I need to take thumbnail from Video playing with MediaElement
For this i learn there is RenderTargetBitmap in windows 8.1 API
RenderTargetBitmap a = new RenderTargetBitmap();
await a.RenderAsync(myMedia);
thumb.Source = a;
and second way i got with help of WinRTXamlToolkit.Composition toolkit which do rendring with WriteableBitmapRenderExtensions class
WriteableBitmap w = await WriteableBitmapRenderExtensions.Render(myMedia);
thumb.Source = w;
Both these methods are working with all UIElement but not with MediaElement
only black screen is visible when source this to Image object.
Can any one tell me why? and how can i take thumbnail from video?
It seems like the methods you mentioned might be limited in that regard. I'd still try RenderTargetBitmap but with something overlaid on top of the MediaElement. I believe if you place anything on top of a MediaElement, like a 0.01 opacity, 1x1 sized, black rectangle - it will switch to run in some different rendering mode where it is possible RenderTargetBitmap would be able to render it. Otherwise I think someone discussed here a while back a question of capturing a frame from a video stream. IIRC it is a pretty involved process though, involving using DirectX or Media Foundation and quite a bit of native code.
Related
I'm trying to capture the content of a WebBrowser control that is not in the visible tree, but the WriteableBitmap.Render() is capturing a (correctly sized) bitmap of all black pixels. If I put the WebBrowser into the visual tree, the capture works fine.
WriteableBitmap doc is emphatic that it works on controls not in the visual tree, and I'm making the required calls to Measure() and Arrange(). Relevant code (originally in WebBrowser_LoadCompleted event, for demo moved to renderButton_OnClick)
hiddenBrowser.Measure(new Size(hiddenBrowser.Width, hiddenBrowser.Height)); // pretend there's plenty of space.
hiddenBrowser.Arrange(new Rect(0.0, 0.0, hiddenBrowser.Width, hiddenBrowser.Height)); // pretend we know where this is going.
//noHelp hiddenBrowser.UpdateLayout();
WriteableBitmap _bitmap = new WriteableBitmap((int)theImage.Width, (int)theImage.Height);
_bitmap.Render(hiddenBrowser, new ScaleTransform());
_bitmap.Invalidate();
theImage.Source = _bitmap;
A complete project demonstrating the problem is available at: https://skydrive.live.com/redir?resid=193BF22F5BBA1A84!10526&authkey=!AGeH6YC_NttOmj0
Press Unhide (webBrowser shows in visual tree), then Go, then Render --> render captures OK.
Then press Hide (webBrowser disappears), then Go, then Render --> Black Screen of Ignorance.
Originally, I thought this was a timing issue (e.g maybe browser hadn't finished painting the web page even though LoadComplete event fired), but it cannot be; in the demo, I wait for 10s of seconds before pressing 'render' button which does the render, and still get black image.
I reproduced your problem. It seems like the Control isn't rendered if not necessary.
Do you really need the WebBrowser to be in the Visual Tree?
If you just want it to be invisible, setting the Visibility to Collapsed won't work either (I tried).
An ugly trick that works for the WebBrowser to be invisible to the user but still allows a WriteableBitmap rendering is to translate the control out of the ViewPort. To do that, just use a TranslateTransform:
hiddenBrowser = new WebBrowser();
hiddenBrowser.Width = theImage.Width;
hiddenBrowser.Height = theImage.Height;
hiddenBrowser.LoadCompleted += hiddenBrowser_LoadCompleted;
hiddenBrowser.NavigationFailed += hiddenBrowser_NavigationFailed;
hiddenBrowser.LayoutUpdated += hiddenBrowser_LayoutUpdated;
hiddenBrowser.RenderTransform = new TranslateTransform { X = 2000, Y = 2000 }; // this is the code I added.
Ugly but working solution!
This turns out to have been doomed from the start.
You can't run the WebBrowser control in the background on WP8, period. It's an Unsupported API.
And, as noted above, there's the issue (maybe not a bug?) that WebBrowser won't provide a bitmap when it's not in the visual tree, anyway.
I have made a flash as3 project in adobe flash pro with the dimensions 20px x 150px.
i would like to ceep it this size, but the problem is that my application needs to ask for the MICROPHONE premissions
( like in the image )
but this only happens if the flash object is big enough.
are there any workarounds with maybe the "overflow = visible" method or something ?
thx for any help
Here are a couple of options:
Temporarily increase the dimensions of the SWF in HTML. I've never done this, but I imagine it would work and is the most simplest solution.
Use wmode="transparent" or wmode="opaque" in your embed code. In both of these modes you can layer HTML on top of or underneath the Flash object. The SWF should be sized so that it is big enough to display the dialog. When the dialog is not visible, you can hide portions of the Flash app by covering them with HTML.
I've used the 2nd option successfully, not for this purpose, but for showing some HTML elements (arrow images and text) to guide the user through these "allow" camera/microphone dialogs.
For both of these options to work, you need to be able to detect when the user has closed the dialog. Though there is no official Flash API for doing this, however, there are some good work arounds for doing that.
I want to write a Windows Store App that can capture video (without any sound) and take pictures. Imagine a digital camera: you can preview the picture on the screen of your device before pushing the button which takes the pic.
The problem I'm facing now is the fact that the Windows.Media.Capture namespace has only classes for objects that capture video with sound (CameraCaptureUI, MediaCapture). I'm not troubled by the objects' capabilities, but by the fact that I will have to include in the manifest of the app the Microphone capability and it does not make sense for the app to use it. I need a class that uses only the Webcam capability.
Any ideas?
I found the answer and I thought I should share it. I'm sorry for answering my own question, but here goes:
One can specify in the settings of the MediaCapture object, when initializing it, that it will use only the Video part:
var mediaCaptureMgr = new MediaCapture();
var captureSettings = new MediaCaptureInitializationSettings();
captureSettings.StreamingCaptureMode = StreamingCaptureMode.Video;
await mediaCaptureMgr.InitializeAsync(captureSettings);
RTFM!
I've built an AIR application with flash/as3 that has a webcam display on the stage. While building the app, and in all my tests everything looks and works just dandy, but when I publish for AIR the image gets stretched. The bounds of the image seem to stay the same, but the actual cam output is what's distorted. Has anyone come into this problem before?
I should add, this is a desktop app, which is permanently installed on one machine, so device compatibility should not be an issue.
this is the camera setup:
var cam:Camera = Camera.getCamera();
cam.setMode(280,380,20);
var video:Video = new Video(380,380);
this is where i first call the camera...
video.attachCamera(cam);
video.x = 355;
video.scaleX = -1;
video.y = -100;
addChildAt(video, 0);
the reason for the odd sizing, is that it sits behind a frame, that changes positions throughout the interactive.
Not necessarily the answer you are looking for, but you should keep this in mind:
You are asking the camera to capture at the resolution of 280 x 380, which is not a standard 4:3 aspect ratio.
When you call cam.setMode(280,380,20); the docs say that Flash will try to set the cameras resolution to your specifications, and if the camera does not support that resolution it will try to find one that matches. So you may or may not be getting this actual resolution.
setMode() has a fourth parameter, which can disable this functionality. Read the docs on that so you understand the implications :)
Then you display the video in a Video object that is 380x380. So I would expect the image to be stretched in the horizontal direction (b/c the original source is only 280).
It's not clear why this behaves differently: are you saying that running the debug version of the app works, but when you export the release build and run that it looks funky?
Finally, what is scaleX = -1 doing? I recall this as some sort of nifty trick I used in the past... but it's purpose here is escaping me :)
Yep, source code would be cool. Btw, i suggest you, as soon as you get the video streaming running, to set by hand the video.width and video.height property.
This will force the cam to display at the correct size.
I want to create a swf or air app that takes an input and displays a graphic representation of it.
The graphic side is fine for the moment, but its always using an mp3 for example
var sound:Sound = new Sound (new URLRequest("myMP3.mp3"));
- i want it to be able to take a 'live' audio feed. How would I do that and is there a better way than using the microphone input?
thanks
dai2
Microphone input is probably the easiest way and using flash player 10.1 or AIR 2.0 you can do this. Take a look at http://www.adobe.com/devnet/air/flex/articles/using_mic_api.html
It's not as easy as using SoundMixer.computeSpectrum but offers the possibility (+ more). You'll for instance most likely want to run the data through FFT to use in visualization