//Create samples to scale based on the current timeline ticks period.
//Runs in background to keep the ui free.
private void bw_createScaleSamples(object sender, DoWorkEventArgs args)
{
_creatingSamples = true;
BackgroundWorker worker = sender as BackgroundWorker;
if (audio == null)
{
_creatingSamples = false;
return;
}
if (!audio.MediaLoaded)
{
audio.LoadMedia(TimeSpan.MinValue);
}
samplesPerPixel = (double)pixelsToTime(1).Ticks / TimeSpan.TicksPerMillisecond * audio.Frequency / 1000;
int step = audio.BytesPerSample;
samples.Clear();
double samplesRead = 0;
while (samplesRead < audio.NumberSamples)
{
if ((worker.CancellationPending))
{
args.Cancel = true;
break;
}
int low = 0;
int high = 0;
//Might need a better way to dither the partial samples out. Casting to int rounds it out while
//the counter tries to maintian some sanity. A few random samples might be off at some zoom levels,
//but we are doing a fair amount of averaging to begin with. The farther in the zoom the more chances
//a artifact might be visible.
byte[] waveData = audio.GetSamples((int)samplesRead, (int)samplesPerPixel);
samplesRead += samplesPerPixel;
if (waveData == null)
{
break;
}
for (int n = 0; n < waveData.Length; n += step)
{
//Allow for 16 or 32 bit data. Should be 16 most of the time.
int sample = step == 2 ? BitConverter.ToInt16(waveData, n) : BitConverter.ToInt32(waveData, n);
if (sample < low)
{
low = sample;
}
if (sample > high)
{
high = sample;
}
}
samples.Add(new SampleAggregator.Sample {
High = ClampValue(high), Low = ClampValue(low)
});
}
_creatingSamples = false;
}
private void waveformGenerateWorker_DoWork()
{
#if (MARKERS)
var span = Markers.EnterSpan("waveformGen");
#endif
using (Mp3FileReader waveformMp3Stream = new Mp3FileReader(song.FileName))
using (WaveChannel32 waveformInputStream = new WaveChannel32(waveformMp3Stream))
{
waveformInputStream.Sample += waveStream_Sample;
int frameCount = (int)((float)waveformInputStream.Length / frameLength);
byte[] readBuffer = new byte[frameLength];
waveformAggregator = new SampleAggregator(frameLength);
int currentPointIndex = 0;
float[] waveformArray = new float[frameCount * 2];
float waveformLeftMax = 0;
float waveformRightMax = 0;
while (currentPointIndex < frameCount * 2)
{
waveformInputStream.Read(readBuffer, 0, readBuffer.Length);
var leftMaxVolume = waveformAggregator.LeftMaxVolume;
var rightMaxVolume = waveformAggregator.RightMaxVolume;
waveformArray[currentPointIndex++] = leftMaxVolume;
waveformArray[currentPointIndex++] = rightMaxVolume;
if (leftMaxVolume > waveformLeftMax)
{
waveformLeftMax = leftMaxVolume;
}
if (rightMaxVolume > waveformRightMax)
{
waveformRightMax = rightMaxVolume;
}
waveformAggregator.Clear();
tkn.ThrowIfCancellationRequested();
}
byte[] waveformBytes = new byte[waveformArray.Length];
float factor = 31f / Math.Max(Math.Abs(waveformLeftMax), Math.Abs(waveformRightMax));
for (int ndx = 0; ndx < waveformArray.Length; ndx++)
{
waveformBytes[ndx] = (byte)Math.Abs(Math.Abs(waveformArray[ndx]) * factor);
}
song.WaveformData = waveformBytes;
}
#if (MARKERS)
span.Leave();
#endif
}
private void inputStream_Sample(object sender, SampleEventArgs e)
{
sampleAggregator.Add(e.Left, e.Right);
long repeatStartPosition = (long)((SelectionBegin.TotalSeconds / ActiveStream.TotalTime.TotalSeconds) * ActiveStream.Length);
long repeatStopPosition = (long)((SelectionEnd.TotalSeconds / ActiveStream.TotalTime.TotalSeconds) * ActiveStream.Length);
if (((SelectionEnd - SelectionBegin) >= TimeSpan.FromMilliseconds(repeatThreshold)) && ActiveStream.Position >= repeatStopPosition)
{
sampleAggregator.Clear();
ActiveStream.Position = repeatStartPosition;
}
}
private void waveformGenerateWorker_DoWork(object sender, DoWorkEventArgs e)
{
WaveformGenerationParams waveformParams = e.Argument as WaveformGenerationParams;
Mp3FileReader waveformMp3Stream = new Mp3FileReader(waveformParams.Path);
WaveChannel32 waveformInputStream = new WaveChannel32(waveformMp3Stream);
waveformInputStream.Sample += waveStream_Sample;
int frameCount = (int)((double)waveformInputStream.Length / (double)frameLength);
byte[] readBuffer = new byte[frameLength];
waveformAggregator = new SampleAggregator(frameLength);
int currentPointIndex = 0;
float[] waveformArray = new float[frameCount * 2];
float waveformLeftMax = 0;
float waveformRightMax = 0;
int readCount = 0;
while (currentPointIndex < frameCount * 2)
{
waveformInputStream.Read(readBuffer, 0, readBuffer.Length);
waveformArray[currentPointIndex++] = waveformAggregator.LeftMaxVolume;
waveformArray[currentPointIndex++] = waveformAggregator.RightMaxVolume;
if (waveformAggregator.LeftMaxVolume > waveformLeftMax)
{
waveformLeftMax = waveformAggregator.LeftMaxVolume;
}
if (waveformAggregator.RightMaxVolume > waveformRightMax)
{
waveformRightMax = waveformAggregator.RightMaxVolume;
}
waveformAggregator.Clear();
if (waveformGenerateWorker.CancellationPending)
{
e.Cancel = true;
break;
}
readCount++;
}
byte[] waveformBytes = new byte[waveformArray.Length];
float factor = 31f / Math.Max(Math.Abs(waveformLeftMax), Math.Abs(waveformRightMax));
for (int ndx = 0; ndx < waveformArray.Length; ndx++)
{
waveformBytes[ndx] = (byte)Math.Abs(Math.Abs(waveformArray[ndx]) * factor);
}
//UI.Invoke(new Action(() => { WaveformData = waveformBytes; }));
waveformData = waveformBytes;
waveformInputStream.Close();
waveformInputStream.Dispose();
waveformInputStream = null;
waveformMp3Stream.Close();
waveformMp3Stream.Dispose();
waveformMp3Stream = null;
}
