/// <summary>
/// Reads one HMM stream instance from text reader instance.
/// </summary>
/// <param name="rewinder">The text reader to read stream from.</param>
/// <returns>HMM stream instance loaded.</returns>
private static HmmStream ReadStream(RewindableTextReader rewinder)
{
Helper.ThrowIfNull(rewinder);
HmmStream stream = new HmmStream();
string line = rewinder.PeekLine();
int streamIndex = 0;
if (line.StartsWith("<STREAM>"))
{
streamIndex = ParseTagValue(rewinder.ReadLine(), "<STREAM>");
}
int mixtureNumber = 1;
line = rewinder.PeekLine();
if (line.StartsWith("<NUMMIXES>"))
{
mixtureNumber = ParseTagValue(rewinder.ReadLine(), "<NUMMIXES>");
}
List<Gaussian> gaussians = new List<Gaussian>();
for (int i = 0; i < mixtureNumber; i++)
{
int mixtureIndex = 0;
float weight = 0.0f;
line = rewinder.PeekLine();
if (line.StartsWith("<MIXTURE>"))
{
string[] values = ParseTagValues(rewinder.ReadLine(), "<MIXTURE>");
mixtureIndex = int.Parse(values[0], CultureInfo.InvariantCulture);
weight = float.Parse(values[1], CultureInfo.InvariantCulture);
if (mixtureIndex != i + 1)
{
throw new InvalidDataException(
Helper.NeutralFormat("The mixture index is mis-matched between {0} and {1} in line [{2}]",
i, mixtureIndex, line));
}
}
Gaussian gaussian = ReadGaussian(rewinder);
gaussian.Weight = weight;
gaussians.Add(gaussian);
}
stream.Gaussians = gaussians.ToArray();
return stream;
}
/// <summary>
/// Converts the HMM stream instance into string in MMF format.
/// </summary>
/// <param name="stream">The stream instance to convert.</param>
/// <returns>Stream instance in string format.</returns>
private static string ToString(HmmStream stream)
{
Helper.ThrowIfNull(stream);
StringBuilder builder = new StringBuilder();
if (stream.Gaussians.Length > 1)
{
builder.AppendFormat(CultureInfo.InvariantCulture,
"<NUMMIXES> {1}{0}", Environment.NewLine, stream.Gaussians.Length);
}
for (int i = 0; i < stream.Gaussians.Length; i++)
{
if (stream.Gaussians.Length > 1)
{
builder.AppendFormat(CultureInfo.InvariantCulture,
"<MIXTURE> {1} {2:e6}{0}", Environment.NewLine, i + 1, stream.Gaussians[i].Weight);
}
builder.Append(ToString(stream.Gaussians[i]));
}
return builder.ToString();
}
/// <summary>
/// Tell whether two stream macro name equal with each other.
/// It will ignore the compare on intern leaf node index.
/// </summary>
/// <param name="left">Left.</param>
/// <param name="right">Right.</param>
/// <returns>True if yes, otherwise false.</returns>
public static bool IsNameEqual(HmmStream left, HmmStream right)
{
Helper.ThrowIfNull(left);
Helper.ThrowIfNull(right);
return left.PhoneLabel == right.PhoneLabel &&
left.ModelType == right.ModelType &&
left.StateIndex == right.StateIndex &&
left.StreamIndex == right.StreamIndex;
}
/// <summary>
/// Tell whether two HMM streams equals with each other.
/// </summary>
/// <param name="left">Left stream object.</param>
/// <param name="right">Right stream object.</param>
/// <param name="comareData">Flag to indicate whether comparing data in Gaussian distribution.</param>
/// <returns>True if equal, otherwise false.</returns>
public static bool IsEqual(HmmStream left, HmmStream right, bool comareData)
{
Helper.ThrowIfNull(left);
Helper.ThrowIfNull(right);
return (left.Name == null || right.Name == null || IsNameEqual(left, right)) &&
IsEqual(left.Gaussians, right.Gaussians, comareData);
}
/// <summary>
/// Prune dimension in HMM Stream.
/// </summary>
/// <param name="stream">Stream to prune.</param>
/// <param name="keepDimension">First dimensions to keep.</param>
/// <returns>Pruned stream.</returns>
private static HmmStream Prune(HmmStream stream, int keepDimension)
{
Helper.ThrowIfNull(stream);
HmmStream prunedStream = new HmmStream();
prunedStream.Name = stream.Name;
prunedStream.Gaussians = new Gaussian[stream.Gaussians.Length];
for (int i = 0; i < stream.Gaussians.Length; i++)
{
prunedStream.Gaussians[i].Weight = stream.Gaussians[i].Weight;
prunedStream.Gaussians[i].Variance = stream.Gaussians[i].Variance;
prunedStream.Gaussians[i].Mean = stream.Gaussians[i].Mean.Take(keepDimension).ToArray();
prunedStream.Gaussians[i].Variance = stream.Gaussians[i].Variance.Take(keepDimension).ToArray();
prunedStream.Gaussians[i].Length = Math.Min(keepDimension, stream.Gaussians[i].Length);
}
return prunedStream;
}
/// <summary>
/// Get a stream distribution.
/// </summary>
/// <returns>HMM stream.</returns>
public HmmStream ReadStream()
{
HmmStream hmmStream = new HmmStream();
hmmStream.Name = ReadString();
hmmStream.Gaussians = ReadGaussian();
return hmmStream;
}
