Mainline Hardware Decoding
Onboard most SoCs there is what is referred to as a VPU (Video Processing Unit). The VPU is reponsible for efficient encoding and decoding of videos. Video decoding can be extremely useful for example if you wanted to watch or stream video from your device without a high CPU utilization (which results from software decoding). Below information can be found on the various SoCs used by PINE64 and their state of video decoding as a result of the mainline Linux drivers and software.
Allwinner-based devices
In 2018 Bootlin launched a crowdfunding campaign to bring a open source Allwinner VPU driver to mainline Linux, which became called Cedrus.
The Cedrus media driver (For Allwinner SOCs such as A64) supported by mainline Linux supports H.264 and H.265 video decoding as of Linux 5.10, and with 5.11 came VP8 decoding support and a H.264 stateless video decoder interface. For more information refer to the Sunxi wiki.