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Mac OS Screenshot does not Allow DVD Player to Appear in Captured Region
- EvilLook 13y agoHurray for the DMCA!
- kentwistle 13y agoI think if you use VLC you can circumvent this despicable attack upon our freedoms.
- nwh 13y agoOf course, it only applies to the inbuilt DVD Player application.
- Tyrannosaurs 13y agoObviously Apple would have known this. I wonder if part of the reason they agreed to it is that they knew ultimately it was, in reality, basically no restriction at all.
- DannyBee 13y agoI have trouble seeing it as that complex of a calculus They wanted to make a DVD player. DVDCCA (or someone) required them to block screen grabs during playback as a condition of giving them a proper license for CSS (or something) for their DVD player. They blocked screen grabs during playback. I doubt "is this really going to achieve anything" ever entered anyone's mind. It would just complicate the licensing negotiation for something Apple doesn't really give a crap about (some random third party app)
- Tyrannosaurs 13y agoThinking as a software developer, if a third party asked me to do something I thought wasn't a good idea for the end user, part of how heavily I'd push back on it would be how big a deal it really was to the user. You may be right though.
- cmircea 13y agoSo much for fair use.
- willvarfar 13y agoIt would be plausible if this was actually that the screenshot code could not get at the hardware-decoded pixels that are composited by hardware. This used to happen on Windows laptop screenshots a lot - often chroma-keyed - and it was how the video on the generation of phones I worked on worked.
- michael_h 13y agoI couldn't do this on Windows a while back because hardware acceleration was on.
- robterrell 13y agoNot really news... this has been the case since the first Mac shipped with a DVD player. Wait until he tries to attach gdb while a Fairplay-encoded file is being played.
- lukegb 13y agoWhat does happen if you try to attach gdb? You can't, or the application just quits, or do you get some error message? I'm somewhat curious now.
- lordgilman 13y agoI think this is the story that the parent was referencing. Here's the story from 2005 and a kernel module loadable at runtime that gets around the problem. https://blogs.oracle.com/ahl/entry/mac_os_x_and_the https://blogs.oracle.com/ahl/entry/mac_os_x_and_the http://landonf.bikemonkey.org/code/macosx/Leopard_PT_DENY_ATTACH.20080122.html http://landonf.bikemonkey.org/code/macosx/Leopard_PT_DENY_AT...
- hjaltij 13y agoIt's probably just PT_DENY_ATTACH that causes the debugger to quit.
- FigBug 13y agoSame thing happens on Windows if hardware acceleration is enabled. The video is decoded and drawn by the video card.
- fmoralesc 13y agoBut in that case (iirc), the video is displayed as a black square. There's no window borders here either.
- simias 13y agoWell if the video is hardware blended there could be anything in the framebuffer, so it could be black or checkered, I see no incompatibility. The lack of borders is definitely harder to explain that way though. Definitely looks like some form of deliberate "limitation".
- anonymfus 13y agoOld hardware accelearation method. http://msdn.microsoft.com/en-us/library/windows/desktop/dd390946.aspx http://msdn.microsoft.com/en-us/library/windows/desktop/dd39... Since Vista it's disabled by default and incompatible with DWM.
- JD557 13y agoCame here to post this. I rememver having to disable hardware accelaration in windows to take screenshots of videos. It was actually pretty weird the way the picture apeared in paint. It was like having a "frame"in the editor. Everything was fine until you closed the media player.
- nakedrobot2 13y agoIt has been this way for years. VLC is ok of course :)
- deleted 13y ago[deleted]
- kalleboo 13y agoIt used to actually give you an error dialog box - http://imgb.mp/jaY.jpg http://imgb.mp/jaY.jpg It's not due to hardware acceleration, I've never been unable to take a screenshot of anything else in OS X, I think it's due to how Quartz does its compositing (everything is a 3D texture, there are no 2D-style overlays).
- workbench 13y agoUsed to get round it with a terminal command, until Lion IIRC.
- DanBC 13y agoThat person tried, and failed, to take a screen shot. If he now installs VLC and takes a screen shot is he breaking DMCA anti-circumvention laws?
- deleted 13y ago[deleted]
- cs702 13y agoCould you ever imagine buying a house that doesn't allow you to perform certain activities inside its walls, because the architects and engineers who built it disapprove, and they're fully in control of it? Neither would I. It wouldn't be true ownership. Yet that's exactly what's happening here. The OP bought a Mac, but he can't perform certain activities, because the company that built it disapproves, and they control his machine. "Your" Mac does what you want, but only if Apple and its partners are OK with it. Is it really "yours?"
- nemof 13y agoImagine a world where a little eye stares balefully at you from above your TV. If it sees what it thinks is a recording device, say a phone or a video camera pointed at the TV, it turns the screen off until you lower your device. Kinect the dots. Say goodbye to your living rooms sovereignty.
- S_A_P 13y agoI see what you did there! I chuckled, then I realized it was probably not too far off, as MS already is collaborating with NYC and using object recognition on its network of 6000 street cams.
- Cthulhu_ 13y agoActually, that technology (camera detectors) are used today in cinemas, especially during premieres and early screenings.
- kalleboo 13y agoCars and mopeds have speed limiters. When I was a kid there was a little industry around removing the 30 km/h governer on mopeds.
- brudgers 13y agoThey are there to keep people from maiming and death due to exceeding the design envelop. Despite the rhetoric of media interests, bootleg clips of Saturday Nigh Live or The Little Mermaid are not a threat to anyone's health.
- danso 13y agoThat's funny...I know this has been around for awhile, but I only first experienced it this weekend when I was trying to excerpt part of a movie scene (for educational purposes)...I didn't go the Handbrake route because I wanted to say that I had avoided breaking the DRM law...while the copyright law may be ambiguous on backups, cracking the DRM is pretty much always a breach of the DMCA
- k-mcgrady 13y agoThis also happens in iTunes. Is it really that big of a problem? Why would you need to screenshot something you're watching? The OP doesn't say why he wanted to take the screenshot. Also, does anyone know the reason Mac OS does this?
- acuozzo 13y ago> Is it really that big of a problem? Why would you need to screenshot something you're watching? The OP doesn't say why he wanted to take the screenshot. Wait... are you kidding? Among other things: 1 Fair use: Hey, buddy! Check out this cool still. 2 Fair use: Wow, that's a cool shot! I'd love to make it my background. 3 Fair use: Gee, that sucks! Director Martin M. McStupid made a bunch of CGI changes to his classic award-winning 70s film. I'd like to share some of the most offensive changes with my buddies on the Example.net Forum. 4 Fair use: Totally awesome! The DVD9 release of this film was encoded with a high bitrate. Let's take some stills from fast-moving shots so that we can compare it against the DVD5 release from the 90s. 5 Fair use: This movie no longer has its original theatrical color-timing. I'd like to take a sample from each shot so that I can come up with curves to do a shot-by-shot color-correction.
- robspychala 13y agoalso happens when you try to view iTunes movies or shows while controlling your Mac with a remote desktop connection. super annoying.
- deleted 13y ago[deleted]
- veidr 13y agoExtremely annoying and similar: if a Mac is playing back purchased content in iTunes, any anybody has a Remote Desktop connection to that Mac open, it will show that same checkerboard "fuck you, consumer peon, your corporate overlords prohibit you from viewing this content" view. This happened to me when we had people over for dinner, somebody wanted to show some video, we bought it from iTunes (in the dining room while eating), and it wouldn't play back. Of course, at that point we gave up so as not to let DRM ruin dinner. Later, I discovered that it was because somewhere in the house there was a notebook remoting to the TV mac (normal, since that is how we mainly control it). I don't think this has any underlying technical rationale (hardware acceleration, etc); I'm sure it is just a relic of Apple's deals with the 'content providers'.
- 616c 13y agoThe Windows System Internals book (6th edition IIRC) also mentions that even debug builds of Microsoft Windows Vista and newer have certain restrictions in observing the kernel, and seeing CSS decryption keys was the thing they mentioned in particular.
- incanus77 13y agoThis has been the case for like a decade.
- BadCRC 13y agoit's not because of hardware acceleration at all. It's actively preventing the window to be captured (I believe iTunes does some similar). It uses a private API and an example is here: https://github.com/heardrwt/RHAdditions/blob/master/RHAdditions/NSWindow%2BRHPreventCaptureAdditions.m https://github.com/heardrwt/RHAdditions/blob/master/RHAdditi...
- matthewmacleod 13y agoRather more annoying, the same issue occurs if Screen Sharing is in use when DVD Player.app starts. Needless to say, this is a total pain when controlling a media machine remotely. VLC's DVD playback is a little ropey in my experience, but at least it works. It's the pointlessness of this feature that irritates me. If I wanted to copy the contents of a DVD, I'd insert it and use one of the squillions of programs that are freely available to do so. I'm pretty sure I wouldn't take frame-by-frame screenshots.
- lloeki 13y ago> I'm pretty sure I wouldn't take frame-by-frame screenshots. Quicktime allows to record a video of your screen. I bet QT leverages the same framework as the screen capture thing.
- youngerdryas 13y agoNow is the time for armed revolution, our human rights are being violated. :b
- supercoder 13y agoIt's also the case on iOS. You can't screen cap the inbuilt movie player output. Nor can you programatically grab the bitmap layer contents of the movie.
- Macha 13y agoYou could back when I had an iPod Touch 2G, unless the limitation only applies to iTunes DRMed videos and not your own videos you put on there.
- Cthulhu_ 13y agocjbprime's explanation (https://news.ycombinator.com/item?id=5792745 https://news.ycombinator.com/item?id=5792745) could apply to that one as well; did the iPod Touch 2G have a dedicated GPU chip yet, or was video rendering done on the CPU?
- supercoder 13y agoEverything on iOS is sent as a texture and displayed via the GPU. This has been happening since iOS 1 / First iPhone. Macha is actually reporting the opposite, it worked fine. So if it wasnt doing it on a particular version of iOS it was probably just that they were doing the extra work to hide it then.
- withad 13y agoI've never quite understood this. There are so many simpler and more effective ways of copying DVDs than using screen capture software (let alone taking a single screenshot) that it doesn't seem worth the effort to deliberately block.
- qb45 13y agoI guess it's more about "educating" the public that The Content is a holy cow which can only be watched and admired, solely by paying customers, of course.
- nchase 13y agoWhat if you just want a single frame of the DVD the same way you might want a screengrab of anything else on your desktop?
- cjbprime 13y agoLinux does the same thing. In the case of Linux/X11, it's because an accelerated video overlay is being used -- instead of writing to a framebuffer that's then rendered onto the screen, you coordinate with the video card to have it handle scaling, colorspace conversions and blitting of that data directly onto a memory-mapped portion of the display. Then the screenshot tool runs and dumps the framebuffer, and finds no image where your DVD playback is happening, because there isn't anything in the framebuffer for that window.
- jstanley 13y agoThanks for that. I (and I guess a lot of other commenters) hadn't considered that there might be a totally innocent explanation. Come to think of it, I've noticed this behaviour in the past.
- shadesandcolour 13y agoWell why should you consider something like that when it's easier for the other commenters to just assume that it's some draconian company with horrible intentions?
- supercoder 13y agoYeah not the case on OSX. Everything is sent as a texture to the GPU. It's just that they'd be explicitly excluding that texture from being grabbed in a screencap.
- Glyptodon 13y agoIt's not that clear cut. "Linux" has many options when it comes to rendering and overlaying video and many of them let you take screenshots. The experience can also be vastly altered by particular video card and driver combos.
- so898 13y agoI think there are more than 3 video player which could play DVD on Mac. So why we use this BAD application? BTW, the new retina macbook shipped without DVD driver, there is not that much which we need to worry about.
- mml 13y agoDVD player also can't be "seen" over airplay.
- mmuro 13y agoIt doesn't matter what type of DVD is playing. It could be one you made yourself and this limitation would still be in place.
- da_n 13y agoI'm not sure why, but I always find it irrationally annoying when I see someone using their desktop as a filesystem.
- paulschreiber 13y agoThis has been true for years — since Mac OS X 10.1. I believe third-party tools like Snapz Pro (and perhaps even the command line screen capture tool) get around this limitation.
- markdown 13y agoOT: Wow, that's a messy desktop. Makes me feel a little better about my own desktop.
- JacobIrwin 13y ago@acuozzo I was running dual monitors and was watching the movie on the tinier MacBook Pro screen. I had no intention of using an image from the film for anything at all. But I always open both screenshots (two screenshots are saved to your desktop when you are on two monitors; again, with the shortcut "CMD+Shift+3") to be sure I delete the one I don't want (i.e. the GUI of the monitor I don't care about), in this case, I just noticed this empty region (where the DVD Player app was running) in Preview right before deleting the image. @mosteveryoneElse yes, it must be mostly related to DMCA BS. And Apple is just being overprotective here. Since the DVD Player App is native to the Mac OS, surely it is mpy difficult to hide 'designated app[s']' windows when a user takes a screenshot.
- superchink 13y agoPeople still use DVDs?