6 Replies Latest reply: Dec 5, 2013 10:03 PM by ev-dude
hoehneb Level 1 Level 1 (0 points)

Hi All,


I have been working with a lot of 1080p HD video where I've been applying a bunch of color correction and filters to give the video a "film look" and to buff up some badly white-balanced video.   Most commonly, I've been stacking two tracks of the same video, each with a Color 3-Way filter applied and composited with "overlay" or "add" or some amount of blending.  Sometimes there will be one or two other filters applied as well, such as vignette or a gamma correction.  


My problem is I've been finding the amount of time needed to render a "preview" of video every time I make a small change to this setup to be a drain on my workflow.   For just 30 seconds or so of video, I must wait several minutes for a preview to render.   I'm taking a lot of coffee breaks and things are progressing very slowly.


By "rendering" I mean renderding those segments of the video that are marked by the orange line- video which plays, albeit very jerkily. I am usually rendering to get a sense of the look of transitions, and the expressons of my subjects' faces at these moments- so I don't like the way the "orange line" preview look.  I don't usally get the red line.  Some of my blends that don't have color three-way applied are tagged green.


I have a Dual Core 2009 Mac Pro 2.66Ghz tower with 5GB of ram and the video card it came with.  I'm using only one monitor.  I have FCS 3 and FCP 7.   I have tons of HD space available (200 GB out of 1 TB left on my main drive and a 2 TB scratch drive with about 800 GB used for TimeMachine and the rest partitioned for video.  I'm not using it yet, though.)   I usuallly run FCP with little or no other software in the background.   The video source I'm using is HDV 1080p30 (shot at 1440x1080, but  16:9) or 1080p24 (some of my source video came from a second camera.)  I have about 6 hours of video that I'm working with now, and have not, therefore, converted it to another format for editing purposes as this would take a long, long time.   I set the render settings to RGB, which doesn't seem to speed things up much.


I'm looking for advice on how to speed up my preview render times (I'm not worried about compressor or QuickTime conversion render times as that can be done in batches overnight).   Should I be choosing a different codec?  Should I be rendering and editing at a different resolution (this seems to me to take even longer.)  I'd be willing to spend a few hundred dollars for a new video card, if it came to that, but that's obviously my last recourse.   Do I need more RAM?   Are there some settings that I should change?  Should I bite the bullet and convert my whole mess 'o video to ProRes 4:2:2 or something of the sort?

Any advice would be appreciated.

Power Mac, Mac OS X (10.6), 4 core intel
  • 1. Re: Speeding up preview Rendering in FCP 7
    hoehneb Level 1 Level 1 (0 points)

    After a bit of testing I notice that color 3-way by itself does not slow things down appreciably.  It is mainly the compositing of two tracks (mostly "overlay") that seems to result in the Orange line.

  • 2. Re: Speeding up preview Rendering in FCP 7
    Shane Ross Level 8 Level 8 (41,895 points)

    Nothing you can do....other than get a computer with a faster processor.  When you start doing intense things like what you are doing, it slows things down. Layering, composite modes, other effects (film effects slow things a lot)...those slow things down.  The 3-way alone is real time...dark green bar...full res preview But all that other stuff, now you are getting into deep compositing and that slows things down.


    Faster processors are your only option there.

  • 3. Re: Speeding up preview Rendering in FCP 7
    hoehneb Level 1 Level 1 (0 points)

    Thanks, Shane.    That's kind of a bummer. 


    I'm curious about how others deal with this in their workflow.   Do you edit both tracks that you intend to composite in parallel, but turn one off when previewing transitions and filters and whatnot?   Or do you export a rendered, composited video and work with that?  Or something else?

  • 4. Re: Speeding up preview Rendering in FCP 7
    Shane Ross Level 8 Level 8 (41,895 points)

    Well, you need to know what it looks like...so you render it.  I do the basic cutting to get the basic story down.  so that the timing is right. But then when it comes to doing effects, you do them, and then render.  Look at them, tweak, and render. 


    A neat way to preview your effect, that won't be in real time, but will play back (slowly) is to press OPT-P.  This will have FCP play back as fast as it can through the effect.  A slow way to preview the look.

  • 5. Re: Speeding up preview Rendering in FCP 7
    hoehneb Level 1 Level 1 (0 points)

    Thanks for the suggestion of OPT-P.   I forgot about that. 


    What I've done in the past is make and render a "color test sequence" featuring little clips that I'll commonly use.  I then edit the whole darn thing with no compositing at all (leaving a "gap" between tracks for the future compositing) eyballing the changes by looking at my "color test sequence."     


    The problem with this is, I use color shifts and "film look" tricks a lot in my videos, and it's not always possible to guess what the effect is going to look like short of rendering.   I was hoping to figure out a way of speeding this up.    Moreover, the new Mac Pros are not all that much faster than my current one.  


    Oh well.

  • 6. Re: Speeding up preview Rendering in FCP 7
    ev-dude Level 1 Level 1 (10 points)

    I kmow this iss a year later.


    Have you messed with the "render" preferences so that it renders less detail

    for preview and then when you output, it outputs full Resolution?