Comparison of Open and Free Video Compression Systems - A Performance Evaluation

Abstract

This article gives a technical overview of two open and free video compression systems, Dirac and Theora I, and evaluates the rate distortion performance and visual quality of these systems regarding lossy and lossless compression, as well as intra-frame and inter-frame coding. The evaluation shows that there is a substantial performance gap of Theora and Dirac when compared to H.264and Motion JPEG2000-compliant reference systems. However, an algorithm subset of Dirac, Dirac Pro, achieves a performance comparable to that of Motion JPEG2000, and which can be less than one dB below the PSNR performance of H.264 with TV-size and HD video material. It is further shown that the reference implementations of the codecs of concern still have potential for efficiency improvements.