public virtual void Process(AudioRecord item, AudioInfo info)
{
//build amplitude envelope
var s = Build(info.Samples);
//resample
var resampler = factory.CreateResampler();
var resampled = resampler.Resample(s, info.Samples.BitRate * ((float)EnvelopeLength / info.Samples.Values.Length));
//build packed array
var envelope = new Envelope(resampled);
//save into audio item
item.Data.Add(envelope);
}
public void Process(AudioRecord item, AudioInfo info)
{
var tempogram = new Tempogram();
var s = info.Samples;
s = new EnvelopeProcessor(factory).Build(info.Samples, 32, false);
var s2 = new Samples() { Values = new float[s.Values.Length], BitRate = s.BitRate };
var intensity = 0;
for (int i = 0; i < s.Values.Length - 1; i++)
{
var d = s.Values[i + 1] - s.Values[i];
var dd = d > 0 ? d : 0;
s.Values[i] = dd;
s2.Values[i] = d;
if (d > minAmplitudeChangeForIntensityRate)
intensity++;
}
s.Values[s.Values.Length - 1] = 0;
s2.Values[s.Values.Length - 1] = 0;
var time = s.Values.Length / s.BitRate;//time of sound
var maxShift = (int)(s.Values.Length * (maxRithmDuration / time));
var autoCorr1 = AutoCorr(s.Values, maxShift, 5);
var autoCorr2 = AutoCorr(s2.Values, maxShift, 2);
var l = (float)autoCorr1.Length;
var k = Math.Log(2);
var list1 = new List<KeyValuePair<float, float>>();
var list2 = new List<KeyValuePair<float, float>>();
for (int i = 0; i < l; i++)
{
var j = i / (float)l;
j = (float)(Math.Log(j + 1) / k);
list1.Add(new KeyValuePair<float, float>(j, autoCorr1[i]));
var v = autoCorr2[i];
list2.Add(new KeyValuePair<float, float>(j, v > 0 ? v : 0));
}
tempogram.LongTempogram.Build(list1);
tempogram.ShortTempogram.Build(list2);
tempogram.Intensity = (float)intensity / time;
CalcTempo(tempogram);
//save to audio item
item.Data.Add(tempogram);
}
/// <summary>
/// Loads data from db
/// </summary>
public ICollection<AudioRecord> Load()
{
Collection<AudioRecord> records = new Collection<AudioRecord>();
if (File.Exists(Path))
using (var fs = new FileStream(Path, FileMode.Open, FileAccess.Read))
using (var zip = new GZipStream(fs, CompressionMode.Decompress, false))
using (var br = new BinaryReader(zip, Encoding.UTF8))
try
{
var count = br.ReadInt32();
for (int i = 0; i < count; i++)
{
var item = new AudioRecord();
item.Load(br);
records.Add(item);
}
}
catch (EndOfStreamException) {/*end of stream*/}
return records;
}
private void ScanPath(string path)
{
try
{
IEnumerable<string> audioIndexes = DataBase.Records.Select(r => r.FullPath);
foreach (string filePath in DirectoryScanner.Scan(path, ApplicationConstants.SupportedAudioFileExtensions))
{
if (!audioIndexes.Contains(filePath))
{
AudioRecord item = new AudioRecord()
{
FullPath = filePath
};
lock (DataBase.Records)
{
DataBase.Records.Add(item);
}
DataBase.IsChanged = true;
}
}
}
catch (Exception e)
{
//TODO process possible exceptions
}
}