Android录制WAV文件- 带去回声

http://blog.csdn.net/hewenhao2014/article/details/50704473

 分类：

Android多媒体

版权声明：本文为博主原创文章，未经博主允许不得转载。

实现思路：用AudioRecorder录制PCM数据以WAV格式保存

一）AudioRecord录制PCM数据

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1. // default: mSampleRate = 8000  
2. int channelConfig = AudioFormat.CHANNEL_IN_MONO;  
3. int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;  
4. minBufferSize = AudioRecord.getMinBufferSize(mSampleRate, channelConfig, audioEncoding);      
5. Log.i(LOG_TAG, "minBufferSize: " + minBufferSize);  
6.   
7. mRecord = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION,   
8.                 mSampleRate,  
9.                 channelConfig,   
10.                 audioEncoding,        
11.                 minBufferSize*2);  
12. mAudioSessionId = mRecord.getAudioSessionId();  

二）保存WAV文件

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1.                   
2. File f = new File(mRecordfile);  
3. if(f.exists()){  
4. f.delete();  
5. }  
6.                   
7. randomAccessWriter = new RandomAccessFile(mRecordfile, "rw");     
8. initWavHeader(randomAccessWriter, (short)channelConfig, (int)mSampleRate, (short)16);  
9. payloadSize = 0;  

//初始化WAV文件头

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1. static void initWavHeader(RandomAccessFile randomAccessWriter, short Channels, int SamplesPerSec, short BitsPerSample){   
2.         try {  
3.         randomAccessWriter.setLength(0);  
4.         // Set file length to 0, to prevent unexpected behavior in case the file already existed  
5.             randomAccessWriter.writeBytes("RIFF");  
6.             randomAccessWriter.writeInt(0); // Final file size not known yet, write 0   
7.             randomAccessWriter.writeBytes("WAVE");  
8.             randomAccessWriter.writeBytes("fmt ");  
9.             randomAccessWriter.writeInt(Integer.reverseBytes(16)); // Sub-chunk size, 16 for PCM  
10.             randomAccessWriter.writeShort(Short.reverseBytes((short) 1)); // AudioFormat, 1 for PCM  
11.             randomAccessWriter.writeShort(Short.reverseBytes((short) 1));// Number of channels, 1 for mono, 2 for stereo  
12.             randomAccessWriter.writeInt(Integer.reverseBytes(SamplesPerSec)); // Sample rate  
13.             randomAccessWriter.writeInt(Integer.reverseBytes(SamplesPerSec*BitsPerSample*Channels/8)); // Byte rate, SampleRate*NumberOfChannels*BitsPerSample/8  
14.             randomAccessWriter.writeShort(Short.reverseBytes((short)(Channels*BitsPerSample/8))); // Block align, NumberOfChannels*BitsPerSample/8  
15.             randomAccessWriter.writeShort(Short.reverseBytes(BitsPerSample)); // Bits per sample  
16.             randomAccessWriter.writeBytes("data");  
17.             randomAccessWriter.writeInt(0); // Data chunk size not known yet, write 0  
18.         } catch (IOException e) {  
19.             // TODO Auto-generated catch block  
20.             e.printStackTrace();  
21.     }   
22. }  

//读取PCM写入WAV文件

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1. byte[] pcmData = new byte[minBufferSize*2];  
2.             final Object threadLock = new Object();  
3.             Thread.currentThread().setPriority(MAX_PRIORITY);  
4.             Thread.currentThread().setName("AudioSourceMicr");  
5.             mRecord.startRecording();  
6.               
7.             synchronized (threadLock)   
8.             {  
9.                 while (mThreadLoop && !Thread.currentThread().isInterrupted())  
10.                 {  
11.                     if (mPauseFlag) continue;  
12.                       
13.                     int bufferReadResult = mRecord.read(pcmData, 0, minBufferSize*2-512);  
14.                     Log.i(LOG_TAG, "bufferReadResult = "+bufferReadResult);  
15.                       
16.                     if (bufferReadResult > 0){  
17.                         saveWaveData(pcmData, bufferReadResult);  
18.                     }  
19.                     else{  
20.                         Log.i(LOG_TAG, "Error to read pcm from AudioRecorder.");  
21.                     }  
22.                 }      
23.             }  
24.               

//录制完成之后将数据长度回写到WAV文件头

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1. randomAccessWriter.seek(4);  
2. randomAccessWriter.write(Integer.reverseBytes(36+payloadSize));  
3. randomAccessWriter.seek(40);  
4. randomAccessWriter.write(Integer.reverseBytes(payloadSize));  
5. randomAccessWriter.close();  

三）回音消除&去噪（android4.1版本以上支持）

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1. if (mAudioSessionId != 0 && android.os.Build.VERSION.SDK_INT >= 16)  
2.         {  
3.             if (NoiseSuppressor.isAvailable())  
4.             {  
5.                 if (mNoiseSuppressor != null)  
6.                 {  
7.                     mNoiseSuppressor.release();  
8.                     mNoiseSuppressor = null;  
9.                 }  
10.                   
11.                 mNoiseSuppressor = NoiseSuppressor.create(mAudioSessionId);  
12.                 if (mNoiseSuppressor != null)   
13.                 {  
14.                     mNoiseSuppressor.setEnabled(true);  
15.                 }  
16.                 else  
17.                 {  
18.                     Log.i(LOG_TAG, "Failed to create NoiseSuppressor.");                                  
19.                 }  
20.             }  
21.             else  
22.             {  
23.                 Log.i(LOG_TAG, "Doesn't support NoiseSuppressor");                                
24.             }     
25.               
26.             if (AcousticEchoCanceler.isAvailable())  
27.             {  
28.                 if (mAcousticEchoCanceler != null)  
29.                 {  
30.                     mAcousticEchoCanceler.release();  
31.                     mAcousticEchoCanceler = null;  
32.                 }  
33.                   
34.                 mAcousticEchoCanceler = AcousticEchoCanceler.create(mAudioSessionId);  
35.                 if (mAcousticEchoCanceler != null)  
36.                 {  
37.                     mAcousticEchoCanceler.setEnabled(true);  
38.                     // mAcousticEchoCanceler.setControlStatusListener(listener)setEnableStatusListener(listener)  
39.                 }  
40.                 else  
41.                 {  
42.                     Log.i(LOG_TAG, "Failed to initAEC.");     
43.                     mAcousticEchoCanceler = null;  
44.                 }  
45.             }  
46.             else  
47.             {  
48.                 Log.i(LOG_TAG, "Doesn't support AcousticEchoCanceler");                               
49.             }  
50.   
51.             if (AutomaticGainControl.isAvailable())  
52.             {  
53.                 if (mAutomaticGainControl != null)  
54.                 {  
55.                     mAutomaticGainControl.release();  
56.                     mAutomaticGainControl = null;  
57.                 }  
58.                   
59.                 mAutomaticGainControl = AutomaticGainControl.create(mAudioSessionId);  
60.                 if (mAutomaticGainControl != null)   
61.                 {  
62.                     mAutomaticGainControl.setEnabled(true);  
63.                 }  
64.                 else  
65.                 {  
66.                     Log.i(LOG_TAG, "Failed to create AutomaticGainControl.");                                 
67.                 }  
68.                   
69.             }  
70.             else  
71.             {  
72.                 Log.i(LOG_TAG, "Doesn't support AutomaticGainControl");                               
73.             }  
74.         }  

源码工程：http://download.csdn.NET/detail/hewenhao2014/9437513