Resolved poor 4K performance on my 6-core trashcan

Discussion in 'Mac Pro' started by seenew, Jul 29, 2015.

  1. seenew macrumors 68000

    seenew

    Joined:
    Dec 1, 2005
    Location:
    Brooklyn
    #1
    Hey guys,

    I recently purchased a new Mac Pro at work as a long overdue upgrade to my aging iMac from 2011. The project that pushed me over the edge is a series of time lapses I shot a couple of weeks ago which will be compiled into five 4K video files. Each time lapse is about 4000 10MP raw images, so it's got a lot of data to crunch.
    I expected even with this power (see attached specs), the machine would still chug along to export 4000 raw files, but I did not expect issues with playback once everything is compiled.

    I exported the sequence in 4K, 3K, and 1080P. The 4K plays smoothly for few seconds and then starts to skip and then falls apart altogether. 3K is a bit better, but still struggles. 1K plays all the way through, but won't scrub very well. I don't get that, especially the last part.

    The file specs for the 1K and 4K file are also attached.

    I'm not even playing them on a 4K monitor.

    Any ideas what the issue could be?

    (PS: I'm using Lightroom 5 and LR TimeLapse 4 to compile the shots)

    Screen Shot 2015-07-29 at 12.53.21 AM.jpg Screen Shot 2015-07-29 at 12.42.16 PM.jpg Screen Shot 2015-07-29 at 12.41.51 PM.jpg
     
  2. Inutopia, Jul 29, 2015
    Last edited: Jul 29, 2015

    Inutopia macrumors 6502

    Inutopia

    Joined:
    Apr 8, 2009
    Location:
    South of Heaven
    #2
    LOL DAT BITRATE :)

    Edit: Sorry, I don't know what came over me there! I think your bit rate might be a bit high there my man. Try lowering it when you make the 4k file and it should play swimmingly :)
     
  3. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #3
    Same suggestion. Over 200Mbit/s is too much.

    With proper encoding, even 20Mbit/s can produce very good image already (tested on my 84" 4K TV).

    You may try to set the bit rate to 80, I personally believe which is already more than enough. In fact, I can hardly tell the difference once over 30.

    If still have problem. It seems 60 is a good number for you.

    For 1080P, 20 should be more than enough.
     
  4. seenew thread starter macrumors 68000

    seenew

    Joined:
    Dec 1, 2005
    Location:
    Brooklyn
    #4
    As soon as I posted the screenshots, the bitrate occurred to me. :D
    Thanks for confirming the suspicions! I'll give it a shot.
    (and maybe post the results when all is said and done!)

    Cheers guys!
     
  5. rkuo macrumors 6502a

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    Sep 25, 2010
  6. seenew thread starter macrumors 68000

    seenew

    Joined:
    Dec 1, 2005
    Location:
    Brooklyn
    #6
    quicktime and VLC
     
  7. larrylaffer macrumors 6502

    larrylaffer

    Joined:
    Aug 1, 2009
    Location:
    Los Angeles
    #7
    You people are nuts. A Mac Pro, or pretty much any SSD-based Mac should have no problem playing back up to 400+ Mbps H.264. How do I know this? I regularly edit AVC-Ultra footage on a Mac Pro, which is (da da da) 440Mbps H.264

    440Mbps translates to about 55MB/sec (not including audio, which adds about 2MB/sec). That's megaBYTES per second, not megaBITS. For reference, the Blackmagic Disk Speed Test on a new Mac Pro will read/write to a Mac Pro's SSD at over 700MB/sec.

    So, the data rate is NOT the problem. Perhaps it's the encoding itself? Do you know what your H.264 parameters were, such as the number of b-frames, etc.?
     
  8. ProjectManager101 Suspended

    ProjectManager101

    Joined:
    Jul 12, 2015
    #8
    I may be a little ignorant here but what kind of drive if he using? And I believe no every playback software or codec uses all the ram or resources equally, probably allocating more memory. I do not know, just a wild guess.
     
  9. seenew thread starter macrumors 68000

    seenew

    Joined:
    Dec 1, 2005
    Location:
    Brooklyn
    #9
    I don't know the specific H264 parameters-- LR TimeLapse doesn't really let you mess around much with the settings. It doesn't actually let you specify bitrate, even-- just quality settings like low, medium, high, very high, and ultra high. Very high is where I got my results from for the 4K export.

    I could figure out how to render the video using AfterEffects but I don't have the time to learn that right now.

    I'm reading the file off the internal flash drive.
     
  10. radiotamarillo macrumors newbie

    Joined:
    Jun 2, 2015
    #10
    Yes, it's those unknown H.264 encoding parameters.

    Try rendering/exporting the sequence to ProRes 4444 or 422 HQ.
     
  11. larrylaffer macrumors 6502

    larrylaffer

    Joined:
    Aug 1, 2009
    Location:
    Los Angeles
    #11
    This is good advice. ProRes 4444 will provide stunning image quality. The bitrate will be high, but your system should have no problem playing it back in realtime.
     
  12. rkuo macrumors 6502a

    Joined:
    Sep 25, 2010
    #12
    VLC is very poor at hi res accelerated playback. Quicktime is more representative. ProRes is also good if your IO can keep up (sounds like it should be able to).
     
  13. seenew thread starter macrumors 68000

    seenew

    Joined:
    Dec 1, 2005
    Location:
    Brooklyn

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