How to take snapshot of surfaceview?

Question

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. When

Answer 1

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.