public class TrackSelectionBox extends FullBox
Constructor and Description |
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TrackSelectionBox() |
Modifier and Type | Method and Description |
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void |
decode(MP4InputStream in)
Decodes the given input stream by reading this box and all of its
children (if any).
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java.util.List<java.lang.Long> |
getAttributes()
A list of attributes, that should be used as descriptions of tracks or
differentiation criteria for tracks in the same alternate or switch
group.
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long |
getSwitchGroup()
The switch group is an integer that specifies a group or collection of
tracks.
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getChild, getChildren, getChildren, getLeft, getName, getOffset, getParent, getSize, getType, hasChild, hasChildren, readChildren, readChildren, setParams, toString
public void decode(MP4InputStream in) throws java.io.IOException
BoxImpl
public long getSwitchGroup()
public java.util.List<java.lang.Long> getAttributes()
A list of attributes, that should be used as descriptions of tracks or differentiation criteria for tracks in the same alternate or switch group. Each differentiating attribute is associated with a pointer to the field or information that distinguishes the track.
The following attributes are descriptive:
Name | Attribute | Description |
---|---|---|
Temporal scalability | 'tesc' | The track can be temporally scaled. |
Fine-grain SNR scalability | 'fgsc' | The track can be fine-grain scaled. |
Coarse-grain SNR scalability | 'cgsc' | The track can be coarse-grain scaled. |
Spatial scalability | 'spsc' | The track can be spatially scaled. |
Region-of-interest scalability | 'resc' | The track can be region-of-interest scaled. |
The following attributes are differentiating:
Name | Attribute | Pointer |
---|---|---|
Codec | 'cdec' | Sample Entry (in Sample Description box of media track) |
Screen size | 'scsz' | Width and height fields of Visual Sample Entries. |
Max packet size | 'mpsz' | Maxpacketsize field in RTP Hint Sample Entry |
Media type | 'mtyp' | Handlertype in Handler box (of media track) |
Media language | 'mela' | Language field in Media Header box |
Bitrate | 'bitr' | Total size of the samples in the track divided by the duration in the track header box |
Frame rate | 'frar' | Number of samples in the track divided by duration in the track header box |
Descriptive attributes characterize the tracks they modify, whereas differentiating attributes differentiate between tracks that belong to the same alternate or switch groups. The pointer of a differentiating attribute indicates the location of the information that differentiates the track from other tracks with the same attribute.