SECTION 9.1
765
Multimedia
KEY
TYPE
VALUE
MH
dictionary
dictionary
(Optional)
A dictionary whose entries (see Table 9.11) must be honored for the me-
dia clip data to be considered viable.
(Optional)
A dictionary whose entries (see Table 9.11) need only be honored in a
“best effort” sense.
BE
The media clip data object must be considered non-viable if the object referenced
by the
D
entry does not contain a
Type
entry, the
Type
entry is unrecognized, or
the referenced object is not a dictionary or stream. Note that this excludes the use
of simple file specifications (see Section 3.10, “File Specifications”).
If
D
references a file specification that has an embedded file stream (see Section
Subtype
entry is ig-
nored if present, and the media clip data dictionary’s
CT
entry identifies the type
of data.
If
D
references a form XObject, the associated player is implicitly the viewer ap-
plication, and the form XObject should be rendered as if it were any other data
type. For example, the
F
and
D
entries in the media play parameters dictionary
(see Table 9.14) apply to a form XObject just as they do to a QuickTime movie.
For media other than form XObjects, the media clip object must provide enough
information to allow a viewer application to locate an appropriate player. This can
be done by providing one or both of the following entries:
•
A
CT
entry that specifies the content type of the media (the preferred method).
If this entry is present, any player that is selected must support this content
type.
•
A
PL
entry that specifies one or more players that can be used to play the refer-
enced media. It is highly recommended if
CT
is present. However, see imple-
The
P
entry specifies a
media permissions dictionary
(see Table 9.10) specifying
the manner in which the data referenced by the media may be used by a viewer
application. These permissions allow authors control over how their data is ex-
posed to operations that could allow it to be copied. If the dictionary contains un-
recognized entries or entries with unrecognized values, it should be considered
non-viable, and the viewer application should not play the media.