Wikipedia:Reference desk/Archives/Computing/2012 January 13

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January 13

Split files unrecognized

So I downloaded a movie and it was 10.1 GB, mkv format. The original opens fine using VLC and quicktime. I wanted to split it into smaller parts so I downloaded an application, "pif splitter". I successfully split the file into ten parts. The parts are each named name001.mkv, name002.mkv and so on. However when I try to open any of those with VLC I get an error message: "No suitable decoder module. VLC does not support the audio or video format "undf"". When I try to open any of them with Quicktime I get the message "...is not in a format that Quicktime understands". I though "okay, this splitter didn't work right let me try another." So then I downloaded "split@concat". That program likewise successfully split the original into ten parts. However, I am getting the same error messages when I try to open them. So I guess even though it's keeping mkv in the name it's not actually keeping the format? Something else? Can anyone explain what I'm doing wrong or what I can do?--108.46.103.88 (talk) 01:44, 13 January 2012 (UTC)

The purpose of a file splitter is to allow you to move the file to different media, which may have size limitations (eg, some file systems have a 4 GB file size limit; single-sided DVDs only take 4.something GBs). You might use such media in the process of copying your big file to another computer. To actually use the file, you need to rejoin the pieces back to a single file again. Each program to split a file will come with a method to rejoin the results.-gadfium 01:52, 13 January 2012 (UTC)

To split a video so that the chunks can be opened separately, you'll need an MKV-specific tool. Google:MKV splitter. NeonMerlin 01:59, 13 January 2012 (UTC)

Thank you NeonMerlin. That's very helpful. Gadfium there must be other people whose reasons for splitting is otherwise. Me, I want to burn to dvd but standard disks won't allow files of large sizes.--108.46.103.88 (talk) 02:40, 13 January 2012 (UTC)

Ya, as merlin said I think the MKV format doesn't deal well with arbitrary splits. Other containers seem to handle it. Depending on your uses, different formats might be more appropriate. Shadowjams (talk) 07:34, 13 January 2012 (UTC)

Quantum OpenCL?

How does the performance of a classical computer simulating a quantum computer tend to compare with that of a classical algorithm solving the same problem? Would it be practical for a quantum programming language to converge with OpenCL to help make quantum and classical computers interchangeable to the programmer? NeonMerlin 01:49, 13 January 2012 (UTC)

Let me start with saying I don't know anything about OpenCL. However, a classical computer simulating a quantum computer would still be doing classical computation and, thus, would be running a classical algorithm. Are you asking, perhaps, how classical algorithms that attempt to be "quantum" compare to one's that don't? From the phrasing of your question and that you seem to be asking if programming languages can make quantum and classical computation interchangeable on a single device, but quantum computation is quantum computation because of the physics of the device, not any abstract elements of the programming language. Or do you mean to ask if OpenCL could be used to program in parallel a quantum and classical device? It looks like you are crossing the roles of algorithms and physics in your question, is there some specific thing you are considering that might help to clarify this? Phoenixia1177 (talk) 10:15, 13 January 2012 (UTC)

I think the question is just whether quantum algorithms running in a quantum-on-classical emulator perform as well as classical algorithms. I'm not sure, but I think the answer is a strong no for known algorithms (which includes known emulation algorithms). For example, the quantum part of Shor's algorithm involves finding the period of a^x mod N with a QFT, where N is the number to be factored, and I don't think a classical emulation will do better than O(N) on this, making the algorithm worse than trial division. But it could be that the "real" answer is yes, with as-yet-undiscovered quantum and emulation algorithms. -- BenRG (talk) 18:34, 13 January 2012 (UTC)

Quantum computing is not "pin-for-pin" interchangeable with parallel computing. OpenCL doesn't seem to be the optimal language set for the best expression of quantum algorithms. Nimur (talk) 18:31, 13 January 2012 (UTC)

Can you blackout jan 18 to protest the SOPA act?

i love wikipedia, actually one of my friends father met with one of the fouders, my friend is kiran sonty from boyton beach florida, anyways, this site has so much information and i think it will really have a big effect on people if they seen this site closed down, reddit is huge but wikipedia is bigger, it will be much appreciated and it would be so cool to see that real people control the internet, pelase consider — Preceding unsigned comment added by 174.61.66.210 (talk) 18:22, 13 January 2012 (UTC)

That would be a clear-cut case of breaking Wikipedia to make a point. I do not believe there would be traction in the Wikipedia community to intentionally disrupt Wikipedia in order to make a political point, irrespective of the validity of the point, even if the stance has (hypothetically) widespread consensus approval among Wikipedia contributors. Nimur (talk) 18:29, 13 January 2012 (UTC)

Not actually so clear cut. As Nil Einne mentions, there's a consensus to "blackout" wiki on the 18th... and before you freak out, "blackout" means providing a clickthrough. I almost consider that less annoying than the annual fundraising banners. Shadowjams (talk) 23:11, 13 January 2012 (UTC)

Please explain using an embarrassingly obvious use case. Does this mean If I'm already on a Wikipedia article page and click on a wikilink to stick, it won't work, but if I type in my browser www.wikipedia.org/wiki/Stick it will, and if I type 'stick' in the search box on the English Wikipedia homepage, it will work? 69.243.220.115 (talk) 15:47, 17 January 2012 (UTC)

I believe that most Wikipedia users would strongly disagree with any attempt to take down an international resource because one country is discussing a law that is very similar to ones already in force in Denmark, Finland, Ireland and Italy. -- kainaw™ 18:34, 13 January 2012 (UTC)

I believe that none of us really know what "most Wikipedia users" would think about this. The US is a big player in the content-generation and web-hosting market, much less the place where Wikipedia's servers are hosted. --Mr.98 (talk) 02:44, 14 January 2012 (UTC)

This is under active consideration and debate at Wikipedia:SOPA initiative/Action. -- Finlay McWalterჷTalk 21:34, 13 January 2012 (UTC)

This is semi OT but note that it currently appears consensus is leading to a click thruable blackout for US users and a banner for non USs. If you want your opinion heard, I suggest you make your views heard soon the current plan is that this will be decided in 2 days to be implemented on the 18th. It is semi supported by the foundation. Nil Einne (talk) 21:59, 13 January 2012 (UTC)

One thing that's needed, even here, is to tell non-US users what SOPA is. I've seen it mentioned a few times now and made a point of finding out a little about it, but non-Americans generally haven't heard of it. This is definitely a time when American editors need to broaden their own perspective if they want broader support. HiLo48 (talk) 02:51, 14 January 2012 (UTC)

Actually I think most Americans don't have any idea what it is either. That's one of the points of the proposed action Nil Einne (talk) 17:01, 14 January 2012 (UTC)

Even most US Wikieditors. The page above has only hundreds of watchers. Jim.henderson (talk) 17:07, 14 January 2012 (UTC)

The issue is potential censorship by the American government. Surely there's a way to get that word into any title we use to decribe this action. HiLo48 (talk) 21:52, 14 January 2012 (UTC)

I think that's the point of the blackout. In any case, it now seems a full global blackout is likely, if the foundation can implement it. I would suggest people keep a local copy of Wikipedia:Mirrors and forks if they feel they may need it. I would not suggest they rely on Google cache since Google updates Wikipedia fast. I have no idea how they will handle the blackout, but still seems a bad idea to rely on them. Nil Einne (talk) (sorry forgot to sign)

Hi guys. The discussion here does seem to forget that the Italians blacked their Wikipedia out. Did it work? I think it achieved their goals. (It had to do with some stuff Berlusconi was doing I think). Can someone comment further? 80.98.112.4 (talk) 18:25, 15 January 2012 (UTC)

No. The Italian blackout did nothing except piss off a bunch of Wikipedia users. Some claimed they would never use Wikipedia again. I am of the same opinion. I really don't give a shit of some teenagers might lose access to some website to trade stolen music and videos. I do give a shit when those teenagers become assholes and decide that if they don't get what they want then they can take Wikipedia away from me. I believe that this is a direct result of telling every kid he or she is special. They are not special. They are assholes who are acting like immature brats who cry, "If you don't do what I want, I'm taking my game and I'm going home." -- kainaw™ 23:26, 16 January 2012 (UTC)

Really? I don't see it as clear cut as that at all. I know this is not a soapbox, but in fact it sounds like you are the one with the indignant reaction: access to wikipedia is not a human right (yet ;) ), it's free and run by volunteers, getting "pissed off" and claiming you'll never use it again because you can't access it for ONE DAY is, well, make up your own minds. I don't mean anything personal of course. Vespine (talk) 02:10, 17 January 2012 (UTC)

If the blackout happens it will be with the approval and active involvement of Jimmy Wales and the Wikimedia Foundation. It's not a bunch of editors blanking the pages. Many people oppose SOPA for the wrong reasons, but when isn't that true? You should always be suspicious of bills that claim to protect you from a currently fashionable bugaboo. -- BenRG (talk) 06:57, 17 January 2012 (UTC)

My reaction is that I spent nearly 8 years contributing to this with plenty of money and time. This is now a non-free political baby toy for a select few idiots. So, I want my donations back. I want my money back. I want my content back. Further, I do not support this in any way. Instead of contributing security fixes, I will spend my time developing hacking and vandalism tools. Previously, the tools I've found have been written by those who obviously didn't understand how Mediawiki works. I've worked on the code a lot and understand it very well. So, I believe I can make major contributions into continuing this blackout as long as possible. -- kainaw™ 14:12, 17 January 2012 (UTC)

Personally I opposed any action affecting non US users from the beginning, when it was first propose by Jimbo Wales on his user page. I continued to voice my opposition and in the final call, I again said I didn't want anything, not even a banner affecting non US users, and also said that although I felt it was up to US users what to do that would affect US users, I was opposed to a full blackout feeling it went to far. (I also suggested I felt the process with about 2 days required for a decision was rushed. ironically I had been thinking of suggesting if people want to do something they really need to start planning and get a proposal together because it would ideally need ~ a month for proper consensus. I never bothered but I never thought the foundation themselves would push for a decision to be reached in about 2 days.)

However your earlier comment ignores that many experts have raised concerns of the risks the bill poses, not just to those who want to 'trade stolen music and videos' but to people using the internet in general, in a number of ways. These people may or may not be right, clearly the experts don't agree. And the nature of laws being drafted is it depends on the final law, as well as how various parties respond after the law is in force, particularly in the US how constitutional issues play out. But you can't deny that the law has raised serious concerns. Even our own lawyer has said there is some minor risk to wikipedia, although my reading is it's unlikely to be an issue since we are already fairly strict with the stuff that could be a problem.

As you said, other countries have similar laws. Here in NZ we have a law targetting users, which is slightly controversial although much less so then the earlier law which would have allowed mandatory loss of internet access without a court case which was abandonded partially as a result of a public outcry (including from a number of blogs). In Malaysia, despite the government promosing no censorship (and to be fair, they have been much more restrained then a number of countries like Singapore or even I'd say Thailand, let alone China) a number of P2P and file sharing WWW sites (like RapidShare) have been blocked (see Censorship in Malaysia). Usually by DNS filtering which in that case is trivial to circumvent for the technically inclined since you can just use a non Malaysia DNS like Google. This of course is something proposed in the US, but give the large percentage of root servers in the US, it does raise much more serious concerns.

The foundations letter, and some of the people involved have suggested they support the blackout because of the other countries. This incidentally is one of the reasons I opposed, there are indeed laws in other countries, some of which seem worse. And other countries lack something like the first amendment which seems to greatly restrict anything closely resembling censorship in the US. (Other countries may have their own constitutional guarantees of free speech but for most they don't seem to be intepreted as widely as US courts do.) Yet despite half hearted mentions of other countries, this action is clearly targetted at the US, there isn't even any reason why that particular day should be chosen. However getting back to my point, none of this means the US law is okay.

As to your latest comments, to be honest it makes you sound more childish then those you say are behind the action. (I didn't get my way, so let me break all the toys so no one gets to play.) As I said, I opposed the action, and I'm disappointed that the decision was made for a full global blackout. But it was a decision made by a majority. (I hesitate to say consensus since people mostly voted often without any real explaination, but the number and percentages for a wikipedia community decision were rather large. And for such large polls, IMO and with due respect to people like Jayron32 who closed the recent RFC on verifiability, it mostly comes down to a strong majority then a real consensus based process anyway.)

So as much as I dislike the decision and even to some extent the way it was made, I respect that some decision was made and by a large number of people. If I felt strongly enough about it, I may abandon wikipedia, perhaps leaving a strongly worded parting note. (And I respect some people may feel that way.) However I'm not going to threaten to continually damage the work of others, because I, one person, disagrees with a decision made, no matter how radical that decision was. Any content I distributed is still out there on many mirrors and on the WMF servers (although I won't be able to access it for one day). And I'm free, as entitled by the licence I agreed to release my content under, to make a mirror or fork of my own. I can't of course revoke my licence. And I knew from the beginning that the foundation ultimately controls the servers, and they've delegated a large number of decisions to what they intepret as the community but also are free with the legal framework they operate under, to do what they want. (In this case it appears to be a combination of both, a decision made in sme way by the community, but with the backing and pushing of the WMF.)

I made the choice to work under that basis. For those who made that choice, but then when something didn't go the way they wish, do make that abount turn and decide to continually harm the work of others, that I cannot respect. (And if you're a supporter of SOPA/PIPA, no prizes for guessing what this suggests to me of supporters vs opponents.)

P.S. Funnily enough for all your talk of teenagers, I suspect they're the most likely to be negatively affect by the blackout. As I understand it secondary schools in the US are generally in session (but perhaps not universities). They also are in Malaysia (where universities are also I think in session) and I suspect a number of other countries although not New Zealand. I believe you have a history of teaching so I guess you know students tend to leave a lot of work to the last minute. (If you didn't know, I suggest you check out the history of school and university projects on wikipedia and see how the major contributions always seem to come at the same day or two each year after a small amount over the previous few weeks. Definitely it was what I did a lot as a student, but I think I did it to an extreme extent although not being particularly sociable I wasn't sure how much so.) I think it's quite likely a number of horrified teens are going to find one of their major resources they need to finish (or start!) their project due in 18 hours is now offline for at least 18 hours. Adults do have deadlines too, and do sometimes use wikipedia for them, but I suspect the number affected in the same way is going to be small in comparison. A large number aren't even going to notice.

Nil Einne (talk) 16:32, 17 January 2012 (UTC)

Lord, Kainaw, get a grip and get some perspective. It's a community decision done in the way that the community has always operated. If you don't like it, feel free to fork or go home. You didn't donate money or time with any stipulations attached. Nobody owes you anything. --Mr.98 (talk) 19:00, 17 January 2012 (UTC)

Finding names of Flash files/Associated flash content

Hi! I'm trying to archive a website, http://ttmfilm.com/final1.swf , so I can archive information about a film.

• Using the original link http://ttmfilm.com/final1.swf - When I click the "Film" and then the "University of times a dog" (sic) I receive the content related to the film.
• So I archived the file at http://www.webcitation.org/64fi9Rq2q - When I load this file and I click the "Film" and then the "University of times a dog" (sic) the browser says "waiting for www.webcitation.org..." - and then the content never loads. I suspect there is another file that is loaded, that had not been archived, but I am not sure how to get the name of it. I tried using Mozilla Firefox's (2.0.0.20) "Tools -> Page Info -> Media" to get the name of any new files, but I only see the links to the original file.

How do I find the names of the files of the associated content, so I can archive them? Thanks WhisperToMe (talk) 23:27, 13 January 2012 (UTC)

I made a permanent mirror for you (sourcefiles). To answer your question: use a Flash decompiler. You owe me your first-born child. Von Restorff (talk) 08:32, 14 January 2012 (UTC)

I really do. Thank you so much! WhisperToMe (talk) 08:37, 14 January 2012 (UTC)

BTW how do I get a flash decompiler? WhisperToMe (talk) 08:38, 14 January 2012 (UTC)

You are very welcome of course. Sothink SWF Decompiler has a 30 day free trail. Lemme know when the kid is born. Von Restorff (talk) 08:39, 14 January 2012 (UTC)

You will be the first to know ;) ;) WhisperToMe (talk) 16:43, 14 January 2012 (UTC)

That would be kinda cool since I am not a female. Von Restorff (talk) 16:44, 14 January 2012 (UTC)

As always, wikipedia has a helpful article for situations like this: Gender identity Can I be God-farther?--Aspro (talk) 23:01, 14 January 2012 (UTC)