4K 59.94fps Film Stuttering

  • Hi,

    I recently got a new 4K film and its 59.94fps. All my 23.97fps 4K films play perfectly but the 59.94fps ones are stuttering. Its not a full stop kind of stutter but it is noticeable and every 5 - 10 seconds. I tried the 3rd May nightly and the stuttering was definitely less than on the 10.0.2.

    I firstly added hdmi_enable_4kp60=1 to the config and whitelisted the resolutions. I also tried arm_boost=1 to give it more power. I always have force_turbo=1 active. This didn't help.

    I then tried to overclock the Pi as I thought it maybe struggling, to 2000 on the CPU and 700 on the GPU with a over_voltage-=8 but that didn't help either

    I also thought it might be the USB stick not keeping up so I ran a test. On one stick I was getting a consistent read of 101mb/s using three different softwares. On the other stick I was getting a consistent 139mb/s.

    The log I got is below so hope it helps.

    hastebin

    Are there any known issues with running 4K 59.94fps movies?

    Thanks

  • I removed the overclock but kept arm_boost=1 and force_turbo=1.

    On the nightly build using the second audio stream 5.1 there was a big difference. I watched it for ten minutes and noticed one stutter but where it stuttered before was smooth.

    Using 10.0.2 it still stuttered in the same places using 5.1 audio track.

    Do you think the TrueHD processing and the 59.94fps is taking too much out of the Pi or is there a issue with the passthrough?

    Thanks

  • 4K@60/59.94 with a high-bitrate audio stream might be pushing the limits I guess (not that I'm knowlegeable on what the limits are). Do you have "certified" HDMI cables between the RPi4 and AVR? .. the total HDMI bandwidth required for this will be above average and cable quality does become a factor at some point.

  • Hi,

    Yes all the cables I have from TV to AVR to Pi are certified. As I knew I would only be playing high bitrate rips I made sure I got the right cables.

    I bought them from retail HiFi shops and scanned the QR codes on them to make sure.