Camera API

The Android framework includes support for various cameras and camera features available on devices, allowing you to capture pictures and videos in your applications. This document discusses a quick, simple approach to image and video capture and outlines an advanced approach for creating custom camera experiences for your users.

Note: This page describes the Camera class, which has been deprecated. We recommend using the CameraX Jetpack library or, for specific use cases, the camera2, class. Both CameraX and Camera2 work on Android 5.0 (API level 21) and higher.

Considerations

Before enabling your application to use cameras on Android devices, you should consider a few questions about how your app intends to use this hardware feature.

• Camera Requirement - Is the use of a camera so important to your application that you do not want your application installed on a device that does not have a camera? If so, you should declare the camera requirement in your manifest.
• Quick Picture or Customized Camera - How will your application use the camera? Are you just interested in snapping a quick picture or video clip, or will your application provide a new way to use cameras? For getting a quick snap or clip, consider Using Existing Camera Apps. For developing a customized camera feature, check out the Building a Camera App section.
• Foreground Services Requirement - When does your app interact with the camera? On Android 9 (API level 28) and later, apps running in the background cannot access the camera. Therefore, you should use the camera either when your app is in the foreground or as part of a foreground service.
• Storage - Are the images or videos your application generates intended to be only visible to your application or shared so that other applications such as Gallery or other media and social apps can use them? Do you want the pictures and videos to be available even if your application is uninstalled? Check out the Saving Media Files section to see how to implement these options.

The basics

The Android framework supports capturing images and video through the android.hardware.camera2 API or camera Intent. Here are the relevant classes:

android.hardware.camera2

This package is the primary API for controlling device cameras. It can be used to take pictures or videos when you are building a camera application.

Camera

This class is the older deprecated API for controlling device cameras.

SurfaceView

This class is used to present a live camera preview to the user.

MediaRecorder

This class is used to record video from the camera.

Intent

An intent action type of MediaStore.ACTION_IMAGE_CAPTURE or MediaStore.ACTION_VIDEO_CAPTURE can be used to capture images or videos without directly using the Camera object.

Manifest declarations

Before starting development on your application with the Camera API, you should make sure your manifest has the appropriate declarations to allow use of camera hardware and other related features.

• Camera Permission - Your application must request permission to use a device camera.

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

  Note: If you are using the camera by invoking an existing camera app, your application does not need to request this permission.

• Camera Features - Your application must also declare use of camera features, for example:

  <uses-feature android:name="android.hardware.camera" />

  For a list of camera features, see the manifest Features Reference.

  Adding camera features to your manifest causes Google Play to prevent your application from being installed to devices that do not include a camera or do not support the camera features you specify. For more information about using feature-based filtering with Google Play, see Google Play and Feature-Based Filtering.

  If your application can use a camera or camera feature for proper operation, but does not require it, you should specify this in the manifest by including the android:required attribute, and setting it to false:

  <uses-feature android:name="android.hardware.camera" android:required="false" />

• Storage Permission - Your application can save images or videos to the device's external storage (SD Card) if it targets Android 10 (API level 29) or lower and specifies the following in the manifest.

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

• Audio Recording Permission - For recording audio with video capture, your application must request the audio capture permission.

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

• Location Permission - If your application tags images with GPS location information, you must request the ACCESS_FINE_LOCATION permission. Note that, if your app targets Android 5.0 (API level 21) or higher, you also need to declare that your app uses the device's GPS:

  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  ...
  <!-- Needed only if your app targets Android 5.0 (API level 21) or higher. -->
  <uses-feature android:name="android.hardware.location.gps" />

  For more information about getting user location, see Location Strategies.

Using existing camera apps

A quick way to enable taking pictures or videos in your application without a lot of extra code is to use an Intent to invoke an existing Android camera application. The details are described in the training lessons Taking Photos Simply and Recording Videos Simply.

Building a camera app

Some developers may require a camera user interface that is customized to the look of their application or provides special features. Writing your own picture-taking code can provide a more compelling experience for your users.

Note: The following guide is for the older, deprecated Camera API. For new or advanced camera applications, the newer android.hardware.camera2 API is recommended.

The general steps for creating a custom camera interface for your application are as follows:

• Detect and Access Camera - Create code to check for the existence of cameras and request access.
• Create a Preview Class - Create a camera preview class that extends SurfaceView and implements the SurfaceHolder interface. This class previews the live images from the camera.
• Build a Preview Layout - Once you have the camera preview class, create a view layout that incorporates the preview and the user interface controls you want.
• Setup Listeners for Capture - Connect listeners for your interface controls to start image or video capture in response to user actions, such as pressing a button.
• Capture and Save Files - Setup the code for capturing pictures or videos and saving the output.
• Release the Camera - After using the camera, your application must properly release it for use by other applications.

Camera hardware is a shared resource that must be carefully managed so your application does not collide with other applications that may also want to use it. The following sections discusses how to detect camera hardware, how to request access to a camera, how to capture pictures or video and how to release the camera when your application is done using it.

Caution: Remember to release the Camera object by calling the Camera.release() when your application is done using it! If your application does not properly release the camera, all subsequent attempts to access the camera, including those by your own application, will fail and may cause your or other applications to be shut down.

Detecting camera hardware

If your application does not specifically require a camera using a manifest declaration, you should check to see if a camera is available at runtime. To perform this check, use the PackageManager.hasSystemFeature() method, as shown in the example code below:

/** Check if this device has a camera */
private fun checkCameraHardware(context: Context): Boolean {
    if (context.packageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
        // this device has a camera
        return true
    } else {
        // no camera on this device
        return false
    }
}

/** Check if this device has a camera */
private boolean checkCameraHardware(Context context) {
    if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
        // this device has a camera
        return true;
    } else {
        // no camera on this device
        return false;
    }
}

Android devices can have multiple cameras, for example a back-facing camera for photography and a front-facing camera for video calls. Android 2.3 (API Level 9) and later allows you to check the number of cameras available on a device using the Camera.getNumberOfCameras() method.

Accessing cameras

If you have determined that the device on which your application is running has a camera, you must request to access it by getting an instance of Camera (unless you are using an intent to access the camera).

To access the primary camera, use the Camera.open() method and be sure to catch any exceptions, as shown in the code below:

/** A safe way to get an instance of the Camera object. */
fun getCameraInstance(): Camera? {
    return try {
        Camera.open() // attempt to get a Camera instance
    } catch (e: Exception) {
        // Camera is not available (in use or does not exist)
        null // returns null if camera is unavailable
    }
}

/** A safe way to get an instance of the Camera object. */
public static Camera getCameraInstance(){
    Camera c = null;
    try {
        c = Camera.open(); // attempt to get a Camera instance
    }
    catch (Exception e){
        // Camera is not available (in use or does not exist)
    }
    return c; // returns null if camera is unavailable
}

Caution: Always check for exceptions when using Camera.open(). Failing to check for exceptions if the camera is in use or does not exist will cause your application to be shut down by the system.

On devices running Android 2.3 (API Level 9) or higher, you can access specific cameras using Camera.open(int). The example code above will access the first, back-facing camera on a device with more than one camera.

Checking camera features

Once you obtain access to a camera, you can get further information about its capabilities using the Camera.getParameters() method and checking the returned Camera.Parameters object for supported capabilities. When using API Level 9 or higher, use the Camera.getCameraInfo() to determine if a camera is on the front or back of the device, and the orientation of the image.

Creating a preview class

For users to effectively take pictures or video, they must be able to see what the device camera sees. A camera preview class is a SurfaceView that can display the live image data coming from a camera, so users can frame and capture a picture or video.

The following example code demonstrates how to create a basic camera preview class that can be included in a View layout. This class implements SurfaceHolder.Callback in order to capture the callback events for creating and destroying the view, which are needed for assigning the camera preview input.

/** A basic Camera preview class */
class CameraPreview(
        context: Context,
        private val mCamera: Camera
) : SurfaceView(context), SurfaceHolder.Callback {

    private val mHolder: SurfaceHolder = holder.apply {
        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        addCallback(this@CameraPreview)
        // deprecated setting, but required on Android versions prior to 3.0
        setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS)
    }

    override fun surfaceCreated(holder: SurfaceHolder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        mCamera.apply {
            try {
                setPreviewDisplay(holder)
                startPreview()
            } catch (e: IOException) {
                Log.d(TAG, "Error setting camera preview: ${e.message}")
            }
        }
    }

    override fun surfaceDestroyed(holder: SurfaceHolder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    override fun surfaceChanged(holder: SurfaceHolder, format: Int, w: Int, h: Int) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.
        if (mHolder.surface == null) {
            // preview surface does not exist
            return
        }

        // stop preview before making changes
        try {
            mCamera.stopPreview()
        } catch (e: Exception) {
            // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // start preview with new settings
        mCamera.apply {
            try {
                setPreviewDisplay(mHolder)
                startPreview()
            } catch (e: Exception) {
                Log.d(TAG, "Error starting camera preview: ${e.message}")
            }
        }
    }
}

/** A basic Camera preview class */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d(TAG, "Error setting camera preview: " + e.getMessage());
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (mHolder.getSurface() == null){
          // preview surface does not exist
          return;
        }

        // stop preview before making changes
        try {
            mCamera.stopPreview();
        } catch (Exception e){
          // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // start preview with new settings
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e){
            Log.d(TAG, "Error starting camera preview: " + e.getMessage());
        }
    }
}

If you want to set a specific size for your camera preview, set this in the surfaceChanged() method as noted in the comments above. When setting preview size, you must use values from getSupportedPreviewSizes(). Do not set arbitrary values in the setPreviewSize() method.

Note: With the introduction of the Multi-Window feature in Android 7.0 (API level 24) and higher, you can no longer assume the aspect ratio of the preview is the same as your activity even after calling setDisplayOrientation(). Depending on the window size and aspect ratio, you may may have to fit a wide camera preview into a portrait-orientated layout, or vice versa, using a letterbox layout.

Placing preview in a layout

A camera preview class, such as the example shown in the previous section, must be placed in the layout of an activity along with other user interface controls for taking a picture or video. This section shows you how to build a basic layout and activity for the preview.

The following layout code provides a very basic view that can be used to display a camera preview. In this example, the FrameLayout element is meant to be the container for the camera preview class. This layout type is used so that additional picture information or controls can be overlaid on the live camera preview images.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
  <FrameLayout
    android:id="@+id/camera_preview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_weight="1"
    />

  <Button
    android:id="@+id/button_capture"
    android:text="Capture"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    />
</LinearLayout>

On most devices, the default orientation of the camera preview is landscape. This example layout specifies a horizontal (landscape) layout and the code below fixes the orientation of the application to landscape. For simplicity in rendering a camera preview, you should change your application's preview activity orientation to landscape by adding the following to your manifest.

<activity android:name=".CameraActivity"
          android:label="@string/app_name"

          android:screenOrientation="landscape">
          <!-- configure this activity to use landscape orientation -->

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

Note: A camera preview does not have to be in landscape mode. Starting in Android 2.2 (API Level 8), you can use the setDisplayOrientation() method to set the rotation of the preview image. In order to change preview orientation as the user re-orients the phone, within the surfaceChanged() method of your preview class, first stop the preview with Camera.stopPreview() change the orientation and then start the preview again with Camera.startPreview().

In the activity for your camera view, add your preview class to the FrameLayout element shown in the example above. Your camera activity must also ensure that it releases the camera when it is paused or shut down. The following example shows how to modify a camera activity to attach the preview class shown in Creating a preview class.

class CameraActivity : Activity() {

    private var mCamera: Camera? = null
    private var mPreview: CameraPreview? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Create an instance of Camera
        mCamera = getCameraInstance()

        mPreview = mCamera?.let {
            // Create our Preview view
            CameraPreview(this, it)
        }

        // Set the Preview view as the content of our activity.
        mPreview?.also {
            val preview: FrameLayout = findViewById(R.id.camera_preview)
            preview.addView(it)
        }
    }
}

public class CameraActivity extends Activity {

    private Camera mCamera;
    private CameraPreview mPreview;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // Create an instance of Camera
        mCamera = getCameraInstance();

        // Create our Preview view and set it as the content of our activity.
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mPreview);
    }
}

Note: The getCameraInstance() method in the example above refers to the example method shown in Accessing cameras.

Capturing pictures

Once you have built a preview class and a view layout in which to display it, you are ready to start capturing images with your application. In your application code, you must set up listeners for your user interface controls to respond to a user action by taking a picture.

In order to retrieve a picture, use the Camera.takePicture() method. This method takes three parameters which receive data from the camera. In order to receive data in a JPEG format, you must implement an Camera.PictureCallback interface to receive the image data and write it to a file. The following code shows a basic implementation of the Camera.PictureCallback interface to save an image received from the camera.

private val mPicture = Camera.PictureCallback { data, _ ->
    val pictureFile: File = getOutputMediaFile(MEDIA_TYPE_IMAGE) ?: run {
        Log.d(TAG, ("Error creating media file, check storage permissions"))
        return@PictureCallback
    }

    try {
        val fos = FileOutputStream(pictureFile)
        fos.write(data)
        fos.close()
    } catch (e: FileNotFoundException) {
        Log.d(TAG, "File not found: ${e.message}")
    } catch (e: IOException) {
        Log.d(TAG, "Error accessing file: ${e.message}")
    }
}

private PictureCallback mPicture = new PictureCallback() {

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {

        File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
        if (pictureFile == null){
            Log.d(TAG, "Error creating media file, check storage permissions");
            return;
        }

        try {
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();
        } catch (FileNotFoundException e) {
            Log.d(TAG, "File not found: " + e.getMessage());
        } catch (IOException e) {
            Log.d(TAG, "Error accessing file: " + e.getMessage());
        }
    }
};

Trigger capturing an image by calling the Camera.takePicture() method. The following example code shows how to call this method from a button View.OnClickListener.

val captureButton: Button = findViewById(R.id.button_capture)
captureButton.setOnClickListener {
    // get an image from the camera
    mCamera?.takePicture(null, null, picture)
}

// Add a listener to the Capture button
Button captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(
    new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // get an image from the camera
            mCamera.takePicture(null, null, picture);
        }
    }
);

Note: The mPicture member in the following example refers to the example code above.

Caution: Remember to release the Camera object by calling the Camera.release() when your application is done using it! For information about how to release the camera, see Releasing the camera.

Capturing videos

Video capture using the Android framework requires careful management of the Camera object and coordination with the MediaRecorder class. When recording video with Camera, you must manage the Camera.lock() and Camera.unlock() calls to allow MediaRecorder access to the camera hardware, in addition to the Camera.open() and Camera.release() calls.

Note: Starting with Android 4.0 (API level 14), the Camera.lock() and Camera.unlock() calls are managed for you automatically.

Unlike taking pictures with a device camera, capturing video requires a very particular call order. You must follow a specific order of execution to successfully prepare for and capture video with your application, as detailed below.

1. Open Camera - Use the Camera.open() to get an instance of the camera object.
2. Connect Preview - Prepare a live camera image preview by connecting a SurfaceView to the camera using Camera.setPreviewDisplay().
3. Start Preview - Call Camera.startPreview() to begin displaying the live camera images.
4. Start Recording Video - The following steps must be completed in order to successfully record video:
   1. Unlock the Camera - Unlock the camera for use by MediaRecorder by calling Camera.unlock().
   2. Configure MediaRecorder - Call in the following MediaRecorder methods in this order. For more information, see the MediaRecorder reference documentation.
      1. setCamera() - Set the camera to be used for video capture, use your application's current instance of Camera.
      2. setAudioSource() - Set the audio source, use MediaRecorder.AudioSource.CAMCORDER.
      3. setVideoSource() - Set the video source, use MediaRecorder.VideoSource.CAMERA.
      4. Set the video output format and encoding. For Android 2.2 (API Level 8) and higher, use the MediaRecorder.setProfile method, and get a profile instance using CamcorderProfile.get(). For versions of Android prior to 2.2, you must set the video output format and encoding parameters:
         1. setOutputFormat() - Set the output format, specify the default setting or MediaRecorder.OutputFormat.MPEG_4.
         2. setAudioEncoder() - Set the sound encoding type, specify the default setting or MediaRecorder.AudioEncoder.AMR_NB.
         3. setVideoEncoder() - Set the video encoding type, specify the default setting or MediaRecorder.VideoEncoder.MPEG_4_SP.
      5. setOutputFile() - Set the output file, use getOutputMediaFile(MEDIA_TYPE_VIDEO).toString() from the example method in the Saving Media Files section.
      6. setPreviewDisplay() - Specify the SurfaceView preview layout element for your application. Use the same object you specified for Connect Preview.

      Caution: You must call these MediaRecorder configuration methods in this order, otherwise your application will encounter errors and the recording will fail.

   3. Prepare MediaRecorder - Prepare the MediaRecorder with provided configuration settings by calling MediaRecorder.prepare().
   4. Start MediaRecorder - Start recording video by calling MediaRecorder.start().
5. Stop Recording Video - Call the following methods in order, to successfully complete a video recording:
   1. Stop MediaRecorder - Stop recording video by calling MediaRecorder.stop().
   2. Reset MediaRecorder - Optionally, remove the configuration settings from the recorder by calling MediaRecorder.reset().
   3. Release MediaRecorder - Release the MediaRecorder by calling MediaRecorder.release().
   4. Lock the Camera - Lock the camera so that future MediaRecorder sessions can use it by calling Camera.lock(). Starting with Android 4.0 (API level 14), this call is not required unless the MediaRecorder.prepare() call fails.
6. Stop the Preview - When your activity has finished using the camera, stop the preview using Camera.stopPreview().
7. Release Camera - Release the camera so that other applications can use it by calling Camera.release().

Note: It is possible to use MediaRecorder without creating a camera preview first and skip the first few steps of this process. However, since users typically prefer to see a preview before starting a recording, that process is not discussed here.

Tip: If your application is typically used for recording video, set setRecordingHint(boolean) to true prior to starting your preview. This setting can help reduce the time it takes to start recording.

Configuring MediaRecorder

When using the MediaRecorder class to record video, you must perform configuration steps in a specific order and then call the MediaRecorder.prepare() method to check and implement the configuration. The following example code demonstrates how to properly configure and prepare the MediaRecorder class for video recording.

private fun prepareVideoRecorder(): Boolean {
    mediaRecorder = MediaRecorder()

    mCamera?.let { camera ->
        // Step 1: Unlock and set camera to MediaRecorder
        camera?.unlock()

        mediaRecorder?.run {
            setCamera(camera)

            // Step 2: Set sources
            setAudioSource(MediaRecorder.AudioSource.CAMCORDER)
            setVideoSource(MediaRecorder.VideoSource.CAMERA)

            // Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
            setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH))

            // Step 4: Set output file
            setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString())

            // Step 5: Set the preview output
            setPreviewDisplay(mPreview?.holder?.surface)

            setOutputFormat(MediaRecorder.OutputFormat.MPEG_4)
            setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT)
            setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT)


            // Step 6: Prepare configured MediaRecorder
            return try {
                prepare()
                true
            } catch (e: IllegalStateException) {
                Log.d(TAG, "IllegalStateException preparing MediaRecorder: ${e.message}")
                releaseMediaRecorder()
                false
            } catch (e: IOException) {
                Log.d(TAG, "IOException preparing MediaRecorder: ${e.message}")
                releaseMediaRecorder()
                false
            }
        }

    }
    return false
}

private boolean prepareVideoRecorder(){

    mCamera = getCameraInstance();
    mediaRecorder = new MediaRecorder();

    // Step 1: Unlock and set camera to MediaRecorder
    mCamera.unlock();
    mediaRecorder.setCamera(mCamera);

    // Step 2: Set sources
    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
    mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

    // Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
    mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));

    // Step 4: Set output file
    mediaRecorder.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString());

    // Step 5: Set the preview output
    mediaRecorder.setPreviewDisplay(mPreview.getHolder().getSurface());

    // Step 6: Prepare configured MediaRecorder
    try {
        mediaRecorder.prepare();
    } catch (IllegalStateException e) {
        Log.d(TAG, "IllegalStateException preparing MediaRecorder: " + e.getMessage());
        releaseMediaRecorder();
        return false;
    } catch (IOException e) {
        Log.d(TAG, "IOException preparing MediaRecorder: " + e.getMessage());
        releaseMediaRecorder();
        return false;
    }
    return true;
}

Prior to Android 2.2 (API Level 8), you must set the output format and encoding formats parameters directly, instead of using CamcorderProfile. This approach is demonstrated in the following code:

    // Step 3: Set output format and encoding (for versions prior to API Level 8)
    mediaRecorder?.apply {
        setOutputFormat(MediaRecorder.OutputFormat.MPEG_4)
        setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT)
        setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT)
    }

    // Step 3: Set output format and encoding (for versions prior to API Level 8)
    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
    mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);

The following video recording parameters for MediaRecorder are given default settings, however, you may want to adjust these settings for your application:

• setVideoEncodingBitRate()
• setVideoSize()
• setVideoFrameRate()
• setAudioEncodingBitRate()
• setAudioChannels()
• setAudioSamplingRate()

Starting and stopping MediaRecorder

When starting and stopping video recording using the MediaRecorder class, you must follow a specific order, as listed below.

1. Unlock the camera with Camera.unlock()
2. Configure MediaRecorder as shown in the code example above
3. Start recording using MediaRecorder.start()
4. Record the video
5. Stop recording using MediaRecorder.stop()
6. Release the media recorder with MediaRecorder.release()
7. Lock the camera using Camera.lock()

The following example code demonstrates how to wire up a button to properly start and stop video recording using the camera and the MediaRecorder class.

Note: When completing a video recording, do not release the camera or else your preview will be stopped.

var isRecording = false
val captureButton: Button = findViewById(R.id.button_capture)
captureButton.setOnClickListener {
    if (isRecording) {
        // stop recording and release camera
        mediaRecorder?.stop() // stop the recording
        releaseMediaRecorder() // release the MediaRecorder object
        mCamera?.lock() // take camera access back from MediaRecorder

        // inform the user that recording has stopped
        setCaptureButtonText("Capture")
        isRecording = false
    } else {
        // initialize video camera
        if (prepareVideoRecorder()) {
            // Camera is available and unlocked, MediaRecorder is prepared,
            // now you can start recording
            mediaRecorder?.start()

            // inform the user that recording has started
            setCaptureButtonText("Stop")
            isRecording = true
        } else {
            // prepare didn't work, release the camera
            releaseMediaRecorder()
            // inform user
        }
    }
}

private boolean isRecording = false;

// Add a listener to the Capture button
Button captureButton = (Button) findViewById(id.button_capture);
captureButton.setOnClickListener(
    new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (isRecording) {
                // stop recording and release camera
                mediaRecorder.stop();  // stop the recording
                releaseMediaRecorder(); // release the MediaRecorder object
                mCamera.lock();         // take camera access back from MediaRecorder

                // inform the user that recording has stopped
                setCaptureButtonText("Capture");
                isRecording = false;
            } else {
                // initialize video camera
                if (prepareVideoRecorder()) {
                    // Camera is available and unlocked, MediaRecorder is prepared,
                    // now you can start recording
                    mediaRecorder.start();

                    // inform the user that recording has started
                    setCaptureButtonText("Stop");
                    isRecording = true;
                } else {
                    // prepare didn't work, release the camera
                    releaseMediaRecorder();
                    // inform user
                }
            }
        }
    }
);

Note: In the above example, the prepareVideoRecorder() method refers to the example code shown in Configuring MediaRecorder. This method takes care of locking the camera, configuring and preparing the MediaRecorder instance.

Releasing the camera

Cameras are a resource that is shared by applications on a device. Your application can make use of the camera after getting an instance of Camera, and you must be particularly careful to release the camera object when your application stops using it, and as soon as your application is paused (Activity.onPause()). If your application does not properly release the camera, all subsequent attempts to access the camera, including those by your own application, will fail and may cause your or other applications to be shut down.

To release an instance of the Camera object, use the Camera.release() method, as shown in the example code below.

class CameraActivity : Activity() {
    private var mCamera: Camera?
    private var preview: SurfaceView?
    private var mediaRecorder: MediaRecorder?

    override fun onPause() {
        super.onPause()
        releaseMediaRecorder() // if you are using MediaRecorder, release it first
        releaseCamera() // release the camera immediately on pause event
    }

    private fun releaseMediaRecorder() {
        mediaRecorder?.reset() // clear recorder configuration
        mediaRecorder?.release() // release the recorder object
        mediaRecorder = null
        mCamera?.lock() // lock camera for later use
    }

    private fun releaseCamera() {
        mCamera?.release() // release the camera for other applications
        mCamera = null
    }
}

public class CameraActivity extends Activity {
    private Camera mCamera;
    private SurfaceView preview;
    private MediaRecorder mediaRecorder;

    ...

    @Override
    protected void onPause() {
        super.onPause();
        releaseMediaRecorder();       // if you are using MediaRecorder, release it first
        releaseCamera();              // release the camera immediately on pause event
    }

    private void releaseMediaRecorder(){
        if (mediaRecorder != null) {
            mediaRecorder.reset();   // clear recorder configuration
            mediaRecorder.release(); // release the recorder object
            mediaRecorder = null;
            mCamera.lock();           // lock camera for later use
        }
    }

    private void releaseCamera(){
        if (mCamera != null){
            mCamera.release();        // release the camera for other applications
            mCamera = null;
        }
    }
}

Caution: If your application does not properly release the camera, all subsequent attempts to access the camera, including those by your own application, will fail and may cause your or other applications to be shut down.

Saving media files

Media files created by users such as pictures and videos should be saved to a device's external storage directory (SD Card) to conserve system space and to allow users to access these files without their device. There are many possible directory locations to save media files on a device, however there are only two standard locations you should consider as a developer:

• Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) - This method returns the standard, shared and recommended location for saving pictures and videos. This directory is shared (public), so other applications can easily discover, read, change and delete files saved in this location. If your application is uninstalled by the user, media files saved to this location will not be removed. To avoid interfering with users existing pictures and videos, you should create a sub-directory for your application's media files within this directory, as shown in the code sample below. This method is available in Android 2.2 (API Level 8), for equivalent calls in earlier API versions, see Saving Shared Files.
• Context.getExternalFilesDir(Environment.DIRECTORY_PICTURES) - This method returns a standard location for saving pictures and videos which are associated with your application. If your application is uninstalled, any files saved in this location are removed. Security is not enforced for files in this location and other applications may read, change and delete them.

The following example code demonstrates how to create a File or Uri location for a media file that can be used when invoking a device's camera with an Intent or as part of a Building a Camera App.

val MEDIA_TYPE_IMAGE = 1
val MEDIA_TYPE_VIDEO = 2

/** Create a file Uri for saving an image or video */
private fun getOutputMediaFileUri(type: Int): Uri {
    return Uri.fromFile(getOutputMediaFile(type))
}

/** Create a File for saving an image or video */
private fun getOutputMediaFile(type: Int): File? {
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this.

    val mediaStorageDir = File(
            Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
            "MyCameraApp"
    )
    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.

    // Create the storage directory if it does not exist
    mediaStorageDir.apply {
        if (!exists()) {
            if (!mkdirs()) {
                Log.d("MyCameraApp", "failed to create directory")
                return null
            }
        }
    }

    // Create a media file name
    val timeStamp = SimpleDateFormat("yyyyMMdd_HHmmss").format(Date())
    return when (type) {
        MEDIA_TYPE_IMAGE -> {
            File("${mediaStorageDir.path}${File.separator}IMG_$timeStamp.jpg")
        }
        MEDIA_TYPE_VIDEO -> {
            File("${mediaStorageDir.path}${File.separator}VID_$timeStamp.mp4")
        }
        else -> null
    }
}

public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;

/** Create a file Uri for saving an image or video */
private static Uri getOutputMediaFileUri(int type){
      return Uri.fromFile(getOutputMediaFile(type));
}

/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type){
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this.

    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
              Environment.DIRECTORY_PICTURES), "MyCameraApp");
    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.

    // Create the storage directory if it does not exist
    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            Log.d("MyCameraApp", "failed to create directory");
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == MEDIA_TYPE_IMAGE){
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
        "IMG_"+ timeStamp + ".jpg");
    } else if(type == MEDIA_TYPE_VIDEO) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
        "VID_"+ timeStamp + ".mp4");
    } else {
        return null;
    }

    return mediaFile;
}

Note: Environment.getExternalStoragePublicDirectory() is available in Android 2.2 (API Level 8) or higher. If you are targeting devices with earlier versions of Android, use Environment.getExternalStorageDirectory() instead. For more information, see Saving Shared Files.

To make the URI support work profiles, first convert the file URI to a content URI. Then, add the content URI to EXTRA_OUTPUT of an Intent.

For more information about saving files on an Android device, see Data Storage.

Camera features

Android supports a wide array of camera features you can control with your camera application, such as picture format, flash mode, focus settings, and many more. This section lists the common camera features, and briefly discusses how to use them. Most camera features can be accessed and set using the through Camera.Parameters object. However, there are several important features that require more than simple settings in Camera.Parameters. These features are covered in the following sections:

• Metering and focus areas
• Face detection
• Time lapse video

For general information about how to use features that are controlled through Camera.Parameters, review the Using camera features section. For more detailed information about how to use features controlled through the camera parameters object, follow the links in the feature list below to the API reference documentation.

Table 1. Common camera features sorted by the Android API Level in which they were introduced.

Note: These features are not supported on all devices due to hardware differences and software implementation. For information on checking the availability of features on the device where your application is running, see Checking feature availability.

Checking feature availability

The first thing to understand when setting out to use camera features on Android devices is that not all camera features are supported on all devices. In addition, devices that support a particular feature may support them to different levels or with different options. Therefore, part of your decision process as you develop a camera application is to decide what camera features you want to support and to what level. After making that decision, you should plan on including code in your camera application that checks to see if device hardware supports those features and fails gracefully if a feature is not available.

You can check the availability of camera features by getting an instance of a camera's parameters object, and checking the relevant methods. The following code sample shows you how to obtain a Camera.Parameters object and check if the camera supports the autofocus feature:

val params: Camera.Parameters? = camera?.parameters
val focusModes: List<String>? = params?.supportedFocusModes
if (focusModes?.contains(Camera.Parameters.FOCUS_MODE_AUTO) == true) {
    // Autofocus mode is supported
}

// get Camera parameters
Camera.Parameters params = camera.getParameters();

List<String> focusModes = params.getSupportedFocusModes();
if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
  // Autofocus mode is supported
}

You can use the technique shown above for most camera features. The Camera.Parameters object provides a getSupported...(), is...Supported() or getMax...() method to determine if (and to what extent) a feature is supported.

If your application requires certain camera features in order to function properly, you can require them through additions to your application manifest. When you declare the use of specific camera features, such as flash and auto-focus, Google Play restricts your application from being installed on devices which do not support these features. For a list of camera features that can be declared in your app manifest, see the manifest Features Reference.

Using camera features

Most camera features are activated and controlled using a Camera.Parameters object. You obtain this object by first getting an instance of the Camera object, calling the getParameters() method, changing the returned parameter object and then setting it back into the camera object, as demonstrated in the following example code:

val params: Camera.Parameters? = camera?.parameters
params?.focusMode = Camera.Parameters.FOCUS_MODE_AUTO
camera?.parameters = params

// get Camera parameters
Camera.Parameters params = camera.getParameters();
// set the focus mode
params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
// set Camera parameters
camera.setParameters(params);

This technique works for nearly all camera features, and most parameters can be changed at any time after you have obtained an instance of the Camera object. Changes to parameters are typically visible to the user immediately in the application's camera preview. On the software side, parameter changes may take several frames to actually take effect as the camera hardware processes the new instructions and then sends updated image data.

Important: Some camera features cannot be changed at will. In particular, changing the size or orientation of the camera preview requires that you first stop the preview, change the preview size, and then restart the preview. Starting with Android 4.0 (API Level 14) preview orientation can be changed without restarting the preview.

Other camera features require more code in order to implement, including:

• Metering and focus areas
• Face detection
• Time lapse video

A quick outline of how to implement these features is provided in the following sections.

Metering and focus areas

In some photographic scenarios, automatic focusing and light metering may not produce the desired results. Starting with Android 4.0 (API Level 14), your camera application can provide additional controls to allow your app or users to specify areas in an image to use for determining focus or light level settings and pass these values to the camera hardware for use in capturing images or video.

Areas for metering and focus work very similarly to other camera features, in that you control them through methods in the Camera.Parameters object. The following code demonstrates setting two light metering areas for an instance of Camera:

// Create an instance of Camera
camera = getCameraInstance()

// set Camera parameters
val params: Camera.Parameters? = camera?.parameters

params?.apply {
    if (maxNumMeteringAreas > 0) { // check that metering areas are supported
        meteringAreas = ArrayList<Camera.Area>().apply {
            val areaRect1 = Rect(-100, -100, 100, 100) // specify an area in center of image
            add(Camera.Area(areaRect1, 600)) // set weight to 60%
            val areaRect2 = Rect(800, -1000, 1000, -800) // specify an area in upper right of image
            add(Camera.Area(areaRect2, 400)) // set weight to 40%
        }
    }
    camera?.parameters = this
}

// Create an instance of Camera
camera = getCameraInstance();

// set Camera parameters
Camera.Parameters params = camera.getParameters();

if (params.getMaxNumMeteringAreas() > 0){ // check that metering areas are supported
    List<Camera.Area> meteringAreas = new ArrayList<Camera.Area>();

    Rect areaRect1 = new Rect(-100, -100, 100, 100);    // specify an area in center of image
    meteringAreas.add(new Camera.Area(areaRect1, 600)); // set weight to 60%
    Rect areaRect2 = new Rect(800, -1000, 1000, -800);  // specify an area in upper right of image
    meteringAreas.add(new Camera.Area(areaRect2, 400)); // set weight to 40%
    params.setMeteringAreas(meteringAreas);
}

camera.setParameters(params);

The Camera.Area object contains two data parameters: A Rect object for specifying an area within the camera's field of view and a weight value, which tells the camera what level of importance this area should be given in light metering or focus calculations.

The Rect field in a Camera.Area object describes a rectangular shape mapped on a 2000 x 2000 unit grid. The coordinates -1000, -1000 represent the top, left corner of the camera image, and coordinates 1000, 1000 represent the bottom, right corner of the camera image, as shown in the illustration below.

Figure 1. The red lines illustrate the coordinate system for specifying a Camera.Area within a camera preview. The blue box shows the location and shape of an camera area with the Rect values 333,333,667,667.

The bounds of this coordinate system always correspond to the outer edge of the image visible in the camera preview and do not shrink or expand with the zoom level. Similarly, rotation of the image preview using Camera.setDisplayOrientation() does not remap the coordinate system.

Face detection

For pictures that include people, faces are usually the most important part of the picture, and should be used for determining both focus and white balance when capturing an image. The Android 4.0 (API Level 14) framework provides APIs for identifying faces and calculating picture settings using face recognition technology.

Note: While the face detection feature is running, setWhiteBalance(String), setFocusAreas(List<Camera.Area>) and setMeteringAreas(List<Camera.Area>) have no effect.

Using the face detection feature in your camera application requires a few general steps:

• Check that face detection is supported on the device
• Create a face detection listener
• Add the face detection listener to your camera object
• Start face detection after preview (and after every preview restart)

The face detection feature is not supported on all devices. You can check that this feature is supported by calling getMaxNumDetectedFaces(). An example of this check is shown in the startFaceDetection() sample method below.

In order to be notified and respond to the detection of a face, your camera application must set a listener for face detection events. In order to do this, you must create a listener class that implements the Camera.FaceDetectionListener interface as shown in the example code below.

internal class MyFaceDetectionListener : Camera.FaceDetectionListener {

    override fun onFaceDetection(faces: Array<Camera.Face>, camera: Camera) {
        if (faces.isNotEmpty()) {
            Log.d("FaceDetection", ("face detected: ${faces.size}" +
                    " Face 1 Location X: ${faces[0].rect.centerX()}" +
                    "Y: ${faces[0].rect.centerY()}"))
        }
    }
}

class MyFaceDetectionListener implements Camera.FaceDetectionListener {

    @Override
    public void onFaceDetection(Face[] faces, Camera camera) {
        if (faces.length > 0){
            Log.d("FaceDetection", "face detected: "+ faces.length +
                    " Face 1 Location X: " + faces[0].rect.centerX() +
                    "Y: " + faces[0].rect.centerY() );
        }
    }
}

After creating this class, you then set it into your application's Camera object, as shown in the example code below:

camera?.setFaceDetectionListener(MyFaceDetectionListener())

camera.setFaceDetectionListener(new MyFaceDetectionListener());

Your application must start the face detection function each time you start (or restart) the camera preview. Create a method for starting face detection so you can call it as needed, as shown in the example code below.

fun startFaceDetection() {
    // Try starting Face Detection
    val params = mCamera?.parameters
    // start face detection only *after* preview has started

    params?.apply {
        if (maxNumDetectedFaces > 0) {
            // camera supports face detection, so can start it:
            mCamera?.startFaceDetection()
        }
    }
}

public void startFaceDetection(){
    // Try starting Face Detection
    Camera.Parameters params = mCamera.getParameters();

    // start face detection only *after* preview has started
    if (params.getMaxNumDetectedFaces() > 0){
        // camera supports face detection, so can start it:
        mCamera.startFaceDetection();
    }
}

You must start face detection each time you start (or restart) the camera preview. If you use the preview class shown in Creating a preview class, add your startFaceDetection() method to both the surfaceCreated() and surfaceChanged() methods in your preview class, as shown in the sample code below.

override fun surfaceCreated(holder: SurfaceHolder) {
    try {
        mCamera.setPreviewDisplay(holder)
        mCamera.startPreview()

        startFaceDetection() // start face detection feature
    } catch (e: IOException) {
        Log.d(TAG, "Error setting camera preview: ${e.message}")
    }
}

override fun surfaceChanged(holder: SurfaceHolder, format: Int, w: Int, h: Int) {
    if (holder.surface == null) {
        // preview surface does not exist
        Log.d(TAG, "holder.getSurface() == null")
        return
    }
    try {
        mCamera.stopPreview()
    } catch (e: Exception) {
        // ignore: tried to stop a non-existent preview
        Log.d(TAG, "Error stopping camera preview: ${e.message}")
    }
    try {
        mCamera.setPreviewDisplay(holder)
        mCamera.startPreview()

        startFaceDetection() // re-start face detection feature
    } catch (e: Exception) {
        // ignore: tried to stop a non-existent preview
        Log.d(TAG, "Error starting camera preview: ${e.message}")
    }
}

public void surfaceCreated(SurfaceHolder holder) {
    try {
        mCamera.setPreviewDisplay(holder);
        mCamera.startPreview();

        startFaceDetection(); // start face detection feature

    } catch (IOException e) {
        Log.d(TAG, "Error setting camera preview: " + e.getMessage());
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {

    if (holder.getSurface() == null){
        // preview surface does not exist
        Log.d(TAG, "holder.getSurface() == null");
        return;
    }

    try {
        mCamera.stopPreview();

    } catch (Exception e){
        // ignore: tried to stop a non-existent preview
        Log.d(TAG, "Error stopping camera preview: " + e.getMessage());
    }

    try {
        mCamera.setPreviewDisplay(holder);
        mCamera.startPreview();

        startFaceDetection(); // re-start face detection feature

    } catch (Exception e){
        // ignore: tried to stop a non-existent preview
        Log.d(TAG, "Error starting camera preview: " + e.getMessage());
    }
}

Note: Remember to call this method after calling startPreview(). Do not attempt to start face detection in the onCreate() method of your camera app's main activity, as the preview is not available by this point in your application's the execution.

Time lapse video

Time lapse video allows users to create video clips that combine pictures taken a few seconds or minutes apart. This feature uses MediaRecorder to record the images for a time lapse sequence.

To record a time lapse video with MediaRecorder, you must configure the recorder object as if you are recording a normal video, setting the captured frames per second to a low number and using one of the time lapse quality settings, as shown in the code example below.

mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_TIME_LAPSE_HIGH))
mediaRecorder.setCaptureRate(0.1) // capture a frame every 10 seconds

// Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_TIME_LAPSE_HIGH));
...
// Step 5.5: Set the video capture rate to a low number
mediaRecorder.setCaptureRate(0.1); // capture a frame every 10 seconds

These settings must be done as part of a larger configuration procedure for MediaRecorder. For a full configuration code example, see Configuring MediaRecorder. Once the configuration is complete, you start the video recording as if you were recording a normal video clip. For more information about configuring and running MediaRecorder, see Capturing videos.

The Camera2Video and HdrViewfinder samples further demonstrate the use of the APIs covered on this page.

Camera fields that require permission

Apps running Android 10 (API level 29) or higher must have the CAMERA permission in order to access the values of the following fields that the getCameraCharacteristics() method returns:

• LENS_POSE_ROTATION
• LENS_POSE_TRANSLATION
• LENS_INTRINSIC_CALIBRATION
• LENS_RADIAL_DISTORTION
• LENS_POSE_REFERENCE
• LENS_DISTORTION
• LENS_INFO_HYPERFOCAL_DISTANCE
• LENS_INFO_MINIMUM_FOCUS_DISTANCE
• SENSOR_REFERENCE_ILLUMINANT1
• SENSOR_REFERENCE_ILLUMINANT2
• SENSOR_CALIBRATION_TRANSFORM1
• SENSOR_CALIBRATION_TRANSFORM2
• SENSOR_COLOR_TRANSFORM1
• SENSOR_COLOR_TRANSFORM2
• SENSOR_FORWARD_MATRIX1
• SENSOR_FORWARD_MATRIX2

Additional sample code

To download sample apps, see the Camera2Basic sample and Official CameraX sample app.