Just bought a UP Squared board, and installed a standard Ubuntu 16.04 LTS desktop system on it. The board has an N4200 CPU, 8GB RAM and 64GM eMMC. Per Intel's description I believe this board should be able to decode 4K video, but I can't play 4K video smoothly in Linux. I installed the VLC play, from Ubuntu's repo, and selected VAAPI through DRM as the accelerated decoder, only to find that it is slower than software decoding. VAAPI through X11 is the same.The video plays stuttering, and the CPU utilization is quite high (80%~90%). Playing videos with ffplay is basically the same.
I also tried some 1080p videos. Playing one stream of 1080p video is just fine, and the CPU utilization averages at around 30%. Playing two streams simultaneously and the CPU% doubles. Playing three streams the CPU reaches nearly 100% and all the three streams become stuttering.
I think the CPU goes high because the VAAPI driver, i965-va-driver installed by default, is not working properly, although the information printed by vainfo seems to be correct. As an experiment, I tried to download the latest versions of libva and Intel VA drivers' source code from https://01.org/linuxgraphics , and compiled and installed them. But I found that they are based on VA API 1.1.0 version. The Ubuntu 16.04 comes with 0.39, and installing a new version is not working. For example the Ubuntu's libva is libva.so.1.3900.0, and the Intel's code base generates libva.so.2.100.0. To utilize the new versions from Intel, one has to recompile all existing software and link with the new lib(s), which is too tedious.
So here are my questions:
1. Is the N4200 and HD Graphics 505 capable of decoding and playing a 4K video fluently?
2. Can I play 4 streams of 1080p video simultaneously on N4200? (Yeah I'm a developer and this is for a home project to host 4 CCTV cams.)
3. How can I ensure that the video streams are decoding in the GPU and not on the CPU?
4. What is the needed software configurations (components and their versions) to fully utilize the processing power of N4200 and its GPU?
5. Is there a simple way to migrate the existing software to the new VA API? For instance, must I recompile VLC from source? Are there any available binaries of fast players based on the latest versions of Intel's drivers?
Thank you in advance for hearing and answering!