AFsetHinfo
Routine
-
void AFsetHinfo (const char String[])
-
char *AFgetHinfo (void)
Purpose
-
Set the audio file header information string
-
Get the audio file header information string
Description
This routine sets the information string to be written to an AFsp audio file
header. This file format allows for an arbitrary information string to be
written at the end of the header. By default the header information string
gives date and user information. This routine allows the user to specify an
information string that is used in addition to, or in place of, the standard
header information string. This routine must be called before the audio
file to be created is first opened using AFopenWrite. AFopenWrite resets
the header string to a NULL string.
Standard Header Information:
date:1994/01/25 19:19:39 UTC date
sample_rate:8012.5 sampling frequency (if non-integer)
user:kabal@aldebaran user
program:CopyAudio program name (set by UTsetProg)
Additional structured information records should follow this format; a named
field terminated by a colon followed by numeric data or a character string.
Comments can follow as unstructured information. For the purpose of this
routine, records are separated by newline characters. The last record need
not be terminated by a newline character. When written to the header, the
newline characters are replaced by nulls. To place a newline character
into the header without having it serve as a record separator, escape the
newline character by preceding it with a backslash character, i.e. in a
C-language string an escaped newline character would appear as "\\\n".
If the input header information string is a NULL pointer, the standard
information string is used. If the first character of the header information
string is a newline character, the the input header information string is
added to the existing information string (the standard information string
and/or any previously specified header strings). Otherwise the input header
information string replaces the standard information string. The following
examples illustrate the behaviour.
-
- AFsetHinfo (NULL)
-
Reset, use only the standard information string
-
- AFsetHinfo ("")
-
No header information string
-
- AFsetHinfo ("<info>")
-
Replace existing information string with <info>, do not use the standard
information string
-
- AFsetHinfo ("\n<info>")
-
Add <info> to the existing information string, if the overall information
string begins with a newline character, the overall information string
appears in the header after the standard information string
The procedure AFgetHinfo is used internally by the audio file routines to
retrieve the user supplied header information string.
Parameters
-
AFsetHinfo:
-
-> const char String[]
-
String containing the user supplied header information
-
AFgetHinfo:
-
<- char *AFgetUinfo
-
Pointer to the header information string. A NULL pointer indicates that
no information string has been set.
Author / revision
P. Kabal
/ Revision 1.27 1996/05/31
See Also
AFopenWrite
Main Index libtsp