How to take snapshot of surfaceview?
android, surfaceview
Solution
Unless you're rendering H.264 video frames in software with Canvas onto a View, the drawing-cache approach won't work (see e.g. this answer).
You cannot read pixels from the Surface part of the SurfaceView. The basic problem is that a Surface is a queue of buffers with a producer-consumer interface, and your app is on the producer side. The consumer, usually the system compositor (SurfaceFlinger), is able to capture a screen shot because it's on the other end of the pipe.
To grab snapshots while rendering video you can render video frames to a SurfaceTexture, which provides both producer and consumer within your app process. You can then render the texture for display with GLES, optionally grabbing pixels with `glReadPixels()` for the snapshot.
The Grafika app demonstrates various pieces, though none of the activities specifically solves your problem. For example, "continuous capture" directs the camera preview to a SurfaceTexture and then renders it twice (once for display, once for video encoding), which is similar to what you want to do. The GLES utility classes include a saveFrame() function that shows how to use `glReadPixels()` to create a bitmap.
See also the Android System-Level Graphics Architecture document.
Problem
Am working in H264 video rendering in Android application using `SurfaceView`. It has one feature to take snapshot while rendering the video on surface view. Whenever I take a snapshot, I get the Transparent/Black screen only. I use `getDrawingCache()` method to capture the screen that returns a null value only. I use the below code to capture the screen. ``` SurfaceView mSUrfaceView = new SurfaceView(this); //Member variable if(mSUrfaceView!=null) mSUrfaceView.setDrawingCacheEnabled(true); // After video render on surfaceview i enable the drawing cache Bitmap bm = mSUrfaceView.getDrawingCache(); // return null ```