Performance comparison of AV1, JEM, VP9, and HEVC encoders

This work presents a performance evaluation of the current status of two distinct lines of development in future video coding technology: the so-called AV1 video codec of the industry-driven Alliance for Open Media (AOM) and the Joint Exploration Test Model (JEM), as developed and studied by the Joint Video Exploration Team (JVET) on Future Video Coding of ITU-T VCEG and ISO/IEC MPEG. As a reference, this study also includes reference encoders of the respective starting points of development, as given by the first encoder release of AV1/VP9 for the AOM-driven technology, and the HM reference encoder of the HEVC standard for the JVET activities. For a large variety of video sources ranging from UHD over HD to 360° content, the compression capability of the different video coding technology has been evaluated by using a Random Access setting along with the JVET common test conditions. As an outcome of this study, it was observed that the latest AV1 release achieved average bit-rate savings of ~17% relative to VP9 at the expense of a factor of ~117 in encoder run time. On the other hand, the latest JEM release provides an average bit-rate saving of ~30% relative to HM with a factor of ~10.5 in encoder run time. When directly comparing AV1 and JEM both for static quantization parameter settings, AV1 produces an average bit-rate overhead of more than 100% relative to JEM at the same objective reconstruction quality and, in addition, with a factor of ~2.7 in encoder run time. Even when operated in a two-pass ratecontrol mode, AV1 lags behind both the JEM and HM reference encoder with average bit-rate overheads of ~55% and ~9.5%, respectively, although the latter being configured along one-pass static quantization parameter settings.