Android - Camera Preview

Question

Hi, i'm trying the camera preview

This is my code and it doesnt throw any error, but the screen still black, any ideas?

this.setContentView(R.layout.camerapreview);    
SurfaceView cameraSurface = (SurfaceView)findViewById(R.id.cpPreview);
SurfaceHolder holder = cameraSurface.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
this.camera = Camera.open();
this.camera.setPreviewDisplay(holder);
this.camera.startPreview();

camerapreview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content">
    <SurfaceView
        android:id="@+id/cpPreview"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:layout_gravity="center">

    </SurfaceView>
</LinearLayout>

thx a lot!!!

Answer 1

You are calling the last three lines too early. You have to wait for the surface to be prepared before calling setPreviewDisplay() and you have to wait for the surface to be sized (surfaceChanged()) before calling startPreview(). This project has what you need.

Answer 2

Anybody knows how to switch off the Preview while still getting frame callbacks? I just need data in a callback and don't want to waste time in the other thread that paints on my screen 30fps.