InfoAudio(1audio)

Routine
InfoAudio [options] AFile1 [AFile2 ... ]

Purpose
Print audio file information

Description
This program prints information about a number of audio files to standard output. The information about the internal structure of the files is in a form that can be easily parsed by a shell script.

The full output consists of the file type and name (indented part of the output below), the file data parameters, and the header information records.
   AU audio file: /usr/local/src/audio/InfoAudio/test/xx.au
     Number of samples : 23808  1994/02/04 14:12:50 UTC
     Sampling frequency: 8000 Hz
     Number of channels: 1 (16-bit integer)
  File name: xx.au
  Header length: 104
  Sampling frequency: 8000
  No. samples: 23808
  No. channels: 1
  Data type: integer16           (A-law8, mu-law8, unsigned8, integer8,
                                  integer16, float32, float64, or text)
  File byte order: big-endian    (big-endian, little-endian, or byte-stream)
  Host byte order: big-endian    (big-endian or little-endian)
  --Header information records--
  date: 1994-02-04 14:12:50 UTC
  user: library@aldebaran
  program: CopyAudio

For single byte or text data, the "File byte order" field is set to "byte-stream".

Non-printing characters (as defined by the routine isprint) in the header information records are replaced by question marks.

Options
Input file(s): AFile1 [AFile2 ... ]:
The environment variable AUDIOPATH specifies a list of directories to be searched for the input audio file(s).
-t FTYPE, --type=FTYPE
Input audio file type. In the default automatic mode, the input file type is determined from the file header. For input from a non-random access file (e.g. a pipe), the input file type can be explicitly specified to avoid the lookahead used to read the file header. This option can be specified more than once. Each invocation applies to the input files that follow the option. See the description of the environment variable AF_FILETYPE below for a list of file types.
-P PARMS, --parameters=PARMS
Parameters to be used for headerless input files. This option may be given more than once. Each invocation applies to the input files that follow the option. See the description of the environment variable AF_NOHEADER below for the format of the parameter specification.
-i ICODE, --info_code=ICODE
Parameter to choose the information to be printed. The information that can be printed consists of three parts. The ICODE parameter is the sum of the codes which control printing of the individual parts.
  1:  Print the file type and name
  2:  Print the file data parameters
  4:  Print the header information records
The default is to print all of the information (ICODE=7). For ICODE=0, no information is printed, but the program return code indicates if all files were opened successfully.
-h, --help
Print a list of options and exit.
-v, --version
Print the version number and exit.

Environment variables
AF_FILETYPE:
This environment variable defines the input audio file type. In the default mode, the input file type is determined from the file header.
  "auto"       - determine the input file type from the file header
  "AU" or "au" - AU audio file
  "WAVE" or "wave" - RIFF WAVE file
  "AIFF" or "aiff" - AIFF or AIFF-C audio file
  "noheader"   - headerless (non-standard or no header) audio file
  "SPHERE"     - NIST SPHERE audio file
  "ESPS"       - ESPS sampled data feature file
  "IRCAM"      - IRCAM soundfile
  "SPPACK"     - SPPACK file
  "INRS"       - INRS-Telecom audio file
  "SPW"        - Comdisco SPW Signal file
  "text"       - Text audio file

AF_NOHEADER:
This environment variable defines the data format for headerless or non-standard input audio files. The string consists of a list of parameters separated by commas. The form of the list is
  "Format, Start, Sfreq, Swapb, Nchan, ScaleF"
Format: File data format
 "undefined" - Headerless files will be rejected
 "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
 "integer24" - two's-complement 24-bit integer data
 "integer32" - two's-complement 32-bit integer data
 "float32"   - 32-bit floating-point data
 "float64"   - 64-bit floating-point data
 "text"      - text data
Start: byte offset to the start of data (integer value)
Sfreq: sampling frequency in Hz (floating point number)
Swapb: Data byte swap parameter
 "native"        - no byte swapping
 "little-endian" - file data is in little-endian byte order
 "big-endian"    - file data is in big-endian byte order
 "swap"          - swap the data bytes as the data is read
Nchan: number of channels
The data consists of interleaved samples from Nchan channels
ScaleF: Scale factor
Scale factor applied to the data from the file
The default values for the audio file parameters correspond to the following string.
  "undefined, 0, 8000., native, 1, 1.0"

AUDIOPATH:
This environment variable specifies a list of directories to be searched when opening the input audio files. Directories in the list are separated by colons (semicolons for Windows).

Author / version
P. Kabal / v3r2a 2000-11-21 Copyright (C) 2000

See Also
CompAudio, AFsp