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I have been trying to measure the amount of battery that the microphone uses while operating in the background on my device, so i wrote a little app to test it with.

On my phones external storage, i have a 600mb PCM file recording created with the app, as well as a second 100mb one.

When i run the app and try and play the 100mb file, it works fine. However when i try and play the larger 600mb one, it crashes on the code line:

InputStream is = new FileInputStream(file);

And the logcat gives the errors:

`11-03 16:31:03.654  16916-16916/com.bacon.corey.audiotimeshift I/art﹕ Alloc sticky concurrent mark sweep GC freed 6307(421KB) AllocSpace objects, 1(12KB) LOS objects, 33% free, 15MB/23MB, paused 678us total 14.444ms
11-03 16:31:03.663  16916-16916/com.bacon.corey.audiotimeshift I/art﹕ Alloc partial concurrent mark sweep GC freed 213(22KB) AllocSpace objects, 0(0B) LOS objects, 40% free, 15MB/26MB, paused 659us total 7.132ms
11-03 16:31:03.679  16916-16916/com.bacon.corey.audiotimeshift I/art﹕ Alloc concurrent mark sweep GC freed 15(12KB) AllocSpace objects, 0(0B) LOS objects, 40% free, 15MB/26MB, paused 830us total 14.191ms
11-03 16:31:03.681  16916-16916/com.bacon.corey.audiotimeshift I/art﹕ Forcing collection of SoftReferences for 641MB allocation
11-03 16:31:03.695  16916-16916/com.bacon.corey.audiotimeshift I/art﹕ Alloc concurrent mark sweep GC freed 11(344B) AllocSpace objects, 0(0B) LOS objects, 39% free, 15MB/26MB, paused 645us total 13.989ms
11-03 16:31:03.700  16916-16916/com.bacon.corey.audiotimeshift E/art﹕ Throwing OutOfMemoryError "Failed to allocate a 672164876 byte allocation with 11094652 free bytes and 176MB until OOM"
11-03 16:31:03.703  16916-16916/com.bacon.corey.audiotimeshift D/AndroidRuntime﹕ Shutting down VM
11-03 16:31:03.713  16916-16916/com.bacon.corey.audiotimeshift E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.bacon.corey.audiotimeshift, PID: 16916
    java.lang.IllegalStateException: Could not execute method of the activity
            at android.view.View$1.onClick(View.java:4007)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: java.lang.reflect.InvocationTargetException
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at android.view.View$1.onClick(View.java:4002)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: java.lang.OutOfMemoryError: Failed to allocate a 672164876 byte allocation with 11094652 free bytes and 176MB until OOM
            at com.bacon.corey.audiotimeshift.MainActivity.play(MainActivity.java:87)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at android.view.View$1.onClick(View.java:4002)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)`

I have not done much file IO stuff with android, so i am not really sure what i am doing wrong here. If someone wouldnt mind pointing out where i have gone wrong, i would be very grateful.

The code for the class is below.

Thanks in advance Corey :)

        public void play(View view) {
        Toast.makeText(this, "play", Toast.LENGTH_SHORT).show();

// Get the file we want to playback.
        File file = new File(Environment.getExternalStorageDirectory() + File.separator + "ACS.pcm");
// Get the length of the audio stored in the file (16 bit so 2 bytes per short)
// and create a short array to store the recorded audio.
        int musicLength = (int)(file.length()/2);
        short[] music = new short[musicLength];


        try {
// Create a DataInputStream to read the audio data back from the saved file.
            InputStream is = new FileInputStream(file);
            BufferedInputStream bis = new BufferedInputStream(is);
            DataInputStream dis = new DataInputStream(bis);

// Read the file into the music array.
            int i = 0;
            while (dis.available() > 0) {
                music[musicLength-1-i] = dis.readShort();
                i++;
            }


// Close the input streams.
            dis.close();


// Create a new AudioTrack object using the same parameters as the AudioRecord
// object used to create the file.
            AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                    44100,
                    AudioFormat.CHANNEL_OUT_MONO,
                    AudioFormat.ENCODING_PCM_16BIT,
                    musicLength,
                    AudioTrack.MODE_STREAM);
// Start playback
            audioTrack.play();

// Write the music buffer to the AudioTrack object
            audioTrack.write(music, 0, musicLength);


        } catch (Throwable t) {
            Log.e("AudioTrack","Playback Failed");
        }
    }
Fishingfon
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1 Answers1

0

It looks like you're loading the entire audio file into memory before trying to do anything with it. That's a bad approach because your file looks like it's 672164876 bytes (641MB), and I'm guessing that's way more RAM than you're allowed to allocate on a mobile device which probably has at most 1-2GB of RAM in total to share between all the apps that are running (plus the Android OS itself).

While it's kind of awesome that you tried to do this at such a low level (read in all the bytes and write them directly into something that will play them), I'd recommend looking into built-in Android media APIs like the MediaPlayer explained in this other StackOverflow post or some higher-level library, any of which should handle all the details of streaming the file into memory and playing it so you don't have to.

Community
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Dan
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