Wikipedia:Reference desk/Archives/Computing/2008 November 22

= November 22 =

Zigbee or CAN
Which is more efficient and the promise for the future?CAN or Zigbee —Preceding unsigned comment added by 117.196.164.217 (talk) 15:32, 22 November 2008 (UTC)


 * Comparing apples and oranges; CAN is a popular wired bus standard originally used in cars, Zigbee is a wireless standard used in control and automation. Both are widely used and both don't have problems with their future. CAN is more efficient because it doesn't involve radio communication, Zigbee is more efficient because it doesn't require laying down wires between devices.
 * As a consumer, you're unlikely to interact directly with CAN devices, but you might encounter Zigbee in home automation, for example. MaxVT (talk) 21:11, 22 November 2008 (UTC)

One program, one/two file formats
Some programs use one file format (i.e. Word). You open, work and save your work in the same file. Other programs have a file format for working and export the results in another format (i.e. Adobe Flash uses .fla format for working but exports .swf files for presenting the result). What are the advantages of both approaches? Mr.K. (talk) 19:02, 22 November 2008 (UTC)
 * Programs use one file format for editing/drafts (i.e., the .fla for Flash, or .MSWMM for Windows Movie Maker), and another for final projects (.swf for Flash or .mpg for Movie Maker). Usually, the editing/drafts files are smaller, but cannot open in any programs except what it was made it. The final files are bigger and able to be read by just about anything. An example: Windows Movie Maker. You can make your vid, blah, but you want to be able to edit it later. So you save it as a .MSWMM file. This keeps all the seperate "scenes," lets you change inter-scene animation, etc. But when you save it to a .mpg file, it puts it all into one file that only has one scene, etc. With MS Word, it only has one file format - it's a final file, yet still editable. flaminglawyerc neverforget 21:49, 22 November 2008 (UTC)


 * I'm not sure the statement that the final files are bigger is likely to be true - in fact, I would imagine it would often be the reverse. Take, for instance, an Adobe Photoshop PSD file: it could contain hundreds of layers of high-resolution raster images, various filters, text effects, vector objects, etc; export it as a single JPEG and all that information is lost. The PSD file could be 10s of megabytes, but export to a JPEG of a few 100 kilobytes.
 * And that, to answer the original question, is the advantage of using separate formats: a file used when editing needs lots of additional information about the current state of the editing environment. If you just want to view the content, this is unnecessary complexity: it will probably take up space, and certainly require a more complex program to view.
 * It's also worth pointing out that this isn't about different programs going down different routes: many programs, including MS Word, have the ability to "export" a file in a variety of formats, it just depends what you want to do with the file. In a sense, the .swf file is the "final result" of working with a Flash project only in the same way as the printed copy is the "final result" of writing a letter in MS Word. - IMSoP (talk) 23:35, 22 November 2008 (UTC)
 * Again on the issue of final file size - I guess it varies from program to program. Take .svg files against a .png file, for example - .svg's are smaller, but store more information, but are not renderable by most browsers. But if you save as a PNG file, the file is much larger, but easier to display. flaminglawyerc neverforget 23:50, 22 November 2008 (UTC)
 * Good point. I guess exported formats generally contain less information (e.g. objects that are independent to the editor, such as "layers" of an image, will be merged in the output), but may have more redundancy (e.g. objects that can be described with elegant abstractions by the editor, such as bézier curves, have to be described in detail in the output). - IMSoP (talk) 00:04, 23 November 2008 (UTC)
 * And to get back to the example of the SWF and .fla files, SWFs are not designed to be edited. They can even be protected from import when you compile them in Flash. That's one reason Flash movies are so popular for delivering content. PDFs, too, are technically a finished format, and the format you use to create them is something editable like a Word document or an InDesign file. There are companies that want to prevent people from copying their content. Otherwise, they might swap the logo and use it for their own site or brochure.--Rjnt (talk) 03:34, 23 November 2008 (UTC)
 * It's not just about copyright issues. Exporting to a PDF, for example, allows me to guarantee that it will look exactly the same on your computer as it does on mine, even if you don't have the right fonts installed. It's a lot easier to distribute a PDF file than it is a Word file and get the same results; it's very difficult to distribute InDesign files and all of the necessary additional files you need to view and edit them. The copy protection functions of PDF are very weak and easily circumvented, in any case. --98.217.8.46 (talk) 15:40, 23 November 2008 (UTC)
 * Yes, that's another reason for the popularity of PDFs. As for circumvention, SWFs can also be decompiled relatively easily into .fla files using special programs. If you browse a torrent search engine or a warez bulletin-board, you will see many PSDs of hacked company logos, .indd brochures, and decompiled Flash sites. So, copy protection is an important ingredient in any company's publishing strategy. PDFs can have up to four layers of protection: a password, a signature, custom fonts, and compression. The last converts plain-text PDF markup to binary, and custom fonts prevent certain versions of Acrobat and Illustrator from editing the document. In the end, all forms of copy protection can be broken if the cracker is determined enough, but you can definitely make it a huge pain if you want to.--Rjnt (talk) 17:30, 23 November 2008 (UTC)

Converting standalone program into web-application
If I have a program like NLTK, that runs as a stand-alone application on my desktop, and want to use it as a web-service, what should I do? --Mr.K. (talk) 19:04, 22 November 2008 (UTC)


 * Easiest way: write a program in an easy-to-install/already-installed scripting language that just calls it through shell commands (like PHP's exec). Harder way: install a web framework for your language of choice (here's a list of python ones), and then figure out how to get it to work with the particular libraries you require. Which one, if either, is feasible will depend on how much control you have over the server. I'm assuming this is a console program. If you're talking about GUIs that requires all sorts of extra conversion (as you have to recreate the GUI in HTML). --98.217.8.46 (talk) 21:04, 22 November 2008 (UTC)

Wiring an RCA-to-VGA adapter
hey, can anyone help me? I want to connect my xbox to my computer monitor. I don't want to spend a gazillion dollars on a special device, so i want to make my own. My plan is this:

1) Wire an RCA male connector to a VGA male adapter. 2) Wire the RCA Left and Right Audio male connectors to a 3.5mm stereo jack.

I know how to wire the audio cable, but i have no clue about how to wire the video component. Just to be clear, the Xbox will output to a male-to-female RCA adapter, then goes into my custom cable with the VGA connector connected to the monitor. Using TV-in on my computer is not an option, nor is using Component Video Out (the YCbCr thingie). Can someone help me? Buffered Input Output 19:08, 22 November 2008 (UTC)


 * I am assuming you have three RCA cables: Video (Yellow), Right Audio (Red), and Left Audio (Right). The audio is easy.  The video is not.  The video signal on the RCA cable is completely incompatible with VGA.  You need a converter.  They are not expensive, but you can build one yourself.  It will cost more to build it than buy it.  You will want a circuit board to put this on.  You will want an RCA and VGA connector for the board.  You then need a chip that converts video to VGA (ATMega makes them - you can buy them at Radio Shack - well, you'll probably have to order one out of the catalog).  The manual for the chip will tell you what to solder where.  You will likely need a separate clock (I haven't seen a video-to-VGA converter with one built it).  Then, you will need power for the chip - 5VDC is common.  It is impossible to give exact instructions until you pick a VGA converter chip. --  k a i n a w &trade; 20:39, 22 November 2008 (UTC)


 * Rather than going from Xbox -> Composite video -> VGA converter (which will be lossy and more expensive), you can just roll your own Xbox VGA connector. A quick Googling reveals plenty of guides. -- Consumed Crustacean (talk) 08:51, 23 November 2008 (UTC)


 * Converting Composite to VGA is far from just wiring one conductor to another. It require demodulating the analogue QAM signal to recover the Chroma information of the signal, converting the Luma Chroma red Chroma Blue information into Red Green Blue Components, then clock those components precisely and transmit that timing with the Red Green and Blue electrical signal. Now that part is not really complicated, for the simple reason every tv got at least a component to rgb analogue converter to be able to display the picture on the Red Green and Blue photophores. Now come the part where you'll probably have to say good bye to your courageous project. TV receive a signal in interlaced form where only half (odds line or even lines) of the screen is transmitted each 1/60th of a second, VGA instead will receive the rgb components line by line. Resulting into 1 full picture every 1/30 second for Composite, and 1 full picture every 1/60th 1/75th or any valid mode for VGA. If you just duplicate each tv frame to get 60 frame per second, here will be the result you will get on the screen, I don't think that is exactly what you would expect. If you want better, you need to deinterlace the signal and for that I honestly think you will need to do the whole conversion within a digital signal processor, which you'll need to program one way to bob the picture for example. Now if the whole cost in time and money is inferior to the current offering of Composite to VGA adapters and you feel nothing can stop you. Then I wish you the best of luck and would love to hear the result you'll have. Esurnir (talk) 19:57, 24 November 2008 (UTC)


 * Of course, that's why I suggested he just put together a plain VGA cable. The Xbox 360 is capable of a VGA connection, no need to convert between composite and VGA. See ; you just ground a certain pin and the console outputs VGA, which is how it works with the Microsoft branded VGA cable (which, just to note, could probably be found pretty cheap on eBay, or a third party brand). Thus all that's needed is the wiring, which again there are guides for (including that one). Now, if it's an old Xbox he's talking about, then that is less good. has talk about that. -- Consumed Crustacean (talk) 23:04, 24 November 2008 (UTC)


 * If however by RCA, you mean component video (which the Xbox and Xbox 360 both output, according to the articles), it is easier (and therefore cheaper) - a quick google finds them for under GBP 10 . Hope this helps, cheers, davidprior (talk) 20:35, 24 November 2008 (UTC)

HP PSC 1350xi All-in-One
I have recently bought a HP laptop Pavilion dv9000 with Vista. My old desktop was running my PSC 1350xi just fine after I loaded the driver software. The laptop apparently will not. It prints only. It does not accept the driver software. Is there an update for this All-in-One from HP that will allow it to operate correctly on Vista. Scanner and OCR functions won't work with Vista with the software CD I have. --Doug Coldwell talk 23:39, 22 November 2008 (UTC)

Here is a list of drivers for your printer for various OSes. I don't know if you have Vista x86 or Vista x64, but if you know just pick it from there and download it. Gunrun (talk) 09:10, 24 November 2008 (UTC)