I am looking for an addition for our "livestream and podcast" solution, which uses a camera to film speeches in our house.
It has been requested to view the slides of our speakers directly as a image in the webbrowser instead of the video stream. We don't want/can not install software on the speakers laptop, so I thought about a Java applet, which the speaker can just run via a webbrowser.
So what I need is technically this:
[speakers laptop] -> [Screencapture every N seconds via applet on a webpage] -> [Displaying the screen of the speaker on a different webpage for the external viewers]
I know there are Java applications which do record the screen, but save the file output locally. I need something that does the same, but sends the image to the server. On the server side I thought about a websocket.js accepting and displaying the image (other suggestions are welcome).
It would be great if somebody could help me out here. Btw, I never programmed in Java, so telling me which frameworks I need won't really help me.
Thanks!!
I was recently asked to evaluate possibilities for live screen-cast via applet. Most video APIs do not support codecs that have high enough compression (e.g. JMF). Some APIs can do advanced formats (JFFMPEG, Xuggle) but also use natives. While natives are normally no problem for an app. launched (free floating) using Java Web Start or a Plug-In 2 applet, the makers of Xuggle identify 'the order of loading natives' as a problem (e.g. won't work) for both JWS and applets.
It is a pity that more than a decade into its development, Java has no reasonable API for video capture/processing that can be deployed for a wide use (applet/JWS based - for the 'general public') GUI.
Perhaps you can find a solution using Flash.
Update 1
In fact, I do not need the screen to be recorded as a video.
In fact, you mentioned much of that in your initial question, but I focused on just a few keywords before drafting a reply. My bad. :P
OK.
Getting an image is relatively easy. An applet would need to be trusted in order to get a screenshot, but once trusted, it is just a few lines of code to get the image.
Encoding the image to JPEG of particular quality/compression setting (in memory) is also doable.
Sending the image to the server would depend on the size in bytes and connection speed, but one image with a high compression, every 10 seconds, should be doable. The server would need to implement functionality to accept the image.
As far as displaying the image on the client, it seems you already have some ideas based around JS. If you can make that work that would be optimal, since it can then be viewed in browsers with no Java.
I would still recommend you deploy the app. to the 'speaker' using Java Web Start, rather than embed an applet. A JWS app. will give you less deployment & maintenance troubles, and the JWS launch is ..nicer. Further, a free floating frame launched using JWS can minimize itself (or in later JREs, become transparent), during the action of taking a screen image - thereby capturing everything on the screen except itself.
Update 2
I actually found this code here.
That is ..horrible. Not the code, the site. When I visited it I got a message saying a pop-up had been suppressed (fair enough). Then there was the irritating 'vibrating dialog' hovering in the middle of the page (and following the scroll). You click the little x to see - another tab opened with yet another floating dialog, saying some other rubbish about how "You've won.." - with sound loud enough to drown out my high volume trance/dance playlist.
Then after closing that the hell out of my FF, I go back to the original page, close the damn 'dialog', scroll down & see.. a red background to the code (shudder). That is as far as I could manage. I closed the page with the code.
Try this code instead, for a single screen-shot.
Would it be possible to use this on the client side..
Yes.
.. and receive it with javascript on the server side?
Not really. Unless you mean an IIS based server running Microsoft's JScript. JavaScript is a client side technology.
For security reasons, servers need to protect themselves. E.G. From:
Someone creating a slavebot that uploads all the 1000s of docs on the slave machine's to the site - to make it crash.
People high-jacking your server for storing and serving bestiality porn (or worse).
Because of things like that (bad people have lots of imagination), while servers can easily accept uploads, they are generally not configured by default to allow them.
.. (I don't want Java on my server ;-)
It can be done using PHP, ASP, CGI etc. It does not need Java specifically, but it does need some active involvement from the server, if only to check the size of what is being uploaded and abort if it gets too large!
..Will take a look at the link you posted, but as I said, I can't program in Java, though I can understand some of it. Thanks!
It sounds like you'll need some help getting the server-side of it ready, as well. It is trivial for someone that knows how (not me), but a potential security nightmare for the inexperienced.
Update 3
where do I add the function to send the picture?
Sorry. I've not tried to implement that - you'd want to want to encode it to JPEG before sending, to reduce the size. See this code for how to provide an adjustable compression/quality where the user can see the effect.
There are various ways to get an image to a server. E.G. sockets, HTTP, FTP.. AFAIU it would depend on how the server is accepting it. I am unfamiliar with the specific term 'websocket' or the node.js script. Can you link to what you mean?
..the old code added to pastebin, so it's readable
Smart thinking. I notice it uses sockets, it was in the back of my mind that sockets would be best for this, since they have low overhead and short wait times.
Related
Without thinking, I created an entire program in Java and began designing a website to use this applet. All it does is create image in a certain way but there is a bit more code (classifications and default values/images) that I just felt was easiest to do with Java. Now I have a Java app and HTML CSS and JavaScript that I can't seem to do much with.
I have thought of 2 ideas (below) but I don't know what the general alternative is to applets nowadays.
I have a spare PC I may use and just alter my applet to run the back-end of a server-based site instead, but I am hesitant to use my own IP and bandwidth for something like this. Also, this app doesn't even need access to the internet so this just seems like way overkill.
I could just release the .jar, but I plan on expanding the available options. I also told people that this website was coming. I'd like to be able to just update the website.
I don't really plan on writing my program in another language. This took me time to make. If there is no way to work Java into my site, I may just abandon the project altogether.
I am mainly concerned with Chrome for this problem.
Edit: I would like to use GitHub as my host, just in case this helps at all.
You can run anything you want on the server, including java programs. So
you could run the image creation program in the server and present the
resulting image using a standard img tag.
I've inherited a Java web app that actually uses a Silverlight XAP for one small section of functionality, which allows users to upload large batches (1+) of images to a directory on the server.
The business requirements are provided in more detail below, but can be summarized as follows:
Users must be able to upload multiple images at the same time - if the user has 500 images to upload they shouldn't have to click a button, select the next file, and click "upload" 500 times; they should be able to select all 500 files from the local file system and upload them as a single "batch"
The file upload component must be AJAX or AJAX-like (does not require a page redirect/refresh)
The developer who chose Silverlight did so because:
He knew C# and used to be a Silverlight developer ;-)
Silverlight does meet those requirements
Silverlight has (according to him) better browser coverage than our JS technology (jQuery)
When management found out that Silverlight was chosen (which they only did during this hand-off!), they flipped out because Microsoft/Silverlight is not a part of our standards/platform.
I've been asked to research what it would take to re-write this in something that isn't Silverlight and is standards-compliant. We're a Java camp, and have been given the following acceptable candidates for technology selection:
Any Java view technology that could satisfy these requirements (GWT, maybe even JSF?!?) - this would be my preference
JavaScript/jQuery/QooxDoo/etc.
Applets (ehhh...)
Flash (I have no experience developing Flash/Flex and prefer this the least but will entertain the idea for the company's sake)
Of course, developer skill sets weigh-in heavily. The project has been handed to me and one other developer. Both of us have decent JS experience, strong Java and JSP background, but zero Flash.
The most important thing here is that a user can have the following experience:
They click a button (which would be a part of this component) that reads "Select Images"
A modal dialog pops up (modality is my personal "requirement", but not mandatory though)
Dialog allows them to pick a folder on their local file system, and select 1+ image files from inside that folder
Dialog has an "Upload Now" button, once user clicks it the dialog disappears and the component shows a progress bar of each photo being uploaded, sequentially
I've spent all afternoon researching GWT, JSF, ICEFaces and jQuery, and they all seem like they could handle these requirements, but I have not seen anything that assures me.
My question is: is there a Java solution that can accomplish this, and if so, what (GWT, JSF, RichFaces, etc.)?
If not, then can jQuery or any other JS lib do this?
If not, do I have any other options besides applets or Flash (and, of course, Silverlight)?
I would honestly rather consider pitching a new technology to our Enterprise Architecture committee than to do an applet (which is the anethma of Java development) or Flash (which I would have to learn from scratch).
Thanks in advance for any nudges in the right direction!
Edit
I know many of you may be tempted to answer by suggesting completely different alternative solutions. Please see my comment to #GolezTol's answer, but basically these constraints are hard-bounded and beyond my control.
Java must be installed and available too. But if a use should be able to upload 500 files, I would choose to give them an FTP account, or upload the files in a compressed format like a zip file, which I think any OS can create natively. Java, Flash, Silverlight.. All of those are components that are not always available. And I don't think a web interface is the most suitable for uploading so many images.
No, Im not asking for a full made program :) Im kind of new to Java as language so Im not familiar with java libraries at all and my experience is mostly about php, but I understand OOP well.
My scenario:
I want to build a Java applet to my website, by which different users can share a same screen window in which they can drag and drop things(images) to specific positions and when one does, it would update the screen to the others. Before connecting, user would choose to build a new screen or join other. If he wants to join other he would just enter some existing (random) screen id to connect to. If he wants to create a new one he would access this screen in which he would see the screen id to share with someone else. I dont care if two persons wants to drag and drop different item to same spot, it would then just use the one that came last.
Now that you understand what I want to build...
What I really just need is the skeleton structure of something like this. What parts I will need to build something like this? Libraries and such, where should I look for tutorials, Best practices, hierarchy, should I use tcp or udp? I just need something where to start from.
An applet is run in the system memory of each individual client. There are strict rules about what applets can and cannot do, and I am not sure whether or not applets would be allowed to make remote connections to other users. I would advice doing some google leg work on java applet security and seeing what you dig up.
Assuming this is possible:
In terms of architecture, I think you would want one person designated as the host create the game and run all the game logic, while the clients just receive information pertinent to graphics being displayed (location, size, texture, what have you) and sends back information about what the client is doing.
I did something like this as a school project in high school, but I was forced to sign the applet to make it do remote http connections. I would assume this is still the same case.
Hope that helps a little bit.
I need to display any web page as a browser field,not browser session.I am building the app in 4.7 OS.Can anyone help me with sample code?
On 4.7 you are stuck with the old browser field. Also known as Browser Field 1. It renders HTML pretty close to how it was on 4.5 devices. There is no way to take advantage of the newer browser that you invoke via browser session. So, you can forget about CSS2 or or JavaScript on the pages you want to render as a browser field. But for the fairly basic stuff it is good enough.
For the sample code - you really should check out and understand all the examples there are in the development package before starting writing the code. It will really save more time than take for learning. Look at components\samples\com\rim\samples\device\blackberry\browser\BrowserFieldDemo.java
I doubt that the problem lies with the browser field per se. Rather with communications.
The people in the post that you refer to were probably suggesting ";deviceside=true" as this gets around the "BES effect" in a simulator.
You may wish to experiment with running the MDS emulator alongside the simulator session as well. There are a number of posts that discuss the impact of deviceside and simulation. You can test in code to see if you are running a simulator so that you can programmatically influence the "BES effect".
I have been trying to use Java to connect to X3270 (actually, wc3270, since I'm working on a windows environment) and control it to access a mainframe, login, navigate a few screens and get the data returned from x3270's command "ascii" for further processing (like separating the needed fields).
Even if I can connect to x3270 and login into the server, I'm having trouble to reliably retrieve the screens from x3270 after sending a command, even using threads to read the socket continuously.
Can anyone tell me what I should be doing to get things right?
I cannot more highly recommend Jagacy 3270, a Java screen scraping library that's incredibly reliable and dead easy to use. I had tried rolling my own, and also both IBM HATS and IBM Host on Demand, and found Jagacy to be easy, quick, lightweight, and already done for me.
A full license isn't cheap, but was worth it to us.