Name

audio - TSP Audio Programs

Description

The AFsp package provides several audio file utility programs and a library of routines for reading and writing audio files.

Audio File Utilities

CompAudio: Compare audio files, producing statistics and signal-to-noise ratio figures.
CopyAudio: Copy audio files. This program combines samples from input audio files (an arbitrary linear combination) and writes them to the output file in a user selectable format. One application is to provide format conversion for an audio file; another is to combine samples from multi-channel files.
FiltAudio: Filter audio files. This program filters an audio file with an FIR, IIR or all-pole filter. This program can be used with an appropriate filter for sample rate conversion. The AFsp package includes a number of filter from the ITU-T Software Tool Library (G.191) in a form that can be used directly with the FiltAudio program.
GenNoise: Generate noise. This program generates an audio file containing Gaussian white noise.
GenTone: Generate a sinusoid. This program generates an audio file containing a sine wave of a given amplitude and frequency.
InfoAudio: Display information about an audio file.
LPanal: Demonstration program to do LPC analysis on a speech file.
LPsyn: Demonstration program to do LPC synthesis from a residual file.
PWevalAudio: Perceptual evaluation of audio quality.
ResampAudio: Resample data from an audio file. This process involves interpolating between the samples in the original file to create a new sequence of samples with a new spacing (sampling rate).

Audio File Library Routines

The audio file open routine automatically senses the input file type. The data format for the file is passed to the audio file reading routines. The audio file reading routine does byte swapping and format conversion on the fly as the file is read. The user sees float data without needing to worry about the underlying data format.

Once a file is opened for writing, the user calls routines which take the user's float data and do byte swapping and format conversion of the data transparently.

The library routines supplied in AFsp package form part of the libtsp signal processing library. The AFsp routines are written in C and have been tested on Unix and Windows.

AFclose: Close an audio file
AFopenRead: Open an audio file for reading
AFopenWrite: Open an audio file for writing
AFreadData: Read data from an audio file (return float values)
AFsetFileType: Explicitly set the input audio file type
AFsetInfo: Set the audio file information string
AFsetNHpar: Set defaults for headerless audio files
AFwriteData: Write data to an audio file (float input values)

Audio File Formats

The following file formats are supported for reading.

Headerless audio files
AU audio files
RIFF WAVE files
AIFF/AIFF-C audio files
NIST SPHERE audio files
IRCAM soundfiles
INRS-Telecom audio files
ESPS sampled data feature files
Comdisco SPW Signal files
Text audio files

The following file formats are supported for writing.

Headerless audio files (including text data)
AU audio files
RIFF WAVE files
AIFF-C audio files

Audio File Data Types

The following (uncompressed) data types are supported.