Very low framerate on Ryzen 5000 CPUs when playing HEVC 12 bit content
When attempting to play content using the video codec of "MPEG-H Part2/HEVC (H.265) (hevc)
Decoded format: Planar 4:2:0 YUV 12-bit LE"
If it is done on a system using a Ryzen 5000 CPU, the frame rate will drop to around 2-3 FPS, while audio playback remains smooth. The video will skip frames to keep up.
VLC will use 100% of 1 CPU core during playback, which will in turn cause that CPU core to run at 5GHz.
Playback of the same file on a system with an Intel CPU, including low end ones such as the Core i5 4300Y, will result in smooth playback and low CPU usage (40% of 1 core that will run at half of its rated clock speed). In both cases, the GPU in both systems lacks hardware acceleration for this type of HEVC content
I am unsure of the exact cause, but was informed in this thread that I should post the issue here, and include a sample of the video, as well as some debug logs. https://forum.videolan.org/viewtopic.php?f=14&t=156643
Sample video in which the issue can be reproduced: https://www28.zippyshare.com/v/yZZLgiME/file.html
Link to the debug logs which were collected for a duration of 60 seconds of video playback: https://pastebin.com/x5UkpSv2
System specifications relevant to the video playback:
CPU: AMD Ryzen 7 5800X RAM: 32GB DDR4 3400 16-16-16-36 Storage where sample video was stored: Samsung 970 Pro 512GB NVMe SSD. GPU: GTX 970
To reproduce the issue:
1: Acquire the sample video file or any video file using the the codec and decoded format in question. 2: On a Ryzen 5000 based system, attempt to play the video file using VLC player.