public void CalculateSamplesTest()
{
AudioProperties audioProperties = new AudioProperties(2, 44100, 32, AudioFormat.IEEE);
double sampleTicks = AudioUtil.CalculateSampleTicks(audioProperties);
for (int x = 0; x < audioProperties.SampleRate * 60; x++)
{
TimeSpan timeSpan = new TimeSpan((long)Math.Ceiling(x * sampleTicks));
int expected = x;
int actual;
actual = AudioUtil.CalculateSamples(audioProperties, timeSpan);
Assert.AreEqual(expected, actual);
}
}
protected override void OnRender(DrawingContext drawingContext)
{
base.OnRender(drawingContext);
bool debug = DebugOutput;
// draw background
drawingContext.DrawRectangle(Background, null, new Rect(0, 0, ActualWidth, ActualHeight));
if (audioStream != null)
{
Interval audioInterval = new Interval(TrackOffset, TrackOffset + audioStream.TimeLength.Ticks);
Interval viewportInterval = VirtualViewportInterval;
if (!audioInterval.Intersects(viewportInterval))
{
// audio track is outside the viewport
return;
}
Interval visibleAudioInterval = audioInterval.Intersect(viewportInterval);
Interval audioToLoadInterval = visibleAudioInterval - TrackOffset;
// align interval to samples
Interval audioToLoadIntervalAligned = AudioUtil.AlignToSamples(audioToLoadInterval, audioStream.Properties);
int samplesToLoad = AudioUtil.CalculateSamples(audioStream.Properties, new TimeSpan(audioToLoadIntervalAligned.Length)) + 1;
double sampleLength = AudioUtil.CalculateSampleTicks(audioStream.Properties);
// calculate drawing measures
double viewportToDrawingScaleFactor = ActualWidth / VirtualViewportWidth;
int drawingOffsetAligned = (int)((-(audioToLoadInterval.From - audioToLoadIntervalAligned.From)
+ (visibleAudioInterval.From - viewportInterval.From)) * viewportToDrawingScaleFactor);
int drawingWidthAligned = (int)((samplesToLoad - 1) * sampleLength * viewportToDrawingScaleFactor);
int drawingOffset = (int)((visibleAudioInterval.From - viewportInterval.From) * viewportToDrawingScaleFactor);
if (visibleAudioInterval.Length < sampleLength)
{
drawingContext.DrawText(DebugText("VISIBLE INTERVAL WARNING: " + visibleAudioInterval.Length + " < SAMPLE LENGTH " + sampleLength), new Point(0, 0));
return;
}
if (drawingWidthAligned <= 1)
{
// the visible width of the track is too narrow to be drawn/visible, so draw a line to visually indicate the presence of a waveform
drawingContext.DrawRectangle(_lineBrush, null, new Rect(drawingOffsetAligned, 0, 1, ActualHeight));
return;
}
// load audio samples
DateTime beforeLoading = DateTime.Now;
float[][] samples = null;
int sampleCount = 0;
if (RenderMode != WaveViewRenderMode.None)
{
bool peaks = samplesToLoad > drawingWidthAligned;
// TODO don't recreate the array every time -> resize on demand
samples = AudioUtil.CreateArray <float>(audioStream.Properties.Channels, drawingWidthAligned * 2);
audioStream.TimePosition = new TimeSpan(audioToLoadIntervalAligned.From);
if (peaks)
{
sampleCount = audioStream.ReadPeaks(samples, samplesToLoad, drawingWidthAligned);
}
else
{
sampleCount = audioStream.ReadSamples(samples, samplesToLoad);
}
if (sampleCount <= 1)
{
drawingContext.DrawText(DebugText("SAMPLE WARNING: " + sampleCount), new Point(0, 0));
return;
}
}
DateTime afterLoading = DateTime.Now;
DateTime beforeDrawing = DateTime.Now;
// draw background
drawingContext.DrawRectangle(_backgroundBrush, null, new Rect(drawingOffsetAligned, 0, drawingWidthAligned, ActualHeight));
if (debug)
{
drawingContext.DrawRectangle(null, new Pen(Brushes.Brown, 4), new Rect(drawingOffsetAligned, 0, drawingWidthAligned, ActualHeight));
}
// draw waveform guides & create drawing guidelines
GuidelineSet guidelineSet = new GuidelineSet();
drawingContext.PushGuidelineSet(guidelineSet);
int channels = audioStream.Properties.Channels;
double channelHeight = ActualHeight / channels;
double channelHalfHeight = channelHeight / 2;
for (int channel = 0; channel < channels; channel++)
{
// waveform zero-line
guidelineSet.GuidelinesY.Add((channelHeight * channel + channelHalfHeight) + 0.5);
drawingContext.DrawLine(new Pen(Brushes.LightGray, 1),
new Point(drawingOffsetAligned, channelHeight * channel + channelHalfHeight),
new Point(drawingOffsetAligned + drawingWidthAligned, channelHeight * channel + channelHalfHeight));
// waveform spacers
if (channel > 0)
{
guidelineSet.GuidelinesY.Add((channelHeight * channel) + 0.5);
drawingContext.DrawLine(new Pen(Brushes.DarkGray, 1),
new Point(drawingOffsetAligned, channelHeight * channel),
new Point(drawingOffsetAligned + drawingWidthAligned, channelHeight * channel));
}
}
drawingContext.Pop();
// draw waveforms
if (channelHeight >= 1)
{
IWaveformRenderer[] renderers = null;
switch (RenderMode)
{
case WaveViewRenderMode.None:
renderers = null;
break;
case WaveViewRenderMode.Bitmap:
renderers = waveformBitmapRenderers;
break;
case WaveViewRenderMode.Geometry:
renderers = waveformGeometryRenderers;
break;
case WaveViewRenderMode.Auto:
// Automatically select the waveform renderer:
// - when zoom to sample level, draw a nice geometry
// - when zoomed out and single samples are not visible, draw bitmap because geometry is too slow
if (sampleCount >= drawingWidthAligned)
{
renderers = waveformBitmapRenderers;
}
else
{
renderers = waveformGeometryRenderers;
}
break;
}
if (renderers != null)
{
for (int channel = 0; channel < channels; channel++)
{
// calculate the balance factor for the first two channels only (balance only applies to stereo)
// TODO extend for multichannel (needs implementation of a multichannel balance adjustment control)
float balanceFactor = 1;
if (channels == 2)
{
if (channel == 0)
{
balanceFactor = AudioTrack.Balance < 0 ? 1 : 1 - AudioTrack.Balance;
}
else if (channel == 1)
{
balanceFactor = AudioTrack.Balance > 0 ? 1 : 1 + AudioTrack.Balance;
}
}
Drawing waveform = renderers[channel].Render(samples[channel], sampleCount, drawingWidthAligned, (int)channelHeight, AudioTrack.Volume * balanceFactor);
DrawingGroup drawing = new DrawingGroup();
drawing.Children.Add(waveform);
drawing.Transform = new TranslateTransform((int)drawingOffsetAligned, (int)(channelHeight * channel));
drawingContext.DrawDrawing(drawing);
}
}
}
DateTime afterDrawing = DateTime.Now;
// draw track name
if (DrawTrackName)
{
FormattedText formattedTrackName = new FormattedText(AudioTrack.FileInfo.Name, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, new Typeface("Segoe UI"), 10f, Brushes.White);
drawingContext.DrawRectangle(Brushes.Black, null, new Rect(4 + drawingOffset, 5, formattedTrackName.Width + 4, formattedTrackName.Height + 2));
drawingContext.DrawText(formattedTrackName, new Point(6 + drawingOffset, 6));
}
if (debug)
{
// DEBUG OUTPUT
drawingContext.DrawText(DebugText(String.Format("source:" + "n/a" + " load:{0}ms render:{1}ms", (afterLoading - beforeLoading).TotalMilliseconds, (afterDrawing - beforeDrawing).TotalMilliseconds)),
new Point(0, 20));
drawingContext.DrawText(DebugText("visibleAudioInterval: " + visibleAudioInterval + ", audioToLoadInterval: " + audioToLoadInterval + ", audioToLoadIntervalAligned: " + audioToLoadIntervalAligned),
new Point(0, ActualHeight) + new Vector(0, -50));
drawingContext.DrawText(DebugText("Drawing Offset: " + drawingOffsetAligned + ", Width: " + drawingWidthAligned + ", ScalingFactor: " + viewportToDrawingScaleFactor + ", Samples: " + sampleCount + ", Peakratio 1:" + Math.Round(VirtualViewportWidth / sampleLength / ActualWidth, 2)),
new Point(0, ActualHeight) + new Vector(0, -40));
}
}
if (debug)
{
// DEBUG OUTPUT
drawingContext.DrawText(DebugText("ActualWidth: " + ActualWidth + ", ActualHeight: " + ActualHeight),
new Point(0, ActualHeight) + new Vector(0, -30));
drawingContext.DrawText(DebugText("TrackLength: " + TrackLength + ", TrackOffset: " + TrackOffset),
new Point(0, ActualHeight) + new Vector(0, -20));
drawingContext.DrawText(DebugText("ViewportOffset: " + VirtualViewportOffset + ", ViewportWidth: " + VirtualViewportWidth),
new Point(0, ActualHeight) + new Vector(0, -10));
}
}
