Crear forma de onda de archivo de audio en android

Question

Quiero crear las formas de onda del archivo de audio en Android. ¿Alguien puede proporcionarme un código fuente de ejemplo?

Answer 1

Crea clase y extiende la Vista. Luego crea la interfaz de escucha para tu clase.

public class WaveformCls extends View { 
    public interface WaveformListener { 
     public void waveformTouchStart(float x); 
     public void waveformTouchMove(float x); 
     public void waveformTouchEnd(); 
     public void waveformFling(float x); 
     public void waveformDraw(); 
    }; 

Crear objeto de pintura según su requisito.
Cree un método que inicialice todos los objetos Paint.

public WaveformView(Context context, AttributeSet attrs) { 
     super(context, attrs); 

     // We don't want keys, the markers get these 
     setFocusable(false); 

     mGridPaint = new Paint(); 
     mGridPaint.setAntiAlias(false); 
     mGridPaint.setColor(
      getResources().getColor(R.drawable.grid_line)); 
     mSelectedLinePaint = new Paint(); 
     mSelectedLinePaint.setAntiAlias(false); 
     mSelectedLinePaint.setColor(
      getResources().getColor(R.drawable.waveform_selected)); 
     mUnselectedLinePaint = new Paint(); 
     mUnselectedLinePaint.setAntiAlias(false); 
     mUnselectedLinePaint.setColor(
      getResources().getColor(R.drawable.waveform_unselected)); 
     mUnselectedBkgndLinePaint = new Paint(); 
     mUnselectedBkgndLinePaint.setAntiAlias(false); 
     mUnselectedBkgndLinePaint.setColor(
      getResources().getColor(
       R.drawable.waveform_unselected_bkgnd_overlay)); 
     mBorderLinePaint = new Paint(); 
     mBorderLinePaint.setAntiAlias(true); 
     mBorderLinePaint.setStrokeWidth(1.5f); 
     mBorderLinePaint.setPathEffect(
      new DashPathEffect(new float[] { 3.0f, 2.0f }, 0.0f)); 
     mBorderLinePaint.setColor(
      getResources().getColor(R.drawable.selection_border)); 
     mPlaybackLinePaint = new Paint(); 
     mPlaybackLinePaint.setAntiAlias(false); 
     mPlaybackLinePaint.setColor(
      getResources().getColor(R.drawable.playback_indicator)); 
     mTimecodePaint = new Paint(); 
     mTimecodePaint.setTextSize(12); 
     mTimecodePaint.setAntiAlias(true); 
     mTimecodePaint.setColor(
      getResources().getColor(R.drawable.timecode)); 
     mTimecodePaint.setShadowLayer(
      2, 1, 1, 
      getResources().getColor(R.drawable.timecode_shadow)); 

    mGestureDetector = new GestureDetector(
      context, 
     new GestureDetector.SimpleOnGestureListener() { 
      public boolean onFling(
        MotionEvent e1, MotionEvent e2, float vx, float vy) { 
      mListener.waveformFling(vx); 
      return true; 
      } 
     }); 

     mSoundFile = null; 
     mLenByZoomLevel = null; 
     mValuesByZoomLevel = null; 
     mHeightsAtThisZoomLevel = null; 
     mOffset = 0; 
     mPlaybackPos = -1; 
     mSelectionStart = 0; 
     mSelectionEnd = 0; 
     mDensity = 1.0f; 
     mInitialized = false; 
    } 

Necesita anular onTouchEvent

@Override 
    public boolean onTouchEvent(MotionEvent event) { 
    if (mGestureDetector.onTouchEvent(event)) { 
     return true; 
    } 

     switch(event.getAction()) { 
     case MotionEvent.ACTION_DOWN: 
      mListener.waveformTouchStart(event.getX()); 
      break; 
     case MotionEvent.ACTION_MOVE: 
      mListener.waveformTouchMove(event.getX()); 
      break; 
     case MotionEvent.ACTION_UP: 
      mListener.waveformTouchEnd(); 
      break; 
     } 
     return true; 
    } 

public void setSoundFile(CheapSoundFile soundFile) { 
    mSoundFile = soundFile; 
    mSampleRate = mSoundFile.getSampleRate(); 
    mSamplesPerFrame = mSoundFile.getSamplesPerFrame(); 
    computeDoublesForAllZoomLevels(); 
    mHeightsAtThisZoomLevel = null; 
} 

anular el método de sorteo que dibujar la onda en la pantalla.

@Override 
    protected void onDraw(Canvas canvas) { 
     super.onDraw(canvas); 
     if (mSoundFile == null) 
      return; 

     if (mHeightsAtThisZoomLevel == null) 
      computeIntsForThisZoomLevel(); 

     // Draw waveform 
     int measuredWidth = getMeasuredWidth(); 
     int measuredHeight = getMeasuredHeight(); 
     int start = mOffset; 
     int width = mHeightsAtThisZoomLevel.length - start; 
     int ctr = measuredHeight/2; 

     if (width > measuredWidth) 
      width = measuredWidth; 

     // Draw grid 
     double onePixelInSecs = pixelsToSeconds(1); 
     boolean onlyEveryFiveSecs = (onePixelInSecs > 1.0/50.0); 
     double fractionalSecs = mOffset * onePixelInSecs; 
     int integerSecs = (int) fractionalSecs; 
     int i = 0; 
     while (i < width) { 
      i++; 
      fractionalSecs += onePixelInSecs; 
      int integerSecsNew = (int) fractionalSecs; 
      if (integerSecsNew != integerSecs) { 
       integerSecs = integerSecsNew; 
       if (!onlyEveryFiveSecs || 0 == (integerSecs % 5)) { 
        canvas.drawLine(i, 0, i, measuredHeight, mGridPaint); 
       } 
      } 
     } 

     // Draw waveform 
     for (i = 0; i < width; i++) { 
      Paint paint; 
      if (i + start >= mSelectionStart && 
       i + start < mSelectionEnd) { 
       paint = mSelectedLinePaint; 
      } else { 
       drawWaveformLine(canvas, i, 0, measuredHeight, 
           mUnselectedBkgndLinePaint); 
       paint = mUnselectedLinePaint; 
      } 
      drawWaveformLine(
       canvas, i, 
       ctr - mHeightsAtThisZoomLevel[start + i], 
       ctr + 1 + mHeightsAtThisZoomLevel[start + i], 
       paint); 

      if (i + start == mPlaybackPos) { 
       canvas.drawLine(i, 0, i, measuredHeight, mPlaybackLinePaint); 
      } 
     } 

     // If we can see the right edge of the waveform, draw the 
     // non-waveform area to the right as unselected 
     for (i = width; i < measuredWidth; i++) { 
      drawWaveformLine(canvas, i, 0, measuredHeight, 
          mUnselectedBkgndLinePaint);    
     } 

     // Draw borders 
     canvas.drawLine(
      mSelectionStart - mOffset + 0.5f, 30, 
      mSelectionStart - mOffset + 0.5f, measuredHeight, 
      mBorderLinePaint); 
     canvas.drawLine(
      mSelectionEnd - mOffset + 0.5f, 0, 
      mSelectionEnd - mOffset + 0.5f, measuredHeight - 30, 
      mBorderLinePaint); 

     // Draw timecode 
     double timecodeIntervalSecs = 1.0; 
     if (timecodeIntervalSecs/onePixelInSecs < 50) { 
      timecodeIntervalSecs = 5.0; 
     } 
     if (timecodeIntervalSecs/onePixelInSecs < 50) { 
      timecodeIntervalSecs = 15.0; 
     } 

     // Draw grid 
     fractionalSecs = mOffset * onePixelInSecs; 
     int integerTimecode = (int) (fractionalSecs/timecodeIntervalSecs); 
     i = 0; 
     while (i < width) { 
      i++; 
      fractionalSecs += onePixelInSecs; 
      integerSecs = (int) fractionalSecs; 
      int integerTimecodeNew = (int) (fractionalSecs/
              timecodeIntervalSecs); 
      if (integerTimecodeNew != integerTimecode) { 
       integerTimecode = integerTimecodeNew; 

       // Turn, e.g. 67 seconds into "1:07" 
       String timecodeMinutes = "" + (integerSecs/60); 
       String timecodeSeconds = "" + (integerSecs % 60); 
       if ((integerSecs % 60) < 10) { 
        timecodeSeconds = "0" + timecodeSeconds; 
       } 
       String timecodeStr = timecodeMinutes + ":" + timecodeSeconds; 
       float offset = (float) (
        0.5 * mTimecodePaint.measureText(timecodeStr)); 
       canvas.drawText(timecodeStr, 
           i - offset, 
           (int)(12 * mDensity), 
           mTimecodePaint); 
      } 
     } 

     if (mListener != null) { 
      mListener.waveformDraw(); 
     } 
    } 

Aquí está el código fuente completo de Rindroid que es útil para usted
Source code for waveform