JVET-Y0066 Update on Ali266, the optimized VVC encoder implementation by Alibaba [X. Dong, S. Fang, Z. Huang, J. Liu, S. Xu, R. Yang, L. Yu, J. Chen, R.-L. Liao, Y. Ye (Alibaba)]

This contribution reports updated information on runtime and coding efficiency of Ali266, an optimized software VVC encoder developed by Alibaba. Ali266 was first presented in JVET-W0127, it supported two presets, with its fast preset aimed at real-time encoding applications. In JVET-W0127, Ali266 was able to achieve encoding speed of 37.7 fps for 720p sequences.

In JVET-X0104, further improvement in Ali266’s encoding speed at its fast preset was reported. Under the configuration of fast preset with 8-bit internal bit depth, Alibaba reported that a 1.9x encoding speedup had been achieved compared with that in JVET-W0127 for video sequences at 1920x1080 or 1080x1920 resolutions. The average encoding speeds achieved 36.3 fps for classes 1920x1080 / 1080x1920 and 63.4 fps for classes 1280x720 / 720x1080. Based on such data, Alibaba concluded that Ali266 was a VVC encoder capable of real-time encoding for 1080p sequences.

Further updates to Ali266 are reported. First, Ali266 was enhanced with 4 predefined quality/speed presets, slow, medium, fast, and faster, to meet different application needs. Furthermore, Alibaba has achieved 10-bit real time encoding for 1080p video-on-demand (VOD) content with the “faster” preset and has also improved the coding efficiency. Their experiments reportedly demonstrate that Ali266 achieves BD rates for {YUV-PSNR, YUV-SSIM} of {-42.01%, -42.90%} over the widely used open-source HEVC software encoder x265 at the medium preset, compared to the previously reported results of {-38.10%, -41.10%} in JVET-X0104 over the same anchor.