ulaw

Functions

int main(int argc, char *argv[])

ulaw [ option ] [ infile ]

  • -v double

    • absolute maximum value of input \((0 < V)\)

  • -u double

    • compression factor \((0 < \mu)\)

  • infile str

    • double-type input data sequence

  • stdout

    • double-type compressed data sequence

In the below example, 16-bit data read from data.short is compressed to 8-bit u-law format.

x2x +sd data.short | ulaw | quantize > data.ulaw
Parameters:

  • argc – [in] Number of arguments.

  • argv – [in] Argument vector.

Returns:

0 on success, 1 on failure.

See also

iulaw alaw

class MuLawCompression

Nonlinearly compress data based on \(\mu\)-law algorithm.

Given the input data \(x(n)\), the compression is performed as follows:

\[ y(n) = V \, \mathrm{sgn}(x(n)) \frac{\log (1 + \mu \frac{|x(n)|}{V})}{\log (1 + \mu)} \]
where \(V\) is the absolute maximum value of the input data and \(\mu\) is the compression factor, which is typically set to 255.

Public Functions

MuLawCompression(double abs_max_value, double compression_factor)
Parameters:

  • abs_max_value – [in] Absolute maximum value.

  • compression_factor – [in] Compression factor, \(\mu\).

inline double GetAbsMaxValue() const
Returns:

Absolute maximum value.

inline double GetCompressionFactor() const
Returns:

Compression factor.

inline bool IsValid() const
Returns:

True if this object is valid.

bool Run(double input, double *output) const
Parameters:

  • input – [in] Input data.

  • output – [out] Output data.

Returns:

True on success, false on failure.

bool Run(double *input_and_output) const
Parameters:

input_and_output – [inout] Input/output data.

Returns:

True on success, false on failure.