Wikipedia:Reference desk/Archives/Computing/2013 January 30

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January 30

.MOV or .MP4 to .OGV file conversion

The free Miro Video Converter software that I am using does not do so well with creating .ogv files from 640x480 .mov video files (or .mp4 crops of those files). See File:20130126 Simeon-Whitney Young pregame shootaround layup lines.ogv. Although my original is not so great, I was hoping not to lose so much quality in the conversion. Also, is there a way to remove the sound of the people sitting nearby. Here is an example of the original quality: File:20130126 Simeon-Whitney Young game at start of 4th quarter at Emil and Patricia Jones Convocation Center.jpg.--TonyTheTiger (T/C/BIO/WP:CHICAGO/WP:FOUR) 00:31, 30 January 2013 (UTC)

On Windows, you might try WinFF or HandBrake. Personally I’d use FFmpeg (used as a backend by both of the aforementioned apps), but it can be kind of a pain to get working on its own on Windows (http://sourceware.org/cygwinports/ is probably the “simplest” way). Complex random sounds can be hard to remove; if they have some regularity to them, you could try Audacity’s noise removal. ¦ Reisio (talk) 18:32, 30 January 2013 (UTC)

What do you mean by the term backend? Also, I am not talking about removing the guys next to me but keeping the PA announcer. How do I remove all sound?--TonyTheTiger (T/C/BIO/WP:CHICAGO/WP:FOUR) 19:13, 30 January 2013 (UTC)

By backend he means a command line tool. Some of the GUI based software will be using FFmpeg behind the scenes to do the job. Graeme Bartlett (talk) 21:11, 30 January 2013 (UTC)

Remove all sound with FFmpeg: ffmpeg -i input.mov -an -vcodec copy output.mov ¦ Reisio (talk) 00:05, 31 January 2013 (UTC)

Unless I am missing something, I do not see a way to produce .ogv files in WinFF.--TonyTheTiger (T/C/BIO/WP:CHICAGO/WP:FOUR) 05:27, 3 February 2013 (UTC)

Same with handbrake.--TonyTheTiger (T/C/BIO/WP:CHICAGO/WP:FOUR) 05:31, 3 February 2013 (UTC)

Try following http://sourceware.org/cygwinports/ to get ffmpeg and ffmpeg2theora, it’s pretty simple; or if you have access to a real Unix install, it’s even simpler. ¦ Reisio (talk) 23:39, 3 February 2013 (UTC)

• I think handbrake may not work with uploads to commons. I tried and it kept puking on upload. I think it is because commons doesn't allow its sound formats because they aren't free. Without sound it may not be an issue.--Canoe1967 (talk) 00:28, 5 February 2013 (UTC)

What is spooled to the printer driver?

Say you have two word processing programs, like Microsoft Word and Apache OpenOffice Writer, and you have two printers with their own specific drivers, like an HP printer and an Epson printer. Say I put "Heading" in h1 heading at the top with 1" top margins and 1.5" left and right margins and "Hello world" spaced 1.5 line spaces down in Times New Roman, and save as .doc and .odf files. There are four different printing possibilities. Do the word processing programs output some standard page description language? I hardly suspect word processing applications could be expected to know the specific page description languages different printer drivers require, and I could hardly expect printer drivers to know every word processor application's output to printers (I suspect that to-printer format has nothing to do with saved document format) if they were different. So is the interface point a common page description language applications promise output to conform to and printer drivers to read? I'm mainly wondering about non PostScript printer systems. 67.163.109.173 (talk) 01:04, 30 January 2013 (UTC)

OK, I found Printer Command Lanugage which says it's a de facto industry standard. But in that article it says "At a consumer level, PCL data streams are generated by a print driver. PCL output can also be easily generated by custom applications." Which makes the PCL in standard printing from a word processor? The application or the driver? I want to better understand what comes out of the word processing applications of the world and goes into the print drivers of the world. 67.163.109.173 (talk) 01:23, 30 January 2013 (UTC)

At the word-processor level (or any application level), print commands are generic "draw this here"-type commands that are made via the operating system. The printer driver then turns these into something that the printer understands. The interface to the driver is specific to a particular OS, but within that OS all applications that want to print use the same set of "draw this here" commands. 81.159.111.140 (talk) 02:55, 30 January 2013 (UTC)

Under Windows and MacOS X, printing works more or less like this:

• The application asks the OS for a drawing surface suitable for printing.
• The application draws to that surface as if it were drawing to the screen (telling the OS things like "put text here using this font, style, and color", "draw a line from point a to point b using this pen style", "render this bitmap at this location using these scaling parameters", and so on).
• The print driver takes these drawing commands and turns them into instructions to the printer (the details vary from printer to printer).

I'm not sure how Linux or other Unix-like operating systems handle printing. --Carnildo (talk) 03:36, 30 January 2013 (UTC)

Typically, Linux and Unix systems use CUPS. As described above, a high-level drawing API is exposed to the system, abstracting details about the type of printer or its actual mechanical control. The word processor or other user software generates an input, and CUPS schedules the job, converts to a lower-level back-end printer representation, and sends the commands to a printer. Nimur (talk) 16:51, 30 January 2013 (UTC)

Link to the Windows drawing commands that word processing applications translate documents to when the print button is pressed on a document, please. 67.163.109.173 (talk) 03:24, 31 January 2013 (UTC)

Documents and Printing (Windows). You'll find that it's not at all like a post-script or printer-control-language. Part of the Windows printing API is the XPS document representation, which is possibly closer to what you're expecting. Nimur (talk) 03:42, 31 January 2013 (UTC)

ISBN "splitting"

Hello,

I am searching for a software that "splits" ISBNs into a well-formatted system with hyphens. It is sometimes difficult to do it by myself, especially checking publisher code and item number is sometimes time-wasting. Regards.--Tomcat (7) 12:18, 30 January 2013 (UTC)

I doubt this is possible, as the block lengths are unpredictably variable. See ISBN#Publisher code. The hyphens are not really necessary and do not strictly-speaking form part of the ISBN, which is just a number.--Shantavira|^{feed me} 17:16, 30 January 2013 (UTC)

Actually, there's some Linux software that appears to do just that called Tellico. I've never used it, but it is one of the features. Since it's presumably Open Source, I dare say that if you're technically minded enough you could find out how it does it. - Cucumber Mike (talk) 17:24, 30 January 2013 (UTC)

User:Helpful Pixie Bot did just that recently in an article on my watchlist. Even if you don't need it for wikipedia work, perhaps there is some useful information if you dig in that direction. bamse (talk) 19:51, 30 January 2013 (UTC)

The algorithm for it is fairly straightforward,[1] just tedious to do by humans. Looking up a few of the digits in a couple of tables tells you the hyphenation pattern. I don't know of code kicking around for it but it should be easy to implement. However, it doesn't seem to be done on any websites other than Wikipedia for bibliographic data (library sites, Amazon, Goodreads, etc. all use unhyphenated ISBN's, and Wikipedia's Special:BookSources page removes the hyphens from hyphenated ones). Unless you've got a good reason for wanting the hyphenation I think it's best to stick with the unhyphenated versions. I think it was a mistake for Helpful Pixie Bot to have gone and hyphenated all the ISBN's in Wikipedia. Among other things, the bot made it impossible to find ISBN mentions with the Wikipedia search function unless you know the number is hyphenated, which means having to run that algorithm or find the hyphenated version some other way (not always easy). 67.117.146.66 (talk) 08:50, 31 January 2013 (UTC)

No, hyphens are required. Some sites are just lazy to add them. --Tomcat (7) 14:16, 31 January 2013 (UTC)

Required by who? And do you know of any site other than Wikipedia that uses them? They just get in the way of human editing. 67.117.146.66 (talk) 17:53, 31 January 2013 (UTC)

you've got me wondering now - it would maybe be better if isbn's were stored on wikipedia in both the hyphenated and unhyphenated form in the markup - presumably this would be sufficient for the purpose of everyone searching? maybe the search function already handles it. well, there's only one way to find out...... — Preceding unsigned comment added by Nonsenseferret (talk • contribs) 00:31, 1 February 2013 (UTC)

I'm pursuing the discussion further here: Wikipedia_talk:ISBN#ISBN_Searching ---- _nonsense ferret 01:51, 1 February 2013 (UTC)

Playing DVDs

I downloaded and installed WinAmp, assuming I could use it instead of Windows Media Center to watch DVD's from my laptop's internal DVD drive. However, I can't see any controls that would allow me to do so. Is that possible? If so, how do I do it? If not, what other free software is available? (Windows7) Thanks, Rojomoke (talk) 13:18, 30 January 2013 (UTC)

Best free video/dvd playing software I've used is VLC ---- _nonsense ferret 14:47, 30 January 2013 (UTC)

Yes, for Windows, definitely VLC. ¦ Reisio (talk) 18:28, 30 January 2013 (UTC)

• I third that VLC media player is a very good one. Don't you have Windows Media Player installed? That should be able to play DVDs too! I watch regularly (though my default media player is VLC)! --Tito Dutta (talk) 01:24, 31 January 2013 (UTC)

I use VLC to watch dvd's but my Winamp is capable of it. it just didn't give me full pausing/frame by frame/speed controls. and it doesn't work well with subtitles. I'm not sure if the free version supports it however.--96.29.242.188 (talk) 15:40, 3 February 2013 (UTC)

Why can't I use Shadowman with a Blaze Xplorer FX Cheat Cartridge ?

I've bought a Blaze Xplorer Cheat Cartridge for the Playstation but when I try to play Shadow Man (UK/ PAL) version) with it all I get is a black screen & the intro music starts going funny (as in not playing properly). And when I try it with the cartridge just turned on without any codes activated the same thing happens.
I can get past all the 'Loading' screens but when I get to the 'Press Start' screen I get that black screen with the intro music that doesn’t play right. Any help ? 80.254.146.140 (talk) 14:19, 30 January 2013 (UTC)

That question is better suited to a Google search or forum about the topic than an encyclopedia. Try Googling keywords from your problem, or search for Playstation forums or Blaze Xplorer forums. --Kierkkadon ^{talk/contribs} 17:28, 30 January 2013 (UTC)

Maybe he tried that already, it's an old game (1999), an old console and an old cartridge. With a search for the exact terms you get a few eBay pages, long lists of games and some hungarian websites. I didn't see anything helpful. Ssscienccce (talk) 20:00, 30 January 2013 (UTC)

Begone SATA! Get ye behind me.

Can I now, or will I soon be able to buy a PC that casts out SATA in favor of memory addressable Flash chips? It's not like I'll be able to fill up a 64 bit address space anytime soon, so I might as well setup filesystems (flash aware ones) in flash based memory. Hcobb (talk) 15:21, 30 January 2013 (UTC)

All-flash storage is a major advantage of the MacBook Air and MacBook Pro. Here's a promotional video outlining the performance benefits. Nimur (talk) 16:54, 30 January 2013 (UTC)

That's Flash with SATA. When are we going to cut that cord and just plug into the memory bus? Hcobb (talk) 17:27, 30 January 2013 (UTC)

Also a major disadvantage. ¦ Reisio (talk) 18:27, 30 January 2013 (UTC)

Flash memory is about an order of magnitude slower than DRAM, so it'd be daft to put it on the RAM bus off the northbridge. What's sensible is to put it on a PCI-X card off the southbridge, and map the flash pages into the host CPU's address space using PCI page mapping. Workstation vendors have sold these for a few years (often on their own bus standards); they're now available as generic add-in PCI-X cards (here's a Sandisk one). 176.250.31.78 (talk) 17:41, 30 January 2013 (UTC)

hi, do 3d camera rigs ever use convergence info for depth?

pretty simple question, it seems our eyes actually converge toward near objects, extent of convergence helps with 3d reconstruction. do two camera systems have cameras that converge the same way (I mean with servos, moving angle moment by moment)? why/why not? is it theor. possible? interested int he near field... --91.120.48.242 (talk) 16:45, 30 January 2013 (UTC)

I'm writing this short note because the logs don't indicate that you are an experienced Wikipedia editor. The reason that your question has not been answered yet is that, although is is a "pretty simple question", as you phrased it, none of the regular contributors yet have been able to give a sourced reply. --NorwegianBlue ^talk 23:09, 2 February 2013 (UTC)

Kinect and similar systems use it, I think. I have seen 3D cameras as a pair of lenses spaced and also two cameras rigged on support bars.--Canoe1967 (talk) 00:16, 5 February 2013 (UTC)

Rechargeable power sources for electronic devices

I hear lots of 'wisdom' get tossed around about how you should charge your devices (like a mobile phone). Never leave it plugged into the charger past full charge, try to make sure it charges slowly, only charge when it's almost empty, and so on. The reason given is that charging it 'wrong' will decrease the effectiveness of the battery.

Is there a source in Wikipedia that might prove/refute this, or explain the science behind it? --Kierkkadon ^{talk/contribs} 17:36, 30 January 2013 (UTC)

I've checked Rechargeable battery, and it gives a mention to quick charging damaging the battery, but has no source for this information (the article as a whole could use a lot more sources, or at least more in-line citations). I've taken the liberty of adding {{refimprove}} to the article. --Kierkkadon ^{talk/contribs} 17:36, 30 January 2013 (UTC)

I've actually read a lot of our Wiki articles on this subject, and they're moderate in quality I'd say. There's a lot of FUD surrounding rechargeable batteries. In almost all cases with a phone we're going to be talking about lithium ion batteries. The question about memory is dealt with in our various articles, including lithium battery, lithium polymer battery, lithium ion battery, thin film rechargeable lithium battery, and rechargeable battery. The general overview I've gained reading those is that 1) rechargeable lithium batteries need sophisticated circuitry to keep them from overcharging (and lighting on fire), and to maintain their useful term (undercharging), and that circuitry does a lot of the hard work, 2) all rechargeables have a lifespan and the more you use it the quicker that goes, 3) there is some debate on the internet (not sure what someone who worked on these as a job would say) about how much if any memory effect there is in lithium rechargeable batteries. The corollary question is, is it a bad idea to recharge my phone when it's at say 75%, or to let it get down to 10%? I don't know the answer to that definitively. Shadowjams (talk) 17:58, 30 January 2013 (UTC)

Hurm. Alright, thanks. --Kierkkadon ^{talk/contribs} 18:50, 30 January 2013 (UTC)

Let me be a bit more specific to your particular question. The "never leave it plugged in" is probably irrelevant on the vast majority of modern lithium ion devices. That's because they'll shut off the charging when they get full. If they didn't, they'd risk overheating. The exception to that is old devices, and counterfeit chargers (which can be a real problem). Older battery types might actually have this issue. I know I have some batteries that say not to charge over 24 hours. So read the labels on those. It's probably not irrelevant advice on a lot of other-rechargeables. Like NiCad.

I don't know how you'd make sure it charged slowly. That seems beyond regular control. The only charge when it's almost empty advice is an attempt to either eliminate memory effects (see the articles above for details on that), or to maximize battery life by not recharging it too many times. As I said above, a question I'd really like answered, is the answer to your third question. That is to say, say you have 200 "duty cycles" in a battery, does that mean that going from 80 to 100 is = 1, and going to 10 to 100 is = 1? or is 80 to 100 = 0.2 and 10 to 100 = 0.9. Like I said, that I don't know, but I'd love to hear about. Shadowjams (talk) 19:24, 30 January 2013 (UTC)

On a li-ion battery, charging from 90% and charging from 10% are not the same amount of cycles. There's a table somewhere, where you can charge from near-empty about 200 times (typical Li-ion rating). At 90%, you can charge something around 2000 times. Here's where it gets tricky though. At somewhere lower, like 50% or 70%, it almost seems like not charging is a slightly better option. I don't remember the figures off the top of my head, but you're supposed to get just under 400 cycles at 50% (something like 380). Then they go on to recommend charging as often as you can. But if you do the math, the total energy recharged for a 50% capacity battery at 380 cycles is less than 100% capacity at 200 cycles.

As for longevity, common consumer Li-ion batteries lose about 40% capacity a year from use. If you keep it cool and dry (warmer than a fridge, but not by much), you can store them for a year and have it lose a couple percent of its capacity. Unused, in normal circumstances, I think it loses in the neighborhood of 20% capacity a year. So yes, buying a new battery for future use isn't really a great idea. I don't have a lot of time right now to find the sources, but I will if I can remember later. --Wirbelwind(ヴィルヴェルヴィント) 00:06, 31 January 2013 (UTC)

Actually, have a look at Battery University. My example of 100% and 50% was incorrect, but does seem to look like charging at 50% is better than charging at 75%. --Wirbelwind(ヴィルヴェルヴィント) 00:12, 31 January 2013 (UTC)

Lithium batteries can be damaged by deep discharge. That's why these devices switch themselves off when the battery goes low. With older type batteries, you could use them until the voltage was too low to power whatever you were using, but with Li-ion the circuitry decides to turn off. If this happens, it's not a good idea to leave it like that for a long time. Batteries self-discharge even when not in use, deep discharges shorten the lifespan and damage may occur when it discharges too much. With the old Ni batteries that was merely inconvenient, but damaged lithium batteries can be dangerous. That's why if the voltage drops too much, the internal circuit will shut it down permanently i.e. you won't be able to charge it or use it again. Ssscienccce (talk) 20:35, 30 January 2013 (UTC)

Also, lithium rechargeable batteries age even when not cycled. Don't buy a spare battery thinking you'll have a brand new battery when the first one expires. In contrast, disposable lithium batteries have a very long shelf-life. Ssscienccce (talk) 21:09, 30 January 2013 (UTC)

I always follow the instructions. My camera recommends actually storing spare batteries at a state less than full charge. Storing fully charged ones messes them somehow. Each manufacturer may have tested different charging rates and come up with the optimum for their charger/battery sets.--Canoe1967 (talk) 00:23, 5 February 2013 (UTC)

Division of labour in computer game development

What are the different tasks that needed to be completed in making a major computer game? What fraction of the game's development team will work on each task, and how long does each task take? I heard that once an engine is created/acquired, importing and coding entities that go in the game is only a small task compared to everything else that has to be done. Is this true?

Wargaming.net for example has over 800 employees. How many of its employees are making new vehicles for its games, compared to doing other tasks? What are the other tasks that need to be done?--89.101.237.2 (talk) 18:56, 30 January 2013 (UTC)

here is one link you might find helpful which discusses the different sort of roles are recruited for a major games development company [2] ---- _nonsense ferret 19:16, 30 January 2013 (UTC)