Which View is best choice for android camera preview?

Question

As we know, we can choose TextureView, SurfaceView and GLSurfaceView for android camera preview.

Which one is best choice for camera preview ? I'm focused on the camera performance.

Answer 1

From a performance perspective, SurfaceView is the winner.

With SurfaceView, frames come from the camera and are forwarded to the system graphics compositor (SurfaceFlinger) with no copying. In most cases, any scaling will be done by the display processor rather than the GPU, which means that instead of scanning the pixels once for scaling and again for scan-out, they're only scanned once.

GLSurfaceView is a SurfaceView with some wrapper classes that handle EGL setup and thread management. You can't use OpenGL ES on a Surface that is receiving camera frames, so you're doing extra work with no benefit. (The overhead is minor one-time setup, not per-frame, so you likely won't be able to measure the difference.)

TextureView receives the frames in a SurfaceTexture as an "external" OpenGL ES texture, then uses GLES to render them onto the app's UI surface. The scaling and rendering are performed by the GPU, and the result is then forwarded to SurfaceFlinger. This is the slowest option, but also the most flexible of the Views.

If you'd like to learn more about how the system works, see the Android Graphics Architecture document.

Answer 2

" The SurfaceView creates a new window in the Android Windowsystem. Its advantage is, that if the SurfaceView gets refreshed, only this window will be refreshed. If you additionally update UI Elements (which are in another window of the windowsystem), then both refresh operations block themselfes (especially when ui drawing is hardwaresupported) because opengl cannot handle multi thread drawing properly.

For such a case it could be better using the TextureView, cause it's not another window of the Android Windowsystem. so if you refresh your View, all UI elements get refreshed as well. (Probably) everything in one Thread.

Hope I could help some of you! " Source : stackoverflow.com

GLSurfaceView is a SurfaceView with a wrapper class that does all the EGL setup and inter-thread messaging for you.

Its completely upto you what you put to use.. They have their pros and cons over eachother :)