August 2008 - Pro-apps-dev - lists.apple.com

Re: Preventing fcp from switching back to rgb
by Paul Schneider 05 Aug '08

05 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com Hi Brad, The short answer is no, you can't. - Paul On Aug 5, 2008, at 11:34 AM, Brad Wright wrote: Brad Wright _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/pschneider%40apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… The long answer is that this is controlled by the user. See the Video Tab in the Sequence Settings dialog. By default it is set to "Render YUV material in 8-bit YUV", but the user can override this to render everything in RGB. Note that YUV-ness is also dependent on your footage format (and output format). Almost all users are working with YUV footage, but many plugin developers test with RGB media such as Tiff images or RGB movies compressed with the Animation codec. We won't render in YUV if your input and output are RGB. Your output format is controlled by your sequence's codec. Check out the FCP manual for more information. I'd definitely recommend doing your initial testing with DV-NSTC media and sequences created using the DV-NTSC preset, and then moving on to handle other cases from there. If you're working in YUV, you should definitely test with both 601 and 709 media. Also keep in mind that while practically all consumer cameras generate YUV footage, some high-end cameras are starting to be natively RGB, and this trend is likely to continue and work its way to the more affordable end of the market in the future. Finally, I'd recommend reading the "Rendering FxPlugs in Final Cut" document if you haven't already. Rendering in Final Cut is fairly complicated, and seemingly innocuous changes can change the way we call your plugin. I don't know if it's possible, but I'd like to lock final cut pro into only using YUV fximages. Currently, during previewing in the timeline I get YUV, but when I try render out, final cut seems to switch into rgb fximages. Is there any way to lock it YUV? This email sent to pschneider(a)apple.com This email sent to site_archiver(a)lists.apple.com

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Re: YCbCr continued
by Brad Wright 05 Aug '08

05 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com Brad Wright On Aug 5, 2008, at 9:15 AM, Darrin Cardani <dcardani(a)apple.com> wrote: On Aug 4, 2008, at 3:23 PM, Brad Wright wrote: Hi Pro Apps Team: Zero Saturation point 112 Maximum Cb and Cr value of 255 112/255 = .43921569 approximately .439 Darrin -- Darrin Cardani dcardani(a)apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… I'll try that. I don't know how to work with ARB shaders, but I'll see what I can do. I think the color is set up correctly, as there is no shift in color when I write the ciimage which I took from the FxTexture that was passed in to the pluggin. I tried creating a ciimage from retrieved YUV data from the same frame, and I didn't notice any color shift. Is there any known problems with using CIImages that could cause a color shift? The only way I could see this happens is if core image is somehow apply a color transform before my shader is activated and the reversing it back out before it gets displayed. Here's what I did. I created a core image filter that generates a color that fills the entire screen. All this filter does is display what ever values you feed into it for the vec4 color that is returned (pre-multiplied of course). I then used the built in Final Cut Scopes to read the color values back. It appears that the color neutral point is when both U and V are at 0.42 - 0.44 depending on the value for Y. At least that's what the Final Cut Scopes are saying. I looked at both the RGB parade and the Vectorscope to verify that these values line up. I'm apply this filter directly over a video frame from an FxTexture mapped into a CIImage. I've been through the documentation and I can't figure out how Final Cut is mapping these values. The U and V values should stay color neutral while the Y value varies up or down. I'm not seeing that happening. It appears the Hue is being shifted around as the Y varies. I'm not sure how the U and V values arrive at between 0.42 and 0.44. The best I can figure is that Cb and Cr are mapped at between 0 - 224 without the offset that the documentation says there is. If I assume that the color neutral point is .42-0.44 in float point, then I can get this value by mapping: Does anyone know why this would happen? Brad, Is it possible that you're not setting up Core Image's color space correctly? What happens when you try the same thing in a straight OpenGL ARB Fragment program with no Core Image involved? Do you see the same problems? This email sent to site_archiver(a)lists.apple.com

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Preventing fcp from switching back to rgb
by Brad Wright 05 Aug '08

05 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com Brad Wright _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… I don't know if it's possible, but I'd like to lock final cut pro into only using YUV fximages. Currently, during previewing in the timeline I get YUV, but when I try render out, final cut seems to switch into rgb fximages. Is there any way to lock it YUV? This email sent to site_archiver(a)lists.apple.com

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Re: YCbCr continued
by Darrin Cardani 05 Aug '08

05 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com On Aug 4, 2008, at 3:23 PM, Brad Wright wrote: Hi Pro Apps Team: Zero Saturation point 112 Maximum Cb and Cr value of 255 112/255 = .43921569 approximately .439 Darrin -- Darrin Cardani dcardani(a)apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… Here's what I did. I created a core image filter that generates a color that fills the entire screen. All this filter does is display what ever values you feed into it for the vec4 color that is returned (pre-multiplied of course). I then used the built in Final Cut Scopes to read the color values back. It appears that the color neutral point is when both U and V are at 0.42 - 0.44 depending on the value for Y. At least that's what the Final Cut Scopes are saying. I looked at both the RGB parade and the Vectorscope to verify that these values line up. I'm apply this filter directly over a video frame from an FxTexture mapped into a CIImage. I've been through the documentation and I can't figure out how Final Cut is mapping these values. The U and V values should stay color neutral while the Y value varies up or down. I'm not seeing that happening. It appears the Hue is being shifted around as the Y varies. I'm not sure how the U and V values arrive at between 0.42 and 0.44. The best I can figure is that Cb and Cr are mapped at between 0 - 224 without the offset that the documentation says there is. If I assume that the color neutral point is .42-0.44 in float point, then I can get this value by mapping: Does anyone know why this would happen? Brad, Is it possible that you're not setting up Core Image's color space correctly? What happens when you try the same thing in a straight OpenGL ARB Fragment program with no Core Image involved? Do you see the same problems? This email sent to site_archiver(a)lists.apple.com

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Re: Final Cut Pro and Final Cut Express XML formats
by Simon Hargreaves 05 Aug '08

05 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com User-agent: Thunderbird 2.0.0.16 (Macintosh/20080707) Simon... Andreas On 05.08.2008, at 14:36, Simon Hargreaves wrote: _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… It would seem that a plugin for FCE that could export FCP XML would be very beneficial and not that difficult to do, is there anyone working on something like this? Or is this something that Apple may be planning for a future FCE release, it would fit with their policy of interoperability between the products. What do you mean by long version? Do you mean not supporting nested sequences? Andreas Kiel wrote: You can't export XML out of FCE, but FCP can open FCE files. FCE does not officially import XML, but you can drag a XML to the FCE program icon and it will import the XML as long version and used effects etc will match. I'm interested in the compatibility between the project/timeline formats of Final Cut Express and Final Cut Pro. If they are both XML is it possible to share the files between the two applications and if not is there a simple conversion tool (Bi-directional)? I'm not talking about sophisticated LiveType or Motion functionality, just basic timeline editing with simple common filters and transitions. As I'm aware that there are some functional differences between the two applications. Thanks, Simon... _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/andreas.kiel%40spherico… This email sent to andreas.kiel(a)spherico.com This email sent to site_archiver(a)lists.apple.com

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Re: Final Cut Pro and Final Cut Express XML formats
by Andreas Kiel 05 Aug '08

05 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com Andreas On 05.08.2008, at 14:36, Simon Hargreaves wrote: _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… You can't export XML out of FCE, but FCP can open FCE files. FCE does not officially import XML, but you can drag a XML to the FCE program icon and it will import the XML as long version and used effects etc will match. I'm interested in the compatibility between the project/timeline formats of Final Cut Express and Final Cut Pro. If they are both XML is it possible to share the files between the two applications and if not is there a simple conversion tool (Bi-directional)? I'm not talking about sophisticated LiveType or Motion functionality, just basic timeline editing with simple common filters and transitions. As I'm aware that there are some functional differences between the two applications. Thanks, Simon... _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/andreas.kiel% 40spherico.com This email sent to andreas.kiel(a)spherico.com This email sent to site_archiver(a)lists.apple.com

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Final Cut Pro and Final Cut Express XML formats
by Simon Hargreaves 05 Aug '08

05 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com User-agent: Thunderbird 2.0.0.16 (Macintosh/20080707) Thanks, Simon... _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… I'm interested in the compatibility between the project/timeline formats of Final Cut Express and Final Cut Pro. If they are both XML is it possible to share the files between the two applications and if not is there a simple conversion tool (Bi-directional)? I'm not talking about sophisticated LiveType or Motion functionality, just basic timeline editing with simple common filters and transitions. As I'm aware that there are some functional differences between the two applications. This email sent to site_archiver(a)lists.apple.com

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FxScript known limitation in MeasureString?
by Andy Mees 04 Aug '08

04 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com Hi all Can you confirm that the maximum width that can be reported by FxScript's MeasureString function is 32767, regardless of the actual string length? Cheers Andy _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… This email sent to site_archiver(a)lists.apple.com

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YCbCr continued
by Brad Wright 04 Aug '08

04 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com Hi Pro Apps Team: Zero Saturation point 112 Maximum Cb and Cr value of 255 112/255 = .43921569 approximately .439 Does anyone know why this would happen? Brad Wright _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… Here's what I did. I created a core image filter that generates a color that fills the entire screen. All this filter does is display what ever values you feed into it for the vec4 color that is returned (pre-multiplied of course). I then used the built in Final Cut Scopes to read the color values back. It appears that the color neutral point is when both U and V are at 0.42 - 0.44 depending on the value for Y. At least that's what the Final Cut Scopes are saying. I looked at both the RGB parade and the Vectorscope to verify that these values line up. I'm apply this filter directly over a video frame from an FxTexture mapped into a CIImage. I've been through the documentation and I can't figure out how Final Cut is mapping these values. The U and V values should stay color neutral while the Y value varies up or down. I'm not seeing that happening. It appears the Hue is being shifted around as the Y varies. I'm not sure how the U and V values arrive at between 0.42 and 0.44. The best I can figure is that Cb and Cr are mapped at between 0 - 224 without the offset that the documentation says there is. If I assume that the color neutral point is .42-0.44 in float point, then I can get this value by mapping: This email sent to site_archiver(a)lists.apple.com

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Re: What color transformation formula are you using in FCP for Y Pb Pr ?
by Paul Schneider 04 Aug '08

04 Aug '08

site_archiver(a)lists.apple.com Delivered-To: pro-apps-dev(a)lists.apple.com Hi Brad, http://developer.apple.com/quicktime/icefloe/dispatch027.html Hope that helps, - Paul On Aug 4, 2008, at 12:23 AM, Brad Wright wrote: Hi Pro Apps: Brad Wright _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/pschneider%40apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Pro-apps-dev mailing list (Pro-apps-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/pro-apps-dev/site_archiver%40lists.a… Our YCbCr images are in R408 format (or r4fl for floating point). If you're accessing the 8-bit images from a CI kernel (or other fragment shader), the 0-255 values will be scaled to 0-1. In R408, the white point is at Y = 235, so I would expect white to be at (235 / 255) from the perspective of your CI kernel. As mentioned in the FxImage.h header, the documentation for our YCbCr format, along with conversion matrices, can be found here: I'm trying to convert the Final Cut YUV into floating point RGB and then back to Final Cut YUV. I'm doing this in Core Image using a custom CIFilter kernel. So far, I'm stumped on how Final Cut is converting the raw image data into FxTextures. The values in the Texture don't match Y Pb Pr floating point. I've found that the value of white lies somewhere between Cb and Cr equaling 0.42 to 0.44 depending on the value of Y. How are 8 bit Y Cb Cr values getting mapped into FxTextures? Is it converted from Y Pb Pr values of +112 to -112 for Cb and Cr to some floating point value? I can't find any documentation on the mapping to and from YUV to RGB This email sent to pschneider(a)apple.com This email sent to site_archiver(a)lists.apple.com

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