Wikipedia:Reference desk/Archives/Computing/2008 January 19

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January 19

Compressing a video file

Dear All,

Hi.

I need help compressing a file... its a movie AVI file... how do i do that? i tried to send the file via email.. for some reason its not working.. the file size is not even big... its almost 3 minutes long...2.0 megapixels ... sorry i really need help its for a school project... I'm not really a what you call a techie...

--202.175.29.2 (talk) 03:15, 19 January 2008 (UTC) xsy

If you are on a Mac, you can use iMovieHD. If you are using Windows, you can use Windows Movie Maker. If you only want to compress the video just import it to the application and export it in the desired settings without any editing.

Hope that helps,

Kushal^t 13:04, 19 January 2008 (UTC)

Many (most?) video files already are compressed and can't be compressed any further. See data compression and video compression.

Atlant (talk) 15:01, 19 January 2008 (UTC)

What type of codec is used for the file anyway ? If it's a file you downloaded through the net, odds are that it's already compressed in mpeg4 or a variant of it, and it would be pointless to compress it any further. Try to play it and see the property of the file in windows media player (there is a video codec and an audio codec). —Preceding unsigned comment added by Esurnir (talk • contribs) 20:15, 19 January 2008 (UTC)

Could you upload it to a website and then email the recipient just the link? E-mail providers have certain limits on attachment size. Gmail has 20 MB, Yahoo! Mail has 10 MB but some providers are really stingy. Kushal^t 01:56, 20 January 2008 (UTC)

"Live" screensaver?

What would you call a screensaver that prevents burn-in whilst still leaving the screen contents legible for most, if not all, of the time? Rawling4851 13:01, 19 January 2008 (UTC)

It might interest you to know that burn-in is a thing of the past. Online your monitor is a plasma TV, you should be able to keep the same image on for months if not years without fear of burn-in. —Preceding unsigned comment added by 212.51.122.18 (talk) 13:28, 19 January 2008 (UTC)

Presumably, in the above answer, the word "online" was meant to be "unless". But even LCDs suffer some temporary ghosting if a static image is left on them for hours on end. Plus screen-savers can still be fun.

Atlant (talk) 15:03, 19 January 2008 (UTC)

At work, several of our LCD monitors have a permant burned image of the system login screen. It seems to be related to the brand of monitor; the GNRs have it and the Neovos don't. All about 3 years old. --80.176.225.249 (talk) 20:18, 19 January 2008 (UTC)

What makes you so sure that Rawling uses an LCD? I know I occasionally use my 10-years old CRTs, and since they have several advantages, I am considering buying a new one. -- Meni Rosenfeld (talk) 20:24, 19 January 2008 (UTC)

Heh; yes, I am using an LCD, but given that they, plus other modern displays such as plamas and (am I right) DLPs can suffer some kind of burn-in, this isn't wholly irrelevant. I was just curious if anyone had made screen-savers that specifically didn't make the sceen content illegible... Rawling4851 20:46, 19 January 2008 (UTC)

DLPs are absolutely immune to burn-in. They may be the one kind of display that I can think of that is, although LCDs are immune to permanent burn-in damage.

Atlant (talk) 21:22, 19 January 2008 (UTC)

sandisk sansa c250

This is a 2 GB flash memory mp3 player. If I deleted every file and folder on it, have I bricked it? When I turn it on, only the navigation key backlights turn on. I tried both the recovery mode and diag mode as in RockBox but to no avail. The device does not even show up in my macbook now. Is there anyway I can make it reusable again? Please help. Kushal^t 15:19, 19 January 2008 (UTC)

Hmm. I guess if it were mine, and if I were feeling it was likely in trouble, I'd 1. reformat it, 2. try and reinstall whatever software the company had available for it on their website. --24.147.69.31 (talk) —Preceding comment was added at 20:15, 19 January 2008 (UTC)

The main problems are that the display is not showing anything and that the computer does not show anything when I connect it to the computer. Kushal^t 22:19, 19 January 2008 (UTC)

Right. So again, I'd reformat it, and then probably install any drivers/firmware updates available from their website. It sounds to me like you've either got some sort of hard disk problem (which formatting/error checking might help) and/or you've deleted whatever firmware bits that it had to interface with the computer. --24.147.69.31 (talk) 17:13, 20 January 2008 (UTC)

Mac OS X does not even "see" the device when connected. Maybe I can ask someone on Windows XP or Windows Vista to lend me his or her computer. I will update you on any thing that I get. Thanks a lot. Kushal^t 00:54, 21 January 2008 (UTC)

File transfer on Lan

I got multiple computer on my soho local network, connected through a 802.11g wifi. I would like to transfer file between multiple computer, both using Windows XP.

What is the fastest way to do that (in terms of file transfer speed I mean). Right now I tried the "normal" copy and paste (i think it use the SMB protocol or something like that) and utorrent (was quite surprised to see that bittorent was slower in my case but anyway). Is there any other type of file transfer protocol that would be faster to transfer "big bulky files" ? And for a collection of small files ? Esurnir (talk) 20:12, 19 January 2008 (UTC)

Well, torrents aren't optimized for speed, they're optimized for bandwidth, so that isn't necessarily the best way. If bandwidth isn't an issue, FTP is probably as fast as anything else, and reliable. --24.147.69.31 (talk) 20:16, 19 January 2008 (UTC)

I fail to comprehend the distinction between bandwidth and speed. Perhaps bittorent slower because of his non-sequential nature (which would stress the hard drive with too much random i/o ?) In good condition, what can I expect from a 802.11g connection in terms of "usable" bandwith.

Oh and right now I get 1mb/s with standard transfer and 700kb/s with bittorent.- Esurnir (talk) 20:22, 19 January 2008 (UTC)

The absolute maximum is 54 MBit per second according to 802.11g. That means you can get a maximum of about 7 MBps? As a layman, I would say I would be satisfied with 3.5 MBPS. Kushal^t 01:50, 20 January 2008 (UTC)

rsync if your files don't change much? Or get 20 times the speed with wired gigabit ethernet. --antilived^{T | C | G} 23:59, 20 January 2008 (UTC)

Programming manual of style

Did someone or some organisation published instructions for achieving a good programming style? I mean for example how variables, functions are named and case used, how brackets are used... Thank you. CG (talk) 20:54, 19 January 2008 (UTC)

One of the oldest (but good) books was titled The Elements of Progamming Style. There was also a specific Fortran version. More recently, Brian Kernighan has certainly written a good book about programming in the C language including style advice; see his The Practice of Programming.

Atlant (talk) 21:30, 19 January 2008 (UTC)

Thank you, but I think that the article Programming style answers well my question. CG (talk) 08:42, 20 January 2008 (UTC)

Computer hardware for dummies

Hi. Does anyone know of a good source of information about computer hardware - of the kind that a technically oriented layman could use to make better decisions about which to buy? (Yes, I am looking at one, but I was thinking about something more oriented towards the stated goal). Thanks. -- Meni Rosenfeld (talk) 21:24, 19 January 2008 (UTC)

Newegg seems to be pretty good. You can also look at reviews in Amazon.com. Amazon has a wealth of reviews. Kushal^t 01:45, 20 January 2008 (UTC)

Tom's Hardware Guide? --Ouro (blah blah) 07:33, 20 January 2008 (UTC)

Thanks. Tom's seems to be more oriented towards people who are already "hardware experts" and want to learn all the specific details about new innovations (I'm looking for something that starts with the basics and moves on from there). Also, it seems to be structured as a bunch of unrelated articles, when I would like something a bit more coherent. Newegg's knowledge center seems to be just a collection of links to other sites. Reviews can be helpful but still not what I am currently looking for. I'll be glad to hear any other suggestions. -- Meni Rosenfeld (talk) 09:55, 20 January 2008 (UTC)

How about Anandtech for reviews? You can often find good reviews on websites of PC magazines, like PC Pro, PC Format and others. Finally there are sites dedicated only to one category of hardware - like DPreview, which is dedicated to digital photography. --Ouro (blah blah) 10:54, 20 January 2008 (UTC)

Again, I'm not looking for collections of articles. I am looking for a coherently structured guide. Let's take RAM for example - it should have a page which describes what RAM is, what types of RAM exist, what are the advantages of having greater sizes and FSB speeds of RAM, what are the possible compatibility issues, a few words about which are the respected brands, and so on. Then it might have links to pages with more in-depth information about specific RAM-related topics, but again, something which is a compilation of knowledge, not just some article that one guy wrote once about his impression from some new device. Of course, it should have this for any type of hardware. -- Meni Rosenfeld (talk) 14:35, 20 January 2008 (UTC)

Well, there's always this Wikipedia thing... they got lots of articles on RAM and stuff. --Ouro (blah blah) 15:09, 20 January 2008 (UTC)

Yes, as I have subtly mentioned, I am well aware of Wikipedia, but it is not a guide, thus its value for the stated purpose is diminished. A google search has produced this, which is more in the spirit of what I'm after, but I'm not sure it satisfies the "good" criterion, and it appears to be seriously outdated. -- Meni Rosenfeld (talk) 15:20, 20 January 2008 (UTC)

I don't know if it's at the level you're looking for, but the information on this page and its subpages is current and (in my estimation) quite accurate. -- BenRG (talk) 19:22, 20 January 2008 (UTC)

This will be useful, thanks! -- Meni Rosenfeld (talk) 19:42, 20 January 2008 (UTC)

You might want to look at A+ Certification guides. Gavint0 (talk) 13:00, 24 January 2008 (UTC)

virtualPC, qemu, etc I can run *UNDER* windows 3.1

Is there any vm software I can run UNDER windows 3.1? Thank you. —Preceding unsigned comment added by 212.51.122.4 (talk) 22:45, 19 January 2008 (UTC)

You'd probably be better off scrapping Windows and putting on some Linux variant and run a virtualizer under that (maybe one that was running 3.1, if you need 3.1). It's pretty unlikely that there's much of anything these days that could run under 3.1, much less an OS virtualizer. --24.147.69.31 (talk) 03:45, 20 January 2008 (UTC)

Why would you even need a virtual machine for Windows 3.1? It runs in real mode anyway. --wj32 ^t/c 05:20, 20 January 2008 (UTC)

Actually Windows 3.1 only ran in standard (286 protected) and 386-enhanced mode. Windows 3.0 was the last version to support real mode. -- BenRG (talk) 12:26, 21 January 2008 (UTC)