2 is widely used, and the video resources encoded by MPEG-2 are abundant. With the continuous development of multimedia technology, video coding technology has made rapid progress. H.264 is a recently announced new coding standard. Compared with previous coding standards, it has excellent performance, flexible coding, and different video coding from low bit rate (such as mobile phone) to high bit rate (such as HDTV). application requirements can be met. If the existing rich MPEG-2 video resources can be quickly converted into H.264 video with excellent coding performance, it will have very important application significance. [0003] There are various types of video transcoding, which are mainly divided into two categories according to the structure: Pixel-...

AI Technical Summary

Problems solved by technology

The most direct video transcoding method is cascade transcoding, that is, refer to the transcoder, first fully decode the video to be transcoded, and then re-encode the decoded reconstructed data in a new encoding format. This method can Get the best transcoding effect (rate-distortion performance), but at the same time it also has the highest complexity, has a large time overhead, and is not suitable for applications with high latency requirements such as real-time systems

"Efficient block size selection for MPEG-2 to H.264" published by Gao Chen et al. on "Proceeding MULTIMEDIA '04 Proceedings of the 12th annual ACM international conference on Multimedia" transcoding" ("MPEG-2 to H.264 Transcoding Efficient Block Size Selection Algorithm"), an efficient variable block size matching mode selection algorithm for MPEG-2 to H.264 transcoding is proposed. The algorithm uses the motion information in the MPEG-2 code stream to determine the block size mode of each macroblock (MB). Simulation experiments show that the video quality of the algorithm is similar to that of cascaded pixel domain transcoding (refer to transcoder) , but compared to the reference transcoder, the transcoding time of this algorithm is only reduced by 20%, while the code rate has increased

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