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我試圖從我的平板電腦的前置攝像頭和其運行的2.2 Android Froyo中捕獲視頻。我真的無法弄清楚這個錯誤背後的原因。由於該平板電腦是Tegra 2 Nvigia芯片組可以導致問題，是平板電腦有前置攝像頭。請任何人給我一個方向休息，我會弄清楚。在Android 2.2的前端攝像頭視頻錄製失敗
這是我使用的代碼，
Camera cam = openFrontFacingCamera();
m_recorder = new MediaRecorder();
cam.unlock();
m_recorder.setCamera(cam);
m_recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
m_recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
m_recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
m_recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
m_recorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
m_recorder.setMaxDuration((int) 1000);
m_recorder.setVideoSize(320, 240);
m_recorder.setVideoFrameRate(15);
m_recorder.setOutputFile("/sdcard/myvideo");
try {
m_recorder.prepare();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// CRASHING HERE:
m_recorder.start();
這是我這個方法
private Camera openFrontFacingCamera() {
Camera camera = null;
// Look for front-facing camera, using the Gingerbread API.
// Java reflection is used for backwards compatibility with pre-Gingerbread APIs.
try {
Class<?> cameraClass = Class.forName("android.hardware.Camera");
Object cameraInfo = null;
Field field = null;
int cameraCount = 0;
Method getNumberOfCamerasMethod = cameraClass.getMethod("getNumberOfCameras");
if (getNumberOfCamerasMethod != null) {
cameraCount = (Integer) getNumberOfCamerasMethod.invoke(null, (Object[]) null);
}
Class<?> cameraInfoClass = Class.forName("android.hardware.Camera$CameraInfo");
if (cameraInfoClass != null) {
cameraInfo = cameraInfoClass.newInstance();
}
if (cameraInfo != null) {
field = cameraInfo.getClass().getField("facing");
}
Method getCameraInfoMethod = cameraClass.getMethod("getCameraInfo", Integer.TYPE, cameraInfoClass);
if (getCameraInfoMethod != null && cameraInfoClass != null && field != null) {
for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
getCameraInfoMethod.invoke(null, camIdx, cameraInfo);
int facing = field.getInt(cameraInfo);
if (facing == 1) { // Camera.CameraInfo.CAMERA_FACING_FRONT
try {
Method cameraOpenMethod = cameraClass.getMethod("open", Integer.TYPE);
if (cameraOpenMethod != null) {
camera = (Camera) cameraOpenMethod.invoke(null, camIdx);
}
} catch (RuntimeException e) {
Log.e(TAG, "Camera failed to open: " + e.getLocalizedMessage());
}
}
}
}
}
// Ignore the bevy of checked exceptions the Java Reflection API throws - if it fails, who cares.
catch (ClassNotFoundException e ) {Log.e(TAG, "ClassNotFoundException" + e.getLocalizedMessage());}
catch (NoSuchMethodException e ) {Log.e(TAG, "NoSuchMethodException" + e.getLocalizedMessage());}
catch (NoSuchFieldException e ) {Log.e(TAG, "NoSuchFieldException " + e.getLocalizedMessage());}
catch (IllegalAccessException e ) {Log.e(TAG, "IllegalAccessException" + e.getLocalizedMessage());}
catch (InvocationTargetException e ) {Log.e(TAG, "InvocationTargetException" + e.getLocalizedMessage());}
catch (InstantiationException e ) {Log.e(TAG, "InstantiationException" + e.getLocalizedMessage());}
catch (SecurityException e ) {Log.e(TAG, "SecurityException" + e.getLocalizedMessage());}
if (camera == null) {
// Try using the pre-Gingerbread APIs to open the camera.
try {
camera = Camera.open();
} catch (RuntimeException e) {
Log.e(TAG, "Camera failed to open: " + e.getLocalizedMessage());
}
}
return camera;
}
之前使用相機初始化函數這是錯誤：
07-03 08:01:09.220: A/dalvikvm(32523): Exception!!! threadid=1: thread exiting with uncaught exception (group=0x4001d860)
07-03 08:01:09.230: E/AndroidRuntime(32523): FATAL EXCEPTION: main
07-03 08:01:09.230: E/AndroidRuntime(32523): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.webvideo.com/com.webvideo.com.MainActivity}: java.lang.IllegalStateException
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.os.Handler.dispatchMessage(Handler.java:99)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.os.Looper.loop(Looper.java:123)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-03 08:01:09.230: E/AndroidRuntime(32523): at java.lang.reflect.Method.invokeNative(Native Method)
07-03 08:01:09.230: E/AndroidRuntime(32523): at java.lang.reflect.Method.invoke(Method.java:521)
07-03 08:01:09.230: E/AndroidRuntime(32523): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
07-03 08:01:09.230: E/AndroidRuntime(32523): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
07-03 08:01:09.230: E/AndroidRuntime(32523): at dalvik.system.NativeStart.main(Native Method)
07-03 08:01:09.230: E/AndroidRuntime(32523): Caused by: java.lang.IllegalStateException
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.media.MediaRecorder.start(Native Method)
07-03 08:01:09.230: E/AndroidRuntime(32523): at com.webvideo.com.MainActivity.onCreate(MainActivity.java:71)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-03 08:01:09.230: E/AndroidRuntime(32523): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)