const float bufferSize = 0.05f; // 1/20 second buffer
/// <summary>
/// Find the start of music or silence
/// </summary>
/// <param name="start">seconds</param>
/// <param name="silence">true to find silence, false to find music</param>
/// <param name="maxLength">Max seconds to process (0 or less means rest of file)</param>
/// <returns>True if music or silence found</returns>
public bool FindGap(float start, bool silence, float maxLength) {
if (start < 0)
start = 0;
// End of file
Position = m_Reader.WaveFormat.BytesToSeconds(m_Reader.Length);
AverageVolume = 0;
if (start > Position)
return false; // Beyond end of file
m_Reader.Position = Math.Max(0, m_Reader.WaveFormat.SecondsToBytes(start));
// Try to work out where the music starts and/or ends
m_Provider = new FilteredSampleProvider(m_Reader, Properties.Settings.Default.SilenceFilterCentre, Properties.Settings.Default.SilenceFilterQ);
int length = m_Provider.StandardBufferSize;
// Number of samples from beginning of file
long count = m_Reader.WaveFormat.SecondsToSamples(start);
float silenceThreshold = silence ? Properties.Settings.Default.StartSilenceThreshold : Properties.Settings.Default.EndSilenceThreshold;
int foundCount = 0; // Number of contiguous matching buffers found so far
int minBuffers = 10; // Number of contiguous buffers required
int maxBuffers = maxLength <= 0 ? int.MaxValue : (int)(maxLength / bufferSize); // Max buffers to read
float[] volumes = new float[minBuffers + 1]; // Volumes of each of the last few buffers
float totalVolume = 0; // Lags minBuffers behind current read
bool result = false;
int i = 0;
try {
for ( ; i < maxBuffers; i++) {
float avg = m_Provider.AvgBlockVolume();
totalVolume += volumes[0]; // Accumulate total from minBuffers ago
Array.Copy(volumes, 1, volumes, 0, minBuffers); // Shift array down 1
volumes[minBuffers] = avg; // And add latest value
if (silence == (avg <= silenceThreshold)) {
// Found a buffer of what we are looking for
if (++foundCount == minBuffers) {
// Have found minBuffers contiguous of what we are looking for
count -= foundCount * length; // Go back to first buffer that was what we are looking for
if (!silence)
count--; // leave a buffer of silent gap before the start of the music
Position = m_Reader.WaveFormat.SamplesToSeconds(count); // Position in seconds
result = true;
break;
}
} else {
foundCount = 0; // Not enough contiguous buffers - restart count
}
count += length;
}
} catch (System.IO.EndOfStreamException) {
}
AverageVolume = totalVolume / (i - foundCount);
return result;
}
private void WaveControl_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e) {
stopPlayer();
if (e.Button == MouseButtons.Left) {
cursorEvent = null;
m_DragStart = e;
if (m_Cursors != null) {
// Work out which cursor we are close to
float pixelsPerSecond = Width / m_LengthSeconds;
int l = -1, r = -1;
for (int i = 0; i < m_Cursors.Length; i++) {
PositionCursor c = m_Cursors[i];
if (!c.Active)
continue;
float x = (c.Position - m_StartSeconds) * pixelsPerSecond; // Position of cursor in pixels
if (Math.Abs(x - e.X) < 10) {
// We are close to this cursor
if (x < e.X) {
// Cursor to left of mouse
if (l == -1 || c.Position >= m_Cursors[l].Position)
l = i; // It's the closest one to the mouse, or same position but larger cursor no
} else {
// Cursor to right of mouse
if (r == -1 || c.Position < m_Cursors[r].Position)
r = i; // It's the closest one to the mouse or same position but smaller cursor no
}
}
}
int csr = -1; // Cursor we want to drag
if(l == -1) {
// No cursor to left
if(r == -1) // Or right either
return;
csr = r; // Choose one to right
} else if (r == -1) {
// No cursor to right
csr = l; // Choose one to left
} else {
// Cursors on both sides - choose closest
float lx = (m_Cursors[l].Position - m_StartSeconds) * pixelsPerSecond;
float rx = (m_Cursors[r].Position - m_StartSeconds) * pixelsPerSecond;
if (rx - e.X < e.X - lx)
csr = r;
else
csr = l;
}
// Set up cursor event for cursor
cursorEvent = new CursorMovedEventArgs(m_Cursors[csr]);
m_Dragging = false; // Not dragging yet
}
} else if (e.Button == System.Windows.Forms.MouseButtons.Right) {
// Right click displays filtered average volume in a tooltip
try {
float pixelsPerSecond = Width / m_LengthSeconds;
float p = m_StartSeconds + e.X / pixelsPerSecond; // Position of click in seconds
m_Wavefile.Position = WaveFormat.SecondsToBytes(p);
FilteredSampleProvider f = new FilteredSampleProvider(m_Wavefile, Properties.Settings.Default.SilenceFilterCentre, Properties.Settings.Default.SilenceFilterQ);
// Display average volume of block at this position
float avg = f.AvgBlockVolume();
string tip = string.Format("pos={0} level={1:#0.0####}", p.ToTimeSpanString(), avg);
Program.Trace(tip);
toolTip.Show(tip, this);
} catch {
}
}
}
