[Android, 19] android camera, video recording, enabling system camera and video recording

Camera development: 1. Camera Interface Design: 1. camera interface requirements:

① The camera screen is displayed on a horizontal screen: android: screenOrientation of the activity element in the list file

Attribute specifies the display status, landscape is displayed on a horizontal screen, and portrait is displayed on a vertical screen. If this attribute is not specified, the screen can be switched.

Android: icon = "@ drawable/ic_launcher"

Android: label = "@ string/app_name">

Android: screenOrientation = "landscape"

Android: name = ". DemoActivity"

Android: label = "@ string/app_name">

 

 

 

 

 

 

② Full screen display on the camera: the status bar and title bar of the activity are hidden.

 

In the onCreate method of the activity, use the requestWindowFeature () method to set the status of the display form, which is Window. FEATURE_NO_TITLE with no title.

Note: you must write it before the setcontentview () method.

 

Public class DemoActivity extends Activity implementsOnClickListener {

 

Public voidonCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

// Do not display the title:

// Be sure to write it before setcontentview

RequestWindowFeature (Window. FEATURE_NO_TITLE );

SetContentView (R. layout. main );

// Set the form to hide the status bar

GetWindow (). setFlags (

WindowManager. LayoutParams. FLAG_FULLSCREEN,

WindowManager. LayoutParams. FLAG_FULLSCREEN );

}

}

2. Camera UI layout:

Xmlns: android = "http://schemas.android.com/apk/res/android"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent">

 

Android: id = "@ + id/sv"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent"/>

 

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: layout_alignParentBottom = "true"

Android: layout_alignParentRight = "true"

Android: orientation = "horizontal">

 

Android: id = "@ + id/autofocus"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: text = "Auto Focus"/>

 

Android: id = "@ + id/takepic"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: text = "photo"/>

 

 

 

Ii. Development code:

// Obtain each component

SurfaceView sv = (SurfaceView) this. findViewById (R. id. sv );

// Focus button

Button autofocus = (Button) this. findViewById (R. id. autofocus );

// Take a photo

Button takepic = (Button) this. findViewById (R. id. takepic );

// Click the button to register the click event:

Autofocus. setOnClickListener (this );

Takepic. setOnClickListener (this );

// Obtain the SurfaceHolder object

SurfaceHolder holder = sv. getHolder ();

// Note: before creating holder:

Holder. setType (SurfaceHolder. SURFACE_TYPE_PUSH_BUFFERS );

// Set the SurfaceHolder callback function

Holder. addCallback (new Callback (){

 

// Method of SurfaceHolder destruction

Public voidsurfaceDestroyed (SurfaceHolder holder ){

Camera. release (); // release resources

Camera = null;

}

 

// Method called when SurfaceHolder is created:

Public voidsurfaceCreated (SurfaceHolder holder ){

// Set the SurfaceHolder object to the member variable.

DemoActivity. this. holder = holder;

// Camera object

Camera = Camera. open ();

// Obtain the key-value pairs of all parameters of the camera.

// String parrten = camera. getParameters (). flatten ();

 

// TODO: set the camera parameters

// Obtain the Camera Parameter object:

Camera. Parameters parms = camera. getParameters ();

System. out. println (parms. flatten ());

// Set the value for the parameter:

Parms. setPreviewFrameRate (5); // Number of frames per second

Parms. setPictureSize (1280,960); // set the width and height.

Parms. setPictureFormat (PixelFormat. JPEG); // set the photo output format

Parms. set ("jpeg-quality", 100); // photo quality

//

// Camera. setParameters (parms );

// Set the preview interface. surfaceHolder is used as the parameter:

Camera. setPreviewDisplay (holder );

 

// Display the screenshot through SurfaceView

Camera. startPreview (); // start previewing

}

 

@ Override

Public voidsurfaceChanged (SurfaceHolder holder, int format,

Int width, int height ){

 

}

});

 

 

Button click event method:

Public void onClick (View v ){

Switch (v. getId ()){

Case R. id. autofocus: // click the focus button.

Camera. autoFocus (null); // Method for focusing the phone:

Break;

Case R. id. takepic: // click the camera button:

// Parameter 1 of the takePicture method: the callback when the camera sounds when the shutter is pressed.

Parameter 2: callback of the uncompressed image after the photo

Parameter 3: callback for compressing a photo into a jpeg Image

Camera. takePicture (null, null, new PictureCallback (){

// Method parameter 1: the binary byte array of the photo

Public voidonPictureTaken (byte [] data, Camera camera ){

// Determine whether sd is available

If (Environment. MEDIA_MOUNTED.equals (

Environment. getExternalStorageState ())){

// TODO: Save the image to the SD card.

 

File file = new File (

Environment. getExternalStorageDirectory (),

System. currentTimeMillis () + ". jpg ");

FileOutputStream fos = new FileOutputStream (file );

// Fos. write (data );

// Fos. flush ();

// Fos. close ();

// DecodeByteArray () method to obtain the Bitmap object

Bitmap bm = BitmapFactory. decodeByteArray (data, 0, data. length );

// Compression method:

Parameter 1: The compressed image format.

Parameter 2: file Quality

Parameter 3: output stream of the file

Bm. compress (CompressFormat. JPEG, 50, fos );

 

Fos. flush ();

Fos. close ();

Toast. makeText (

GetApplicationContext (), "saved image succeeded", 1). show ();

Camera. startPreview (); // preview the image again

 

} Else {

Toast. makeText (getApplicationContext (), "SD card unavailable", 1). show ();

}

 

}

});

Break;

 

}

 

}

 

 

Video Recording Development: mediaRecorder Class I. UI layout:

 

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent">

 

Android: id = "@ + id/sv"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent"/>

 

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: layout_alignParentBottom = "true"

Android: layout_alignParentRight = "true"

Android: orientation = "horizontal">

 

Android: id = "@ + id/recoder"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: text = "Recording"/>

 

Android: id = "@ + id/stop"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: enabled = "false"

Android: clickable = "false"

Android: text = "stop"/>

 

 

 

Ii. Business Code: activity Class,

Public class DemoActivity extends Activity implementsOnClickListener {

Private SurfaceView sv;

Private Buttonstart, stop;

Private SurfaceHolderholder;

 

 

Private MediaRecorderrecorder;

@ Override

Public voidonCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

SetContentView (R. layout. main );

// Obtain the component

Sv = (SurfaceView) this. findViewById (R. id. sv );

// Obtain surfaceHolder

Holder = sv. getHolder ();

Holder. setType (SurfaceHolder. SURFACE_TYPE_PUSH_BUFFERS );

Start = (Button) this. findViewById (R. id. recoder );

Stop = (Button) this. findViewById (R. id. stop );

Start. setOnClickListener (this );

Stop. setOnClickListener (this );

// Callback of SurfaceHolder

Holder. addCallback (new Callback (){

 

@ Override

Public void surfaceDestroyed (SurfaceHolder holder ){

//

 

}

 

@ Override

Public void surfaceCreated (SurfaceHolder holder ){

 

DemoActivity. this. holder = holder;

// Create a MediaRecorder object

Recorder = newMediaRecorder ();

Recorder. reset ();

// Capture video from camera

Recorder. setVideoSource (MediaRecorder. VideoSource. CAMERA );

// Set the audio collection

Recorder. setAudioSource (MediaRecorder. AudioSource. MIC );

// Set the output format

Recorder. setOutputFormat (MediaRecorder. OutputFormat. THREE_GPP );

// Set the size

Recorder. setVideoSize (720,480); // TODO?

 

Recorder. setVideoFrameRate (3); // 3 frames per second

// Sets the video encoding method.

Recorder. setVideoEncoder (MediaRecorder. VideoEncoder. H263 );

Recorder. setAudioEncoder (MediaRecorder. AudioEncoder. AMR_NB );

// Determine whether sd is available if (Environment. getExternalStorageState (). equals (Environment. MEDIA_MOUNTED )){

 

// Create a video file object

File file = new File (

Environment. getExternalStorageDirectory (),

System. currentTimeMillis () + ". 3gp ");

// Video output file

Recorder. setOutputFile (file. getAbsolutePath ());

// Set display

Recorder. setPreviewDisplay (DemoActivity. this. holder. getSurface ());

 

} Else {

Toast. makeText (getApplicationContext (), "SD card unavailable", 1). show ();

}

}

 

@ Override

Public void surfaceChanged (SurfaceHolder holder, int format, intwidth,

Int height ){

// TODO Auto-generatedmethod stub

 

}

});

 

}

// Button clicking event Method

Public void onClick (Viewv ){

 

Switch (v. getId ()){

Case R. id. recoder: // recording button

Try {

Recorder. prepare (); // prepare for recording

} Catch (Exception e ){

Toast. makeText (getApplicationContext (), "Recording preparation failed", 0). show ();

E. printStackTrace ();

} // Expected preparation

Recorder. start ();

Stop. setEnabled (true );

Stop. setClickable (true );

 

Start. setEnabled (false );

Start. setClickable (false );

Break;

Case R. id. stop: // stop button

Recorder. stop ();

Recorder. release ();

 

Start. setEnabled (true );

Start. setClickable (true );

 

Stop. setEnabled (false );

Stop. setClickable (false );

Break;

}

}

}

 

Intention to enable system camera:

 

1. Activate the System camera component:

Public class DemoActivity extends Activity {

/** Called when theactivity is first created .*/

Private ImageView iv;

@ Override

Public voidonCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

SetContentView (R. layout. main );

Iv = (ImageView) this. findViewById (R. id. iv );

}

// Event Method for clicking the button:

Public void click (Viewview ){

// Implicitly intends to obtain the System camera component

Intent intent = new Intent ();

Intent. setAction ("android. media. action. IMAGE_CAPTURE ");

Intent. addCategory ("android. intent. category. DEFAULT ");

StartActivityForResult (intent, 0); // you can call this operation to obtain the returned value.

}

 

// Enable the component in the form of a returned value. The trigger method is as follows:

Protected voidonActivityResult (int requestCode, int resultCode, Intent data ){

// TODO Auto-generated method stub

Super. onActivityResult (requestCode, resultCode, data );

// New Intent ("inline-data"). putExtra ("data", bitmap );

System. out. println ("get photo ");

 

If (data! = Null ){

Uri uri = data. getData ();

// Iv. setImageURI (uri );

// System. out. println (uri. toString ());

String str = data. getAction ();

If (str! = Null ){

System. out. println (str );

}

// View the source code to obtain the image

Bitmap bitmap = data. getParcelableExtra ("data ");

// Set the image to display in ImageView:

Iv. setImageBitmap (bitmap );

}

}

}

Ii. Activate the video recording component of the system:

Public class DemoActivity extends Activity {

/** Called when theactivity is first created .*/

Private ImageView iv;

@ Override

Public voidonCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

SetContentView (R. layout. main );

Iv = (ImageView) this. findViewById (R. id. iv );

}

// Button clicking Method

Public void click (Viewview ){

// Implicitly activates the recorded video component.

Intent intent = new Intent ();

Intent. setAction ("android. media. action. VIDEO_CAPTURE ");

Intent. addCategory ("android. intent. category. DEFAULT ");

StartActivityForResult (intent, 0 );

}

 

@ Override

Protected voidonActivityResult (int requestCode, int resultCode, Intent data ){

// TODO Auto-generated method stub

Super. onActivityResult (requestCode, resultCode, data );

// New Intent ("inline-data"). putExtra ("data", bitmap );

System. out. println ("get photo ");

 

If (data! = Null ){

Uri uri = data. getData ();

Play the recorded video through the retrieved uri

 

}

}

}