gd_nframes(3) [debian man page]

gd_nframes(3)							      GETDATA							     gd_nframes(3)

NAME

       gd_nframes -- report the size of a dirfile

SYNOPSIS

       #include <getdata.h>

       off_t gd_nframes(DIRFILE *dirfile);

DESCRIPTION

       The  gd_nframes() function queries a dirfile(5) database specified by dirfile and returns the number of frames in the database.	Since dif-
       ferent fields may have differing number of frames, the Dirfile Standards (see dirfile(5)) dictate that the number of frames in the database
       is defined to be equal to the number of frames in the reference field defined by the /REFERENCE directive (see dirfile-format(5)) or, if no
       such reference field is defined, by the first raw field specified in the format specification.

       If no vector fields are defined in the database, gd_nframes() returns zero and succeeds.

       The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).

RETURN VALUE

       Upon successful completion, gd_nframes() returns the number of frames in the dirfile.  On error, it returns zero and sets the dirfile error
       to a non-zero error value.  Possible error values are:

       GD_E_BAD_DIRFILE
	       The supplied dirfile was invalid.

       GD_E_RAW_IO
	       An attempt to stat(2) the file associated with the reference field failed.

       GD_E_UNKNOWN_ENCODING
	       The  size  of the decoded data file associated with the reference field could not be not be determined because its encoding was not
	       understood.

       GD_E_UNSUPPORTED
	       The size of the decoded data file associated with the reference field could not be not be determined because its encoding  was  not
	       supported.

       The  dirfile error may be retrieved by calling gd_error(3).  A descriptive error string for the last error encountered can be obtained from
       a call to gd_error_string(3).

SEE ALSO

       dirfile(5), dirfile-encoding(5), gd_open(3), gd_bof(3), gd_eof(3), gd_error(3), gd_error_string(3)

Version 0.7.0							   22 July 2010 						     gd_nframes(3)

gd_bof(3)							      GETDATA								 gd_bof(3)

NAME

       gd_bof -- report the start of data in a field

SYNOPSIS

       #include <getdata.h>

       off_t gd_bof(DIRFILE *dirfile, const char *field_code);

DESCRIPTION

       The gd_bof() function queries a dirfile(5) database specified by dirfile and returns the sample number of the beginning-of-field marker for
       the vector field given by field_code.

       The caller should not assume that the beginning-of-field marker falls on a frame boundary.  The beginning-of-field marker  is  never  nega-
       tive.

       For  a RAW field, the beginning-of-field corresponds to the frame offset of that field (see gd_frameoffset(3)).	The beginning-of-field for
       all other vector field type is the same as the beginning-of-field of whichever of its input fields that starts latest.	The  beginning-of-
       field marker for the special field INDEX is always zero.

       The beginning-of-field marker for a field containing no data is in the same location as, or after, its end-of-field marker (see gd_eof(3)).
       For a RAW field, the difference between the locations of the beginning- and end-of-field markers indicates the number of  samples  of  data
       actually stored on disk.

       The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).

RETURN VALUE

       Upon successful completion, gd_bof() returns the sample number of the end-of-field marker for the indicated field.  On error, it returns -1
       and sets the dirfile error to a non-zero error value.  Possible error values are:

       GD_E_BAD_CODE
	       The field specified by field_code or one of the fields it uses as input was not found in the database.

       GD_E_BAD_DIRFILE
	       The supplied dirfile was invalid.

       GD_E_BAD_REPR
	       The representation suffix specified in field_code, or in one of its inputs was not recognised.

       GD_E_DIMENSION
	       A scalar field was found where a vector field was expected in the definition of field_code or one of its inputs, or else field_code
	       itself specified a scalar field.

       GD_E_RECURSE_LEVEL
	       Too  many levels of recursion were encountered while trying to resolve field_code.  This usually indicates a circular dependency in
	       field specification in the dirfile.

       The dirfile error may be retrieved by calling gd_error(3).  A descriptive error string for the last error encountered can be obtained  from
       a call to gd_error_string(3).

SEE ALSO

       dirfile(5), dirfile-encoding(5), gd_open(3), gd_eof(3), gd_error(3), gd_error_string(3), gd_nframes(3)

Version 0.7.0							  15 October 2010							 gd_bof(3)