live camera feed in background of android app

Question

I want to make an android app which runs the live video feed captured by the rear camera in the background . I am fairly new to android app dev . Can anyone help .

Answer 1

Instead of having the CameraActivity implement SurfaceHolder.Callback, it is better to provide a separate Callback implementation like:

    camHolder.addCallback(callback);
    private SurfaceHolder.Callback callback = new Callback () {
    public void surfaceCreated(SurfaceHolder holder) {}

    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {}

    public void surfaceDestroyed(SurfaceHolder holder) {}
}

In my Android device, Samsung S3, I get an error, "app passed null surface" with Camera tag, if the callback is not separately implemented.

Answer 2

What you are asking is fairly complicated and its a bit too much to start android with. But you can use this and will work:

---->>>>!!!!I REVISED MY ANSWER. NOW YOU CAN USE IT AS IS AND WILL WORK FINE.<-----

package com.mreprogramming.test;

import java.io.IOException;

import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.Toast;
import android.app.Activity;
import android.content.Context;
import android.hardware.Camera;
import android.os.Bundle;


public class CameraActivity extends Activity implements SurfaceHolder.Callback{

    protected static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 0;
    private SurfaceView SurView;
    private SurfaceHolder camHolder;
    private boolean previewRunning;
    final Context context = this;
    public static Camera camera = null;

    @SuppressWarnings("deprecation")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.camera);


    SurView = (SurfaceView)findViewById(R.id.sview);
    camHolder = SurView.getHolder();
    camHolder.addCallback(this);
    camHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);


    }


    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    if(previewRunning){
        camera.stopPreview();
    }
    Camera.Parameters camParams = camera.getParameters();
    Camera.Size size = camParams.getSupportedPreviewSizes().get(0); 
    camParams.setPreviewSize(size.width, size.height);
    camera.setParameters(camParams);
    try{
        camera.setPreviewDisplay(holder);
        camera.startPreview();
        previewRunning=true;
    }catch(IOException e){
        e.printStackTrace();
    }
    }

    public void surfaceCreated(SurfaceHolder holder) {
    try{
        camera=Camera.open();
    }catch(Exception e){
        e.printStackTrace();
        Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
        finish();
    }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
    camera.stopPreview();
    camera.release();
    camera=null;
    }


}

And for the layout camera.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"   xmlns:app="http://schemas.android.com/apk/lib/com.google.ads"
android:id="@+id/camview">

<SurfaceView
    android:id="@+id/sview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true" />


</RelativeLayout>

Good luck

Also include this in your manifest

<uses-permission android:name="android.permission.CAMERA" />

Also in the manifest add the following to the "CameraActivity" activity tab to make sure that your activity will always be in landscape orientation because otherwise holding the phone in protrait(upright) unless you change the code it will reverse the image's aspect ratio and severely distort it.

<activity
    android:name="com.mreprogramming.test.CameraActivity"
    android:label="@string/app_name"
    android:screenOrientation="landscape" >   <-------ADD THIS ---!!!!!
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

If you want to make the layout full screen put this in your styles xml

<resources>

<!--
    Base application theme, dependent on API level. This theme is replaced
    by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
-->
<style name="AppBaseTheme" parent="android:Theme.NoTitleBar.Fullscreen">
    <!--
        Theme customizations available in newer API levels can go in
        res/values-vXX/styles.xml, while customizations related to
        backward-compatibility can go here.
    -->
</style>

<!-- Application theme. -->
<style name="AppTheme" parent="android:Theme.NoTitleBar.Fullscreen">
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowNoTitle">true</item>
</style>