late-2009 iMac playing 1080p

Discussion in 'iMac' started by Amnesia180, Jun 1, 2017.

  1. Amnesia180 macrumors newbie

    Joined:
    Apr 29, 2017
    #1
    Hi All,

    I'm using my late-2009 iMac to play 1080p footage - should it be able to cope with this? I notice that sometimes it goes a bit laggy/choppy.

    I am using iMovie to edit my GoPro footage. I mainly shoot in 1080p 30fps or 60fps. When playing in full screen, it goes a little choppy. Again, is this normal?

    I'm looking for a way that I can continue to edit, but keep the final render in a decent 1080p quality.

    Cheers!
     
  2. casperes1996 macrumors 68040

    casperes1996

    Joined:
    Jan 26, 2014
    Location:
    Horsens, Denmark
    #2

    Depends what hardware configuration you're using - video editing can be really taxing on computer hardware. With enough effects and whatnot, I can bring my 2014 top-end iMac to its knees with 720p content. But "normal" edits of course it handles fine up to 4k and beyond - anyway, back to the point. You can always use proxy footage. I haven't used iMovie for a long time, so don't know what it supports and what it doesn't, but at least in Final Cut and any other high end software, you can edit on low quality "proxy" footage, such as half resolution or quarter resolution, and then link the proxy files to the real files, such that, at render time, all edits will happen to the original footage and not the proxies you've done the temp edits on.
     
  3. Amnesia180 thread starter macrumors newbie

    Joined:
    Apr 29, 2017
    #3
    Thanks very much. I'm literally just using my GoPro footage and stitching it together.
    My iMac is 2.66 Ghz i5, 8GB with an ATI Radeon HD 4850 512MB graphics card.

    I'm planning on upgrading to 16 GB (or more) RAM, and installing a SSD hard drive - which I hope will help.

    What you have mentioned - using proxy footage - sounds ideal. I can reduce it down to a size that my iMac can cope with, then render at original quality for Youtube/mobile phone playback, etc (which is all it really gets viewed on anyway).
     
  4. casperes1996 macrumors 68040

    casperes1996

    Joined:
    Jan 26, 2014
    Location:
    Horsens, Denmark
    #4
    I'd say your CPU should handle it, your RAM should be enough unless you start doing more than basic stitching and cutting, and whilst an SSD always helps with some operations, your GPU is probably the biggest downfall in your system. – Regardless, if you can use proxy footage that should eliminate the issue entirely. Full quality on export, half quality while in iMovie - perfect performance and final render quality.
    I've looked into it however, and iMovie does not support offline editing (as in editing with linked media, such as proxy - not online/offline in a networking sense). You'd have to upgrade to pro software for that, and that can be expensive. Alternatively however, you can try and re-render the footage to another codec and see if it runs more smoothly on your machine. You can try converting the footage to ProRes 422 or Cineform before you edit. Depending on the quality of the GoPro footage, there may be the slightest of quality loss, but it should be pretty much inpercievable to the human eye. – ProRes is made by Apple but is widely used across the video and film industry by pretty much everyone to some extend. It's a high end codec that cameras like the BlackMagic Cinema Camera can shoot to natively. Cineform is, as far as I know, actually made by GoPro and they offer a tool for both converting to Cineform and editing Cineform, but I think iMovie can do it too - regardless, iMovie can definitely do ProRes 422 (if you need higher quality or more performance, there are other variants of ProRes, but I would assume ProRes 422 would give you near identical, if not perfect recreation of the quality of the original footage, whilst still being rather speedy). Beware however, these codecs eat a lot more disk space than some other codecs, and an SSD would perhaps help with these codecs, as they rely a lot more on the speed of moving data than the processing power of a system, compared to for instance H.264/X.265, which are more targeted towards final renders, where the decoding process is simple, in that it only just needs to decode it real time as it comes with no edits, and file sizes should be kept relatively small.

    Anyway, I hope that helps. If you have any questions don't hesitate to ask. I do a lot of video editing ;)
     

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