Wikipedia:Reference desk/Archives/Computing/2007 November 29

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[edit] November 29

[edit] Palm Programming

Hi, I'd like to get into making applications/databases for the Palm Pilot but don't know where to start . I'm more a designer then a programmer so something easy to pick up and visual would be great . I'm mainly looking at designing free interactive fiction / educational databases (solar system, periodic tables etc) - so must import imagery . Any ideas of what to look out for ? Free apps preferred but not essential... Cheers Boomshanka (talk) 01:22, 29 November 2007 (UTC)

I would probably visit Palm's website first - the developer's page is here. You will need to join the the Palm Developer Network to download the Palm OS SDK (Software Developers Kit). I think joining and the SDK are both free. BUT... I strongly suspect you will need programming knowledge to develop an application. Astronaut 15:37, 30 November 2007 (UTC)

[edit] Firefox Backspace

Firefox has been driving me nuts lately. I go to type into a field, make a mistake, and hit backspace to fix it. Too late I realize that I wasn't in the correct field, and the browser gos back. Is there a command in the about:config file i can change, or something else so that that hotkey doesnt work?--Omnipotence407 (talk) 01:25, 29 November 2007 (UTC)

Try this: from about:config, change the value of browser.backspace_action from the default 0 to 2. --71.162.242.240 (talk) 01:32, 29 November 2007 (UTC)
You can also use the keyconfig extension to edit keyboard shortcuts. --— Gadget850 (Ed) talk - 01:34, 29 November 2007 (UTC)

[edit] Dual license software

I've heard some softwares have dual licenses system (open source and proprietary). How is it work? If I'm the administrator of the software could I take the code from the open source then implement it in my proprietary codes (consider the codes are two different forks and the open source grows faster)? Thanks for the answers. roscoe_x (talk) 03:54, 29 November 2007 (UTC)

I think yes if you are the copyright holder. --Spoon! (talk) 04:29, 29 November 2007 (UTC)
Depends on the licenses. Generally it doesn't make any difference if you're the "administrator"- unless you contact every single person who contributed to the project and ask them to relicense, or have people willing to relicense rewrite it all, then you can't change any terms. But if it's a permissive license that lets you do that anyway then all should be OK. --ffroth 07:38, 29 November 2007 (UTC)

If the licence states that you can then obviously you are allowed. You might have to include the source of the program you have taken from or something but all this is completely dependant on what the software is licenced under. Also I cannot think of any software that is both open source and proprietary, except possibly OpenOffice and StarOffice both of which are derived from the same code, but are totally seperate bits of software. TheGreatZorko (talk) 09:42, 29 November 2007 (UTC)

You might also want to look at the wikipedia article; dual-licensing. But this is not an option unless you own the copyright of the code you wish to dual license. Taemyr (talk) 10:54, 29 November 2007 (UTC)
It depends on the license. Most licenses, though, say that you can use free content (not the same thing as open source) with proprietary content if there is an easy way to separate the two and to indicate "this is copyrighted this way, and this is copyrighted that way". So if they are in two separate files, for example, it is pretty easy to mix and match licenses, though again it depends on the specifics of the license. Some "free" licenses allow you to incorporate the modified license in your code as long as you make it clear in the credits. Some have different requirements altogether. You have to actually read the license to know for sure, and there are many different flavors of them. The LGPL makes it easier to package free content with non-free content than the GPL does, for example. -24.147.86.187 (talk) 14:39, 29 November 2007 (UTC)
If you own the copyright (which can be tough if the project has a million anonymous contributors!) then you can change the license whenever you like to whatever you like - including providing alternative licenses for the user to choose from. However, versions that are already "out there" in an older license can still be passed around under that license because you can't make the change retroactive. But it's perfectly OK to say "The package may be downloaded either under GPL or you can pay me $100 and get it under the terms of my commercial license"...or whatever. Some people may want to do take the commercial license (and in this case, pay you money) in order to avoid the "viral" nature of the GPL. However, what you CAN'T do is to say "private individuals can have it under GPL but companies have to pay" - that won't work because the GPL guarantees the right of anyone to whom the software is distributed to redistribute it UNDER THE TERMS OF THE GPL. So a private individual gets it - then gives it to a company - thereby circumventing your $100 fee. There isn't much you can do about that because it's the key right bestowed by the GPL that everyone who take a copy is entitled to the same set of rights. If you simply wish to avoid the restrictions of GPL, consider LGPL or something like the Xfree license (which basically allows anyone to do anything providing they keep the license attached to it). SteveBaker (talk) 21:43, 29 November 2007 (UTC)

[edit] Blackberry metronome application

Is software available somewhere so that a Blackberry can be used as a metronome? Thanks. Edison (talk) 04:40, 29 November 2007 (UTC)

[edit] Poor image resolution in webpage

I use R60 model laptop from IBM-lenova. I use windows XP SP2 with IE-7 version. I use wireless modem to connect to the network. It has a speed of 115Kbps(max). Till to date whenever I open any web page with the IE browser,I get poor quality/resolution images like the adds or picture of anyone.But the flash or animation looks great.Also if I download that same image, it appears good. Is it a problem in Thumbnail preview?.All thumbnail preview images appear very poor. What could this be?..Any way to solve?..Thanks in advance —Preceding unsigned comment added by Balan rajan (talk • contribs) 07:02, 29 November 2007 (UTC)

Are you behind any sort of web acceleration program or proxy? I don't know if any actually do this but a proxy could dynamically compress images before downloading to your PC, making it load faster. That would cause the images to look low quality? Have you tried a different web browser? If this is not the case I suggest you try either Opera or Firefox, both of which are free to download and use. If the problem doesn't show in those browsers then it is Internet Explorer causing this most likely. If you see it in the other browsers then it is some sort of proxy or similar. If not then I'm sorry but I haven't got a clue. TheGreatZorko (talk) 09:39, 29 November 2007 (UTC)
Are you using your neighbor's wireless without his permission? It's a common prank to screw with neighbors by inverting or fuzzying their images --ffroth 18:39, 29 November 2007 (UTC)

Ofcourse not!. It's been provided by my organisation. I didin't yet try any other browser. Let me try that and post it here the results. Thanks —Preceding unsigned comment added by Balan rajan (talk • contribs) 12:17, 30 November 2007 (UTC)

Could it be the video-card settings? Astronaut 15:41, 30 November 2007 (UTC)

[edit] Play .avi video clips in reverse

Hello all! I need a (ideally freeware/shareware) program for Windows that will allow the user to play an .avi file in reverse, at 1:1 speed, sound and all (so not just one with a "rewind" button). Any suggestions? Neil ☎ 10:01, 29 November 2007 (UTC)

If you don't mind re-encoding it then this might be of some help (EDIT: Now I look at it it seems as though VirtualDub will let you play it backwards without re-encoding). If not I vaugly recall some sort of time shifting options in VLC although I'm not even 50% sure of that. TheGreatZorko (talk) 10:20, 29 November 2007 (UTC)

I have VLC, abd it doesn't let you play a clip in reverse *with sound* (I tried for ages). I'll take a look at VirtualDub, though, thanks. Neil ☎ 10:26, 29 November 2007 (UTC)
Its pratically impossible because of the way the are encoded. I doupt an avi mpeg based player exists that can play with sound backwards. It would litereally have to decode it forwards to a buffer then play again but backwards--58.111.143.164 (talk) 12:42, 29 November 2007 (UTC)
I don't mind re-encoding it if someone can point me towards a suitable program. Neil ☎ 13:10, 29 November 2007 (UTC)
The guide I posted above details 2 programs you can use in conjunction to re-encode the video backwards.TheGreatZorko (talk) 15:10, 29 November 2007 (UTC)
I'm sorely lacking any technical knowhow, so thanks but a simple program (such as 24.249 suggests below may serve me better). Neil ☎ 09:13, 30 November 2007 (UTC)
Try converting it to Quicktime. QT Player can play movies in reverse with audio at 1:1 speed. Just Control-click (or Command on Mac) the play button. --24.249.108.133 (talk) 17:06, 29 November 2007 (UTC)
Ooh, that sounds promising. How do I convert an avi file to quicktime? Neil ☎ 09:13, 30 November 2007 (UTC)
You should just be able to open AVIs in Quicktime player. You should be able to play them back right there without conversion. But you can save them out using the Export command. There are a bunch of presets for different quality and codecs. --24.249.108.133 21:34, 30 November 2007 (UTC)
The problem lies in the way that video is encoded. To save space, they do something like this:
  1. Save the first frame of the video as a still picture.
  2. Look at what changed between the first and second frames - and only store the differences between the two.
  3. Look at what changed between the second and third frames - and only store the differences between the two.
...until a few hundred frames have gone by - then it'll save another entire frame and then the differences from that.
The trouble with this is that you can't just display (say) the 100th frame from the movie - you have to start at the front, apply all of the differences up to frame 100 and then display it. Now you want frame 99 - but to get that, you have to start again at the beginning. This is either exceedingly slow - or it requires the tool to store hundreds and hundreds of 'previous' frames in memory - which is a real memory hog. While it's clearly not impossible to play videos backwards (because there are tools that do it) - it's really tough to do right. Since it's a rarely needed feature, most people won't bother to implement it.
What I do is to use 'mplayer' to chop the the video into individual frames (with a separate '.png' file per frame) - then renumber them in reverse order and use 'mencoder' to make a new video which is reversed. This takes a lot of time and disk space - but it has the HUGE advantage that now any old player will play it.
SteveBaker (talk) 21:17, 29 November 2007 (UTC)
Memory is not an issue (got 8Gb), so it's just a simple tool I need. I'll try quicktime as suggested above. Thanks all. Neil ☎ 09:13, 30 November 2007 (UTC)
Memory may not be an issue for you - but the authors of whatever software is doing this would have to consider how much their "typical" users might have - and they might decide that's 1Gbyte or something. But unpacked movies can be HUGE - even 8Gb might not be enough if the software tries to do this in an unsophisticated way. I'm not saying it can't be done - just that it's not as easy as it might first appear to the layman - which is why it's not a common feature of movie players. SteveBaker 15:18, 30 November 2007 (UTC)
Steve's a bit too pessimistic about this. To play backward, you only need to deal with one group of pictures at a time. Find the last key frame, decode from there to the end, then feed that group to the display in reverse order, and jump back to the previous key frame. The biggest GOP in an AVI is usually 300 frames. Decoding a group of pictures and displaying them in a different order is not even a new feature for any movie player that supports B frames. --tcsetattr (talk / contribs) 21:05, 30 November 2007 (UTC)

[edit] laptop

i recenly got home and my small sister was playing with my laptop.anyways it has hibernated and i cant acess windows.the machine isnt doing anything.when i boot it says its hibernating and nuthing else.what do i do.i dont know much about pcs.

Hibernating just means it is "asleep" -- it's just a way for it to not really be turned on but not really be turned off (it is not a problem, it is a standard feature). Usually there is a button you can press to make it "wake up". Look for a "wake up" or "sleep" key, and if you don't have one, trying just pressing "esc" or "space" or "return" and one of those should wake it up. --24.147.86.187 (talk) 14:36, 29 November 2007 (UTC)

If the above doesn't work then holding down the power button for about 6 seconds while on the hibernating screen will cause the PC to reset (or turn off) although any work that was open at the time will be lost. TheGreatZorko (talk) 15:09, 29 November 2007 (UTC)

On my laptop, the only way to 'wake' it from hibernation is to press (not hold!) the power button. GaryReggae (talk) 22:11, 29 November 2007 (UTC)
Hibernation is NOT the same as "sleep" or "standby": Sleep just shuts off the screen, stops spinning the hard disks, etc. but keeps everything loaded in memory. Hibernation saves the running memory to the hard disk and completely shuts the machine down. To "wake it up", start the machine the same way you would if you had shut it off. To reply to the original question, what exactly does it do/say when you start it up? Do you get to a dialog box, or is it just white text on a black screen? 68.39.174.238 19:42, 30 November 2007 (UTC)

[edit] Windows XP font problem — newly-installed fonts disappear after reboot

I have a rather unusual problem with a PC that I use, which runs Windows XP Pro SP2. Here's the problem: after I install news fonts on the machine, they will be available to the applications installed on the machine, as they should. However, the new fonts will cease to be visible to the applications after a reboot. Checking Windows' font folder and registry would reveal that the fonts are still installed — if you try to drag-and-drop the fonts in question, again, to Windows' font folder, Windows would tell you that the fonts are already installed. The user data and application config files on the machine were restored from a backup of a previous machine. It's not clear when or how the problem developed, but user-installed fonts from the previous machine are all accessible, i.e. they don't suffer from the same disappearance problem. I've checked the attributes and permissions associated with Windows' font folder, as well those with the font files. Nothing stands out as unusual. I've also tried deleting Windows' font cache file, FNTCACHE.DAT, but that didn't solve the problem either.

Any theory? Suggestions? --64.236.170.228 (talk) 16:44, 29 November 2007 (UTC)

Sounds to me like your culprit might be Windows File Protection. Usually any files in the Windows directories 'automagically' changing/reverting/disappearing/etc on reboot are down to that. WFP has some very strange opinions of what constitute system critical files, and fonts are just the kind of thing it might mess with. WFP can be disabled, but in SP2 it's a non-trivial process involving both registry editing, and hexediting of system files - do not attempt unless you know what you're doing, but if you want to have a go there's a howto here. I'd make totally sure that WFP *is* actually the culprit before doing that though. Good luck! --Monorail Cat 21:12, 1 December 2007 (UTC)

[edit] Difference between VMWare Fusion and Parallels?

I'm really confused by the differences between these two products. Parallels seems to closely mimic the old VirtualPC, where Windows runs inside a master window. Fusion seems to integrate Windows... uh... "windows" with Mac OS X with PC icons in the dock and such. Seems more unified, but potentially more confusing. Is that the only real difference. --24.249.108.133 (talk) 17:23, 29 November 2007 (UTC)

Parallels can integrate it as well if you want (its "Coherence" mode), and it can run either in a window or fullscreen. VMWare Fusion seems to have similar options. Anyway, believe it or not, we have a whole article on the differences: Comparison of VMware Fusion and Parallels Desktop --24.147.86.187 (talk) 18:39, 29 November 2007 (UTC)