I am creating a service that displays videos, but I want to change the video quality before downloading it. I need to detect either the device or the network connection, to see if they're poor or not. What is the most effective way of doing it?
Well first of all, it's not a super straightforward path - because what you are talking about is a video streaming service. To do it properly, as in developing your own solution, requires sophisticated engineering and is not something that I would suggest for a single developer to do.
But, what you do want is a video streaming CDN - and I suggest you look into CDNs as a whole if you're going to deliver rich media to end users - it will likely make it easier, faster and cheaper than whatever solution you can implement yourself.
A good alternative is CloudFlare - probably the gold standard of CDNs - but there are many out there. Video Streaming CDN Docs
This solution automatically detects network capabilities of your client - and transcodes and delivers media in a way that fits. You can read more in the docs.
Good luck.
I want to work on video streaming website. But I want to know what will be the best db for video streaming site? I need to help to know about this. Video streaming site like youtube.com, so what will be the best choice ?
Thanks for advance advice ?
The purpose of a database is to record and relate facts and answer questions. You can certainly capture information about videos in a database, like file name and location, title size, width and height, description, content tags, uploader, access permissions, and so on. A DBMS is an excellent tool for managing all the knowledge you need to make the site work and be useful.
The videos themselves are best served from a file system rather than from a database - most DBMSs are optimized for large sets of small values and don't have dedicated data types or operators for videos, let alone support for modern codecs and advanced video manipulation. In contrast, a LOT of software is available for processing videos stored as files.
I remember reading that scenekit has a polygon limit of 200k. However I haven't been able to find the source where I read it, so I have no idea if it's current information or even correct at all.
It may have been a wwdc session, either way what I need to know is;
Is this correct?
Is this limitation on the entire scene or just what is being rendered at any one time?
I don't think SceneKit has a hard limit on the number of polygons it will render. Instead, you'll see a gradual performance falloff as that number (and other measures of CPU and GPU usage) goes up. 200,000 is probably well into that falloff on some devices and perfectly fine on others.
You might be thinking about some of the advice in the WWDC 2014 session "Building a Game with SceneKit". That talk shows several metrics you can use to gauge a SceneKit app's performance and strategies for dealing with different kinds if bottlenecks. I'd recommend watching the video if you haven't already.
I have to prepare a comparison between the following technologies to present it to my Project Manager, but I fell that I'm lost, so if any one can help I will be thankful
I want to compare between them in the following areas:
the support of online video streaming
the budget of using each one
Learning Time will be needed to learn the technology
Which one is the standard and will target a lot of users
The support if I found any problem
Bugs and security issues
connection to DB, SOA and web services
supporting of multi player
The support of online video streaming
Some of the X3D viewers support video streaming (and some even 3D streaming, for things such as augmented reality).
Which one is the standard and will target a lot of users
X3D is a standardized format, such as JPEG with multiple companies being able to manipulate such data and is even officially recommended by HTML5 specs whereas Unity ties you to a single company. Even if most X3D viewers are plugin-based like Flash, there exists also native implementations such as X3DOM to display/interact with X3D files for any browser that supports WebGL.
Connection to DB, SOA and web services
I would usually recommend using a webservice for interfacing with a DB, and yes, X3D can interact with webservices (XML, JSON). There is even a standard binary format that is fast to transfer and parse large contents faster.
Supporting of multi player
Some X3D-supporting providers offer a multiusers service, such as Bitmanagement's BS Collaborate server, but I've seen people using Darkstar/RedDwarf to make multiusers 3D environments as well.
the support of online video streaming
Unity 3D does not support video streaming, unless done through textures, which will give you a really slow frame rate.
I don't know for sure about X3D, but I would doubt it was really made for such tasks.
Silver light has good video support, it should be easy to stream with.
HTML only supports streaming video if using HTML 5, for which it gives the best user experience when user's browser supports it.
Flash is the de-facto for video streaming. It is extensively widespread. They use it for YouTube for example.
the budget of using each one
The cheapest of them all is HTML, it is free. Then you can theoretically set up something for free in flash using Flex SDK and server streaming technology such as Red5 (both open source and free). After that, I believe that all others would probably be on par cost wise, Unity3D coming in as the cheapest of the paid alternatives.
Learning Time will be needed to learn the technology
Listed in order of fastest one to learn to slowest (assuming no prior experience in any):
HTML
Flash/Silverlight
Unity3D
X3D
Which one is the standard and will target a lot of users
Flash is the most widespread. Its only competitor would be HTML 5, as new browsers tend to support it and its the only possible option on iOS. On the other hand, if 3D is what you want, then Unity3D is the standard for now, might be followed by HTML 5 in the future.
The support if I found any problem
Well, Unity3D would offer you good paid support, flash and silver light also (but only when you pay for streaming server licenses). HTML, X3D will not give you any support, but you can find a lot of information on the internet. There is also extensive information about Flash and Silverlight on the internet, but mostly Flash.
Bugs and security issues
All are pretty secure, I'm just not sure about X3D, but all others are comparable in term of security or bug issues.
connection to DB, SOA and web services
Easy to do with HTML, Flash and Silverlight. Harder with Unity3D, and hardest with X3D.
supporting of multi player
Multi-player what? If you are making a game, then clearly I would say your real options are Unity3D if the game is to be in 3D, Flash if it is to be done in 2D. Check out SmartFoxServer for easy multiplayer server.
My 2 cents:
the support of online video streaming:
Some X3D players do support it. Unity does in some ways : http://unity3d.com/unity/features/audio-and-video
the budget of using each one:
X3D and Unity3d are free. You can pay for Unity licenses for extra features and platforms like iOS and Android. If you need to write plugins for Unity, you'll need the $1500 license. There are no costs for distribution of Unity products.
Learning Time will be needed to learn the technology:
Both X3D and Unity3d have active communities and many online resources and offline books. Unfortunately for X3D, the best content creation tool (Vivaty Studio) is no longer supported officially, but X3D is supported in Maya, Max, Blender, and many other 3D programs. Unity's online docs are excellent and the answers.unity3d.com forum (and other forums) are free and fast.
Which one is the standard and will target a lot of users:
'Standard' Well, HTML is the broadest standard. X3D (if including VRML) is the oldest most widely used 3D standard. HTML you have. HTML5 is coming, 'real soon now' (I'm already turning blue). If you mean 'most readily available' the HTML is #1, Flash is #2 (as everyone has a browser, and most computers come with Flash installed already). Flash needs to be installed. Unity needs to be installed too, but it's at least as fast and easy to install as Flash, and it's gotten millions of downloads, so it's getting pretty pervasive. X3D requires a plugin (this should change sometime 'real soon now' with x3dom on HTML5), but the many X3D players are all a little different from each other.
The support if I found any problem:
All have much online community support. X3D has a spec committee but that's not really support per se, you'd have to contact the X3D plugin provider (Bitmanagement, Cortona, Octaga, Exit Reality, Fraunhoffer, etc.) Unity has great online community forums, you can pay for premium support, but I'd only do that if I needed a serious bug or feature that has no work-around.
Bugs and security issues:
X3D's bugs depend on which player you use. Unity has bugs, but the product is pretty solid (I've only crashed it once, and I use is all day, every day, for over a year). Both have a mind toward security, but neither of these are totally secure, especially since you can write scripts that are inherently not secure. So you have a hand in how secure YOUR content will be. Some X3D players support encryption. Unity products are compiled.
connection to DB, SOA and web services:
You can use something like AJAX or JSON or whatever in all these platforms, no? So if it's by web service, sure. If by direct local access, I know Unity can do that. Both Unity and Flash require cross-server xml files on the server to allow access cross-domain (in the web player for Unity anyway).
supporting of multi player:
Unity has excellent multi player networking components. X3D (spec) supports it too, but it really depends on which X3D player you go with as to how well it actually works. Worst case, you can use AJAX or JSON or whatever to roll your own.
Which you choose depends mostly on what you want to do with it. Flash is generally the best route right now, unless it's all about 3D, then I'd try Unity. But a year from now, HTML5 alternatives will begin to take over. Flash DOES support 3D, there are different ways it can be done. Vivaty had a full-featured X3D player written in Flash, so it can be done. There are several good 3rd party 3d plugins for Flash.
I totally agree with wildpeaks : )
Connection to DB, SOA and web services: easy to do with HTML, Flash and Silverlight. Harder with Unity3D, and hardest with X3D.
Reply: I think X3D is not hardest.
X3D(X3DOM) can interact with webservices (XML) as very easy in this example/tutorial
Flash supports hardware accelerated 3d, and comes out of the box with 3d support. In addition, there is the papervision library for more advanced 3d. Unity3d is also supported
as a flash library.
I would consider Flex as a real alternative to Flash. It has the same actionscript language, but uses a tag based syntax called MXML, similar to silverlight. Database remoting is extremely simple. You can access your .Net/Java/Php objects directly on the front end without having to deal with serialisation issues. All of the Flash libraries are accessible.
There is also the X3D player from instantreality.org, supporting video streaming & decoding, XMLHttp request via scripting and its free for non commercial usage.
Flash 3D isn't good 3D for any application of real-time 3D. It is 2.5D with some tricks.
X3D is easy to learn for simple things and harder as complexity goes up. It does have the advantage of being VRML with pointy brackets so the free content, examples and toolkits are easily found. I did comparison tests of the various players. BS Contact is the best for the ability to handle the most complex content with the fastest frame rate and rich color palette. Network support is still non-standard although XMLHTTP and database connections are easy to bolt on. As others have said, Instant Reality is coming on fast and supported by people with a deep understanding of the past implementations and future requirements.
The decision comes down to the project type. A simple comparison rating such as you are is misleading at best but thanks for giving it a shot. I've used VRML through all of its incarnations and now X3D for world building and now as a source for 3D models in video work in combination with Sony Vegas. For cost-benefit without the need to use very expensive modeling toolkits, it is the best of all the choices.
im creating a game right now and im a bit stuck on how to implement storage of levels. i need to be able to download level files from the internet ota. im not so familiar with transferring files ota, but i have some experience with databases (mysql). what would be a better way of storing the game's level data?
Using sqlite will definetely decrease the time you spend coding, thus you can focus your effort in what is more important: the logic of the game. What you are going to store is simple data, then it won't worth the effort to use another method to save that info.
There are a lot of reasons to use a DB.
If you have data that is only read from and never change (except total overwrite), please think of using flat files. A database may be an overkill in this scenario.
BTW, please consider putting the files in the external storage - it can help the user maintain low app memory - especially if the data files are big.