Tenía la misma pregunta. Iba desde un servicio de grabación de audio en segundo plano y esperaba crear un servicio de grabación de video en segundo plano. No puede grabar realmente el video de fondo, pero puede hacer que la vista previa del video sea muy pequeña en su interfaz de usuario existente. Seguí el tutorial: http://integratingstuff.wordpress.com/2010/10/18/writing-code-that-captures-videos-on-android/ y la muestra de demostración de la cámara de muestra. Pero en última instancia, el código de muestra en http://www.apress.com/downloadable/download/sample/sample_id/39/ fue lo suficientemente simple como para navegar por Internet, pero también lo suficientemente completo como para funcionar con setCamera. Voy a publicar mi solución aquí para ahorrarles tiempo a otros en su progresión de ejemplos de juguetes, a un ejemplo complejo con buena calidad de grabación de video de fondo (usando la cámara frontal si es necesario).
Esta es la fuente para un grabador de video Android con "no" vista previa (la vista previa es un píxel de 1x1 que simula una grabación discreta), para grabar videos sin distraer a los usuarios. Para usar su propia IU, simplemente cambie el video_recorder.xml a su diseño (asegúrese de mantener VideoView). Fue probado en dispositivos Android 2.2 y 3.0.
casos de uso adecuados: biblioteca de seguimiento
- ojo mirada para que los usuarios utilizan los ojos como un ratón para navegar por una página web
- cámara (s) el uso de la tableta para reemplazar la cámara de vídeo en experimentos de laboratorio/clínica (psycholingusitics o patología del habla)
Layout XML:
<?xml version="1.0" encoding="utf-8"?>
<!-- This file is /res/layout/video_recorder.xml based on listing 9-6 in Pro Android 2 -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<RelativeLayout android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center">
<VideoView android:id="@+id/videoView" android:layout_width="1px"
android:layout_height="1px" />
</RelativeLayout>
</LinearLayout>
clase de Java:
import java.io.File;
import android.app.Activity;
import android.hardware.Camera;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.widget.Toast;
import android.widget.VideoView;
/**
* Android video recorder with "no" preview (the preview is a 1x1 pixel which
* simulates an unobtrusive recording led). Based on Pro Android 2 2010 (Hashimi
* et al) source code in Listing 9-6.
*
* Also demonstrates how to use the front-facing and back-facing cameras.
* A calling Intent can pass an Extra to use the front facing camera if available.
*
* Suitable use cases:
* A: eye gaze tracking library to let users use eyes as a mouse to navigate a web page
* B: use tablet camera(s) to replace video camera in lab experiments
* (psycholingusitics or other experiments)
*
* Video is recording is controlled in two ways:
* 1. Video starts and stops with the activity
* 2. Video starts and stops on any touch
*
* To control recording in other ways see the try blocks of the onTouchEvent
*
* To incorporate into project add these features and permissions to
* manifest.xml:
*
* <uses-feature android:name="android.hardware.camera"/>
* <uses-feature android:name="android.hardware.camera.autofocus"/>
*
* <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
* <uses-permission android:name="android.permission.CAMERA" />
* <uses-permission android:name="android.permission.RECORD_AUDIO" />
*
* Tested Date: October 2 2011 with manifest.xml
* <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="11"/>
*/
public class VideoRecorderSubExperiment extends Activity implements
SurfaceHolder.Callback {
public static final String EXTRA_USE_FRONT_FACING_CAMERA ="frontcamera";
private static final String OUTPUT_FILE = "/sdcard/videooutput";
private static final String TAG = "RecordVideo";
private Boolean mRecording = false;
private Boolean mUseFrontFacingCamera = false;
private VideoView mVideoView = null;
private MediaRecorder mVideoRecorder = null;
private Camera mCamera;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.video_recorder);
mVideoView = (VideoView) this.findViewById(R.id.videoView);
//mUseFrontFacingCamera = getIntent().getExtras().getBoolean(
// EXTRA_USE_FRONT_FACING_CAMERA, true);
if(mUseFrontFacingCamera){
// If caller wants to use front facing camera, then make sure the device has one...
// Hard coded to only open front facing camera on Xoom (model MZ604)
// For more universal solution try:
// http://stackoverflow.com/questions/2779002/how-to-open-front-camera-on-android-platform
String deviceModel = android.os.Build.MODEL;
if (deviceModel.contains("MZ604")) {
mUseFrontFacingCamera = true;
} else {
Toast.makeText(
getApplicationContext(),
"The App isn't designed to use this Android's front facing camera.\n " +
"The device model is : " + deviceModel, Toast.LENGTH_LONG).show();
mUseFrontFacingCamera = false;
}
}
final SurfaceHolder holder = mVideoView.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public boolean onTouchEvent(MotionEvent event) {
// can use the xy of the touch to start and stop recording
float positionX = event.getX();
float positionY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// Screen is pressed for the first time
break;
case MotionEvent.ACTION_MOVE:
// Screen is still pressed, float have been updated
break;
case MotionEvent.ACTION_UP:
// Screen is not touched anymore
if (mRecording) {
// To stop recording attach this try block to another event listener,
// button etc
try {
stopRecording();
} catch (Exception e) {
Log.e(TAG, e.toString());
e.printStackTrace();
}
} else {
// To begin recording attach this try block to another event listener,
// button etc
try {
beginRecording(mVideoView.getHolder());
} catch (Exception e) {
Log.e(TAG, e.toString());
e.printStackTrace();
}
}
break;
}
return super.onTouchEvent(event);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
beginRecording(holder);
} catch (Exception e) {
Log.e(TAG, e.toString());
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
Log.v(TAG, "Width x Height = " + width + "x" + height);
}
private void stopRecording() throws Exception {
mRecording = false;
if (mVideoRecorder != null) {
mVideoRecorder.stop();
mVideoRecorder.release();
mVideoRecorder = null;
}
if (mCamera != null) {
mCamera.reconnect();
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
}
@Override
protected void onDestroy() {
try {
stopRecording();
} catch (Exception e) {
Log.e(TAG, e.toString());
e.printStackTrace();
}
super.onDestroy();
}
/**
* Uses the surface defined in video_recorder.xml
* Tested using
* 2.2 (HTC Desire/Hero phone) -> Use all defaults works, records back facing camera with AMR_NB audio
* 3.0 (Motorola Xoom tablet) -> Use all defaults doesn't work, works with these specs, might work with others
*
* @param holder The surfaceholder from the videoview of the layout
* @throws Exception
*/
private void beginRecording(SurfaceHolder holder) throws Exception {
if (mVideoRecorder != null) {
mVideoRecorder.stop();
mVideoRecorder.release();
mVideoRecorder = null;
}
if (mCamera != null) {
mCamera.reconnect();
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
String uniqueOutFile = OUTPUT_FILE + System.currentTimeMillis() + ".3gp";
File outFile = new File(uniqueOutFile);
if (outFile.exists()) {
outFile.delete();
}
try {
if (mUseFrontFacingCamera) {
//hard coded assuming 1 is the front facing camera
mCamera = Camera.open(1);
} else {
mCamera = Camera.open();
}
// Camera setup is based on the API Camera Preview demo
mCamera.setPreviewDisplay(holder);
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(640, 480);
mCamera.setParameters(parameters);
mCamera.startPreview();
mCamera.unlock();
mVideoRecorder = new MediaRecorder();
mVideoRecorder.setCamera(mCamera);
// Media recorder setup is based on Listing 9-6, Hashimi et all 2010
// values based on best practices and good quality,
// tested via upload to YouTube and played in QuickTime on Mac Snow Leopard
mVideoRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mVideoRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mVideoRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);// THREE_GPP
// is big-endian,
// storing and
// transferring
// the most
// significant
// bytes first.
// MPEG_4 as another option
mVideoRecorder.setVideoSize(640, 480);// YouTube recommended size: 320x240,
// OpenGazer eye tracker: 640x480
// YouTube HD: 1280x720
mVideoRecorder.setVideoFrameRate(20); //might be auto-determined due to lighting
mVideoRecorder.setVideoEncodingBitRate(3000000);// 3 megapixel, or the max of
// the camera
mVideoRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);// MPEG_4_SP
// Simple Profile is
// for low bit
// rate and low
// resolution
// H264 is MPEG-4 Part 10
//is commonly referred to
// as H.264 or AVC
int sdk = android.os.Build.VERSION.SDK_INT;
// Gingerbread and up can have wide band ie 16,000 hz recordings
// (Okay quality for human voice)
if (sdk >= 10) {
mVideoRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_WB);
mVideoRecorder.setAudioSamplingRate(16000);
} else {
// Other devices only have narrow band, ie 8,000 hz
// (Same quality as a phone call, not really good quality for any purpose.
// For human voice 8,000 hz means /f/ and /th/ are indistinguishable)
mVideoRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
}
mVideoRecorder.setMaxDuration(30000); // limit to 30 seconds
mVideoRecorder.setPreviewDisplay(holder.getSurface());
mVideoRecorder.setOutputFile(uniqueOutFile);
mVideoRecorder.prepare();
mVideoRecorder.start();
mRecording = true;
} catch (Exception e) {
Log.e(TAG, e.toString());
e.printStackTrace();
}
}
}
No sé, pero me siento a gusto. Acabo de salir de algunos J2ME en esta área. ¡Temperamental por decir lo menos! –
¿Cuál es la excepción? –