android 如何做到播放音乐时动态波形
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发布时间：2022-04-22 14:55
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时间：2023-10-19 02:53
package com.AudioFx;
import android.app.Activity;
import android.content.Context;
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.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.TextView;
public class AudioFxActivity extends Activity
{
private static final String TAG = "AudioFxActivity";
private static final float VISUALIZER_HEIGHT_DIP = 160f;
private MediaPlayer mMediaPlayer;
private Visualizer mVisualizer;
private Equalizer mEqualizer;
private LinearLayout mLinearLayout;
private VisualizerView mVisualizerView;
private TextView mStatusTextView;
private TextView mInfoView;
@Override
public void onCreate(Bundle icicle)
{
super.onCreate(icicle);
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.my_life);
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);
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setVolumeControlStream(AudioManager.STREAM_SYSTEM);
mStatusTextView.setText("音乐播放完毕");
}
});
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setVolumeControlStream(AudioManager.STREAM_MUSIC);
mMediaPlayer.start();
mStatusTextView.setText("播放音乐中....");
}
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("均衡器:");
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()
{
mVisualizerView = new VisualizerView(this);
mVisualizerView.setLayoutParams(new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
(int) (VISUALIZER_HEIGHT_DIP * getResources()
.getDisplayMetrics().density)));
mLinearLayout.addView(mVisualizerView);
mInfoView = new TextView(this);
String infoStr = "";
int[] csr = Visualizer.getCaptureSizeRange();
if(csr != null)
{
String csrStr = "CaptureSizeRange: ";
for(int i = 0; i < csr.length; i ++)
{
csrStr += csr[i];
csrStr +=" ";
}
infoStr += csrStr;
}
final int maxCR = Visualizer.getMaxCaptureRate();
infoStr = infoStr + "\nMaxCaptureRate: " + maxCR;
mInfoView.setText(infoStr);
mLinearLayout.addView(mInfoView);
mVisualizer = new Visualizer(mMediaPlayer.getAudioSessionId());
mVisualizer.setCaptureSize(256);
mVisualizer.setDataCaptureListener(
new Visualizer.OnDataCaptureListener()
{
public void onWaveFormDataCapture(Visualizer visualizer,
byte[] bytes, int samplingRate)
{
mVisualizerView.updateVisualizer(bytes);
}
public void onFftDataCapture(Visualizer visualizer,
byte[] fft, int samplingRate)
{
mVisualizerView.updateVisualizer(fft);
}
}, maxCR / 2, false, true);
}
@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();
private int mSpectrumNum = 48;
private boolean mFirst = true;
public VisualizerView(Context context)
{
super(context);
init();
}
private void init()
{
mBytes = null;
mForePaint.setStrokeWidth(8f);
mForePaint.setAntiAlias(true);
mForePaint.setColor(Color.rgb(0, 128, 255));
}
public void updateVisualizer(byte[] fft)
{
if(mFirst )
{
mInfoView.setText(mInfoView.getText().toString() + "\nCaptureSize: " + fft.length);
mFirst = false;
}
byte[] model = new byte[fft.length / 2 + 1];
model[0] = (byte) Math.abs(fft[0]);
for (int i = 2, j = 1; j < mSpectrumNum;)
{
model[j] = (byte) Math.hypot(fft[i], fft[i + 1]);
i += 2;
j++;
}
mBytes = model;
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());
//绘制波形
// 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;
// }
//绘制频谱
final int baseX = mRect.width()/mSpectrumNum;
final int height = mRect.height();
for (int i = 0; i < mSpectrumNum ; i++)
{
if (mBytes[i] < 0)
{
mBytes[i] = 127;
}
final int xi = baseX*i + baseX/2;
mPoints[i * 4] = xi;
mPoints[i * 4 + 1] = height;
mPoints[i * 4 + 2] = xi;
mPoints[i * 4 + 3] = height - mBytes[i];
}
canvas.drawLines(mPoints, mForePaint);
}
}
}
