YOUR
AudioRecord.getMinBufferSize(SAMPPERSEC,channelConfiguration,audioEncoding);
returns -2 value which crashes while allocation of buffer = new
short[buffersizebytes];
Can you Explain the reason?
On Saturday, May 22, 2010 11:23:34 AM UTC+6, BobG wrote:
>
> try this, turn on audio record permission
>
> package com.aiti.vumeter;
> //vumeter
> //May 21 2010 Bob Gardner at aol.com
>
> import java.util.Timer;
> import java.util.TimerTask;
>
> import android.app.Activity;
> import android.content.Context;
> import android.graphics.Canvas;
> import android.graphics.Color;
> import android.graphics.Paint;
> import android.media.AudioFormat;
> import android.media.AudioRecord;
> import android.os.Bundle;
> import android.os.SystemClock;
> import android.util.DisplayMetrics;
> import android.view.View;
> import android.widget.TextView;
>
> public class vumeter extends Activity {
> public AudioRecord audioRecord;
> public VuView vuview;
> public Timer timer;
> public int channelConfiguration =
> AudioFormat.CHANNEL_CONFIGURATION_MONO;
> public int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;
> public int mSamplesRead; //how many samples read
> public int buffersizebytes;
> public int buflen;
> public int scrwidth;
> public int scrheight;
> public int cursamprate;
> public final int SAMPPERSEC = 48000; //samp per sec 8000, 11025,
> 22050 44100 or 48000
> public float vin; //input volts
> public float iavg; //avg of input volts
> public float ipk; //peak input volts
> public float isum; //sum of ans of input volts
> public float idbavg; //db below 0 of avg input volts
> public float idbpk;
> public float pixperdb;
> public float pixperdiv;
> public final float rangedb=60.0f;
> public final float dbperdiv=3.0f;
> public final float barwid=30f;
> public float scrbot;
> public long t1,t2,dt, t3,t4,dt2;
> public short[] buffer; //+-32767
>
> /** Called when the activity is first created. */
> @Override
> public void onCreate(Bundle savedInstanceState){
> super.onCreate(savedInstanceState);
> // setContentView(R.layout.main);
> DisplayMetrics metrics = new DisplayMetrics();
> getWindowManager().getDefaultDisplay().getMetrics(metrics);
> scrwidth=metrics.widthPixels; //
> scrheight=metrics.heightPixels; //
> scrbot=scrheight-100; //480-100->380
> pixperdb=scrbot/rangedb; //380/60->5
> pixperdiv=dbperdiv*pixperdb; //3*5->15
>
> buffersizebytes =
> AudioRecord.getMinBufferSize(SAMPPERSEC,channelConfiguration,audioEncoding);
> //
> 4096 on ion
> buffer = new short[buffersizebytes]; //4096
> buflen=buffersizebytes/2; //2048
> audioRecord = new
> AudioRecord(android.media.MediaRecorder.AudioSource.MIC,SAMPPERSEC,
> channelConfiguration, audioEncoding,
> buffersizebytes); //constructor
> cursamprate=audioRecord.getSampleRate();
> vuview = new VuView(this);
> setContentView(vuview);
>
> timer = new Timer();
> timer.schedule(new TimerTask(){
> @Override
> public void run(){
> TimerMethod();
> }
> }, 0, 200); //every 200 ms
> // trigger(); //grab samples and calc db
> }//oncreate
>
> private void TimerMethod(){
> //This method is called directly by the timer
> //and runs in the same thread as the timer.
> //We call the method that will work with the UI
> //through the runOnUiThread method.
> this.runOnUiThread(Timer_Tick);
> }
>
> private Runnable Timer_Tick = new Runnable(){
> public void run() {
> //This method runs in the same thread as the UI.
> //Do something to the UI thread here
> trigger();
> }
> };
>
> //--------------------------------------
> public void acquire(){
> try {
> audioRecord.startRecording(); //48khz
> } catch (Throwable t) {
> // Log.e("AudioRecord", "startrecording Failed");
> }
> // SystemClock.sleep(50L); //one period of 20 hz
> mSamplesRead = audioRecord.read(buffer, 0, buflen);
> try{
> audioRecord.stop();
> } catch (Throwable t) {
> // Log.e("AudioRecord", "stoprecording Failed");
> }
> }
>
> //-----------------------
> public void avg(){
> int i;
> float ftmp;
>
> ipk=0f;
> isum=0f;
> for(i=0; i < buflen; i++){ //2048 samples
> vin=(float)buffer[i]; //get a sample
> ftmp=Math.abs(vin); //abs of input sample
> isum += ftmp; //sum of input samples
> if(ftmp > ipk) ipk=ftmp; //remember input peak
> }
> iavg=isum/buflen; //avg of
> input
> samples
> idbavg= (float)(20.0*Math.log10(iavg/32767.0)); //db below
> clip of
> input signal
> idbpk= (float)(20.0*Math.log10(ipk/32767.0)); //db of
> input signal
> }//avg
>
> //--------------------------------
> public void trigger(){
> t1=System.currentTimeMillis();
> acquire(); //grab buffer full of samples
> avg(); //calc avg and db
> // dump();
> vuview.invalidate(); //tell os to call ondraw
> t2=System.currentTimeMillis();
> dt=t2-t1;
> t1=t2;
> }//trigger
>
> //--------------------------------------
> void dump(){
> TextView tv = new TextView(this);
> setContentView(tv);
> tv.setTextColor(Color.WHITE);
> tv.setText("buffersizebytes "+buffersizebytes+"\n");
> for (int i = 0; i < buflen; i++){
> tv.append(" "+buffer[i]);
> }
> }//dump
>
> //-------lifecycle callbacks-------------------
> @Override
> public void onResume(){
> super.onResume();
> trigger();
> }//onresume
>
> @Override
> public void onPause(){
> super.onPause();
> audioRecord.stop();
> }//onpause
>
> @Override
> public void onStop(){
> super.onStop();
> audioRecord.release();
> }//onstop
>
> // @Override
> // public boolean onTouchEvent(MotionEvent motionevent){
> // if(motionevent.getAction()==MotionEvent.ACTION_DOWN){
> // trigger(); //acquire buffer full of samples
> // }
> // return true;
> // }
>
> //--------------------------------------
> private class VuView extends View {
> public VuView(Context context) {
> super(context);
> }
>
> @Override
> protected void onDraw(Canvas canvas) {
> super.onDraw(canvas);
> t3=System.currentTimeMillis();
> graticule(canvas);
> drawvu(canvas);
> t4=System.currentTimeMillis();
> dt2=t4-t3;
> t3=t4;
> }//ondraw
>
> //------------------------------------------------
> public void graticule(Canvas canvas){ //draw graticule
> int i;
> float TL=7;
>
> Paint paint = new Paint();
> paint.setColor(Color.BLACK);
> canvas.drawPaint(paint); //clear screen
>
> paint.setColor(Color.GRAY);
> paint.setStyle(Paint.Style.STROKE);
> paint.setStrokeWidth(1);
> canvas.drawLine(0f,0f,0f,scrbot, paint); //y axis
> (vertical)
> for(i=0; i < (int)scrbot; i++){
> if((i % (int)pixperdiv)==0){
> canvas.drawLine(0,i,TL,i, paint);
> //y axis tics (horizontal)
> }
> }
> }//graticule
>
> //-----------------------------------------
> public void drawvu(Canvas canvas){ //draw vu
> float x;
> float ftmp;
>
> Paint paint = new Paint();
> paint.setColor(Color.GREEN);
> paint.setStyle(Paint.Style.STROKE);
> paint.setStrokeWidth(1);
> x=20f; //left side of vu
> ftmp=Math.abs(idbpk)*pixperdb; //abs of db, cvt to
> pix
> if(ftmp > scrbot) ftmp=scrbot; //clip at bottom
> canvas.drawLine(x, ftmp, x+barwid, ftmp, paint);
> //db peak bar
>
> paint.setStyle(Paint.Style.FILL);
> canvas.drawRect(x,(float)Math.abs(idbavg)*pixperdb,
> x+barwid,
> scrbot, paint); //input db avg
>
> paint.setColor(Color.WHITE);
> paint.setTextSize(15);
> canvas.drawText("ms " + dt, 100, 20, paint);
> //
> canvas.drawText("ms " + dt2, 100, 40, paint);
> //
> canvas.drawText("db/div " + dbperdiv, 100, 60, paint);
> canvas.drawText("range " + rangedb, 100, 80, paint);
> canvas.drawText("avg " + idbavg, 100, 100,
> paint);
> // canvas.drawText("ht " + scrheight, 100, 120,
> paint);
> // canvas.drawText("sr " + cursamprate,100,120,
> paint);
> }//drawvus
> }//graphview
> }//activity
> //-----------------------eof-----------------------
>
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