Android：同时有两个Media Recorder实例

Question

Can i run two instances of Android MediaRecorder class at the same time? For example

public MediaRecorder mrec1 ;
public MediaRecorder mrec2 ;


mrec1.setCamera(mCamera);
mrec1.setPreviewDisplay(surfaceHolder.getSurface());
mrec1.setVideoSource(MediaRecorder.VideoSource.CAMERA)
.
.
.
.
mrec2.setAudioSource(MediaRecorder.AudioSource.MIC);
mrec2.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mrec2.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
.
.  
.
.
mrec1.prepare();
mrec2.prepare();
mrec1.start();
mrec2.start();

I get this error when second start() is called i just want to know is it because there is already a start process called or there is some other problem. Also the second media recorder instance is initialized and used in a separate thread.

04-22 11:08:45.869: E/MediaRecorder(7742): start failed: -2147483648
04-22 11:08:45.869: W/dalvikvm(7742): threadid=9: thread exiting with uncaught exception  (group=0x40018578)
04-22 11:08:45.869: E/AndroidRuntime(7742): FATAL EXCEPTION: Thread-10
04-22 11:08:45.869: E/AndroidRuntime(7742): java.lang.RuntimeException: start failed.

Answer 1

according to documentation :

In addition to unnecessary resources (such as memory and instances of codecs) being held, failure to call this method immediately if a MediaRecorder object is no longer needed may also lead to continuous battery consumption for mobile devices, and recording failure for other applications if no multiple instances of the same codec are supported on a device. Even if multiple instances of the same codec are supported, some performance degradation may be expected when unnecessary multiple instances are used at the same time.

My unsuccessful attempts led to nothing either.