Pi4, hardware acceleration, fast forward freezes

  • I am running a Pi4 with 2GB of ram. SD card for OS. Emby server + nas for data storage, Pi4 is mounted in a Flirc all aluminum case. No fan.

    I was having a display freeze problem when I used fast forward during video playback. The whole display would lock up but I could still access the system with SSH. Still required a reboot to get control through the user interface.

    I turned off Allow Hardware acceleration MMAL and then fast forwarding worked just fine.

    While using fast forward debug is on. I see CPU usage on one of the CPU's runs at 100% while the other 3 are in the teens or lower. After some seconds the high activity moves to a different CPU. I suppose this is happening to manage heat dissipation.

    stepping through replay speeds (1x,2x...32x) on the 1080p video I see a range of cputemp readings from 40c to 46c.

    All this is really great. I can't imagine that I would see a better heat profile even if MMAL worked so I will leave hardware acceleration off.

  • Thank you for the information. I do have x264 and h264 encoded files that MMAL does support but these files have the problem with fast forwarding. Since I have found a solution i'll stick with that.

    Thanks again

    • Official Post

    LE 9.2 reached a point where it worked for the majority of use-cases, and then the focus moved away from legacy MMAL/OMX decoding onto the all-new GBM/V4L2 codebase. The older methods still have rough edges that will never be fixed, so if you have problem media I'd suggest you retest under LE10, because bugs/issues found there are of interest to the developers.