Ripping 3D movies

Discussion in '3DS - Games & Content' started by pachura, Aug 25, 2010.

Aug 25, 2010

Ripping 3D movies by pachura at 5:44 PM (2,672 Views / 0 Likes) 10 replies

  1. pachura
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    Member pachura GBAtemp Advanced Fan

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    I was wondering whether it could be technically possible to rip 3D movies and view them on 3DS ?

    Can you normally buy 3D Blurays in stores nowadays and watch them on your 3D-ready TV ?

    How are these movies encoded - do they use colors (then it would be impossible) or two completely seperate frames (then it could be possible, provided the angle between the two pictures is the same in 3DS)...
     
  2. DigitalDeviant

    Member DigitalDeviant GBAtemp Addict

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    concerning the first question anything technical about the 3DS is mere speculation.

    on the other hand making blu ray rips of 3d movies sound interesting but not sure if it would work. It would have to be tried with a blu-ray player that accepts video files (via usb?) and then outputted to a 3d screen.
     
  3. FAST6191

    Reporter FAST6191 Techromancer

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    +1 to the mere speculation thing.

    However 3d at the core of it all is very simple and very well known- you broadcast two slightly different images to each eye which can be done in many ways ( http://darkfader.net/3dstereo/ covers a bunch of them in brief). It will probably take a minor bit of fiddling on the part of the encoder depending on the 3d method you are ripping from (the 3ds uses a less common method of displaying 3d images compared to "mainstream" modern 3d) but nothing drastic.

    My conclusion technically possible but whether Nintendo will lock down the system against it (see Sony crippling the stock PSP somewhat vs UMD resolutions) or afford reasonable methods (see use of motion JPEG on the wii) is a different matter entirely. 3d is not exactly big in the consumer realms either as far as cameras go so that might be another reason for certain companies to lean on certain people.
     
  4. spiritofcat

    Member spiritofcat GBAtemp Advanced Fan

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    3D movies for 3D TVs use two images per frame, one for the left eye and one for the right eye.
    That's the same thing that the 3DS uses, so yes, I'd say that technically it would be possible, all the required data is tehre, it's just a matter of someone coming up with a method of copying the frames and getting them to be displayed on the 3DS.
     
  5. pachura
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    Member pachura GBAtemp Advanced Fan

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    Everyone knows that. The question is: how are these two frames encoded ? For instance, in some cinemas I've been to, both images are mixed into single frame using slightly different colors, and you watch the movie through colored glasses. (Not the shitty ones from 90s, but not truly polarised). If this is the case with 3D DVDs/3D Blurays/whatever, then there's no chance for ripping them to be watched on 3DS. Also, the angle between images for both eyes can be different on 3D DVDs/3D Blurays/whatever and on 3DS, which would again render ripping to 3DS impossible.
     
  6. dsfanatic5

    Member dsfanatic5 Team ICO Freak

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    First, someone is going to have to find a way to play any video files back on the 3DS, before they can even begin to think about 3D video. I'm guessing the 3D movies on the 3DS are going to release in cartridge form, so when the 3DS is hacks, and games are dumped, so will the 3D movies. Maybe then, someone can decode the file and figure out which format the videos are. Considering the DS(Lite) uses the strange .dpg format for video, I wouldn't be surprised if the 3DS format is something very unique.

    If someone were to rip a 3D Blu-Ray, they'd obviously have to have a BD drive and software, but most everyone would wait until the rip is available for download anyways. This whole idea is interesting, but it would be more likely that 3DS owners would be downloading "official" 3D movie releases, and playing them on a flashcart in the far future.
     
  7. pachura
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    Member pachura GBAtemp Advanced Fan

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    Agree.
     
  8. foob

    Member foob GBAtemp Fan

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    Good info, so my thoughts that Nintendo didn't license anything from the MPEG group for its portables seems to be true.

    Nintendo know how to save yen! ?
     
  9. spiritofcat

    Member spiritofcat GBAtemp Advanced Fan

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    All the 3D TVs that I've seen work by showing left frame, right frame, left frame, right frame, etc. And having glasses that black out each eye in turn so that each eye gets the correct frame as it is displayed.
     
  10. FAST6191

    Reporter FAST6191 Techromancer

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    spiritofcat you just described shutter glasses but there are some polarised light type 3d options available* in general consumer land- the 3DS though is something like those "moving" or dual picture things you might have seen as a kid (the technical term is Lenticular printing) with the thin strings of transparent plastic on top but many times more advanced. This is why glasses are not needed and also why it probably does not have the best viewing angle. In what I imagine is a patent minefield LCD screens were once renowned for bad viewing angles vs crt but in some cases similar technologies/methods were used to improve it.

    *granted the TVs (or more likely projectors) are usually circular polarisation but the idea in linear polarisation is that light as a wave can move up and down and if it is the case you can block it by having a filter (in practice just a few really narrow strips of material with gaps between them). Show one image in one polarisation and one for the other eye in the opposite and you can effectively show a different image to each eye and thus gain 3d.

    To this I will echo my previous comment- technically there should be no problem. In practice it will come down to encoding/display methods- if it is "lenticular" in nature it will look very odd. If you know video imagine combining the fields of two different videos but if not I hate deep linking a site (especially one I respect) but courtesy of frames I am going to have to http://www.doom9.org/video-basics.htm (main site is http://www.doom9.org ), do a page search for "And the corresponding frame:" and now rotate it 90 degrees. To speculate the "3d slider" probably merges/reduces these to adjust the 3d effect.
    Such a thing is a nightmare to encode efficiently using traditional methods (games being generated are not bothered in the slightest by this beyond the obvious having to generate two images) as lossy encodings work by assuming their neighbour is similar to them (see picture on the link for why that would not work) and that the next frame is also similar* in case you were thinking about alternating frames and the extension avi is short for audio video interleave which came about to stop the playback device having to skip all about a disc to read the file (the vast majority of containers having similar behaviours) although it probably will be the best route to try out.
    Were I to be a coder on the hypothetical 3ds 3d film playback/encoder project (assuming the rest of my post is correct of course) I would look at interlaced video storage, playback and handling as it is extremely similar. This would be the "bit of fiddling on the part of the encoder" I mentioned earlier.

    *the difference being any movement in the picture which is actually calculated/account for, similarly if you have ever seen a broken video fuzz up into probably a nice grey, green or pink block and come back according to what moves first you now know why. The reason it might all pop back in at once is usually because a complete frame (i-frame) that does not depend on what came before (or after) is often part of the video. Indeed generating these in the first place is a reason why encoding often takes so long or in the case of high end filters like mvtools ( http://avisynth.org.ru/mvtools/mvtools.html ) takes so many resources but produces such spectacular results vs more brute force methods.

    Now of course Nintendo having to build to cater to the public at large is not going to want to do a crash course in video encoding for them and equally the only real use of it being to watch copied* (copyrighted- fair use maybe but anybody who has followed this arena since the days of decss knows how this game works) videos which others may frown upon and might come as part of a decoder license.
    I know the ability to make your own was touted for the 3ds itself but recording video is quite different in this case from converting it. Your best bet here then is Nintendo leave it open for sharing videos between such devices (quite likely if you ask me) and some seriously bright spark reverse engineers it. That might not be a case of I will hold my breath though as that is a horrific task; this is a breakdown of MPEG 1 http://www.cmlab.csie.ntu.edu.tw/cml/dsp/t...g/coding/mpeg1/ so imagine trying to work that backwards and then consider MPEG1 is ancient and incredibly simple relative to modern formats which the 3ds will not only lean on but probably tweak (see post above) making it even more difficult. You can hope they will use something known just with a nasty container or hope the SDK leaks but again I would not hold my breath.
     
  11. pachura
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    Member pachura GBAtemp Advanced Fan

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    Well, you could always have two completely separate and independent video streams - one for the left eye, one for the right. Just like Dual Channel instead of Joint Stereo in the world of audio compression. Or, as you were saying, try to use interlace to encode the two images.
     

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