/*
* Copyright (C) 2008 Google Inc.
*
* 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.ringdroid;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import com.ringdroid.soundfile.CheapSoundFile;
/**
* WaveformView is an Android view that displays a visual representation
* of an audio waveform. It retrieves the frame gains from a CheapSoundFile
* object and recomputes the shape contour at several zoom levels.
*
* This class doesn't handle selection or any of the touch interactions
* directly, so it exposes a listener interface. The class that embeds
* this view should add itself as a listener and make the view scroll
* and respond to other events appropriately.
*
* WaveformView doesn't actually handle selection, but it will just display
* the selected part of the waveform in a different color.
*/
public class WaveformView extends View {
public interface WaveformListener {
public void waveformTouchStart(float x);
public void waveformTouchMove(float x);
public void waveformTouchEnd();
public void waveformDraw();
};
// Colors
private Paint mGridPaint;
private Paint mSelectedLinePaint;
private Paint mUnselectedLinePaint;
private Paint mUnselectedBkgndLinePaint;
private Paint mBorderLinePaint;
private Paint mPlaybackLinePaint;
private Paint mTimecodePaint;
private CheapSoundFile mSoundFile;
private int[] mLenByZoomLevel;
private double[][] mValuesByZoomLevel;
private double[] mZoomFactorByZoomLevel;
private int[] mHeightsAtThisZoomLevel;
private int mZoomLevel;
private int mNumZoomLevels;
private int mSampleRate;
private int mSamplesPerFrame;
private int mOffset;
private int mSelectionStart;
private int mSelectionEnd;
private int mPlaybackPos;
private float mDensity;
private WaveformListener mListener;
private boolean mInitialized;
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.setAntiAlias(true);
mTimecodePaint.setColor(
getResources().getColor(R.drawable.timecode));
mTimecodePaint.setShadowLayer(
2, 1, 1,
getResources().getColor(R.drawable.timecode_shadow));
mSoundFile = null;
mLenByZoomLevel = null;
mValuesByZoomLevel = null;
mHeightsAtThisZoomLevel = null;
mOffset = 0;
mPlaybackPos = -1;
mSelectionStart = 0;
mSelectionEnd = 0;
mDensity = 1.0f;
mInitialized = false;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
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;
}
public boolean isInitialized() {
return mInitialized;
}
public int getZoomLevel() {
return mZoomLevel;
}
public void setZoomLevel(int zoomLevel) {
while (mZoomLevel > zoomLevel) {
zoomIn();
}
while (mZoomLevel < zoomLevel) {
zoomOut();
}
}
public boolean canZoomIn() {
return (mZoomLevel > 0);
}
public void zoomIn() {
if (canZoomIn()) {
mZoomLevel--;
mSelectionStart *= 2;
mSelectionEnd *= 2;
mHeightsAtThisZoomLevel = null;
int offsetCenter = mOffset + getMeasuredWidth() / 2;
offsetCenter *= 2;
mOffset = offsetCenter - getMeasuredWidth() / 2;
if (mOffset < 0)
mOffset = 0;
invalidate();
}
}
public boolean canZoomOut() {
return (mZoomLevel < mNumZoomLevels - 1);
}
public void zoomOut() {
if (canZoomOut()) {
mZoomLevel++;
mSelectionStart /= 2;
mSelectionEnd /= 2;
int offsetCenter = mOffset + getMeasuredWidth() / 2;
offsetCenter /= 2;
mOffset = offsetCenter - getMeasuredWidth() / 2;
if (mOffset < 0)
mOffset = 0;
mHeightsAtThisZoomLevel = null;
invalidate();
}
}
public int maxPos() {
if (mLenByZoomLevel != null)
return mLenByZoomLevel[mZoomLevel];
else
return 0;
}
public int secondsToFrames(double seconds) {
return (int)(1.0 * seconds * mSampleRate / mSamplesPerFrame + 0.5);
}
public int secondsToPixels(double seconds) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (int)(z * seconds * mSampleRate / mSamplesPerFrame + 0.5);
}
public double pixelsToSeconds(int pixels) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (pixels * (double)mSamplesPerFrame / (mSampleRate * z));
}
public int millisecsToPixels(int msecs) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (int)((msecs * 1.0 * mSampleRate * z) /
(1000.0 * mSamplesPerFrame) + 0.5);
}
public int pixelsToMillisecs(int pixels) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (int)(pixels * (1000.0 * mSamplesPerFrame) /
(mSampleRate * z) + 0.5);
}
public void setParameters(int start, int end, int offset) {
mSelectionStart = start;
mSelectionEnd = end;
mOffset = offset;
}
public int getStart() {
return mSelectionStart;
}
public int getEnd() {
return mSelectionEnd;
}
public int getOffset() {
return mOffset;
}
public void setPlayback(int pos) {
mPlaybackPos = pos;
}
public void setListener(WaveformListener listener) {
mListener = listener;
}
public void recomputeHeights(float density) {
mHeightsAtThisZoomLevel = null;
mDensity = density;
invalidate();
}
/**
* Our waveform is "painted" as a series of vertical lines, not
* anti-aliased.
*
* But, the Cupcake API only supports the standard resolution
* and automatically scales everything up by a factor of 1.5 on
* a high-resolution display, which leaves "gaps" when we try to
* draw one vertical line per "pixel". (The coordinates are
* scaled, but the lines are drawn normally.)
*
* So, if the density is > 1.0, then we draw two vertical lines instead
* of one every other time. This solves the problem for a scale
* factor between 1.0 and 2.0. A future version of Ringdroid will
* use the 1.6 (Donut) API or later and natively support all resolutions.
*/
protected void drawWaveformLine(Canvas canvas,
int x, int y0, int y1,
Paint paint) {
if (mDensity > 1.0 && (x % 2) == 1) {
canvas.drawLine(x + 0.5f, y0, x + 0.5f, y1, paint);
}
canvas.drawLine(x, y0, x, y1, paint);
}
@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, 15,
mTimecodePaint);
}
}
if (mListener != null) {
mListener.waveformDraw();
}
}
/**
* Called once when a new sound file is added
*/
private void computeDoublesForAllZoomLevels() {
int numFrames = mSoundFile.getNumFrames();
int[] frameGains = mSoundFile.getFrameGains();
double[] smoothedGains = new double[numFrames];
if (numFrames == 1) {
smoothedGains[0] = frameGains[0];
} else if (numFrames == 2) {
smoothedGains[0] = frameGains[0];
smoothedGains[1] = frameGains[1];
} else if (numFrames > 2) {
smoothedGains[0] = (double)(
(frameGains[0] / 2.0) +
(frameGains[1] / 2.0));
for (int i = 1; i < numFrames - 1; i++) {
smoothedGains[i] = (double)(
(frameGains[i - 1] / 3.0) +
(frameGains[i ] / 3.0) +
(frameGains[i + 1] / 3.0));
}
smoothedGains[numFrames - 1] = (double)(
(frameGains[numFrames - 2] / 2.0) +
(frameGains[numFrames - 1] / 2.0));
}
// Make sure the range is no more than 0 - 255
double maxGain = 1.0;
for (int i = 0; i < numFrames; i++) {
if (smoothedGains[i] > maxGain) {
maxGain = smoothedGains[i];
}
}
double scaleFactor = 1.0;
if (maxGain > 255.0) {
scaleFactor = 255 / maxGain;
}
// Build histogram of 256 bins and figure out the new scaled max
maxGain = 0;
int gainHist[] = new int[256];
for (int i = 0; i < numFrames; i++) {
int smoothedGain = (int)(smoothedGains[i] * scaleFactor);
if (smoothedGain < 0)
smoothedGain = 0;
if (smoothedGain > 255)
smoothedGain = 255;
if (smoothedGain > maxGain)
maxGain = smoothedGain;
gainHist[smoothedGain]++;
}
// Re-calibrate the min to be 5%
double minGain = 0;
int sum = 0;
while (minGain < 255 && sum < numFrames / 20) {
sum += gainHist[(int)minGain];
minGain++;
}
// Re-calibrate the max to be 99%
sum = 0;
while (maxGain > 2 && sum < numFrames / 100) {
sum += gainHist[(int)maxGain];
maxGain--;
}
// Compute the heights
double[] heights = new double[numFrames];
double range = maxGain - minGain;
for (int i = 0; i < numFrames; i++) {
double value = (smoothedGains[i] * scaleFactor - minGain) / range;
if (value < 0.0)
value = 0.0;
if (value > 1.0)
value = 1.0;
heights[i] = value * value;
}
mNumZoomLevels = 5;
mLenByZoomLevel = new int[5];
mZoomFactorByZoomLevel = new double[5];
mValuesByZoomLevel = new double[5][];
// Level 0 is doubled, with interpolated values
mLenByZoomLevel[0] = numFrames * 2;
mZoomFactorByZoomLevel[0] = 2.0;
mValuesByZoomLevel[0] = new double[mLenByZoomLevel[0]];
if (numFrames > 0) {
mValuesByZoomLevel[0][0] = 0.5 * heights[0];
mValuesByZoomLevel[0][1] = heights[0];
}
for (int i = 1; i < numFrames; i++) {
mValuesByZoomLevel[0][2 * i] = 0.5 * (heights[i - 1] + heights[i]);
mValuesByZoomLevel[0][2 * i + 1] = heights[i];
}
// Level 1 is normal
mLenByZoomLevel[1] = numFrames;
mValuesByZoomLevel[1] = new double[mLenByZoomLevel[1]];
mZoomFactorByZoomLevel[1] = 1.0;
for (int i = 0; i < mLenByZoomLevel[1]; i++) {
mValuesByZoomLevel[1][i] = heights[i];
}
// 3 more levels are each halved
for (int j = 2; j < 5; j++) {
mLenByZoomLevel[j] = mLenByZoomLevel[j - 1] / 2;
mValuesByZoomLevel[j] = new double[mLenByZoomLevel[j]];
mZoomFactorByZoomLevel[j] = mZoomFactorByZoomLevel[j - 1] / 2.0;
for (int i = 0; i < mLenByZoomLevel[j]; i++) {
mValuesByZoomLevel[j][i] =
0.5 * (mValuesByZoomLevel[j - 1][2 * i] +
mValuesByZoomLevel[j - 1][2 * i + 1]);
}
}
if (numFrames > 5000) {
mZoomLevel = 3;
} else if (numFrames > 1000) {
mZoomLevel = 2;
} else if (numFrames > 300) {
mZoomLevel = 1;
} else {
mZoomLevel = 0;
}
mInitialized = true;
}
/**
* Called the first time we need to draw when the zoom level has changed
* or the screen is resized
*/
private void computeIntsForThisZoomLevel() {
int halfHeight = (getMeasuredHeight() / 2) - 1;
mHeightsAtThisZoomLevel = new int[mLenByZoomLevel[mZoomLevel]];
for (int i = 0; i < mLenByZoomLevel[mZoomLevel]; i++) {
mHeightsAtThisZoomLevel[i] =
(int)(mValuesByZoomLevel[mZoomLevel][i] * halfHeight);
}
}
}