android - Android 上的频率检测 - AudioRecord

Question

这是我的第二个问题，因为我有一个问题。我必须在 Android 上实现一个简单的频率检测。对于 DFT，我找到了 jTransform 库 (https://sites.google.com/site/piotrwendykier/software/jtransforms)。

在 jTransform 的 API 中 http://incanter.org/docs/parallelcolt/api/edu/emory/mathcs/jtransforms/fft/DoubleFFT_1D.html#complexForward%28double%5B%5D%29我已经看到我必须在 complexForward() 方法中传递一个双向量，而显然不是一个文件。

那么，首先，我的想法是正确的吗？所以，我不能使用 MediaRecorder，因为它会生成一个文件？我需要一个缓冲区，然后我使用 AudioRecorder。

但问题是:我无法在没有任何配置的情况下初始化 AudioRecorder 对象。

findAudioRecord() 尝试所有可能的配置来初始化 AudioRecord 并且在第一个工作配置方法结束(用于返回)。但它结束了，并返回 null。

真的，我无法理解这个问题。有没有可能是我的手机？

感谢您的帮助!对不起我的英语...

import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaRecorder;
import android.media.MediaRecorder.AudioSource;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class FFTActivity extends Activity {

private TextView textView1;
  private TextView textView2;

  private static final int RECORDSTATE_RECORDING = 3;
  private static final int RECORDER_BPP = 16;
  private static final String AUDIO_RECORDER_FILE_EXT_WAV = ".wav";
  private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
  private static final String AUDIO_RECORDER_TEMP_FILE = "record_temp.raw";
  private static final int RECORDER_SAMPLERATE = 44100;
  private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;
  private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;

  private static int[] mSampleRates = new int[] { 8000, 11025, 22050, 44100 };


  private int bufferSize = 0;
  private AudioRecord recorder = null;

  private int cont;

  int cont2 = 0;
  int contENCODING = 0;
  int contCHANNEL = 0;

  String s ="";



  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
     setContentView(R.layout.main);

      textView1 = (TextView) findViewById(R.id.testo1);
      textView2 = (TextView) findViewById(R.id.testo2);

      bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING);

      recorder = findAudioRecord();



}

  public AudioRecord findAudioRecord() {
        for (int rate : mSampleRates) {

            for (short audioFormat : new short[] { AudioFormat.ENCODING_PCM_8BIT,             AudioFormat.ENCODING_PCM_16BIT }) {
            for (short channelConfig : new short[] { AudioFormat.CHANNEL_IN_MONO, AudioFormat.CHANNEL_IN_STEREO }) {
                try {
                    int bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);

                    if (bufferSize != AudioRecord.ERROR_BAD_VALUE) {
                        // check if we can instantiate and have a success
                        AudioRecord recorder = new AudioRecord(AudioSource.DEFAULT, rate, channelConfig, audioFormat, (bufferSize*2));
                        textView2.setText("NOT ERROR_BAD_VALUE    "+mSampleRates[cont2] +"  "+ bufferSize);

                        if (recorder.getState() == AudioRecord.STATE_INITIALIZED){

                            textView2.setText("getState(): "+recorder.getState()+"   getMinBufferSize(): "+AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING));

                            return recorder;
                        }    
                    }
                } catch (Exception e) {
                    textView2.setText("ECCEZZIONE"+e);
                }
                contCHANNEL++;
            }
            contENCODING++;
        }
        cont2++;  
    }
    textView1.setText("NON INIZIALIZZATO " + contCHANNEL + "   " + contENCODING); 
    return null;
} 

Answer 1

将以下权限uses-permission android:name="android.permission.RECORD_AUDIO放在application标签

之外