/// <summary>
/// Gets the peak byte from the audio file reader.
/// </summary>
/// <param name="reader">The reader.</param>
/// <returns>The peak byte as an absolute value.</returns>
public virtual float GetPeak(IAudioFileReader reader)
{
float peak = 0;
var buffer = new float[reader.WaveFormat.SampleRate];
int read;
// determine the peak
do
{
read = reader.Read(buffer, 0, buffer.Length);
for (int n = 0; n < read; n++)
{
var abs = Math.Abs(buffer[n]);
if (abs > peak)
{
peak = abs;
}
}
} while (read > 0);
// rewind the reader and set the volume
reader.Seek(0, SeekOrigin.Begin);
return(peak);
}
/// <summary>
/// Gets the peak of the audio file.
/// </summary>
/// <param name="reader">The reader.</param>
/// <returns>The peak as an absolute value of the byte.</returns>
public override float GetPeak(IAudioFileReader reader)
{
var key = this.GetKey(reader);
var entry = this.Items.GetOrAdd(key, _ => this.GetNewEntry(key, reader));
return(entry.Peak);
}
/// <summary>
/// Initializes a new instance of the <see cref="AudioReaderStateInfo"/> class.
/// </summary>
/// <param name="reader">The reader.</param>
public AudioReaderStateInfo(IAudioFileReader reader)
{
this.Reader = new WeakReference <IAudioFileReader>(reader);
this._volume = reader.Volume;
this.FileName = reader.FileName;
}
/// <summary>
/// Applies the loudness normalization, based on the percent multiplier.
/// </summary>
/// <param name="reader">The reader.</param>
/// <param name="maxGain">The maximum gain.</param>
public void ApplyLoudnessNormalization(IAudioFileReader reader, float maxGain)
{
var peak = this.GetPeak(reader);
if (peak >= maxGain)
{
reader.Volume = (1.0f / peak) * maxGain;
}
}
/// <summary>
/// Gets the event arguments from a <see cref="IAudioFileReader"/>.
/// </summary>
/// <param name="reader">The reader.</param>
/// <returns>The event arguments.</returns>
internal static PlaybackTimeEventArgs FromReader(IAudioFileReader reader)
{
try
{
return(new PlaybackTimeEventArgs(reader.CurrentTime, reader.TotalTime));
}
catch
{
return(PlaybackTimeEventArgs.Zero);
}
}
/// <summary>
/// Gets a new cache entry for the specified reader.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="reader">The reader.</param>
/// <returns>The cache entry.</returns>
private CacheEntry GetNewEntry(string key, IAudioFileReader reader)
{
var peak = base.GetPeak(reader);
var watcher = new FileSystemWatcher
{
Path = Path.GetDirectoryName(key),
Filter = Path.GetFileName(key)
};
watcher.Changed += this.RemoveCacheEntry;
watcher.Deleted += this.RemoveCacheEntry;
watcher.Renamed += this.RenameCacheEntry;
watcher.EnableRaisingEvents = true;
return(new CacheEntry(peak, watcher));
}
/// <summary> /// Gets the cache entry key. /// </summary> /// <param name="reader">The reader.</param> /// <returns>The key.</returns> private string GetKey(IAudioFileReader reader) => this.GetKey(reader?.FileName);
/// <summary>
/// Normalizes the volume of the audio file reader, based on the peak.
/// </summary>
/// <param name="reader">The reader.</param>
public void ApplyPeakNormalization(IAudioFileReader reader)
{
var peak = this.GetPeak(reader);
reader.Volume = 1.0f / peak;
}
/// <summary>
/// Initializes a new instance of the <see cref="AudioFileEncoder"/> class.
/// </summary>
/// <param name="reader">The reader.</param>
public AudioFileEncoder(IAudioFileReader reader)
{
this.Reader = reader;
}
