Android Red5视频通讯第二篇:音频数据采集

最新推荐文章于 2024-08-27 10:43:06 发布

sclgxt

最新推荐文章于 2024-08-27 10:43:06 发布

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分类专栏： android 文章标签： Speex

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本文介绍在Android平台上实现音频数据采集和使用Speex进行音频编码的方法。通过JNI调用Speex库，实现不同压缩级别的音频编码，并在WechatAudioMicro类中展示音频数据的实时采集和编码流程。

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Android Red5视频通讯第二篇:音频数据采集

1.音频数据编码

采用speex编码。编译so库

https://download.youkuaiyun.com/download/sclgxt/12031721

例子中已经有编译好的so文件

2.jni使用new package com.speex.lib，新建Speex.java

//包名不能改
package com.speex.lib;
public class Speex {

    /* quality
     * 1 : 4kbps (very noticeable artifacts, usually intelligible)
     * 2 : 6kbps (very noticeable artifacts, good intelligibility)
     * 4 : 8kbps (noticeable artifacts sometimes)
     * 6 : 11kpbs (artifacts usually only noticeable with headphones)
     * 8 : 15kbps (artifacts not usually noticeable)
     */
    private static final int DEFAULT_COMPRESSION = 4;
    public Speex() {
        init();
    }
    public void init() {
        load();
        open(DEFAULT_COMPRESSION);
    }
    private void load() {
        //对应的so库名称
        System.loadLibrary("speex");
    }
    public native int open(int compression);
    public native int getFrameSize();
    public native int decode(byte encoded[], short lin[], int size);
    public native int encode(short lin[], int offset, byte encoded[], int size);
    public native void close();
}

3.音频数据采集WechatAudioMicro.java

import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.util.Log;
import com.smaxe.io.ByteArray;
import com.smaxe.uv.client.microphone.AbstractMicrophone;
import com.smaxe.uv.stream.support.MediaDataByteArray;
import com.speex.lib.Speex;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;


public class WechatAudioMicro extends AbstractMicrophone {
    public static final String TAG="WechatAudioMicro";
    private volatile boolean isEncoding = false;
    private Speex speex = new Speex();
    private byte[] SpeexRtmpHead = new byte[]{(byte) 0xB2};
    private byte[] processedData = new byte[1024];
    private ExecutorService singleExecutors = Executors.newSingleThreadExecutor();
    Runnable recordRunnable = new Runnable() {
        @Override
        public void run() {
            int bufferSize = AudioRecord.getMinBufferSize(8000, 
            AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
            short[] mAudioRecordBuffer = new short[bufferSize];
            AudioRecord mAudioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, 
            8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, 
            bufferSize);
            mAudioRecord.startRecording();
            int bufferRead;
            int len;
            isEncoding = true;
            while (isEncoding) {
                bufferRead = mAudioRecord.read(mAudioRecordBuffer, 0, bufferSize);
                if (bufferRead > 0) {
                    try {
                        len = speex.encode(mAudioRecordBuffer, 0, processedData, bufferRead);

                        byte[] speexData = new byte[len + 1];
                        System.arraycopy(SpeexRtmpHead, 0, speexData, 0, 1);
                        System.arraycopy(processedData, 0, speexData, 1, len);
                        fireOnAudioData(new MediaDataByteArray(20, new 
                        ByteArray(speexData)));

                    } catch (Exception e) {
                        //e.printStackTrace();
                        Log.i(TAG, "AudioMicro:" + e.getMessage());
                    }
                }
            }
            mAudioRecord.stop();
            mAudioRecord.release();
        }
    };
    public void start() {
        singleExecutors.execute(recordRunnable);
    }
    public void stop() {
        isEncoding = false;
    }
}