问题
I am just trying to record my voice via mic and listening my own voice from speaker, now the problem is when i m listening my voice, echo sound is added, i tried to cancel/remove the echo by using Speex library, but not succedded. Can someone please help me, below is the code:
Downloaded the code Speex-Android from https://github.com/yayanyang/speex-android.
I have added the echoCanceler.c file in jni as shown below
MainActivity.java
package com.example;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Fragment;
import android.content.Context;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.example.R;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
public class MainActivity extends Activity {
private int minBufSize ;
private AudioTrack track;
private AudioManager am;
private AudioRecord recorder;
private boolean status = true;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
minBufSize = AudioRecord.getMinBufferSize(8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
recorder = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION, 8000, AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT, minBufSize);
int maxJitter = AudioTrack.getMinBufferSize(8000, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
track = new AudioTrack(AudioManager.MODE_IN_COMMUNICATION, 8000, AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_16BIT, maxJitter, AudioTrack.MODE_STREAM);
am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
am.setMode(AudioManager.MODE_IN_COMMUNICATION);
am.setSpeakerphoneOn(true);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
public void startMethod()
{
Thread thread = new Thread(new Runnable()
{
@Override
public void run()
{
try
{
SpeexEchoCanceler speexEchoCanceler = new SpeexEchoCanceler();
short[] buffer = new short[1024];
recorder.startRecording();
track.play();
status = true;
while(status == true)
{
minBufSize = recorder.read(buffer, 0, buffer.length);
speexEchoCanceler.openEcho(8000, minBufSize, minBufSize);
short b[] = speexEchoCanceler.processEcho(buffer, buffer);
track.write(b, 0, b.length);
track.flush();
}
}
catch (Exception e)
{
Log.e(“E”, "Exception"+e);
}
}
});
thread.start();
}
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
//button click event
public void startButtonClick(View view)
{
startMethod();
}
public void stopButtonClick(View view)
{
status = false;
}
}
SpeexEchoCanceler.java
package com.example;
public class SpeexEchoCanceler
{
protected native static void open(int sampleRate, int bufSize, int totalLength);
protected native static short[] process(short[] inputframe, short[] echoframe);
protected native static void close();
public synchronized void openEcho(int sampleRate, int bufSize, int totalLength)
{
open(sampleRate,bufSize,totalLength);
}
public synchronized short[] processEcho(short[] inputframe, short[] echoframe)
{
return process(inputframe, echoframe);
}
public synchronized void closeEcho()
{
close();
}
static {
System.loadLibrary("speex");
}
}
echoCanceler.c
#include <jni.h>
#include "speex/speex_echo.h"
#include "speex/speex_preprocess.h"
#define NULL 0
SpeexEchoState *st;
SpeexPreprocessState *den;
JNIEXPORT void JNICALL Java_com_example_SpeexEchoCanceler_open
(JNIEnv *env, jobject jObj, jint jSampleRate, jint jBufSize, jint jTotalSize)
{
//init
int sampleRate=jSampleRate;
st = speex_echo_state_init(jBufSize, jTotalSize);
den = speex_preprocess_state_init(jBufSize, sampleRate);
speex_echo_ctl(st, SPEEX_ECHO_SET_SAMPLING_RATE, &sampleRate);
speex_preprocess_ctl(den, SPEEX_PREPROCESS_SET_ECHO_STATE, st);
}
JNIEXPORT jshortArray JNICALL Java_com_example_SpeexEchoCanceler_process
(JNIEnv * env, jobject jObj, jshortArray input_frame, jshortArray echo_frame)
{
//create native shorts from java shorts
jshort *native_input_frame = (*env)->GetShortArrayElements(env, input_frame, NULL);
jshort *native_echo_frame = (*env)->GetShortArrayElements(env, echo_frame, NULL);
//allocate memory for output data
jint length = (*env)->GetArrayLength(env, input_frame);
jshortArray temp = (*env)->NewShortArray(env, length);
jshort *native_output_frame = (*env)->GetShortArrayElements(env, temp, 0);
//call echo cancellation
speex_echo_cancellation(st, native_input_frame, native_echo_frame, native_output_frame);
//preprocess output frame
speex_preprocess_run(den, native_output_frame);
//convert native output to java layer output
jshortArray output_shorts = (*env)->NewShortArray(env, length);
(*env)->SetShortArrayRegion(env, output_shorts, 0, length, native_output_frame);
//cleanup and return
(*env)->ReleaseShortArrayElements(env, input_frame, native_input_frame, 0);
(*env)->ReleaseShortArrayElements(env, echo_frame, native_echo_frame, 0);
(*env)->ReleaseShortArrayElements(env, temp, native_output_frame, 0);
return output_shorts;
}
JNIEXPORT void JNICALL Java_com_example_speexjni_SpeexEchoCanceler_close
(JNIEnv *env, jobject jObj)
{
//close
speex_echo_state_destroy(st);
speex_preprocess_state_destroy(den);
}
回答1:
refer to this post: Speex echo cancellation configuration
//send played and recorded shorts into speex,
//returning audio data with the echo removed
filteredShorts = nativeMethod_speexEchoCancel(recordedShorts, recvShorts);
you should process with "recorded frame" and "received frame", i.e. sound from microphone and speaker, rather than same "buffer"
short b[] = speexEchoCanceler.processEcho(buffer, buffer);
来源:https://stackoverflow.com/questions/23010325/android-echo-cancelation-via-speex-library