I copy a large video file to sdcard recently. The video is not well-formed and I change its suffix to make VLC play it. After that, my fairphone 4’s battery drain fast.
I connect to my phone with adb shell and check if any process consume a lot of CPU with command top.
For mine, there was a process media.extractor keep running in 100% CPU, thought Settings / Battery Usage does not show this process or any app consume lots of battery.
I suspect that the media.extractor process was stuck on the video file.
(thought the lsof show nothing about the video file.)
Some google search result said that add a .nomedia file can fix this problem, but not for me.
I restore the video file’s suffix and kill the process with root permission (or just reboot the phone). Everything work fine after that, and media.extractor never stuck in 100% cpu anymore.
If anyone face battery problem in fairphone4, try the top command.