Wikipedia:Reference desk/Archives/Computing/2012 June 30

= June 30 =

Boiling Apple products

 * 1) How long does it take to boil an iPhone, iPad, iPod to damage?
 * 2) What are the redline temperatures (the maximum and minimum survival temperatures) of above products?

--- 171.228.126.153 (talk) 06:24, 30 June 2012 (UTC)


 * My guess would be that submersion in ordinary non-boiling water would likely damage any in a matter of seconds, and in boiling water even faster. http://www.google.com/search?q=%22got%20my%20iphone%20wet%22 ¦ Reisio (talk) 13:15, 30 June 2012 (UTC)


 * I wouldn't want to try this with the battery in, but if you remove the battery, I think electronics can survive extended periods of immersion in water as long as you dry them very thoroughly before repowering them. This may be true even if the water is at 100°C. Nothing special happens to metals or plastics at that temperature. Some consumer CPUs are specified to work (not just survive) at temperatures up to 95°C if not higher. -- BenRG (talk) 20:33, 30 June 2012 (UTC)


 * I knew I should have removed the battery from my phone before accidentally dropping it in water, and then completely disassemble it and ensure it to be dry before using it again. There are a lot of things that theoretically/ideally should not be damaged by a little water that nevertheless are, and a CPU alone is not any of those devices. ¦ Reisio (talk) 21:06, 30 June 2012 (UTC)

'Locked computer' scam
Has anyone been the subject of the 'locked computer' scam? This is where you get a page saying your computer is locked and can only be unlocked on payment of £100 by paypal or some such method. It says this is because of accessing inappropriate web sites. REbooting the computer does not shift the problem and the offending page reappears. Any ideas on how to combat?--78.150.226.117 (talk) 08:52, 30 June 2012 (UTC)


 * You don't say what computer or operating system, but the usual advice for "Windows" is to restart in safe mode, then run some good anti-virus software. If this doesn't work, then I'm sure there will be some experts here soon who can suggest alternatives.    D b f i r s   11:03, 30 June 2012 (UTC)

. I had a virus recently with WinXP. I couldn't access task manager nor the restore features locally. I did discover that I could access a restore point from the online help though. I have my original XP disc, but alas I have lost the access code so I am wary of any strange boot sequences that may require it. Restore points are your friends. I just thought I would add this in case others have similar problems.--Canoe1967 (talk) 12:51, 30 June 2012 (UTC)


 * And also your enemies. ¦ Reisio (talk) 13:17, 30 June 2012 (UTC)


 * Sounds like the UKASH/Metropolitan Police malware. Running tools such as Combofix can remove it. Nanonic (talk) 12:54, 30 June 2012 (UTC)


 * Have you tried trying to start up the system in safe mode? --140.180.5.169 (talk) 02:52, 4 July 2012 (UTC)

RECORDING AN AUDIO
I want to record an audio song playing on the internet. My os is windows 7. How can I record it internally in my computer? Thank you. — Preceding unsigned comment added by 175.157.133.205 (talk) 12:37, 30 June 2012 (UTC)


 * While there are generic ways to capture any audio playing on your computer, they actually tend to be more complex to implement than the more specific ways you can use given particular situations. Please be more specific. ¦ Reisio (talk) 13:18, 30 June 2012 (UTC)


 * Agreed. Specifically there are different methods for extracting and recording the audio from YouTube videos, DVDs, etc. StuRat (talk) 17:04, 30 June 2012 (UTC)

On Windows 7 you may have to enable the "Stereo Mix" first, there is a guide here which explains how. Then with some recording software, Audacity is good for example, set it to record from Stereo Mix, click record and play the music. There is a more in-dept guide here specifically for recording playback with Audacity AvrillirvA (talk) 13:24, 30 June 2012 (UTC)

NOW RESOLVED - Help - Can't play onscreen videos
My PC will no longer play viral videos. I am running Win7 and have not had a problem until the last few days. When I click on a video it tries to load but I just get a white square where the video should be and nothing happens. I have tried restoring to my earliest restore point but the problem must have started prior to that because it hasn't fixed it. I have uninstalled and reloaded Java but that makes no difference either. By the way, if I try playing a YouTube video I get the message "An error has occurred".

Can anyone indentify my problem please? Gurumaister (talk) 12:39, 30 June 2012 (UTC)


 * YouTube uses either Adobe Flash Player or your browser’s built-in video support, so if you’re going to attempt reinstalling something it should be Flash or your browser (or possibly your video driver), and not so much your Java™ plugin. ¦ Reisio (talk) 13:19, 30 June 2012 (UTC)

Thanks. I have just reinstalled my Adobe Flash player and also Firefox but that also hasn't helped :(  I don't think it is my video driver as I can still play saved videos. Gurumaister (talk) 13:54, 30 June 2012 (UTC)

Turns out it was the latest version of Adobe flash does not like Realplayer - I have rolled back my Flash installation to an earlier version. Thanks Reisio. Gurumaister (talk) 16:06, 30 June 2012 (UTC)


 * Note that changing the title to mark a Q resolved isn't a good idea, as any link which has been created to your Q will be broken. Instead, mark the question resolved using  . StuRat (talk) 17:00, 30 June 2012 (UTC)

Adobe warning
For the last several months I have been getting the following warning on top of a lot of videos:

Adobe flash player settings -

... is requesting permission to store information on your computer. --

Is there a way to set it so I don't get this warning, or is it wiser (for security resons) to leave it as it is? Bubba73 You talkin' to me? 17:15, 30 June 2012 (UTC)


 * You can change the settings by going to the flash player settings manager at http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager.html
 * The relevant sections are "Global Storage Settings panel" and "Website Privacy Settings panel". Mitch Ames (talk) 03:45, 1 July 2012 (UTC)

Thanks, I looked at that and decided to leave it as it is. Bubba73 You talkin' to me? 14:49, 1 July 2012 (UTC)

Adaptive frame rate ?
It would be beneficial if streaming videos and DVDs could have a higher frame rate when more action occurs, and a lower frame rate on relatively static scenes. I believe animated GIFs can do this now.

1) What other formats support a variable frame rate ?
 * Comparison of container formats has a list. It seems most do support it. Variable frame rate doesn't say much about how it works though.--Canoe1967 (talk) 17:35, 30 June 2012 (UTC)

2) Determining when to use the higher frame rate would be tricky, too. A simple method would be to look for the total amount of change in every pixel on the screen, but that might see a need for a higher frame rate when the entire screen is slowly panning versus a small object on the screen moving quickly.  What methods are used to determine the optimal frame rate ?

I suppose a human's involvement might ultimately be needed. For example, when watching cars on the road, if the car of interest looks choppy, that's more of a problem than if some other car does.

3) Also, do any DVD/Blu-Ray players support a variable frame rate ? (Presumably they would need to interpolate the missing frames, so a 60 FPS display device might be sent a 60 FPS bit, with no interpolation required, for scenes with lots of motion, down to 30, 20, 15, 12, 10, 6, 5, 4, 3, 2, or even 1 FPS, for still shots.) StuRat (talk) 17:17, 30 June 2012 (UTC)


 * Most modern codecs use a system of I frames and P frames, which is likely to produce superior compression for the same delivered data. This way the P frames only store the information related to the movement of the car. One might describe that as system where the frame rate for non-changing things is 0, but is higher for moving things. -- Finlay McWalterჷTalk 17:33, 30 June 2012 (UTC)


 * Most modern video codecs and container file formats allow both variable frame-rate and variable bit-rate. I'm hard-pressed to think of a recent video technology that does not support variable frame-rate.  In practice, it is much more common and much more useful, in general, to provide a constant frame-rate with variable bit-rate; because very very low-bitrates on information-sparse inter-frames can be achieved by modern codecs.  To answer your second question, the automatic detection of optimal bit-rate and frame-rate is often determined based on scene conditions, including calculating the amount of motion between two or more frames.  Other metrics include perceptual signal to noise.  To answer your last question, "yes."  Perhaps a better way to approach this is to run down the list of common video codecs and containers, and determine whether any particular combination is commonly used with variable frame- or bit-rates.
 * Finally, for the sake of completeness, it's important to emphasize the incredible difference between "is officially supported in the standard" as opposed to "is in common use and has robust support in consumer software." In video codec technology, this contrast can often be pretty stark.  Nimur (talk) 17:41, 30 June 2012 (UTC)


 * Variable frame rate does doesn't have half that info. Could we just copy/paste your answers to the article?--Canoe1967 (talk) 17:51, 30 June 2012 (UTC)


 * (I assume you meant "doesn't".) Good idea, that's just a stub, at present. StuRat (talk) 17:59, 30 June 2012 (UTC)


 * Ooops and fixed. Does one of the wise editors above want to do the copy/paste thing?--Canoe1967 (talk) 18:38, 30 June 2012 (UTC)


 * I was surprised to see that we lack an article on the more general, simpler-to-understand principle, irregular sampling, which is itself a generalization of the mathematics of regular sampling. I did find this excellent page with some worked examples and a thorough discussion of reconstruction errors for various interpolation algorithms.  Ultimately, video coding "performance" is determined by "perceived" error, rather than true error residuals, so there's a lot of room for heuristic algorithms.  At present, those heuristics usually take the form of "quant tables," similar to JPEG coding.  Eventually, if you want to understand video coding, you need to first understand still image coding (because moving images are more complex).  And if you want to understand still-image coding, you'll have to first understand single-dimensional signal processing, because 2D signals are more complex.  So, start by reading about linear systems and transfer functions, and then start learning the way that modern image compression works; and by the time you reach a pretty good mastery of that subject, the fundamentals of video compression technology should be self-evident.  Nimur (talk) 19:25, 30 June 2012 (UTC)


 * Care to create the article ? StuRat (talk) 19:42, 30 June 2012 (UTC)

Strange sound that won't go away
My Windows XP sometimes plays a strange repeating error sound and won't go away until I reboot. I tried disabling the sound card, closing all programs, etc. It has popped up when I am running different programs so I don't think it is one program causing it. Here it is if anyone wants to hear it. All my alert sounds are original default XP ones. File:Windows XP strange error sound.ogg.--Canoe1967 (talk) 17:28, 30 June 2012 (UTC)


 * I sometimes find a button on my mouse or keyboard is mashed down, when I hear such sounds. StuRat (talk) 17:33, 30 June 2012 (UTC)


 * Very good point. Is there any software that shows which keys are being pressed? I don't think that is it, but my kb has no visual indication when a key is stuck. It took me days to figure out that F11 toggles full screen expand in internet explorer after I didn't realize I had touched it. I am tempted to put a special mark on that key.--Canoe1967 (talk) 17:50, 30 June 2012 (UTC)


 * First thing to try (after a visual inspection of the mouse and keyboard to find any keys obviously stuck down) is to pop up a text editor to see if it starts typing any letter. If not, then at least we've eliminated the typable letters.  If you have another keyboard and/or mouse, try those, too.  A reboot might also be in order. StuRat (talk) 17:57, 30 June 2012 (UTC)


 * I think I found it wasn't the kb by turning its power button off (wireless kb) and the same with the mouse. I did try text in wp edits and notepad as well. I may google for a 'stuck key' program. I used to get a fast beep when the kb buffer got full but that I haven't heard in months/years. I just realized that it may be an error from my digital camera that I usually have plugged in. Low battery type thing.--Canoe1967 (talk) 18:25, 30 June 2012 (UTC)


 * OK, let us know if it's fixed, so we can mark this Q resolved. StuRat (talk) 18:29, 30 June 2012 (UTC)

It only happens once a week or so. I will resolve this section for now and when it happens again I will try some more stuff. Like salt water on the circuits.--Canoe1967 (talk) 18:35, 30 June 2012 (UTC)


 * Like tossing the computer overboard into the ocean ? :-) StuRat (talk) 19:43, 30 June 2012 (UTC)

Computer Languages
As a recent graduate with no immediate life plans, I am considering learning two or three computer languages over the next few months to facilitate a move into the computing industry (though I am not sure doing what exactly). Can someone please suggest some useful and general purpose computer languages that I could learn to boost my employability in this sector. I recognise this is an extremely general question but there must surely be one or two languages that stand out as very useful. Thanks. 92.14.225.82 (talk) 17:48, 30 June 2012 (UTC)
 * Linden Scripting Language if you want a quick learn and work in Second Life. I heard some make 20usd an hour.--Canoe1967 (talk) 17:59, 30 June 2012 (UTC)


 * Jeff Atwood recently wrote So You Want to be a Programmer (May 2012), an essay that you may find informative. His other writings are linked profusely throughout his page, and you may find them enlightening.  It is improbable that you can learn two or three computer languages in the span of a few months, unless you are already an expert programmer.  It takes a long time to learn to program; Peter Norvig's infamous essay estimates that you should teach yourself to program in ten years.  Once you've mastered a few critical concepts, switching languages will become a trivial task; programming in a new language will only require a few days to reach basic competency, and only few months to reach mastery: but you'll only reach this stage several years down the road, after you've already mastered C and Java and PHP and perl and BASH and Unix, Linux, Mac, iOS, and Windows (... and n additional platforms).
 * I think, most seriously, that if you caveat your objective with the clause "though I am not sure doing what exactly" - you are not a programmer. It does not matter how many different symbolic code-languages you memorize.  Programmers know what they are doing, and provide formal instructions to machines to automate the process.  This thought-process isn't something that gets learned.  You either are procedural in your thoughts, or you are not; and if you are not, you will never be able to codify those thoughts in a programmed language.
 * Rethink your objective, break the problem down into smaller sub-problems, and tackle those one at a time. It will quickly become obvious which programming-language is optimal for your task, and begin learning it.  Nimur (talk) 19:06, 30 June 2012 (UTC)


 * I'll second what Nimur said. Three languages with a combined total of a few months' experience isn't very impressive; if I saw that on a job application, I'd file it under "can't program".  If you want to start a programming career, pick one language and spend at least a year learning and using it.  Don't simply study the language, find things to do with it and do them.


 * I'll also second his description of learning new languages once you've got experience. My first language (BASIC) took about seven years to really get the hang of, and my second (C) took about five.  I'm currently learning Lua (my 21st language (I think) in about 25 years).  I started learning it about two weeks ago, and I'm comfortable enough with programming in it to use it as part of my Liberated Pixel Cup game entry. --Carnildo (talk) 05:29, 1 July 2012 (UTC)


 * I will just object to one line: "You either are procedural in your thoughts, or you are not; and if you are not, you will never be able to codify those thoughts in a programmed language." This sounds almost like procedural thinking is innate. It is not. It is something that can taught, learned, and improved. But I agree that trying to do it over the course of a few months is foolish. You are not going to be able to retrain yourself to be a computer programmer in a few months, any more than you're going to be able to become a physicist or a carpenter or a expert cook with a few months of training. Skills take longer than that to learn. --Mr.98 (talk) 18:58, 1 July 2012 (UTC)
 * 10 years is my estimate for a programmer to avoid wrong practices because "it feels wrong" rather than "in school we learned that you should". But even then, some people are much better at programming after 5 years than others after 30. But also, every software company also needs programmers to do things that don't need 20 years of experience. For such jobs, I guess learning C# would be the smartest move. Joepnl (talk) 22:19, 1 July 2012 (UTC)

16MB internet - enough for six people?
I'm just about to move into a new house with six friends, and I'm currently in the process of finding the most suitable broadband supplier. O2 are offering me 16MB internet with unlimited downloads at a highly reasonable price - but is this likely to be sufficient? At any one time, 3-4 of us may be using the internet to watch videos or download music, etc. Will 16MB internet be okay, and allow us all to do this with ease and comfort (and high speeds), or should I look into a more expensive deal offering 40MB broadband? Many thanks in advance. — Preceding unsigned comment added by 129.11.102.85 (talk) 20:08, 30 June 2012 (UTC)

Sorry my mistake. Moving into a house with FIVE friends. Six of us in total. — Preceding unsigned comment added by 129.11.102.85 (talk) 20:10, 30 June 2012 (UTC)


 * Is that megabits per second (Mb) or megabytes (MB)? Even if it's megabits that's probably enough. A typical bitrate for streaming video is around 2 Mbps, though high-quality video might be 4–5 Mbps. -- BenRG (talk) 20:47, 30 June 2012 (UTC)


 * Although one thing that worries me is that they always seem to advertise the maximum bit-rate, when what we need to know is the minimum, which they never seem to commit to. I'd also be very careful and research this company to see if they cut down the bit-rate on their heavy users, which you will surely be. StuRat (talk) 20:51, 30 June 2012 (UTC)


 * Look into Quality of Service for your router. It'll make sure no single heavy user ruins it for everyone else. The worst case scenario is one streamer or torrenter sucks the whole system down; this can be easily avoided. There is also discussion of this here, in particular with regards to replacing default router software if it doesn't support it. --Mr.98 (talk) 14:58, 1 July 2012 (UTC)

How to fix interference on a Plasma TV
If anyone here thinks they can help identify the type of interference problem I am getting on my new Plasma TV please see the question I have posted on the science desk: http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#How_to_fix_scrolling.2Ftiling_interference, thanks. μηδείς (talk) 21:29, 30 June 2012 (UTC)

How to extend disk partition space in Windows 7
I know about the option in control panel, but in my case the "extend volume" is disabled. I have lots of unused space on hard disk, I have tried to format that unused space, even create a brand-new volume with lots of empty space, I am able to create a new volume but I want to add to the space of already present partition but the "expand" option still remains disabled. Kindly help... — Preceding unsigned comment added by 124.253.92.214 (talk) 22:04, 30 June 2012 (UTC)


 * You can only expand into free space (if there's another partition there you need to delete it), and as far as I know you can only expand rightwards in Disk Manager (if the free space is to the left of the volume you won't be able to use it). Does that help? There are other repartitioning tools that are more flexible. GNU Parted is free and available on a lot of bootable Linux CDs. -- BenRG (talk) 22:39, 30 June 2012 (UTC)


 * Warning to the OP: please, oh please back up your data before playing with any formatting tools, especially if you don't know what you're doing, which is what it seems like. If you make one small mistake and corrupt the filesystem, your computer won't be able to boot, and you'll have to go through the laborious process (if you've never done it before) of trying to recover your data.  I think GNU Parted has problems resizing partitions to the left--namely, it copies all the data to the left instead of using a smarter algorithm.  Here's a discussion about a program that can do it more efficiently: http://reboot.pro/14823/  --140.180.5.169 (talk) 02:19, 2 July 2012 (UTC)