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Android Sound Recording and Amplitude Reading

I am trying to create an application that records sound for a second and then reads the maximum amplitude from the recorded sound. This is what I still have, but my application crashes and I can’t understand why.

This is my second action, which I call from my first after I press the "Record" button. The application crashes from my emulator and on my phone.

package radu.soundSampler;

import java.io.IOException;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
import android.media.MediaRecorder;

public class DisplayMessageActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //Intent intent = getIntent();
    //String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

    MediaRecorder rec = new MediaRecorder();
    rec.setAudioSource(MediaRecorder.AudioSource.MIC);
    rec.setOutputFormat(MediaRecorder.OutputFormat.RAW_AMR);
    rec.setOutputFile("/newRecording");
    rec.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);

    try {
        rec.prepare();
    } catch (IllegalStateException e) {

    } catch (IOException o) {

    }
    rec.start();
            for(int i=0;i<100000;i++);
    rec.stop();
    int rezultat = rec.getMaxAmplitude();

    TextView textView = new TextView(this);
    textView.setTextSize(40);

    textView.setText(Integer.toString(rezultat));

    setContentView(textView);
}

}

The error log ( updated ) on my computer says:

08-18 13:30:07.968: E/MediaRecorder(687): start called in an invalid state: 4
08-18 13:30:07.968: D/AndroidRuntime(687): Shutting down VM
08-18 13:30:07.968: W/dalvikvm(687): threadid=1: thread exiting with uncaught exception (group=0x40015560)
08-18 13:30:07.978: E/AndroidRuntime(687): FATAL EXCEPTION: main
08-18 13:30:07.978: E/AndroidRuntime(687): java.lang.RuntimeException: Unable to start activity ComponentInfo{radu.soundSampler/radu.soundSampler.DisplayMessageActivity}: java.lang.IllegalStateException
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.os.Looper.loop(Looper.java:123)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.app.ActivityThread.main(ActivityThread.java:3683)
08-18 13:30:07.978: E/AndroidRuntime(687):  at java.lang.reflect.Method.invokeNative(Native Method)
08-18 13:30:07.978: E/AndroidRuntime(687):  at java.lang.reflect.Method.invoke(Method.java:507)
08-18 13:30:07.978: E/AndroidRuntime(687):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-18 13:30:07.978: E/AndroidRuntime(687):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-18 13:30:07.978: E/AndroidRuntime(687):  at dalvik.system.NativeStart.main(Native Method)
08-18 13:30:07.978: E/AndroidRuntime(687): Caused by: java.lang.IllegalStateException
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.media.MediaRecorder.start(Native Method)
08-18 13:30:07.978: E/AndroidRuntime(687):  at radu.soundSampler.DisplayMessageActivity.onCreate(DisplayMessageActivity.java:29)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-18 13:30:07.978: E/AndroidRuntime(687):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
08-18 13:30:07.978: E/AndroidRuntime(687):  ... 11 more

so I thought maybe the emulator cannot “start” the microphone, so I installed it .apkon my phone, but it crashed too. I don’t know what the problem is, so could you help me and / or give me any hints?

Many thanks!

, . catch o.printStackTrace() e.printStackTrace(), , , :

08-18 14:06:11.908: W/System.err(811): java.io.FileNotFoundException: /newRecording (Read-only file system)
08-18 14:06:11.908: W/System.err(811):  at org.apache.harmony.luni.platform.OSFileSystem.open(Native Method)
08-18 14:06:11.908: W/System.err(811):  at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:232)
08-18 14:06:11.918: W/System.err(811):  at java.io.FileOutputStream.<init>(FileOutputStream.java:94)
08-18 14:06:11.918: W/System.err(811):  at java.io.FileOutputStream.<init>(FileOutputStream.java:165)
08-18 14:06:11.918: W/System.err(811):  at java.io.FileOutputStream.<init>(FileOutputStream.java:144)
08-18 14:06:11.918: W/System.err(811):  at android.media.MediaRecorder.prepare(MediaRecorder.java:533)
08-18 14:06:11.918: W/System.err(811):  at radu.soundSampler.DisplayMessageActivity.onCreate(DisplayMessageActivity.java:23)
08-18 14:06:11.918: W/System.err(811):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-18 14:06:11.918: W/System.err(811):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
08-18 14:06:11.918: W/System.err(811):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-18 14:06:11.918: W/System.err(811):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-18 14:06:11.918: W/System.err(811):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-18 14:06:11.918: W/System.err(811):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-18 14:06:11.918: W/System.err(811):  at android.os.Looper.loop(Looper.java:123)
08-18 14:06:11.918: W/System.err(811):  at android.app.ActivityThread.main(ActivityThread.java:3683)
08-18 14:06:11.918: W/System.err(811):  at java.lang.reflect.Method.invokeNative(Native Method)
08-18 14:06:11.928: W/System.err(811):  at java.lang.reflect.Method.invoke(Method.java:507)
08-18 14:06:11.928: W/System.err(811):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-18 14:06:11.928: W/System.err(811):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-18 14:06:11.928: W/System.err(811):  at dalvik.system.NativeStart.main(Native Method)
08-18 14:06:11.928: E/MediaRecorder(811): start called in an invalid state: 4
08-18 14:06:11.928: D/AndroidRuntime(811): Shutting down VM
08-18 14:06:11.928: W/dalvikvm(811): threadid=1: thread exiting with uncaught exception (group=0x40015560)
08-18 14:06:11.948: E/AndroidRuntime(811): FATAL EXCEPTION: main
08-18 14:06:11.948: E/AndroidRuntime(811): java.lang.RuntimeException: Unable to start activity ComponentInfo{radu.soundSampler/radu.soundSampler.DisplayMessageActivity}: java.lang.IllegalStateException
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.os.Looper.loop(Looper.java:123)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.app.ActivityThread.main(ActivityThread.java:3683)
08-18 14:06:11.948: E/AndroidRuntime(811):  at java.lang.reflect.Method.invokeNative(Native Method)
08-18 14:06:11.948: E/AndroidRuntime(811):  at java.lang.reflect.Method.invoke(Method.java:507)
08-18 14:06:11.948: E/AndroidRuntime(811):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-18 14:06:11.948: E/AndroidRuntime(811):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-18 14:06:11.948: E/AndroidRuntime(811):  at dalvik.system.NativeStart.main(Native Method)
08-18 14:06:11.948: E/AndroidRuntime(811): Caused by: java.lang.IllegalStateException
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.media.MediaRecorder.start(Native Method)
08-18 14:06:11.948: E/AndroidRuntime(811):  at radu.soundSampler.DisplayMessageActivity.onCreate(DisplayMessageActivity.java:30)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-18 14:06:11.948: E/AndroidRuntime(811):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
08-18 14:06:11.948: E/AndroidRuntime(811):  ... 11 more
08-18 14:06:14.181: I/Process(811): Sending signal. PID: 811 SIG: 9
+5
7

setOutoutFile(getExternalFilesDir().getAbsolutePath() + "/newRecording")

,

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

busy-wait. .

.

+2

"" , null, :

recorder = new MediaRecorder();
// following calls throw Illegal State Exceptions, but here we follow the proper order

recorder.setAudioSource(AudioSource.MIC);

// After set audio source
recorder.setOutputFormat(OutputFormat.THREE_GPP);

// After set output format
recorder.setAudioEncoder(AudioEncoder.AMR_NB);
recorder.setOutputFile("/dev/null");
// Before prepare

try {
    recorder.prepare();
} catch (IOException e) {
    System.err.println(e);
}
// After prepare
recorder.start();

// Call getMaxAmplitude() with a zero returned value, so you can recall later
recorder.getMaxAmplitude();

, onCreate. :

public void onCreate(Bundle savedInstanceState) {

    // ...

    handler = new Handler();
    handler.postDelayed(this, 1000);
}

public void run() {
    int value = recorder.getMaxAmplitude();
    recorder.stop();

    // etc
}
+2

.....

    int rezultat = 0;   

try {
        rec.prepare();

        rec.start();

        TimeUnit.SECONDS.sleep(1);  

        rec.stop();

    } catch (IllegalStateException e) {

    } catch (IOException o) {

    } catch (InterruptedException e) {      

    }

     rezultat = rec.getMaxAmplitude();
+1

, .

File parent = getContext().getFilesDir();
File recordFile = new File(parent, "newRecording");

- . ( )

+1

, , rec.setOutputFile("/newRecording"). . , getFilesDir() .

, , : FileNotFoundException , prepare() . MediaRecoder , start(), .

: , Thread.sleep(), for . -, , , - , Android ANR.

0

, onCreate(). . prepare() ( , ) , catch.

, : catch {}. ( )

0

Salut!

, , Android. , \, , , .

, :

String externalStoragePath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator;

// Your code here

rec.setOutputFile(externalStoragePath + "newRecording");

. , , .

P.S. onCreate() , , .

0

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