MP 1,1-5,1 Mac Pro 5,1 4K video playback glitchy

Discussion in 'Mac Pro' started by joot, Jul 21, 2019.

  1. joot macrumors member

    Nov 3, 2006
    I have a 12-core 3.33mHz Mac Pro 5,1 with 64GB ram and 980Ti gpu. Using VLC to play 4K video files (.mov) shot on my GH5 (Sigma 18-35mm) always plays back glitchy, pixelated. Not sure if its VLC player or my computer. Anybody has any ideas why the videos are playing back pixelated, glitchy? Videos are shot in 4K Cine-D, 150mbs, 30fps.
  2. ruslan120 macrumors 6502


    Jul 12, 2009
    Maybe your storage is slow?

    What are your results in Blackmagic Disk Speed Test? (it tests whether your disks are fast enough to provide the data to the graphics + CPU to playback)
  3. joot thread starter macrumors member

    Nov 3, 2006
    ^^ I have an internal HP 1TB NVME SSD so disk speed is fast enough I think. Have not done a disk speed test though...
  4. Nunyabinez macrumors 68000


    Apr 27, 2010
    Provo, UT
    I would also suspect the drive. The 5,1 SATA ports are 3Gb/s so you could put the fastest drive in the world in there and it might not perform much better than a good HD.

    I put a PCIe card in my 5,1 that allows the SSD to run at 6Gb/s. Do the test with something like black magic and then if it is the culprit, get a PCIe card.
  5. tsialex macrumors 603


    Jun 13, 2016
    He already have a PCIe NVMe drive, it's not the disk throughput.
  6. ruslan120 macrumors 6502


    Jul 12, 2009
    Are you holding it right?


    Here are my guesses (on a helpful note):
    [1] the NVMe -> PCI-Express card is at fault (Blackmagic Test would help)
    [2] Some OS file clutter, could help cleaning the system (Cleaning library files)
    [3] The software is unoptimized and uses a single core, and single core performance isn’t great on the cMP (activity monitor -> CMD 3 to see CPU usage + try different software maybe)

    hope that helps
  7. Synchro3 macrumors 68000


    Jan 12, 2014
    Try Iina for 4K footage.

    VLC plays back glitchy.
  8. iluvmacs99, Jul 21, 2019
    Last edited: Jul 21, 2019

    iluvmacs99 macrumors regular

    Apr 9, 2019
    Are you on the latest version of VLC; version Vitenari version which defaults to hardware decoding using the GPU with h.264 streams so you can playback 4K and 8K material and will step back to software decoding if the GPU is unable to fulfill the requirements.

    This is the release notes for VLC Vitenari which applies also to the Mac version. I have zero problems playing back such 4K material from my Panasonic 4K camera tested up to 180mbs UHD h.264 stream or even the Jellyfish demo, but I have the Sapphire RX580 8Gb version GPU. The older version defaults to software decoding and you need to manually enable hardware decoding under input/output codec section. There is difficulty in playing back HEVC 10bit files (h.265) though if that is what you are recording in? It will lag and appear pixelated for the first for seconds of the footage and then appears normal later on.
  9. fhturner macrumors 6502


    Nov 7, 2007
    Birmingham, AL & Atlanta, GA
    The footage is simply too taxing for the CPU, which has no hardware acceleration for H.264 playback and isn’t quite quick enough to decompress and render a frame every 1/30 of a second. My 3.46GHz 12-core struggles a little bit and is choppy with my 100Mbps G85 (little brother to your GH5) 4K footage; your GH5 footage at half again the data rate is just choking the CPU.

    You may want to try to get GPU acceleration of the H.264 decode working for you. @h9826790 has come up with instructions for us to enable this with our recent AMD cards in macOS 10.14.5 Mojave, and a couple of us have also had success with this in 10.13.6 High Sierra. My previously choppy G85 4K footage now plays back smoothly with almost no CPU utilization.

    I’m blanking on methods to enable this for your Nvidia 980Ti card tho...someone help me?

  10. h9826790 macrumors G5


    Apr 3, 2014
    Hong Kong
    Just 150bps, which means only need 20MB/s, even a low end HDD can deliver that without any issue.

    Impossible, contacted Nvidia, they have no plan to provide any NVDEC support in macOS. There is literally zero NVDEC working in any OSX / macOS. No way to patch / mod / hack from anything.

    If need to play that video, do that in Windows.
  11. zoltm macrumors member

    May 9, 2017
    I think getting a RX 580 card would solve your problem, big time. With @h9826790 notes on enabling GPU H/W acceleration, I can easily handle youtube VP9 4K footage, even with an RX460 card. That's very sweet.
  12. joot thread starter macrumors member

    Nov 3, 2006

    Synchro3, thank you ! This little app "IINA" linked above did the trick! VLC was my go to video player until it started pixelating (choppy play, pixelated) on 4K video footage. I initially thought the issue was my computer setup or the SD card I was using in my GH5 or even my camera itself. Glad the problem was VLC. Thank you all !!!
  13. orph macrumors 68000


    Dec 12, 2005
    got to ask is it h265 10bit video from the gh5?
    what version of osx, 10.14? or older
    you mention Cine-D, are you going to edit/grade it in a big way?

    if it's just home videos 4K h264 is a good option with natrual is good, if you want to grade the video it may work out best to move to a proxey format depending on your NLE (FCX will do it in background, resolve will do it when asked, PP im not sure).

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12 July 21, 2019