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androidbitmapscreenshotsurfaceview

Taking a ScreenShot of SurfaceView with Camera Preview in it

I am trying to Implement a Functionality that includes taking Pictures While Recording Video. That's the reason i have concluded to use the Screenshot approach of SurfaceView.
However, when i try to take the Screen Shot of SurfaceView. I am always getting a Blank Image.

Here is the code that i am using for taking a Snapshot:

View tempView = (View)MY_SURFACE_VIEW;
tempView.setDrawingCacheEnabled(true);
Bitmap tempBmp = Bitmap.createBitmap(tempView.getDrawingCache());
tempView.setDrawingCacheEnabled(false);
//Saving this Bitmap to a File....

In case you guys may think this is a duplicate Question, let me assure you that i have tried the following Solutions provided on SO for the same Problem before asking this one.

  1. https://stackoverflow.com/questions/24134964/issue-with-camera-picture-taken-snapshot-using-surfaceview-in-android
  2. Facing issue to take a screenshot while recording a video
  3. Take camera screenshot while recording - Like in Galaxy S3?
  4. Taking screen shot of a SurfaceView in android
  5. Get screenshot of surfaceView in Android (This is the correct answer, but Partially Answered. I have already asked @sajar to Explain the Answer)

Other Resources on Internet:
1. http://www.coderanch.com/t/622613/Android/Mobile/capture-screenshot-simple-animation-project 2. http://www.phonesdevelopers.com/1795894/

None of this has worked so far for me. I also know that we need to create some Thread that interacts with the Surface Holder and Gets the Bitmap from It. But i am not sure how to implement that.

Any Help is Highly Appreciated.

Solution

  • Here's another one: Take screenshot of SurfaceView.

    SurfaceViews have a "surface" part and a "view" part; your code tries to capture the "view" part. The "surface" part is a separate layer, and there's no trivial "grab all pixels" method. The basic difficulty is that your app is on the "producer" side of the surface, rather than the "consumer" side, so reading pixels back out is problematic. Note that the underlying buffers are in whatever format is most convenient for the data producer, so for camera preview it'll be a YUV buffer.

    The easiest and most efficient way to "capture" the surface pixels is to draw them twice, once for the screen and once for capture. If you do this with OpenGL ES, the YUV to RGB conversion will likely be done by a hardware module, which will be much faster than receiving camera frames in YUV buffers and doing your own conversion.

    Grafika's "texture from camera" activity demonstrates manipulation of incoming video data with GLES. After rendering you can get the pixels with glReadPixels(). The performance of glReadPixels() can vary significantly between devices and different use cases. EglSurfaceBase#saveFrame() shows how to capture to a Bitmap and save as PNG.

    More information about the Android graphics architecture, notably the producer-consumer nature of SurfaceView surfaces, can be found in this document.