Android使用音频信息绘制动态波纹

<!--波纹视图--><me.chunyu.spike.wcl_visualizer_demo.visualizers.WaveformViewandroid:id="@+id/main_wv_waveform"android:layout_width="match_parent"android:layout_height="match_parent"/>

public class MainActivity extends AppCompatActivity {private static final int CAPTURE_SIZE = 256; // 获取这些数据, 用于显示private static final int REQUEST_CODE = 0;// 权限private static final String[] PERMISSIONS = new String[]{Manifest.permission.RECORD_AUDIO,Manifest.permission.MODIFY_AUDIO_SETTINGS};@Bind(R.id.main_wv_waveform) WaveformView mWvWaveform; // 波纹视图private Visualizer mVisualizer; // 音频可视化类@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);ButterKnife.bind(this);RendererFactory rendererFactory = new RendererFactory();mWvWaveform.setRenderer(rendererFactory.createSimpleWaveformRender(ContextCompat.getColor(this, R.color.colorPrimary), Color.WHITE));}@Override protected void onResume() {super.onResume();PermissionsChecker checker = new PermissionsChecker(this);if (checker.lakesPermissions(PERMISSIONS)) {PermissionsActivity.startActivityForResult(this, REQUEST_CODE, PERMISSIONS);} else {startVisualiser();}}@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (requestCode == REQUEST_CODE && resultCode == PermissionsActivity.PERMISSIONS_DENIED) {finish();}}// 设置音频线private void startVisualiser() {mVisualizer = new Visualizer(0); // 初始化mVisualizer.setDataCaptureListener(new Visualizer.OnDataCaptureListener() {@Overridepublic void onWaveFormDataCapture(Visualizer visualizer, byte[] waveform, int samplingRate) {if (mWvWaveform != null) {mWvWaveform.setWaveform(waveform);}}@Overridepublic void onFftDataCapture(Visualizer visualizer, byte[] fft, int samplingRate) {}}, Visualizer.getMaxCaptureRate(), true, false);mVisualizer.setCaptureSize(CAPTURE_SIZE);mVisualizer.setEnabled(true);}// 释放@Override protected void onPause() {if (mVisualizer != null) {mVisualizer.setEnabled(false);mVisualizer.release();}super.onPause();}}

/*** 音频波纹视图* <p>* Created by wangchenlong on 16/2/11.*/public class WaveformView extends View {private WaveformRenderer mRenderer; // 绘制类private byte[] mWaveform; // 波纹形状public WaveformView(Context context) {super(context);}public WaveformView(Context context, AttributeSet attrs) {super(context, attrs);}public WaveformView(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);}@TargetApi(21)public WaveformView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {super(context, attrs, defStyleAttr, defStyleRes);}public void setRenderer(WaveformRenderer renderer) {mRenderer = renderer;}public void setWaveform(byte[] waveform) {mWaveform = Arrays.copyOf(waveform, waveform.length); // 数组复制invalidate(); // 设置波纹之后, 需要重绘}@Override protected void onDraw(Canvas canvas) {super.onDraw(canvas);if (mRenderer != null) {mRenderer.render(canvas, mWaveform);}}}

/*** 波纹渲染逻辑* <p>* Created by wangchenlong on 16/2/12.*/public class SimpleWaveformRenderer implements WaveformRenderer {private static final int Y_FACTOR = 0xFF; // 2的8次方 = 256private static final float HALF_FACTOR = 0.5f;@ColorInt private final int mBackgroundColor;private final Paint mForegroundPaint;private final Path mWaveformPath;private SimpleWaveformRenderer(@ColorInt int backgroundColor, Paint foregroundPaint, Path waveformPath) {mBackgroundColor = backgroundColor;mForegroundPaint = foregroundPaint;mWaveformPath = waveformPath;}public static SimpleWaveformRenderer newInstance(@ColorInt int backgroundColor, @ColorInt int foregroundColour) {Paint paint = new Paint();paint.setColor(foregroundColour);paint.setAntiAlias(true); // 抗锯齿paint.setStrokeWidth(8.0f); // 设置宽度paint.setStyle(Paint.Style.STROKE); // 填充Path waveformPath = new Path();return new SimpleWaveformRenderer(backgroundColor, paint, waveformPath);}@Override public void render(Canvas canvas, byte[] waveform) {canvas.drawColor(mBackgroundColor);float width = canvas.getWidth();float height = canvas.getHeight();mWaveformPath.reset();// 没有数据if (waveform != null) {// 绘制波形renderWaveform(waveform, width, height);} else {// 绘制直线renderBlank(width, height);}canvas.drawPath(mWaveformPath, mForegroundPaint);}private void renderWaveform(byte[] waveform, float width, float height) {float xIncrement = width / (float) (waveform.length); // 水平块数float yIncrement = height / Y_FACTOR; // 竖直块数int halfHeight = (int) (height * HALF_FACTOR); // 居中位置mWaveformPath.moveTo(0, halfHeight);for (int i = 1; i < waveform.length; ++i) {float yPosition = waveform[i] > 0 ?height - (yIncrement * waveform[i]) : -(yIncrement * waveform[i]);mWaveformPath.lineTo(xIncrement * i, yPosition);}mWaveformPath.lineTo(width, halfHeight); // 最后的点, 水平居中}// 居中画一条直线private void renderBlank(float width, float height) {int y = (int) (height * HALF_FACTOR);mWaveformPath.moveTo(0, y);mWaveformPath.lineTo(width, y);}}