io.humble.video

Class IndexEntry

java.lang.Object

io.humble.ferry.RefCounted

io.humble.video.IndexEntry

public class IndexEntry
extends RefCounted

An index entry for a Stream.

Some ContainerFormats can maintain index of where key-frames
(and other interesting frames) can be found in a byte-stream.
This is really helpful for implementing efficient seeking (for
example, you can find all index entries near a desired timestamp,
and you'll find the nearest key-frame).

We don't maintain a complete list of all ContainerFormats that support
index, but if they do, you can query the Stream#getNumIndexEntries()
method to find how many entires are in the index. Some ContainerFormats can
parse the relevant Container message if an index is embedded in the
container (for example, the MOV and MP4 demuxer can do this). Other
ContainerFormats can create an index automatically as they read the file,
even if an index is not embedded in the container (for example the FLV
demuxer does this).

See Also:

Stream#findTimeStampEntryInIndex(int,int)
, Stream#findTimeStampPositionInIndex(int,int)
, Stream#getIndexEntry(int)
, Stream#getNumIndexEntries()
, Stream#getIndexEntries()

Field Summary

Fields

Modifier and Type	Field and Description
static int	INDEX_FLAG_KEYFRAME A bit mask value that may be set in #getFlags.

Method Summary

Modifier and Type	Method and Description
IndexEntry	copyReference() Create a new IndexEntry object that is actually referring to the exact same underlying native object.
boolean	equals(Object obj) Compares two values, returning true if the underlying objects in native code are the same object.
int	getFlags() Flags set for this entry.
int	getMinDistance() Minimum number of index entries between this index entry and the last keyframe in the index, used to avoid unneeded searching.
long	getPosition() The position in bytes of the frame corresponding to this index entry in the Container.
int	getSize() The size of bytes of the frame this index entry points to.
long	getTimeStamp() The actual time stamp, in units of Stream#getTimeBase(), of the frame this entry points to.
int	hashCode() Get a hashable value for this object.
boolean	isKeyFrame() Is this index entry pointing to a key frame. Really shorthand for #getFlags() & #INDEX_FLAG_KEYFRAME.
static IndexEntry	make(long position, long timeStamp, int flags, int size, int minDistance) Create a new IndexEntry with the specified values.
String	toString() info about this entry.

Methods inherited from class io.humble.ferry.RefCounted

delete, getCurrentRefCount

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

INDEX_FLAG_KEYFRAME

public static final int INDEX_FLAG_KEYFRAME

A bit mask value that may be set in #getFlags.

Method Detail

copyReference

public IndexEntry copyReference()

Create a new IndexEntry object that is actually referring to the exact same underlying native object.

Overrides:

copyReference in class RefCounted

Returns:

the new Java object.

equals

public boolean equals(Object obj)

Compares two values, returning true if the underlying objects in native code are the same object. That means you can have two different Java objects, but when you do a comparison, you'll find out they are the EXACT same object.

Overrides:

equals in class Object

Returns:

True if the underlying native object is the same. False otherwise.

hashCode

public int hashCode()

Get a hashable value for this object.

Overrides:

hashCode in class Object

Returns:

the hashable value.

toString

public String toString()

info about this entry.

Overrides:

toString in class Object

Returns:

information about this entry.

make

public static IndexEntry make(long position,
                              long timeStamp,
                              int flags,
                              int size,
                              int minDistance)

Create a new IndexEntry with the specified
values.

Parameters:

position - The value to be returned from #getPosition().

timeStamp - The value to be returned from #getTimeStamp().

flags - The value to be returned from #getFlags().

size - The value to be returned from #getSize().

minDistance - The value to be returned from #getMinDistance().

getPosition

public long getPosition()

The position in bytes of the frame corresponding to this index entry
in the Container.

Returns:

The byte-offset from start of the Container where the
frame for this IndexEntry can be found.

getTimeStamp

public long getTimeStamp()

The actual time stamp, in units of Stream#getTimeBase(), of the frame this entry points to.

Returns:

The time stamp for this entry.

getFlags

public int getFlags()

Flags set for this entry. See the INDEX_FLAG* constants
above.

Returns:

the flags.

getSize

public int getSize()

The size of bytes of the frame this index entry points to.

Returns:

The size in bytes.

getMinDistance

public int getMinDistance()

Minimum number of index entries between this index entry
and the last keyframe in the index, used to avoid unneeded searching.

Returns:

the minimum distance, in bytes.

isKeyFrame

public boolean isKeyFrame()

Is this index entry pointing to a key frame.
Really shorthand for #getFlags() & #INDEX_FLAG_KEYFRAME.

Returns:

True if this index entry is for a key frame.