Problem:
Inconsistent framerate
Logs:
Started up Kodi and then played movie directly from WD external hard drive (NTFS) for 10 minutes.
System:
Raspberry Pi 4B 8GB
Samsung MicroSD card (32GB)
Notes:
- Framerate sometimes reached 60 FPS for a few seconds but it mostly stays at around 45 to 55 FPS sometimes dropping to as low as 25 FPS.
- Tested with a fresh install: LibreELEC-RPi4.arm-9.97.1.img.gz
- Tested the same movie file playing it from the sd card and it had similar performance.
- CPU stays at about 60%.
- Tested two other videos (see below) and it doesn't seem to matter if it's HDR or not.
Config:
over_voltage=6
arm_freq=2147
gpu_freq=750
hdmi_enable_4kp60=1
Settings:
Display:
3840x2160
60
Every resolution whitelisted
Audio:
ALSA: vc4-HDMI-0 (vc4hdmi0), HEC HISENSE on HDMI
Audio passthrough disabled (tested with it enabled and it made no discernable difference)
Video encoding information:
Further testing with samples:
Notes:
- Similar performance for each.
- Played from SD card
- Samples - Official Kodi Wiki
Videos:
- HEVC 10-bit 59.940fps (Korean ATSC 3.0 satellite TV capture sample)
- HDR10 HEVC 59.940 (in mov, hdmkv's iPhone 11 Pro Max raw 4K footage using 4K HDR Video Recorder app)
Is this a current limitation of LibreELEC with the raspberry pi?
Update:
Tested booting from NVMe drive and with LibreELEC 10.0.0, same framerate.