Friday, December 3, 2010

Camera Preview on SurfaceView

With little bit of modification on last exercise "Play 3gp video file using MediaPlayer", it's easy to implement a app to preview Android camera on SurfaceView.

Camera Preview on SurfaceView

Modify AndroidManifest.xml to grant permission to access Camera
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.exercise.AndroidCamera"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".AndroidCamera"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

</application>
<uses-sdk android:minSdkVersion="4" />

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


Modify main.xml, basically same as the one in the last exercise.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<Button
android:id="@+id/startcamerapreview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="- Start Camera Preview -"
/>
<Button
android:id="@+id/stopcamerapreview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="- Stop Camera Preview -"
/>
<SurfaceView
android:id="@+id/surfaceview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>


Modify the source code, AndroidCamera.
package com.exercise.AndroidCamera;

import java.io.IOException;

import android.app.Activity;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;

public class AndroidCamera extends Activity implements SurfaceHolder.Callback{

Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
boolean previewing = false;;

String stringPath = "/sdcard/samplevideo.3gp";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

Button buttonStartCameraPreview = (Button)findViewById(R.id.startcamerapreview);
Button buttonStopCameraPreview = (Button)findViewById(R.id.stopcamerapreview);

getWindow().setFormat(PixelFormat.UNKNOWN);
surfaceView = (SurfaceView)findViewById(R.id.surfaceview);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

buttonStartCameraPreview.setOnClickListener(new Button.OnClickListener(){

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(!previewing){
camera = Camera.open();
if (camera != null){
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
previewing = true;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}});

buttonStopCameraPreview.setOnClickListener(new Button.OnClickListener(){

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(camera != null && previewing){
camera.stopPreview();
camera.release();
camera = null;

previewing = false;
}
}});

}



@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub

}

@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub

}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub

}
}


Download the files.

Related Article:
- Camera Preview, version II



8 comments:

stefan2k said...

Thank you works like a charm!

Anonymous said...

Tnx! worked at once

Anonymous said...

Thats rock!

Thanks!

Soraia Olveira said...

Thank you very much :D

John said...

Finally a code that really works!

I've been searching for days, thanks.

Sotaya Yakubu said...

Hey, i have been getting this error whenever i press the start preview button, i don't know what is wrong. do you have a guess?


04-07 00:26:32.190: E/AndroidRuntime(18438): java.lang.RuntimeException: startPreview failed
04-07 00:26:32.190: E/AndroidRuntime(18438): at android.hardware.Camera.startPreview(Native Method)
04-07 00:26:32.190: E/AndroidRuntime(18438): at com.Server.camera.Main$1.onClick(Main.java:47)
04-07 00:26:32.190: E/AndroidRuntime(18438): at android.view.View.performClick(View.java:2485)

Sotaya Yakubu said...
This comment has been removed by the author.
Anonymous said...

How do I use this???