Wikipedia:Reference desk/Archives/Computing/2007 April 23

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April 23

Google blurbs

Anyone know where Google get their page descriptions from? Have a look at this discussion and then let us know there how to get the Google display for this search to change from "over two million" to the right figure. Thanks. Carcharoth 00:15, 23 April 2007 (UTC)

It's from Google Directory --h2g2bob 02:32, 23 April 2007 (UTC)

Mp3 files that display very long running times

Hello, I'm sure many of you have seen mp3 files for songs that should be normal length but for some reason have very long running times, possibly due to somebody tampering with the files or something like that. Today I opened up an album (Black Mountain's self titled) in iTunes and the track lengths ranged from 20 minutes to almost an hour - in a playlist the running time for the 8 songs total was almost 5 hours. I assume that in most files with incorrect running times, the file plays and then there is silence for the duration of the song or something like that. However, with these files, they actually played for the entire running time. There was no silence - there actually was 5 hours worth of music. I then opened the files with Windows Media Player. The files were a few minutes longer than usual and still displayed the incorrect times, just not as excessively long as when opened with iTunes. Now upset, I opened the files with a sound editing program called Audacity, and it displayed the songs at their correct running time.

My question is - how is it possible that when I open the songs in iTunes, they magically play for 40 minutes? The beginning and ending of the song is the same no matter what program I play it with, and as I scan through the song with iTunes I can hear the same melody throughout the song. I'm extremely confused because it seems like when I play the file with iTunes, I somehow unlock an extremely lengthy, jammed out version of the song. However, when I open the file with Audacity, it shows the sound wave file at the length that it's supposed to be. Also, with iTunes, it says the bitrate of the song is 32 kb/s. With Windows Media Player, it says it is a 350 kb/s+ VBR file. What is going on!!?!? NIRVANA2764 00:17, 23 April 2007 (UTC)

This only happens with variable bit rate files. The reason is because in a constant bit rate file, it takes the first bitrate it is encoded at and using the file size, it can figure out how long the song is with simple division. However, with variable bitrate, the first chunk might be encoded with a really small bitrate, such as 32kb/s, because it is mostly silence. Programs such as iTunes would see that 32kb/s, and the file size, and figure out the incorrect song length. However, programs which analyze the entire file will have the correct size. --Wirbelwindヴィルヴェルヴィント (talk) 04:02, 23 April 2007 (UTC)

Laptop Screen and Magnet

I have a Dell Inspiron, and I was playing around with a strong magnet near the screen, trying to see if it would distort it as it does CRT monitors. This didn't work, so I ran the magnet along the top edge of the keyboard, where it meets the plane of the screen. As I moved the magnet back and forth along this line, the screen dimmed as I passed over the middle. Finally, as the magnet passed over the middle again, the screen blacked out (though I could barely see it in a very dim form). I hibernated the computer and turned it back on, after which point the screen was completely restored. Does anybody know the mechanism for this effect? --Gujarat10 03:27, 23 April 2007 (UTC)

Speculation here, but the ELP backlight used on many laptop screens involves an itsy bitsy high-frequency high-voltage power supply, which is often located about where you describe. It wouldn't surprise me too much if a strong external magnetic field could somehow collapse the magnetic field inside the HF HV PS's itsy bitsy exotic transformer. —Steve Summit (talk) 03:38, 23 April 2007 (UTC)

Some laptops use magnets in order to determine when the screen is closed (as opposed to using a mechanical switch). If your laptop is set to only turn off the backlight when the screen is closed, rather than turning off the display as well, that could be it. Or not. -- Consumed Crustacean (talk) 05:34, 23 April 2007 (UTC)

Nope - I have it set to activate standby when closed, which did not happen. --Gujarat10 06:54, 24 April 2007 (UTC)

Just a word of advice (forgive me if you already know this). Waving a strong magnet over your laptop may not be the best idea, especially if it ends up near your hard drive. -- mattb 14:22, 23 April 2007 (UTC)

And that's why you never bring your computer through the airport metal detector :) The TSA tell you to put it in a bin anyway though. --TeckWiz is now R ^ParlateContribs_@(Let's go Yankees!) 01:44, 24 April 2007 (UTC)

Your desktop uses an old little technology called LCD. You could have waved it over a cheap calculator and verified the same fact. Root⁴(one) 01:26, 24 April 2007 (UTC)

Huh? LCDs usually don't contain materials that exhibit strong magnetic properties. You can wave a stack of strong rare earth magnets over any TFT LCD you like and you're unlikely to observe any visual response. What's more, the OP described an effect that obviously affected the backlight (which most calculators do not have), not the LCD itself. -- mattb 01:38, 24 April 2007 (UTC)

Right, the original experiment was an experiment with the LCD display itself, which I was commenting on (sorry for being vague). THEN continuing his experiment he found something which brought about the unexpected results, although rather interesting, the knowledge could have come at a hefty price. I was just trying to say, if one feels like monkeying around with some item, he or she should make sure that the item can handle the abuse or that the item is easily replaceable. There's nothing wrong with experimenting in itself, but it must be reasonable. Experimenting with magnets on a relatively new laptop, well, you draw the conclusions. Root⁴(one) 14:13, 24 April 2007 (UTC)

What's wrong with putting a magnet on a laptop or, for that matter through the airport detectors? There are neodymium or samarium rare earth magnets in every hard drive. [Mαc Δαvιs] ❖ 02:00, 24 April 2007 (UTC)

Conveniently oriented sufficiently away from the platters so as to avoid problem. Try taking that same neodymium actuating magnet and place it on top of the disk, right over the platters. :) -- mattb 02:13, 24 April 2007 (UTC)

Video Problem

I downloaded some videos that are apparently in .avi format. I've tried playing them on what I feel to be everything -- Realplayer, Quicktime, DivX, WMP, VLC, InfraView, -- and they just wont play. They are certainly video files. They are about 350 mb each, and I have read online reports from others that they're viewing the videos just fine. What could be going wrong? What should I do? To give you better details, most media players say something to the effect of "Error: ____ media player cannot read this file. Make sure it is a valid media file type." VLC, on the other hand, opens it, but rather than playing the movie, for about five seconds the progression bar (the thing that moves slowly when listening to a song or watching a movie) moves as if something is being played, but nothing can be seen or heard and the clock of the VLC player shows no length to the file being played. Bizarre. Help? 70.108.191.59 04:21, 23 April 2007 (UTC)

If even VLC doesn't want to play it, the file is probably corrupt, or it's some weird format that is very rare. Try checking the CRC? --Wirbelwindヴィルヴェルヴィント (talk) 05:11, 23 April 2007 (UTC)

Thanks, but what do you mean by "try checking the CRC"?

Assuming you downloaded the file, thus the other people can play it, then you can get a program to check its crc (such as quicksfv, see sfv), and see if it matches everyone else's copy. Or if you got it through a torrent, check with the torrent file. --Wirbelwindヴィルヴェルヴィント (talk) 05:40, 23 April 2007 (UTC)

Check what video codec the file uses and whether you have the codec. I use AVIcodec for that check. Then google to see if there is a newer version of the codec. Weregerbil 08:08, 23 April 2007 (UTC)

Or open the video up in VLC and go to View > Messages - usually if you Google the error messages you will be able to deduce the problem. x42bn6 Talk 14:31, 23 April 2007 (UTC)

Try Media Player Classic and all the assosiated codecs which come with it. That plays *everything* for me :) JoshHolloway 18:08, 23 April 2007 (UTC)

Ugh. I downloaded a codec pack with Media Player Classic, and MPC says it can't "render" the file. What does that mean? Any ideas or should I just give up. I did download it by torrent, and saw no complaints on the torrent comment page. 70.108.191.59 19:30, 23 April 2007 (UTC)

Get Gspot to identify the codec it needs...i use that and it gives me info...it did for the Matroska pack... Ag for MemTech —The preceding unsigned comment was added by 200.12.231.42 (talk) 21:24, 23 April 2007 (UTC).

Jesus. This is the file from hell. I used the G-spot thing and it said that it knew neither the file nor the MIME type. 70.108.191.59 21:54, 23 April 2007 (UTC)

It's possible that the file is actually corrupt. This has happened to me in the past! Try downloading another copy of the file, or from another torrent tracker. JoshHolloway 22:31, 23 April 2007 (UTC)

You could try removing the file extension and then using VLC or MPC if that does not work try using one of those mass video file converters...Look on this website http://www.erightsoft.com/SUPER.html this has a converter for almost anything i've ever tried to use and it's free so just look into it.Have you tried opening it in Video Editing programs? Adobe Premiere, Sony Vegas, Windows Movie Maker? What about the option to look for the proper codec with the new Windows Media Player? 200.12.231.42 23:48, 23 April 2007 (UTC) Ag for MemTech

It's also possible the file is a fake. Are you sure people are talking about the file you have not some other file with the same name? Nil Einne 00:38, 24 April 2007 (UTC)

I think thats most likely. If GSpot cant divine its nature, its a fake. Shinhan 13:02, 25 April 2007 (UTC)

As crazy as this sounds, could it be compressed? I've downloaded files before only to learn that they were gzipped or zipped up but the original file extension remained. It was very weird, maybe a Firefox bug or but in the web application I downloaded it from. Root⁴(one)

Sync Byte

Why Sync Byte always posses 0x47 value? Why Sync Byte are inverted for every 8 packets?Barani pdy 18:27, 23 April 2007 (UTC)

I am assuming you are asking about digital television standards. The information in this document might be helpful, although it's a little outside my sphere of knowledge. --LarryMac 18:37, 23 April 2007 (UTC)

computer ideas

Hi, I'm about to build a computer.

Does anyone know of any lists of parts with the best bang for the buck? My limit is about 1200 dollars. —The preceding unsigned comment was added by 128.61.127.37 (talk) 20:00, 23 April 2007 (UTC).

I don't know about the US, but in the UK Scan is good. It may also give you ideas if not pricing. JoshHolloway 22:27, 23 April 2007 (UTC)

It really depends on what you are doing with it, if you want to game then I just built a computer for about that much, but that's excluding a monitor and peripherals. If you build a system based on the intel CD2 e6600 processor, a gigabyte ds3p motherboard and a 8800GTS you'll have a great system and it should come in your budget. All you need extra is some ram, a hard disk, a power supply (550W will be good for that)and a case, doesn't matter what you get but I would recommend not to get the very cheapest, get the "next to the cheapest" and you'll be fine. Vespine 01:48, 24 April 2007 (UTC)

I'm building a PC a little over that budget (at 1600$), 8800GTS and such. Could easily cut it down a few hundred dollars by skimping on case, CPU, and RAM. Try newegg.com- best site i've seen -- Phoeba Wright^OBJECTION! 06:44, 25 April 2007 (UTC)

For good prices try pricewatch and take a look out for an AMD CPU they are the best when it comes to bang for buck. --Lwarf 10:04, 26 April 2007 (UTC)

who made the first computer game

Who made the first computer game? —The preceding unsigned comment was added by Mhalldorsson (talk • contribs) 20:44, 23 April 2007 (UTC).

What do you consider a computer game? -- mattb 20:54, 23 April 2007 (UTC)

Many very early computers were programmed to play games such as Nim and Tic-tac-toe. One of the very first video games on a computer was Spacewar. There is some background for all this, including some names, in our article History of computer and video games. --LarryMac 20:56, 23 April 2007 (UTC)

See also our article on the first video game. --h2g2bob 03:20, 24 April 2007 (UTC)