Wikipedia:Reference desk/Archives/Computing/2012 September 9

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September 9

LG TV that can turn all 2D images into 3D ?

That is their claim. Call me skeptical (SkepticalRat ?). I don't see how this is possible with current technology. I suppose, using some advanced artificial intelligence, by recognizing each object, judging their relative sizes (versus their absolute size, other object's relative sizes, and this object's size in surrounding frames), overlap, focus, etc., a highly advanced program could determine which objects are in front and which are behind, and then render them accordingly, but somehow I doubt if this is what they do. So, what exactly do they do ? StuRat (talk) 04:19, 9 September 2012 (UTC)

Wikipedia's 2D to 3D conversion article seems to link some useful references. -- BenRG (talk) 05:13, 9 September 2012 (UTC)

Interesting links, but have I missed one that explains what StuRat is asking? I share his skepticism. Dbfirs 07:09, 9 September 2012 (UTC)

... Hmm ... it looks as if I'm wrong[1], and these TVs really do some very clever image recognition and lightening-speed processing. They must contain extremely fast processors and a lot more computing power than the laptop on which I am typing this reply! Dbfirs 07:20, 9 September 2012 (UTC)

To quote from the above linked page: "Conversion software looks at the content and performs analysis of its shapes and colours, works out what's in the foreground and background, and then creates a map of the images to create two slightly different versions giving the parallax image our eyes need to receive to 'see' in 3D. Of course, the software is so powerful that it completes all of this at super fast speed. To summarise, what 3D TV conversion software is doing is modifying the depth of field of a 2D image to render it in three dimensions."--Shantavira|^{feed me} 07:58, 9 September 2012 (UTC)

OK, so is it any good ? I picture it working about as well as the first attempts to change black and white TV into color, where they colored the bottom third green and the top third blue, hoping that would be right at least part of the time. StuRat (talk) 14:24, 9 September 2012 (UTC)

Confirming my skepticism, the article says "...it can suffer from a lack of clarity and sharpness. Quick image movements on the screen can also [be] blurring or stuttering." StuRat (talk) 14:38, 9 September 2012 (UTC)

The quality is so-so. At the best it looks like something you would see in a View-Master. There is a perceived depth of field but everything looks flat like in a View-Master. We've had the TV for about a year but other than the first week we haven't used the conversion since. Proper 3-D films look fine on it. CambridgeBayWeather (talk) 02:17, 10 September 2012 (UTC)

OK, thanks, that's good info. It looks like this idea is literally "not ready for prime time", so I won't purchase one until they improve the technology. StuRat (talk) 16:13, 10 September 2012 (UTC)

Which CD/DVD?

I'd like to copy some of my MP3s onto a CD to play in my car stereo. But I'm not sure which formats to use. I have a few questions:

• All of my songs are on iTunes. Can I write to CD/DVD from iTunes?
• My laptop has a DVD-RW on its disk drive. Which CD/DVD formats can it burn?
• Would my car stereo be able to play DVDs containing music files?

Hopefully you'll be able to shed some light on this, or tell me what other things I need to know to be able to answer these questions. — Fly by Night (talk) 13:48, 9 September 2012 (UTC)

1. yes
2. you want to burn Red Book (CD standard), nothing else, on a CD (not a DVD)
3. car audio tends to be much less flexible and forgiving than even the cheapest computer. Some of the fancier lines of car audio, like Sony's Xplod and Philips' Expanium are more likely to play mp3s and to tolerate different formats, but the stock equipment many cars shipped with can be much less flexible. You'll have to burn some samples to see - make sure you start with a CD-audio project on CD-R media with only an hour of music, and once that works in your car you can experiement to find its limits.

-- Finlay McWalterჷTalk 13:56, 9 September 2012 (UTC)

I should qualify the first as perhaps "maybe". I've done it, in iTunes, with audio ripped on that machine - as I've never bought music online, I don't know whether iTunes will let you burn that to disk. -- Finlay McWalterჷTalk 13:58, 9 September 2012 (UTC)

I must say, my advice would be not to bother, but instead to rig up a cable to your car's stereo's AUX port (which most have, buried away somewhere). If you're not happy doing that yourself, any car audio installer should be able to run a cable with either an iPod or 3.5mmTRS connector, allowing you to use any digital audio player through the car's audio system. -- Finlay McWalterჷTalk 14:07, 9 September 2012 (UTC)

Yes, I used the AUX port for many years until I bought a (second-hand) car with a CD player that claimed to play MP3s. To my surprise, this worked, though it can't cope with more than 255 tracks in any one folder, so I create several folders. I have CDs with many hours of music in MP3 format, and the car CD player just chooses tracks at random, starting to play as I switch on, and continuing from the exact place it stopped last time. I find this much more convenient than the AUX input, and I don't need to change CDs. I've never seen a car CD player that can play DVDs of music in MP3 format. Dbfirs 15:33, 9 September 2012 (UTC)

More convenient how? :/ ¦ Reisio (talk) 16:58, 9 September 2012 (UTC)

The ideal thing would be an automotive-grade audio device which takes removable high-capacity solid-state media like Secure Digital. There are some downsides of using a portable player like an iPod and an AUX connection: the haptic-UI and high-contrast display of automotive audio equipment is easier and safer for drivers to use (a touchscreen is difficult to use when you're driving and can't look at it); automotive components have a wider range of temperature tolerance than consumer components (which is an issue for people in Arabia or Canada); and simply having the system built in (and not dangling on a cable) is neater and makes it harder to steal. There are plenty of such players available from the usual aftermarket car audio manufacturers, but they don't ship this on most cars in the base to middle of a range. -- Finlay McWalterჷTalk 17:17, 9 September 2012 (UTC)

The answer depends on the stereo in your car. The options are

• You have a basic CD player that can handle CDRs (most modern players should handle this). In this case you 'll need to burn a cd as an audio cd, and you'll be limited to about 80 minutes of audio.
• You have a CD player that handles MP3s. Look for the MP3 logo on the player. If this is the case you can burn a data CD of the mp3 files. You can store 10 hours or more of audio this way on one CD.
• You use an auxiliary jack and hook up another device (like an mp3 player) to it with a simple phono cable (you can buy one at radio shack for $6).
• You have a player in your car that accepts another media, like an SD card or a usb drive, in which case you can put files onto that and play them off of it. Mostly you'll find these in aftermarket stereos and not original ones. Shadowjams (talk) 18:14, 9 September 2012 (UTC)

Another option: fancy cars (or cars with fancy kits) have iPhone docks, which allow iPhones to play through the stereo, and makes the car the iPhone's hands-free kit . I think this doesn't work for Android or Blackberry phones, as they don't have the docking connector with all the additional connections that makes this work. 146.90.59.151 (talk) 01:58, 10 September 2012 (UTC)

Many newer cars (in the last couple of years) that are available in the UK have an aux port for the car stereo. Read the manual or have a fiddle around with the 'source' control to establish whether there is an aux port at all (it will probably give a choice "radio/CD" or "radio/CD/Aux"). The port is occasionally on the front of the stereo, often in a space near the cigarette lighter (or power jack), but it is sometimes hidden in the armrest. If you have an aux port, any old MP3 player can be connected to it. It can be distracting to play with the MP3 player while driving, and watch out if the MP3 player is also your phone, you might be accused of "using" your phone while driving (a £60 fine and 3 penalty points on your license).

CD players on the other hand have no such restrictions. Burn MP3s onto a CD-R using "audio CD" as the output media. This will give you the best chance of compatibility with the CD drive in your car stereo.

DVDs? No chance, unless you have one of those video things to keep the kids busy on long journeys. The screens are designed to only be hung on the backs of the seats, so the images don't distract the driver. Astronaut (talk) 10:38, 10 September 2012 (UTC)

Video streaming is slow, especially in youtube

Hello there, I am having trouble in streaming video in youtube.com for last couple of months. As for other websites, this problem happens occasionally. I do not have problem with browsing and downloading though. If I pause a video while it is streaming, the streaming usually gets stopped at the middle of playbar. But if I press play button with mouse pointer then streaming continues. Why is this happening? All I want is, video will be streaming while I pause the video so that I can continue watching video after streaming is over. I have updated Mozilla browser along with latest Java and adobe flash player. But nothing happened so far. The problem remain same. Am I missing something or should I change any settings? Thanks--180.234.35.56 (talk) 17:39, 9 September 2012 (UTC)

There are a few sites that suggest fixes on your pc, like http://www.delete-computer-history.com/slow-streaming-video.html or if you have access to google groups maybe this (don't have access myself, so it may be useless for all I know). Found a tip about DNS servers. I had similar problems with video, downloading files etc... a while ago; most likely a cable fault somewhere between my pc and the router, fixed itself after a week, sparing me the trouble of breaking open part of the floor... You could also google to see if other users using the same ISP have similar problems, maybe they put a limit on video streaming bandwidth. Ssscienccce (talk) 15:59, 10 September 2012 (UTC)

It may be that they are reluctant to allow you to download an entire video, then play it, as that makes it easier to copy than if you just stream it. However, as you noted, streaming often has problems, as it's one of the most demanding applications on a PC. It's possible the slow-down is at your PC, not on the Internet. Try a reboot, then don't start any other applications besides the streaming video. You might also try lowering the resolution and frame rate, if you have those options. Also, if you have the ability to play the YouTube video elsewhere, like on your TV or portable device, this will tell us if the problem is just on your PC or not. StuRat (talk) 16:08, 10 September 2012 (UTC)

It's not a problem on your computer, this is just how the YouTube Flash player works now. It only buffers a segment of the video at a time. If you pause, the buffer only fills part of the way. When you play, and the play position moves near the end of the buffered portion, it starts filling the buffer again. I noticed this new buffer behavior around the beginning of this year, but I don't remember exactly when. It might buffer differently on faster internet connections, but I don't have any to test with.

Here's something you can try: Disable the Flash plug-in in your browser. If your browser supports HTML5 video, this will force YouTube to use its HTML5 player. (If your browser doesn't support HTML5 video, you'll just get a message that Flash is required.) To get YouTube to use the Flash player again, you may have to delete cookies and re-enable the Flash plug-in. When I tested in July, YouTube's HTML5 player buffered the entire video when I paused. However, on my computer, the HTML5 player picture would intermittently freeze for a second while the audio continued. You might want to compare YouTube's Flash and HTML5 players to decide if this method is worth it for you.

Here are some other suggestions, but I haven't tried any of these: Force YouTube to always buffer the entire video before playing

In July, another poster here was trying to let the entire video play to fill the buffer, then press the restart button to watch the buffered video, but YouTube was still redownloading segments of the video. I found the URLs the YouTube Flash player was requesting had parts rearranged, causing the URL not to match the existing segment in the cache, even though the downloaded bytes were identical. (I suspect this was an oversight, I can't imagine why YouTube would want to send you the exact same bytes in your cache again.) If you're willing to wait the entire play time of the video you might test and see if the buffer remains on replay or if the bug still exists where it redownloads segments.

@StuRat: The new buffer behavior does prevent you from retrieving a single video file from the cache as you could previously. But I recently found NirSoft VideoCacheView can retrieve the entire video file from the cache. (Let the entire video play, find the newest item in VideoCacheView, then use the "Copy Selected Files To" command.) It seems the cache files are just in segments and only slightly difficult to re-combine. (The segments might overlap slightly so you have to examine the byte positions indicated in the URL to know how to combine them. And the beginning bytes are missing, so I guess you have to know some proper header bytes for the video format. I stopped investigating the details when I found VideoCacheView.) So I'm not sure if download prevention is the main reason YouTube changed the buffer behavior. A hypothesis I came up with is that YouTube doesn't want you to waste your bandwidth (or their bandwidth?) if you leave a video paused. For example, if you are watching YouTube on a mobile device this might be a legitimate concern? I haven't checked example bandwidths to see if this hypothesis makes sense. --Bavi H (talk) 02:33, 12 September 2012 (UTC)

I don't see why people would be going to such complicated arrangements if they want to retrieve YouTube videos anyway. There must be like hundreds of sites like KeepVid with Java applets or similar that allow you to input a Youtube link and then give download links for every quality available. There must be hundreds of other programs for Windows and at least a few for other major OSes which do similar. And unlike with other sites, Youtube rarely even breaks this. (Well with external site Java applets they could simply be updated so fast, unless you check for this. But with installed programs, you know they don't break if you disable any possibility of updating.) Many of these aren't open source, so you do have to trust them. But let's be frank, that's rarely a concern for most users, not to mention AFAIK Nirsoft stuff while useful isn't open source either. In other words, whatever Youtube is doing, they're clealy not putting much effort into stopping people retrieving whole files (some other sites do put a bit more effort).

To the original question, from my experience Youtube has been designed so the (Flash video) streaming stops after downloading a few extra minutes for a long time (I mean like two or three years at least). I suspect reasons for this include saving bandwidth for both the end user and Youtube. (Youtube may have a lot of bandwidth, but there must be many, many people who start a video then pause it either because it's boring of they want to do something else and never come back to it for whatever reason.) And a related reason would be to improve streaming on videos the person is watching. They may have recently reduced the amount it buffers before it stops, but I'm not sure of that. (With a quick test recently, I found with a few different files it only seemed to buffer about 30 seconds - 1 minute before stopping, IIRC, it used to do 3 - 5 minutes before stopping.)

If you want buffering to be complete, you can skip to near the end of the current buffer location as many times as necessary (you don't have to actually play) being careful to not go too far. (At least this used to work, but I haven't actually tested it in a while since my ISP stopped being so iffy with Youtube.) But in truth, if you intend to download the entire video before watching anyway, I suggest just use a tool to download it (whether an applet off an external site or something you personally download and run) rather then trying to convince Youtube to buffer the whole thing. (You can of course watch the video while it's downloading too if you have a player which doesn't mind if the file is in use like VLC.) That also avoids the problem where you may occasionally break the buffer which from my experience even when what I mentioned was working fine, could still happen on occasion.

Nil Einne (talk) 05:58, 12 September 2012 (UTC)