If \a copy is \c true, a copy of the string is stored; otherwise, the object
takes ownership of the pointer. The existing string will be freed if this
function is successful, otherwise the original string will remain if \a copy
is \c true and malloc() fails.
\note It is safe to pass a const pointer to \a description if \a copy is \c true.
\param object A pointer to an existing PICTURE object.
\param description A pointer to the description string. The string must be
valid UTF-8, NUL-terminated. No validation is done.
\param copy See above.
\assert
\code object != NULL \endcode
\code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
\code (description != NULL) \endcode
\retval FLAC__bool
\c false if \a copy is \c true and malloc() fails, else \c true.
Sets the description of a PICTURE block.
If \a copy is \c true, a copy of the string is stored; otherwise, the object takes ownership of the pointer. The existing string will be freed if this function is successful, otherwise the original string will remain if \a copy is \c true and malloc() fails.
\note It is safe to pass a const pointer to \a description if \a copy is \c true.
\param object A pointer to an existing PICTURE object. \param description A pointer to the description string. The string must be valid UTF-8, NUL-terminated. No validation is done. \param copy See above. \assert \code object != NULL \endcode \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode \code (description != NULL) \endcode \retval FLAC__bool \c false if \a copy is \c true and malloc() fails, else \c true.