file: README G. Moody 28 July 1989
Last revised: 23 July 2008
This directory contains sources for WFDB applications that convert signal and
annotation files in various unsupported formats to and from WFDB format (also
known as PhysioBank or MIT format), including EDF/EDF+, WAV (audio), and AHA DB
formats. (Note that EDF input is supported by recent versions of the WFDB
library, however.)
Note that many commonly used formats are supported by the WFDB library. The
program `xform' (in the `app' directory) is a flexible application for
converting between any pair of supported formats, in addition to offering
other capabilities such as resampling (to change the sampling frequency),
deletion or rearrangement of signals, rescaling (to change signal amplitudes),
and removal of unwanted material at the beginning or end of a record.
Programs `rdsamp' and `wrsamp' in the `app' directory convert signals between
supported (binary) formats and text; programs `rdann' and `wrann', also in
the `app' directory, perform similar conversions for annotation files.
European Data Format (EDF) has been used for storage of multiparameter,
multifrequency data (such as polysomnograms) since 1990. Program `edf2mit'
reads an EDF file and generates WFDB-format header and signal files from it.
(Although this conversion is no longer needed since current versions of the
WFDB library can read EDF files directly, the native WFDB files produced by
'edf2mit' can be read more efficiently and with lower latency and memory
requirements than the EDF files.) Program 'mit2edf' performs the inverse
conversion. Program 'rdedfann' creates a WFDB annotation file from the
annotation stream embedded in an EDF+ file. (Although multi-segment WFDB
records can be discontinuous, there is currently no support for reading or
writing discontinuous EDF+ files using the WFDB library, or for writing an EDF+
annotation stream, either natively or using a converter.)
The popular Matlab application (and the mostly compatible open-source Octave
application) cannot read WFDB files unless they have been prepared specifically
for Matlab. Program `wfdb2mat' does this, converting all or any part of the
samples in a record into a Matlab- and Octave-compatible '.mat' file, and also
creating a new .hea file that allows WFDB applications to read the '.mat' file
directly.
The popular .wav format used for audio files is readable by WFDB applications
once a short header (.hea) file that describes the format of the .wav file
has been created; 'wav2mit' does this. Note that there are many variants
of .wav format, and only the common ones are readable in this way. If you
encounter an incompatible .wav file, or a file in another audio format, an
audio format converter such as the open-source SoX (sox.sourceforge.net) may
be helpful. Program 'mit2wav' converts a WFDB record (signals only, not
annotations) into a .wav file.
The AHA Database for Evaluation of Ventricular Arrhythmia Detectors (AHA DB)
is available on DVD from ECRI (www.ecri.org), in a format that is not compatible
with those previously used for the AHA DB on CDs, floppy disks, and tapes.
To convert this format to WFDB format, use 'ahaecg2mit.c'. (There is no support
for performing the inverse conversion.)
AHA DB tape distribution format was used for both the AHA DB and the MIT-BIH
DB between 1980 and 1990. AHA DB tape distribution format requires more space
than the other formats supported by the WFDB library and applications, however,
so it is not recommended for on-line storage. Programs `a2m' and `ad2m' can
also convert AHA DB CD-ROM and diskette distribution format files into standard
WFDB files; the inverse conversion is not supported, however.
Once you have installed 'a2m' and 'ad2m', the shell script 'ahaconvert' can be
used to create a set of AHA DB records in WFDB format from an AHA DB CD-ROM
(or from a set of AHA DB diskettes). Run 'ahaconvert' without command-line
arguments for instructions. Under MS-DOS or MS-Windows, you will need to
have a shell utility, such as 'bash' (included with the free Cygwin software
package from http://www.cygwin.com/) in order to run 'ahaconvert'.
This directory also contains the program `revise', which converts obsolete MIT
header files into new-format WFDB header files. (Unless you have very old
header files, made before 1990, you will not need this program.)
Contributions to this set of format converters are welcome. If you have
written a format converter, please send it together with a short input file and
the output generated from the input to wfdb@physionet.org. (Don't omit the
output; I need to see that I can compile your converter and generate the same
output that you do.)
If a `make' utility is available, follow the instructions in 'Makefile' to
compile and install these applications on your system. If you do not have a
`make' utility, you will have to perform the installation manually; the
comments in 'Makefile' may be helpful in determining how to proceed.
For information about using these applications, see the WFDB Applications
Guide (in the 'doc' directory at the same level as this one), or look in the
respective source files. You can also obtain a brief usage summary for each
application by running it without command-line arguments.
You may wish to set the WFDB environment variable (the database path) before
using these applications. Select and customize the appropriate script for
doing so from among the templates in the `app' directory on the same level as
this one.
The following files will be found in this directory:
Makefile `make' description file for compiling these applications using
ANSI/ISO standard C compilers on supported platforms
Makefile.top Used by ../configure to construct Makefile (comments only)
Makefile.tpl Used by ../configure to construct Makefile (portable section)
README this file
edf2mit.c Converts an EDF file to a WFDB record
mit2edf.c Converts a WFDB record into an EDF file
rdedfann.c Converts an EDF+ annotation stream into a WFDB annotation file
wfdb2mat.c Converts a WFDB record into a .mat file
wav2mit.c Makes .hea file so that a .wav file is readable as a WFDB record
mit2wav.c Converts a WFDB record into a .wav file
ahaecg2mit.c Converts an AHA DB DVD file to a WFDB record
a2m.c Converts an AHA format annotation file to WFDB format
ad2m.c Converts an AHA format signal file to WFDB format
ahaconvert Converts an AHA DB CD-ROM to WFDB format using a2m and ad2m
m2a.c Converts a WFDB format annotation file to AHA format
md2a.c Converts a WFDB format signal file to AHA format
readid.c Extracts record name and file lengths from AHA-format ID block
makeid.c Makes an AHA-format ID block for a database record
revise.c Converts an obsolete WFDB header to a new-format WFDB header