gd_frameoffset3

Usage

Overview

The gd_frameoffset() function queries a dirfile(5) database specified by dirfile and returns the frame offset (see dirfile-format(5)) for the fragment indexed by fragment_index. The frame offset of a fragment indicate the frame number of the first sample of data stored in binary files associated with RAW fields defined in the specified fragment. The frame offset of a fragment containing no RAW fields is ignored.

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_frameoffset() returns a non-negative integer containing the frame offset of the specified fragment. On error, it returns a negative-valued error code. Possible error codes are:
.TP 8 GD_E_BAD_DIRFILE The supplied dirfile was invalid.
.TP 8 GD_E_BAD_INDEX The supplied index was out of range.

The error code is also stored in the DIRFILE object and may be retrieved after this function returns by calling gd_error(3). A descriptive error string for the error may be obtained by calling gd_error_string(3).