Silverlight - Determine if a wma is protected by DRM - silverlight

Is there a way to determine if a wma file is DRM'd? I'd like to be able to do this in a trusted, out of browser Silverlight 4 application so pinvoke isn't an option. I supposed I could just try to play the file in a MediaElement but that doesn't seem efficient.

Yes, check the MediaElement State during StateChanged event and you should be able to figure out if the video is DRMed or not.
There's a code sample # "Digital Rights Management (DRM) - Detecting DRM State".
Quick word of friendly advise, since you're obviously going to work with DRM in Silverlight and you're lacking basic knowledge how that works - read the whole article. It'll do you a world of good.

Is file local or remote? For a local file you can read first N Kb of a file, parse ASF header and check if WMDRM headers are present.

Related

Playing a .mp4 file while writing it

This is a very simple task that I had such a hard time trying to do. My goal is pretty simple: send an mp4 file from my server to my client, and while its buffering and downloading I want to already play it. That means that I need to play a video.mp4 file while writing it, and I need it to display on some platform that I can control - like wxPython or WPF-Ironpython. Naturally, no such platform will let me play an open file for writing.
I have tried to implement and HTTP server (although totally unnecessary for my case, as I am writing an application-based Server-Client app) that would accept Range request, and when I run the server and load the URL on Chrome, it all works perfect and I can seek and buffering is great, but when I load it from WPF MediaElement it fails to play the video for some point (I cant really tell why as there is no documentation for this, any API, tutorials etc). I am really desperate.
I even thought about playing a video from a buffer and then just changing the buffer's content, but it doesn't seem like this possibility exists.
I am really stuck at this and I would love to get some suggestions. Please note that I am not a professional in this so I would appreciate if you could explain this to me in simple terms.
Thanks!
Not possible. MP4 is not the correct container for your application. You must use something like HLS/dash/fragmented MP4.

Proprietary USB device access via browser... possible? Silverlight maybe? (Java is excluded for now)

Probably there are a lot of similar questions around, but since I know only few solutions to this which I am not sure will work for us, I am looking for something else, maybe new technologies...
What we have is this USB device which is not so fancy (of course, it requires a driver to be loaded), and it has couple of C++ dlls to help getting certain output from it. On top, we made a C# desktop application which makes use of the device in a more attractive way (plenty of interop inside).
So far so good, but to have the application lifted up to the web in order to gain more flexibility... What options are there?
Known solutions are:
1) ActiveX - kinda old technology and not cross-browser;
2) .Net 'applet' - not so common (is this even a solution?)
3) Java applet - well known, but JVM needed (since we went for C++ C#
maybe is out of scope);
4) Web service on the usb device itself - our device is very
light, we cannot have it there.
Are there other ways? Is Silverlight 4, 5 (maybe "out of browser") a feasable solution? What about these new technologies nowadays? Html 5 or something?
EDIT1: In particular I am interested in Silverlight. Is there a way using Silverlight?
EDIT2: I found this question: Can Silverlight access a .Net library that accesses a USB port? . What shall I understand from that? Is really Silverlight not a feasable solution for my scenario?
EDIT 3: VERY IMPORTANT!
These devices need to be used on customer side! People browsing must use them locally on their PCs!
Thanks in advance.
to have the application lifted up to the web [...]
Simple solution: Let the webserver (http server) run on the PC connected to the USB device, and use one of the webserver's interfaces like CGI to talk to your USB device. This way you need to code only a USB-to-CGI wrapper program, which can be C++ or C#.
Another way is to write a browser plugin.
The issue that you're going to face is that content in a browser is often run in a sandbox, in such a way that the web app does not have access to the computer. There are good reasons for this - security, primarily. One way to have some code running in the context of the computer is to have a browser plugin that can access the computer's hardware resources, but that can interact with browser content. Unfortunately, you may end up writing a different plugin for different browsers.
There do exist frameworks out there that make writing browser plugins more manageable. A simple search should turn up some of those candidates.
You can use Silverlight 5, it can give you access to your file system and USB storage device. If you want to get control for other USB device (printer, scanner, etc), you should give a device type. I know, Silverlight 5 works fine with a file system and web-cams...)

How to Check / Fix Broken Background Transfers - WP7

I am developing an application which provides video download feature using Background Transfer.
Some times it says download is completed but on loading it in MediaLauncher it says can't play this file immediately or after playing it for partial period. it is my understanding that file is broken.
is there any solution to verify after downloading that file while server do not providing any hashing technique (digital signatures) so that i can check after download if the file is good to play or not and moreover if there is any fixing technique.
I haven't checked but I think server provides partial download (pause / resume).
Thanks

WP7 MediaElement download problems

I'm running into problems on the WP7 with MediaElement downloading a 128kbps mp3 stream from a web service for a music player app that i'm working on. The file downloads correctly when the wp7 is on a wifi connection, but downloading sometimes stops when off of wifi. The problem is that i'm not getting any errors or exceptions when the downloading fails and the MediaElement state is "playing". MediaElement runs right past the downloaded portion of the stream and acts like it is playing, but there is nothing to play since the download stopped. I can somewhat replicate this issue based upon my location and using the 3g instead of wifi, so i believe it is due to a low connection. I don't believe any code needs to be shown in this instance, but i try to post something. I want to know if I have any control over this? Are there any other events I could use to detect when the download has failed? Is there another way I could download a mp3 stream that is more reliable and play it? Is there another player/component I should try?
Thanks in advance
You could always use MediaStreamSource to try to handle the download and implement streaming, to some extent. It is a more "painful" way of doing this since you will have to work with an extra media layer, but it pays off by improving playback stability.
Here is a starter example by Tim Heuer. Take a look specifically at how he takes advantage of a custom implementation of MediaStreamSource. Here is a more complex sample.
If streaming is not a requirement, you could download the file (and store it in the Isolated Storage) and then play from there.

Remote Desktop Project in C

I want to make project for my final year in college.
So someone suggested me to make Remote Desktop in C.
Now I know basic socket functions for windows in C i.e. I know how to make
echo server in C.
But I don't know what to do next. I searched on internet but couldn't find
something informative.
Could someone suggest me how to approach from this point..any tutorial...or any source ?
I think this is do-able. For a college project, you don't need to have something as complex and as full-featured as VNC. Even demonstrating simple keyboard and mouse control and screen feedback would be enough, in my opinion, and that's well within reach.
If you're doing everything from scratch and using Win32, you can get the remote screen using the regular "printscreen" example all around the internet.
http://www.codeproject.com/KB/cpp/Screen_Capture__Win32_.aspx has it, for one. You can then compress the image with a third-party library, or just send it raw; this wouldn't be very efficient but it would still be a viable demonstration.
Apart from capturing the screen data remotely and showing it in the local window, you'll need to listen for local window messages for mouse and keyboard events, send them to the remote host, and then play them back. http://msdn.microsoft.com/en-us/library/ms646310%28VS.85%29.aspx will probably do that for you.
Check tightvnc TightVNC is a free remote control software package. The source code is also available.
For sending the image of the screen I would probably use rtp. The JRTPLIB is really handy for that.
And yes, as KevinDTimm says, an echo server is the very easiest part.
KevinDTimm may well be right, writing an RDP client would a fairly significant undertaking. To give you some idea, the current spec, available at the top of this page, is 419 pages long and includes references to several additional documents for specific aspects of RDP like Audio Redirection and Clipboards.

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