2

我想从手机的麦克风中捕捉声音，并在屏幕上实时显示每 1000 个样本的平均值。这是我到目前为止的代码，但我没有在屏幕上看到任何值，它是空白的。我究竟做错了什么？我是 Android 开发的新手，所以任何帮助都会有所帮助。

import android.os.Bundle;
import android.widget.TextView;
import android.app.Activity;
import android.media.AudioRecord;
import android.media.MediaRecorder.AudioSource;
import android.media.AudioFormat;

public class MainActivity extends Activity {

    public boolean recording;  //variable to start or stop recording
    public TextView averagevalue; //text to appear on screen

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        averagevalue = (TextView) findViewById(R.id.text1);
    }


   public void Record(){
       AudioRecord recorder;
       short audioData[];
       int bufferSize;

       bufferSize=AudioRecord.getMinBufferSize(44100,AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT); //get the buffer size to use with this audio record

recorder = new AudioRecord (AudioSource.MIC,44100,AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT,bufferSize); //instantiate the AudioRecorder

recording=true; //variable to use start or stop recording
audioData = new short [bufferSize]; //short array that pcm data is put into.


while (recording) {  //loop while recording is needed
if (recorder.getState()==android.media.AudioRecord.STATE_INITIALIZED) // check to see if the recorder has initialized yet.
if (recorder.getRecordingState()==android.media.AudioRecord.RECORDSTATE_STOPPED)
     recorder.startRecording();  //check to see if the Recorder has stopped or is not recording, and make it record.

else {

recorder.read(audioData,0,bufferSize); //read the PCM audio data into the audioData array
//analyze sound
        int totalAbsValue = 0;
        int samplesquantity = 1000;
        short sample = 0; 
        float averageAbsValue = 0.0f;

     for (int i = 0; i < samplesquantity; i += 1) {
         sample = (short)audioData[i];
         totalAbsValue += Math.abs(sample);
     }
     averageAbsValue = totalAbsValue / samplesquantity;     

     averagevalue.setText(Float.toString(averageAbsValue));                                           

        }//else recorder started

} //while recording

if (recorder.getState()==android.media.AudioRecord.RECORDSTATE_RECORDING) recorder.stop(); //stop the recorder before ending the thread
recorder.release(); //release the recorders resources
recorder=null; //set the recorder to be garbage collected.



   }

}

这是 XML 文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/text1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"/>


</RelativeLayout>
4

2 回答 2

0

尝试为您的文本视图设置默认值。这样你就可以确保即使你的逻辑没有被执行，也会显示一些东西。您甚至可能想要临时添加一些静态显示内容。还要检查您是否使用了正确的活动。

其次，如果您想要给定数据样本（1000 个点）的平均信号电平，您可以尝试计算二次平均值（均方根）。

于 2013-11-12T13:06:53.207 回答
0

int / int 是 int。

averageAbsValue = (float)totalAbsValue / samplesquantity;

应该做的伎俩。

于 2013-11-11T12:39:08.987 回答