sdtosph.3

speech signal process tools

.\" Copyright (c) 1993 Entropic Research Laboratory, Inc. All rights reserved.
.\" @(#)sdtosph.3	1.2	04 Jan 1993	ERL
.TH SDTOSPHERE 3\-ESPSu 04 Jan 1993
.ds ]W (c) 1993 Entropic Research Laboratory, Inc.
.SH NAME
sd_to_sphere \- convert ESPS FT_SD or FEA_SD header to Sphere header
.SH SYNOPSIS
.ft B
struct header_t *
.br
sd_to_sphere(ifile, ofile, byte_format)
.br
FILE *ifile;
.br
FILE *ofile;
.br
char *byte_format;

.fi
.ft
.SH DESCRIPTION
.PP
\fIsd_to_sphere\fP assumes that \fIifile\fP is non-NULL, is open for
reading, and is positioned to point at the beginning of an ESPS
header.  If \fIofile\fP is non-NULL, it is assumed to be open for
writing.  \fIsd_to_sphere\fP reads the ESPS header and checks to make
sure it describes a single-channel, non-complex, FT_SD or FEA_SD file.
If these conditions are not met, \fIsd_to_sphere\fP writes an error
message to stderr and returns NULL.
.PP
\fIsd_to_sphere\fP converts the input ESPS header to Sphere format.
If \fIofile\fP is non-NULL, the resulting Sphere header is written to
\fIofile\fP followed by all of the data from the input ESPS file.  The
input data can be any type, but are converted to SHORT before output to
\fIofile\fP.  The parameter \fIbyte_format\fP determines the byte 
order of output data; values are restricted to either "10" or "01".  
If \fIbyte_order\fP is "01", the data are byte-reversed before output. (If
\fIbyte_order\fP is some other value, an error message is output 
and \fIsd_to_sphere\fP returns NULL).  
.PP
All scalar generic header items from the input ESPS header are
reproduced as sphere header items in the output header.  Note that
CODED generics from the input header are converted as integers.  In
addition, the Sphere header items \fIchannel_count, sample_count,
sample_rate, sample_min, sample_max, sample_n_bytes,
sample_byte_format,\fP and \fIsample_sig_bits\fP are included in the
output Sphere header.
.PP
\fIsd_to_sphere\fP returns a pointer to the converted Sphere header.
If \fIofile\fP is non-NULL, \fIifile\fP is positioned at the end of
all input data, and \fIofile\fP is positioned at the end of the
written data.  If \fIofile\fP is NULL, \fIsd_to_sphere\fP returns the
Sphere header but writes no output (in this case, \fIifile\fP is
positioned at the end of the ESPS header).
.PP
Note that, since \fIsd_to_sphere\fP is available in an unlicensed
form, it can be used in non-ESPS programs that read ESPS sampled data
files (e.g., if only to skip the ESPS header).
.SH EXAMPLE
.SH DIAGNOSTICS
.SH "FUTURE CHANGES"
.SH BUGS
None known. 
.SH SEE ALSO
read_header(3-ESPSu), skip_header(3-ESPSu), e2sphere (1-ESPS)
.SH AUTHOR
John Shore