samples/ApiDemos/src/com/example/android/apis/media/AudioFxDemo.java - platform/development - Git at Google

 /*
  * Copyright (C) 2010 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.example.android.apis.media;

 import com.example.android.apis.R;

 import android.app.Activity;
 import android.content.Context;
 import android.content.res.AssetFileDescriptor;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Rect;
 import android.media.AudioManager;
 import android.media.MediaPlayer;
 import android.media.audiofx.Equalizer;
 import android.media.audiofx.Visualizer;
 import android.net.Uri;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.LinearLayout;
 import android.widget.SeekBar;
 import android.widget.TextView;

 import java.io.IOException;

 public class AudioFxDemo extends Activity {
     private static final String TAG = "AudioFxDemo";

     private static final float VISUALIZER_HEIGHT_DIP = 50f;

     private MediaPlayer mMediaPlayer;
     private Visualizer mVisualizer;
     private Equalizer mEqualizer;

     private LinearLayout mLinearLayout;
     private VisualizerView mVisualizerView;
     private TextView mStatusTextView;

     @Override
     public void onCreate(Bundle icicle) {
         super.onCreate(icicle);

         setVolumeControlStream(AudioManager.STREAM_MUSIC);

         mStatusTextView = new TextView(this);

         mLinearLayout = new LinearLayout(this);
         mLinearLayout.setOrientation(LinearLayout.VERTICAL);
         mLinearLayout.addView(mStatusTextView);

         setContentView(mLinearLayout);

         // Create the MediaPlayer
         mMediaPlayer = MediaPlayer.create(this, R.raw.test_cbr);
         Log.d(TAG, "MediaPlayer audio session ID: " + mMediaPlayer.getAudioSessionId());

         setupVisualizerFxAndUI();
         setupEqualizerFxAndUI();

         // Make sure the visualizer is enabled only when you actually want to receive data, and
         // when it makes sense to receive data.
         mVisualizer.setEnabled(true);

         // When the stream ends, we don't need to collect any more data. We don't do this in
         // setupVisualizerFxAndUI because we likely want to have more, non-Visualizer related code
         // in this callback.
         mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
             public void onCompletion(MediaPlayer mediaPlayer) {
                 mVisualizer.setEnabled(false);
             }
         });

         mMediaPlayer.start();
         mStatusTextView.setText("Playing audio...");
     }

     private void setupEqualizerFxAndUI() {
         // Create the Equalizer object (an AudioEffect subclass) and attach it to our media player,
         // with a default priority (0).
         mEqualizer = new Equalizer(0, mMediaPlayer.getAudioSessionId());
         mEqualizer.setEnabled(true);

         TextView eqTextView = new TextView(this);
         eqTextView.setText("Equalizer:");
         mLinearLayout.addView(eqTextView);

         short bands = mEqualizer.getNumberOfBands();

         final short minEQLevel = mEqualizer.getBandLevelRange()[0];
         final short maxEQLevel = mEqualizer.getBandLevelRange()[1];

         for (short i = 0; i < bands; i++) {
             final short band = i;

             TextView freqTextView = new TextView(this);
             freqTextView.setLayoutParams(new ViewGroup.LayoutParams(
                     ViewGroup.LayoutParams.FILL_PARENT,
                     ViewGroup.LayoutParams.WRAP_CONTENT));
             freqTextView.setGravity(Gravity.CENTER_HORIZONTAL);
             freqTextView.setText((mEqualizer.getCenterFreq(band) / 1000) + " Hz");
             mLinearLayout.addView(freqTextView);

             LinearLayout row = new LinearLayout(this);
             row.setOrientation(LinearLayout.HORIZONTAL);

             TextView minDbTextView = new TextView(this);
             minDbTextView.setLayoutParams(new ViewGroup.LayoutParams(
                     ViewGroup.LayoutParams.WRAP_CONTENT,
                     ViewGroup.LayoutParams.WRAP_CONTENT));
             minDbTextView.setText((minEQLevel / 100) + " dB");

             TextView maxDbTextView = new TextView(this);
             maxDbTextView.setLayoutParams(new ViewGroup.LayoutParams(
                     ViewGroup.LayoutParams.WRAP_CONTENT,
                     ViewGroup.LayoutParams.WRAP_CONTENT));
             maxDbTextView.setText((maxEQLevel / 100) + " dB");

             LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
                     ViewGroup.LayoutParams.FILL_PARENT,
                     ViewGroup.LayoutParams.WRAP_CONTENT);
             layoutParams.weight = 1;
             SeekBar bar = new SeekBar(this);
             bar.setLayoutParams(layoutParams);
             bar.setMax(maxEQLevel - minEQLevel);
             bar.setProgress(mEqualizer.getBandLevel(band));

             bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
                 public void onProgressChanged(SeekBar seekBar, int progress,
                         boolean fromUser) {
                     mEqualizer.setBandLevel(band, (short) (progress + minEQLevel));
                 }

                 public void onStartTrackingTouch(SeekBar seekBar) {}
                 public void onStopTrackingTouch(SeekBar seekBar) {}
             });

             row.addView(minDbTextView);
             row.addView(bar);
             row.addView(maxDbTextView);

             mLinearLayout.addView(row);
         }
     }

     private void setupVisualizerFxAndUI() {
         // Create a VisualizerView (defined below), which will render the simplified audio
         // wave form to a Canvas.
         mVisualizerView = new VisualizerView(this);
         mVisualizerView.setLayoutParams(new ViewGroup.LayoutParams(
                 ViewGroup.LayoutParams.FILL_PARENT,
                 (int)(VISUALIZER_HEIGHT_DIP * getResources().getDisplayMetrics().density)));
         mLinearLayout.addView(mVisualizerView);

         // Create the Visualizer object and attach it to our media player.
         mVisualizer = new Visualizer(mMediaPlayer.getAudioSessionId());
         mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
         mVisualizer.setDataCaptureListener(new Visualizer.OnDataCaptureListener() {
             public void onWaveFormDataCapture(Visualizer visualizer, byte[] bytes,
                     int samplingRate) {
                 mVisualizerView.updateVisualizer(bytes);
             }

             public void onFftDataCapture(Visualizer visualizer, byte[] bytes, int samplingRate) {}
         }, Visualizer.getMaxCaptureRate() / 2, true, false);
     }

     @Override
     protected void onPause() {
         super.onPause();

         if (isFinishing() && mMediaPlayer != null) {
             mVisualizer.release();
             mEqualizer.release();
             mMediaPlayer.release();
             mMediaPlayer = null;
         }
     }
 }

 /**
  * A simple class that draws waveform data received from a
  * {@link Visualizer.OnDataCaptureListener#onWaveFormDataCapture }
  */
 class VisualizerView extends View {
     private byte[] mBytes;
     private float[] mPoints;
     private Rect mRect = new Rect();

     private Paint mForePaint = new Paint();

     public VisualizerView(Context context) {
         super(context);
         init();
     }

     private void init() {
         mBytes = null;

         mForePaint.setStrokeWidth(1f);
         mForePaint.setAntiAlias(true);
         mForePaint.setColor(Color.rgb(0, 128, 255));
     }

     public void updateVisualizer(byte[] bytes) {
         mBytes = bytes;
         invalidate();
     }

     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);

         if (mBytes == null) {
             return;
         }

         if (mPoints == null || mPoints.length < mBytes.length * 4) {
             mPoints = new float[mBytes.length * 4];
         }

         mRect.set(0, 0, getWidth(), getHeight());

         for (int i = 0; i < mBytes.length - 1; i++) {
             mPoints[i * 4] = mRect.width() * i / (mBytes.length - 1);
             mPoints[i * 4 + 1] = mRect.height() / 2
                     + ((byte) (mBytes[i] + 128)) * (mRect.height() / 2) / 128;
             mPoints[i * 4 + 2] = mRect.width() * (i + 1) / (mBytes.length - 1);
             mPoints[i * 4 + 3] = mRect.height() / 2
                     + ((byte) (mBytes[i + 1] + 128)) * (mRect.height() / 2) / 128;
         }

         canvas.drawLines(mPoints, mForePaint);
     }
 }
	/*
	* Copyright (C) 2010 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.example.android.apis.media;

	import com.example.android.apis.R;

	import android.app.Activity;
	import android.content.Context;
	import android.content.res.AssetFileDescriptor;
	import android.graphics.Canvas;
	import android.graphics.Color;
	import android.graphics.Paint;
	import android.graphics.Rect;
	import android.media.AudioManager;
	import android.media.MediaPlayer;
	import android.media.audiofx.Equalizer;
	import android.media.audiofx.Visualizer;
	import android.net.Uri;
	import android.os.Bundle;
	import android.util.Log;
	import android.view.Gravity;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.LinearLayout;
	import android.widget.SeekBar;
	import android.widget.TextView;

	import java.io.IOException;

	public class AudioFxDemo extends Activity {
	private static final String TAG = "AudioFxDemo";

	private static final float VISUALIZER_HEIGHT_DIP = 50f;

	private MediaPlayer mMediaPlayer;
	private Visualizer mVisualizer;
	private Equalizer mEqualizer;

	private LinearLayout mLinearLayout;
	private VisualizerView mVisualizerView;
	private TextView mStatusTextView;

	@Override
	public void onCreate(Bundle icicle) {
	super.onCreate(icicle);

	setVolumeControlStream(AudioManager.STREAM_MUSIC);

	mStatusTextView = new TextView(this);

	mLinearLayout = new LinearLayout(this);
	mLinearLayout.setOrientation(LinearLayout.VERTICAL);
	mLinearLayout.addView(mStatusTextView);

	setContentView(mLinearLayout);

	// Create the MediaPlayer
	mMediaPlayer = MediaPlayer.create(this, R.raw.test_cbr);
	Log.d(TAG, "MediaPlayer audio session ID: " + mMediaPlayer.getAudioSessionId());

	setupVisualizerFxAndUI();
	setupEqualizerFxAndUI();

	// Make sure the visualizer is enabled only when you actually want to receive data, and
	// when it makes sense to receive data.
	mVisualizer.setEnabled(true);

	// When the stream ends, we don't need to collect any more data. We don't do this in
	// setupVisualizerFxAndUI because we likely want to have more, non-Visualizer related code
	// in this callback.
	mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
	public void onCompletion(MediaPlayer mediaPlayer) {
	mVisualizer.setEnabled(false);
	}
	});

	mMediaPlayer.start();
	mStatusTextView.setText("Playing audio...");
	}

	private void setupEqualizerFxAndUI() {
	// Create the Equalizer object (an AudioEffect subclass) and attach it to our media player,
	// with a default priority (0).
	mEqualizer = new Equalizer(0, mMediaPlayer.getAudioSessionId());
	mEqualizer.setEnabled(true);

	TextView eqTextView = new TextView(this);
	eqTextView.setText("Equalizer:");
	mLinearLayout.addView(eqTextView);

	short bands = mEqualizer.getNumberOfBands();

	final short minEQLevel = mEqualizer.getBandLevelRange()[0];
	final short maxEQLevel = mEqualizer.getBandLevelRange()[1];

	for (short i = 0; i < bands; i++) {
	final short band = i;

	TextView freqTextView = new TextView(this);
	freqTextView.setLayoutParams(new ViewGroup.LayoutParams(
	ViewGroup.LayoutParams.FILL_PARENT,
	ViewGroup.LayoutParams.WRAP_CONTENT));
	freqTextView.setGravity(Gravity.CENTER_HORIZONTAL);
	freqTextView.setText((mEqualizer.getCenterFreq(band) / 1000) + " Hz");
	mLinearLayout.addView(freqTextView);

	LinearLayout row = new LinearLayout(this);
	row.setOrientation(LinearLayout.HORIZONTAL);

	TextView minDbTextView = new TextView(this);
	minDbTextView.setLayoutParams(new ViewGroup.LayoutParams(
	ViewGroup.LayoutParams.WRAP_CONTENT,
	ViewGroup.LayoutParams.WRAP_CONTENT));
	minDbTextView.setText((minEQLevel / 100) + " dB");

	TextView maxDbTextView = new TextView(this);
	maxDbTextView.setLayoutParams(new ViewGroup.LayoutParams(
	ViewGroup.LayoutParams.WRAP_CONTENT,
	ViewGroup.LayoutParams.WRAP_CONTENT));
	maxDbTextView.setText((maxEQLevel / 100) + " dB");

	LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
	ViewGroup.LayoutParams.FILL_PARENT,
	ViewGroup.LayoutParams.WRAP_CONTENT);
	layoutParams.weight = 1;
	SeekBar bar = new SeekBar(this);
	bar.setLayoutParams(layoutParams);
	bar.setMax(maxEQLevel - minEQLevel);
	bar.setProgress(mEqualizer.getBandLevel(band));

	bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
	public void onProgressChanged(SeekBar seekBar, int progress,
	boolean fromUser) {
	mEqualizer.setBandLevel(band, (short) (progress + minEQLevel));
	}

	public void onStartTrackingTouch(SeekBar seekBar) {}
	public void onStopTrackingTouch(SeekBar seekBar) {}
	});

	row.addView(minDbTextView);
	row.addView(bar);
	row.addView(maxDbTextView);

	mLinearLayout.addView(row);
	}
	}

	private void setupVisualizerFxAndUI() {
	// Create a VisualizerView (defined below), which will render the simplified audio
	// wave form to a Canvas.
	mVisualizerView = new VisualizerView(this);
	mVisualizerView.setLayoutParams(new ViewGroup.LayoutParams(
	ViewGroup.LayoutParams.FILL_PARENT,
	(int)(VISUALIZER_HEIGHT_DIP * getResources().getDisplayMetrics().density)));
	mLinearLayout.addView(mVisualizerView);

	// Create the Visualizer object and attach it to our media player.
	mVisualizer = new Visualizer(mMediaPlayer.getAudioSessionId());
	mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
	mVisualizer.setDataCaptureListener(new Visualizer.OnDataCaptureListener() {
	public void onWaveFormDataCapture(Visualizer visualizer, byte[] bytes,
	int samplingRate) {
	mVisualizerView.updateVisualizer(bytes);
	}

	public void onFftDataCapture(Visualizer visualizer, byte[] bytes, int samplingRate) {}
	}, Visualizer.getMaxCaptureRate() / 2, true, false);
	}

	@Override
	protected void onPause() {
	super.onPause();

	if (isFinishing() && mMediaPlayer != null) {
	mVisualizer.release();
	mEqualizer.release();
	mMediaPlayer.release();
	mMediaPlayer = null;
	}
	}
	}

	/**
	* A simple class that draws waveform data received from a
	* {@link Visualizer.OnDataCaptureListener#onWaveFormDataCapture }
	*/
	class VisualizerView extends View {
	private byte[] mBytes;
	private float[] mPoints;
	private Rect mRect = new Rect();

	private Paint mForePaint = new Paint();

	public VisualizerView(Context context) {
	super(context);
	init();
	}

	private void init() {
	mBytes = null;

	mForePaint.setStrokeWidth(1f);
	mForePaint.setAntiAlias(true);
	mForePaint.setColor(Color.rgb(0, 128, 255));
	}

	public void updateVisualizer(byte[] bytes) {
	mBytes = bytes;
	invalidate();
	}

	@Override
	protected void onDraw(Canvas canvas) {
	super.onDraw(canvas);

	if (mBytes == null) {
	return;
	}

	if (mPoints == null \|\| mPoints.length < mBytes.length * 4) {
	mPoints = new float[mBytes.length * 4];
	}

	mRect.set(0, 0, getWidth(), getHeight());

	for (int i = 0; i < mBytes.length - 1; i++) {
	mPoints[i * 4] = mRect.width() * i / (mBytes.length - 1);
	mPoints[i * 4 + 1] = mRect.height() / 2
	+ ((byte) (mBytes[i] + 128)) * (mRect.height() / 2) / 128;
	mPoints[i * 4 + 2] = mRect.width() * (i + 1) / (mBytes.length - 1);
	mPoints[i * 4 + 3] = mRect.height() / 2
	+ ((byte) (mBytes[i + 1] + 128)) * (mRect.height() / 2) / 128;
	}

	canvas.drawLines(mPoints, mForePaint);
	}
	}