Wikipedia:Reference desk/Archives/Computing/2013 August 18

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August 18

p2p

anyone know why there's so many videos dubbed in non-English on peer-to-peer networks? and so many in non-stranded resolutions? thank you, 70.114.248.114 (talk) 03:35, 18 August 2013 (UTC)

A large amount of the world does not speak english, but does use computers. RudolfRed (talk) 07:32, 18 August 2013 (UTC)

LOL. Great non response. What a douchebag response.... wow. Shadowjams (talk) 16:28, 18 August 2013 (UTC)

Well, "non-stranded" is quite douchebaggy, too. At least for an apparent English speaker. - ¡Ouch! (^{hurt me} / _{more pain}) 06:30, 23 August 2013 (UTC)

Didn't mean for it to be a snarky reply. It just seems obvious. There's lots of people who don't speak english, so lots on content on the internet will be in non-english. RudolfRed (talk) 19:19, 18 August 2013 (UTC)

I don't know that any reference to this will exist, but it is possible that the existence of NetFlix and other legitimate ways to access copyrighted content online has decreased the need for English speakers to resort to piracy. These services may not be available in all countries, thus they may resort to piracy in the absence of a legal, practical method of access. Couple that with DMCA crackdowns on filesharers in the United States, and what you have is not an increase in the number of "foreign" file shares, but rather a decrease of English file shares, thus making the number of "foreign" file share look more numerous in proportion. Effovex (talk) 17:35, 18 August 2013 (UTC)

It's because people who watch videos in different languages also use p2p sites. Someone on the <insert language here> ref desk could be asking the opposite "Why are there so many videos not dubbed in <their language>?" As for the quality: there's no quality control for what people put up on such sites. You should always read the comments before downloading; because chances are, other people have found out if it's worthwhile or not... --.Yellow1996.^(ЬMИED¡) 17:35, 18 August 2013 (UTC)

why do speakers have different sensitivities to different frequencies?

70.114.248.114 (talk) 03:52, 18 August 2013 (UTC)

Are we talking about Loudspeakers? (eg, as opposed to orators). If so, Loudspeaker#Driver_design and Loudspeaker#Driver_types shed some light on the subject. Mitch Ames (talk) 07:04, 18 August 2013 (UTC)

recording a tv

when you record a crt-tv with a video camera, why do those dark and light bands appear? (i know it has to do with the asynchronous of the camera and tv, but i want more detail.) thanks, 70.114.248.114 (talk) 04:07, 18 August 2013 (UTC)

The electron guns at the back of the TV scan across the screen to draw the new image. They don't emit across the entire screen all at once. So this scanning is what you see when it's recorded with a video camera. You can't see it with your naked eye because it scans across too quickly. Have you read the cathode ray tube article? It might help your understanding of it. Dismas|^(talk) 04:44, 18 August 2013 (UTC)

And if you don't want those lines, or bad quality recording; check out capture card. There's other ways too. --.Yellow1996.^(ЬMИED¡) 17:36, 18 August 2013 (UTC)

More detail on the asynchronous aspect: see Wagon-wheel_effect for a similar phenomenon, where timing messes things up. Also, Moiré_pattern produces similar bands, but in space and not time. The way the bands emerge has to do with the modular arithmetic of the systems. For CRT/video camera, that's governed by the refresh rate on each end. SemanticMantis (talk) 02:50, 19 August 2013 (UTC)

And it gets even trickier when the video-camera is actively working to change its exposure to avoid flicker, which is now a standard feature on nearly all consumer cameras. Here's an IEEE paper from several years ago explaining how one such implementation works: An automatic flicker detection method for embedded camera systems (2006). The sensor may be designed to dynamically adjust its exposure to avoid room light flickering; and the television CRT screen may be confusing the flicker-correcting circuit. The long and short is, your aliasing artifact might be much more sinister than a simple composite of the camera frame-rate and the CRT frame-rate, because of all the additional time-varying factors in a modern camera. Nimur (talk) 01:32, 20 August 2013 (UTC)

And now add an electric fan

I have an electric fan on a dimmer switch, so I can adjust the speed precisely. When I place it in front of my CRT TV, I get the strobe light effect, and can adjust it to make the fan blades appear to stop, move slowly forward, or slowly backward. The "virtual fan blades" appear semi-transparent and there are only 3 fat blades, versus 5 actual thinner fan blades, so some strange resonance effect is going on there. I also notice that the leading edges of the virtual fan blades are bluish and the trailing edges are greenish. I take it that has to do with the different color scans happening at different times. If you have this setup, I suggest you try it (in a darkened room, except for the TV). It's quite interesting. StuRat (talk) 06:48, 20 August 2013 (UTC)

That's sounds quite cool. I tried it, but I couldn't reproduce that effect... maybe it's because all I had as far as display was the flashing green/purple death screen of my NES (the only thing hooked up to that old thing!! ;) Hopefully others get better results. --.Yellow1996.^(ЬMИED¡) 15:58, 20 August 2013 (UTC)

Google blocking thehackernews.com from Comcast customers?

If I type in http://thehackernews.com, the page won't load. Instead, I get the following message:

Our systems have detected unusual traffic from your computer network. Please try your request again later. Why did this happen?
IP address: 67.184.12.68
Time: 2013-08-18T14:49:55Z
URL: http://thehackernews.com/

67.184.12.68 resolves to Comcast Cable Communications, Inc, my ISP.

I first got this message after doing a Google search for "hacker news" so I assumed Google was blocking it the Google Search level. However, if I manually type "http://thehackernews.com" into my browser, Google is still blocking access. How in the world can Google possibly intercept this request when it shouldn't be going thru Google's network? A Quest For Knowledge (talk) 14:58, 18 August 2013 (UTC)

What leads you to believe it's Google specifically that's blocking you? -- Finlay McWalterჷTalk 15:41, 18 August 2013 (UTC)

@Finlay McWalter: Because the domain in the URL of the error message is google.com and the expanded text when you click on "Why did this happen?" says "This page appears when Google automatically detects requests coming from your computer network..." A Quest For Knowledge (talk) 16:04, 18 August 2013 (UTC)

Perhaps the message is generated by your ISP, and the IP address listed is actually the one assigned to your household's router or modem. It sounds like the "Why did this happen?" text likely links to more information. Try reading that and see what it says. --Bavi H (talk) 15:44, 18 August 2013 (UTC)

After searching online, the message may be generated by Google. See "Unusual traffic from your computer network" notification. How could Google generate this message when you enter an address manually?

• Check to make sure you are entering the address in your browser's actual address box and not into a search box or add-on toolbar.
• Software on your computer or network might be redirecting every address you enter through Google. Perhaps some kind of parental control or security software is trying to use Google to guage the saftey of every address you enter, but Google doesn't like this kind of automated usage of its servers. --Bavi H (talk) 16:07, 18 August 2013 (UTC)

@Bavi H: No, it's definitely the address bar. It's not any parental control or security software I'm using. I get the error on both an iPad and a Windows computer. I also tried VPN-ing to my computer at work and interestingly I got to the site on the first try and on the second, I got the same error message. My work computer is on a completely different ISP. A Quest For Knowledge (talk) 16:13, 18 August 2013 (UTC)

BTW, you can see the error message yourself by going directly to Google: http://www.google.com/sorry/?continue=http://thehackernews.com/. A Quest For Knowledge (talk) 16:15, 18 August 2013 (UTC)

Hm. I'm not familiar with the details of how a VPN works, but did you change the DNS server settings in your computer, iPad, or home router in order to get your VPN to work? If both your home network and work network are using the same DNS server, perhaps the DNS server might be redirecting the addresses you enter to Google in some way. --Bavi H (talk) 16:36, 18 August 2013 (UTC)

@Bavi H: I'm using Cisco VPN. Once established, I remote desktop to my computer at work and then made the request from my work computer. It should be no different than if I was physically at work and made the request.

Maybe this is some sort of service with Google provides to various ISPs? A Quest For Knowledge (talk) 16:42, 18 August 2013 (UTC)

Ok, I finally gave in and visited the site. When I clicked the back button in my browser, I saw several Facebook addresses in the history that looks like the site was sending automated Like requests. Perhaps something similar is happening to you, but the site is sending automated Google Plus +1 requests. Try viewing the site with JavaScript disabled. --Bavi H (talk) 17:00, 18 August 2013 (UTC)

The actual source code of that page is loaded with various references to Google. Since I'm not getting the error myself it's hard to guess where it is coming from, but I assume it's generated in the course of the normal page load, when one or more of those accesses causes an error?? Wnt (talk) 22:37, 20 August 2013 (UTC)

Actual URL of a PDF file

Hi! At http://www.gpiaa.gov.pt/?cr=9530 there is a link to a PDF file about "1977/DEZ/18 - Acidente com o Super Caravelle - HB-ICK - Proximidades do Aeroporto de Santa Catarina, Madeira (Relatório Final)" but the link is "javascript:linkFicheiro('9530',%20,%20false,%200);" and not an actual URL. How do I get the real URL of the file? I want to archive it on http://webcitation.org

Thanks, WhisperToMe (talk) 20:53, 18 August 2013 (UTC)

This is the direct link. Noom (t) 21:31, 18 August 2013 (UTC)

Thank you! WhisperToMe (talk) 22:51, 18 August 2013 (UTC)

How the hell I use unicode with python 2.5???

I tried to search using google but the places I found didnt explained very well. As some example, how the hell would I do this? object.tile_list[row][collumn] = '▓▓' — Preceding unsigned comment added by 201.78.177.180 (talk) 21:28, 18 August 2013 (UTC)

Assuming you do indeed want two copies of the character, you'd write

 object.tile_list[row][collumn] = u'\u2593\u2593'

at least in a recent python 2.x; I've no idea how good Unicode support was in a version as ancient as 2.5. -- Finlay McWalterჷTalk 22:21, 18 August 2013 (UTC)

Confirmed that

 print(u'\u2593\u2593') 

produced the expected output in Python 2.5.2, so I'd imagine that you'd be looking for :exactly what Mr. McWalter posted Jdphenix (talk) 03:16, 19 August 2013 (UTC)

Its not working, its giving me charmap codecs cant encode..... — Preceding unsigned comment added by 201.78.177.180 (talk) 23:46, 19 August 2013 (UTC)