GenNoise

Routine

GenNoise [options] AFile

Purpose

Generate an audio file containing uncorrelated Gaussian noise samples

Description

This program generates zero-mean uncorrelated pseudo-random Gaussian deviates. These white noise samples are written to an audio file. Each invocation of this program generates a different random sequence. Options are available to specify the number of samples, the sampling frequency and the data format of the output file.

Options

The command line specifies options and the output file name.
-l LENGTH, --length=LENGTH
Number of samples in the output audio file.
-d SDEV, --std_deviation=SDEV
Standard deviation of the noise samples, default 1000.
-x SEED, --seed=SEED
Seed for the random number generator, default from current time.
-s SFREQ, --srate=SFREQ
Sampling frequency for the output audio file, default 8000.
-D DFORMAT, --data_format=DFORMAT
Data format for the output file, default integer 
  "mu-law8"   - 8-bit mu-law data
  "A-law8"    - 8-bit A-law data
  "unsigned8" - offset-binary 8-bit integer data
  "integer8"  - two's-complement 8-bit integer data
  "integer16" - two's-complement 16-bit integer data
  "float32"   - 32-bit IEEE floating-point data
  "text"      - text data
The data formats available depend on the output file type. AFsp (Sun) audio files: 
  mu-law, A-law, 8-bit integer, 16-bit integer, float
RIFF WAVE files: 
  mu-law, A-law, offset-binary 8-bit integer, 16-bit integer
AIFF-C audio files: 
  mu-law, A-law, 8-bit integer, 16-bit integer
Headerless files: 
  all data formats
-F FTYPE, --file_type=FTYPE
File type, default "AFsp". 
  "AFsp", "Sun" or "sun" - AFsp (Sun) audio file
  "WAVE" or "wave"       - RIFF WAVE file
  "AIFF-C"               - AIFF-C audio file
  "raw" or "raw_native"  - Headerless file (native byte order)
  "raw_swap"             - Headerless file (byte swapped)
  "raw_big-endian"       - Headerless file (big-endian byte order)
  "raw_little-endian"    - Headerless file (little-endian byte order)
-I INFO, --info=INFO
Header information string.
-h, --help
Print a list of options and exit.
-v, --version
Print the version number and exit.

For AFsp output files, the audio file header contains an information string. 

  Standard Header Information:
    date:1994/01/25 19:19:39 UTC    date
    user:kabal@aldebaran            user
    program:GenNoise                program name
This information can be changed with the header information string which is specified as one of the command line options. Structured information records should adhere to the above format with a named field terminated by a colon, followed by numeric data or text. Comments can follow as unstructured information. For the purpose of this program, records are terminated by newline characters. However in the header itself, the newline characters are replaced by nulls. To place a newline character into the header, escape the newline character by preceding it with a '\' character. If the first character of the user supplied header information string is a newline character, the header information string is appended to the standard header information. If not, the user supplied header information string replaces the standard header information.

Author / version

P. Kabal / v1r7 1996/08/13

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