Get the application ID of the \c APPLICATION block at the current
position. This avoids reading the actual block data which can save
time for large blocks.
\param iterator A pointer to an existing initialized iterator.
\param id A pointer to a buffer of at least \c 4 bytes where
the ID will be stored.
\assert
\code iterator != NULL \endcode
\code id != NULL \endcode
\a iterator has been successfully initialized with
FLAC__metadata_simple_iterator_init()
\retval FLAC__bool
\c true if the ID was successfully read, else \c false, in which
case you should check FLAC__metadata_simple_iterator_status() to
find out why. If the status is
\c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT, then the
current metadata block is not an \c APPLICATION block. Otherwise
if the status is
\c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR or
\c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR, an I/O error
occurred and the iterator can no longer be used.
Get the application ID of the \c APPLICATION block at the current position. This avoids reading the actual block data which can save time for large blocks.
\param iterator A pointer to an existing initialized iterator. \param id A pointer to a buffer of at least \c 4 bytes where the ID will be stored. \assert \code iterator != NULL \endcode \code id != NULL \endcode \a iterator has been successfully initialized with FLAC__metadata_simple_iterator_init() \retval FLAC__bool \c true if the ID was successfully read, else \c false, in which case you should check FLAC__metadata_simple_iterator_status() to find out why. If the status is \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT, then the current metadata block is not an \c APPLICATION block. Otherwise if the status is \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR or \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR, an I/O error occurred and the iterator can no longer be used.