Re: RenderInfo scale factors are lying - FCPX only
On 05/09/2013 12:06 AM, Paul Miller wrote: On 5/8/2013 6:40 PM, Darrin Cardani wrote: On May 7, 2013, at 3:57 PM, Paul Miller <paul@fxtech.com> wrote: On 5/7/2013 5:37 PM, Darrin Cardani wrote: On May 7, 2013, at 6:55 AM, Paul Miller <stelefx@gmail.com> wrote: Here's a really frustrating one. In FCPX, I'm working on a 1920x1080 clip, using TEXTURE mode, and for some reason the scale factors are both 1.5. What is the reason for this? Typically I would look at the output image size and use the scale factors to determine the full image size, but in this case the scale factors are clearly wrong. Is there another way around this? Usually I see this when the input is something like 720 (1280x720) being scaled up to fit within 1080 (1920x1080). Is your input the same size as the Motion Effect was created at? If not, then the scaling is likely correct. If so, then it sounds like a bug. Ahhhh - that explains it. The media is 1080P but the motion template was made at 720P. But - how is this information useful? I need to know the full media size in FCPX. In this case, the input/output images are at the full media size (since FCPX doesn't seem to be doing any down-sampling). But the scale factors indicate the media should actually be 50% larger, which isn't true. Well, it has to do with what our designers think users will expect when using the app. If you apply a blur set to some value (say 5) to an image in an SD project it gives you a certain look. If you have the same footage in HD, a user will likely want the same parameter value to give the same look. So a value of "5" should look "as blurry" in HD as it does in SD. Using the scale information we provide, that should happen. Does that make sense? Yes, but I'm already doing that myself in my plugin logic, since my blur values aren't in pixels - they are in "image units", which I can derive accurately if I know the image size and downsample factors. Maybe there is another way to determine the proper original media size? In Motion (and other hosts), this is usually (image_size / scale_size), but not in FCPX. -- . . . . . . . . . . . . . . . . . . . . . . . . . Nathan Weston nathan@genarts.com GenArts, Inc. Tel: 617-492-2888 955 Mass. Ave Fax: 617-492-2852 Cambridge, MA 02139 USA www.genarts.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com We've run into this as well. IMO it doesn't make sense and is a bug. The render scale should indicate the scale factor between the original footage and the input/output images. We worked around this by clamping the scale factors at 1. Scales less than 1 usually seem to be correct and indicate downsampling. Scales greater than 1 are always bogus, and when they occur the real scale factor is always 1.
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Nathan Weston