Package tv.amwa.maj.enumeration

Defines Java enumerations representing the enumerations specified in the AAF object specification and other enumerations used across the MAJ API.

See:
Description

Interface Summary

AAFEnumerationValue

Implemented by enumeration specifications that includes an integer value representing an AAF enumeration data type.

Enum Summary

AlphaTransparencyType	Specifies whether the minimum alpha value or the maximum alpha value represents transparency.
AppendOption	Specifies whether a file writing operation should append to or overwrite existing data.
AuxBitsModeType	Represents the 3 bit auxiliary bits mode of audio essence stored in the AES/EBU audio file format and described by a AES3 PCM descriptor.
Boolean	Representation of Boolean values as an enumeration.
ByteOrder	Specifies the byte order of a file, such as an AAF file.
ChannelStatusModeType	Specifies how channel status data is encoded as part of a AES3 PCM descriptor.
ColorSitingType	Specifies color siting that indicates where colored pixels are located with respect to their associated luminance value.
ColorSpace	Specifies a kind of color space, such as "RGB" or "YCrCb".
CompressEnable	Specifies whether compression or decompression should be enabled for an operation on essence.
ContentScanningType	For MPEG coded content, specifies if the scanning type of underlying coded content is known and, if it is, what kind of scanning type it is.
CriteriaType	A criteria can be used to select media by the kind of representation for that media.
DefinitionKind	Specifies the kind of a definition, such as Class, Property, Operation etc..
Depend	Specifies whether metadata dependencies should be followed or not as part of a cloning operation.
EdgeType	Specifies the kind of film edge code.
EditHintType	Specifies hints to be used when editing control points.
ElectroSpatialFormulation	Specifies electro-spatial formulation, a property used to describe sound essence.
EmphasisType	Specifies the encoded audio signal pre-emphasis for sound data.
EssenceType	Specifies the kind of essence data in terms of its relationship with time.
FadeType	Specifies the kind of an audio fade.
FieldNumber	Specifies the first or second field of an interlaced image.
FileRev	Specifies the revision of a file.
FilmType	Specifies the format of a film.
IncludedMedia	Specifies whether media is included or not by an operation, such as a clone.
LayoutType	Specifies whether all the data for a complete sample is in one frame or is split into more than one field.
MaterialType	Identifies the material type of content according the the SMPTE UMID specification SMPTE S330M.
MediaOpenMode	Specifies whether media should be opened for reading only or whether it could be appended to.
MobKind	Specifies the kind of a media object (mob).
OperationChoice	TODO this comment or remove?
ProductReleaseType	Specifies the release type of a product, for example released, debug alpha etc..
PulldownDirectionType	Specifies whether a pulldown operation is converting from tape to film speed or from film to tape speed.
PulldownKindType	Specifies whether a pulldown operation is converting from nominally 30 Hz or 25 Hz video frame rate and whether frames are dropped or the video is played at another speed.
ReferenceType	Specifies the type of a reference.
RGBAComponentKind	Specifies the color or function of a component within a pixel, for example whether the component a red level, palette index etc..
ScanningDirectionType	Describes the scanning direction of an image.
SignalStandardType	Specifies an underlying signal standard used to define the raster.
TapeCaseType	Describes the physical size of a tape.
TapeFormatType	Describes the format of the tape.
TCSource	Specifies the kind of a timecode.
TypeCategory	Specifies a categorisation of an AAF data type.
UserDataModeType	Represents the value of the 4 bits of channel status indicating the format of user data of audio essence stored in the AES/EBU audio file format and described by a AES3 PCM descriptor.
VideoSignalType	Specifies the type of video signal on a videotape.

Annotation Types Summary

ExtendibleEnumerationItem

Labels an AUID that represents an element of an extendible enumeration.

Package tv.amwa.maj.enumeration Description

Defines Java enumerations representing the enumerations specified in the AAF object specification and other enumerations used across the MAJ API. Also included in this package is the extendible enumeration annotation that allows AUID values to become named enumeration elements.

Enumeration kinds

Section 21.2 of the AAF object specification v1.1 specifies a number of enumeration data types. Enumerations are made up of a fixed set of elements with each element represented by a name and an ordinal value. All of these enumerations are represented in this package by a Java enumeration.

As Java enumerations do not have to have an ordinal value associated with them, the AAF-specified ordinal value is provided through the AAFEnumerationValue interface that is implemented by all enumerations. The ordinal value of an element can be retrieved using the value() method. Some of the enumerations also provide a static fromOrdinal(int) method that can be used to return an enumeration element from its specified ordinal value.

Other enumerations are defined for implementation-specific reasons, such as ByteOrder. In general, these enumerations provide a convenient way to configure features the API or refer to property values in a user-friendly way.

Extendible enumeration

Extendible enumeration data types do not have a fixed set of specified elements, although a currently known set of built-in elements is provided in section 23.1 of the AAF object specification v1.1. An extendible enumeration element consists of a name and AUID unique identifier pair. The built-in elements are defined in the constant package using the extendible enumeration annotation. Additional elements can be registered with a JVM using the registration methods of the extendible enumeration warehouse.

Heritage

The original versions of the enumerations of this package were derived from the enum type definitions in the existing C-based AAF reference implementation, from file "AAFTypes.h". A typical source enum definition looks like the code below:

    typedef aafInt32 aafContentScanningType_t;
    typedef enum _aafContentScanningType_e
    {
        kAAFContentScanning_NotKnown = 0,
        kAAFContentScanning_Progressive = 1,
        kAAFContentScanning_Interlace = 2,
        kAAFContentScanning_Mixed = 3
    } aafContentScanningType_e;

The following steps have been taken to convert the C-based enum type definitions into Java enumerations, taking advantage of Java's class-based representation of enumerations wherever possible:

• The name of the enumeration has had "aaf" removed from its start and "_e" removed from the end. Where the enumeration is specified in the AAF object specification then the name has been matched to that. In the example above, the enumeration name becomes "ContentScanningType".
• The characters "kAAF" have been removed from the start of each element name.
• As the name of elements of Java enumerations are scoped by the enumeration they belong to and so do not require a globally unique name, any enumeration-specific label used for each element name has been removed. This should make code written to use the MAJ API easier to read. In the example above, the characters "ContentScanning_" have been removed from the element names, for example "Progressive" instead of "ContentScanning_Progressive".
• The constant ordinal value associated with each enumeration element has become a value passed the the private constructor for each enumeration element. It is then stored within the enumeration element ready to be retrieved with a call to the value() method.

The resulting underlying Java code for the content scanning type is:

    public enum ContentScanningType 
        implements AAFEnumerationValue {
        
        NotKnown(0),
        Progressive(1),
        Interlace(2),
        Mixed(3);
        
        private int value;
        
        private ContentScanningType(
                int value) {
                
            this.value = value;
        }
        
        @Int64 public long value() {
    
            return (long) value;
        }
    }

Author:

Richard Cartwright

See Also:

TypeDefinitionEnumeration, TypeDefinitionExtendibleEnumeration