Package com.github.kokorin.jaffree.nut

Class MainHeader

java.lang.Object

com.github.kokorin.jaffree.nut.MainHeader

public class MainHeader
extends Object

Nut format main header.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	MainHeader.Flag	Main Header's flags.

Field Summary

Fields

Modifier and Type	Field	Description
final long[]	elisionHeaderSize	For frames with a final size <= 4096 this header is prepended to the frame data.
final Set<MainHeader.Flag>	flags	Main Header flags.
final FrameCode[]	frameCodes	Nut frame codes.
final long	majorVersion	Nut major version.
final long	maxDistance	Maximum distance between startcodes.
final long	minorVersion	Nut minor version.
final int	streamCount	Number of streams in a file.
final Rational[]	timeBases	Different time bases used in a file.

Constructor Summary

Constructors

Constructor	Description
MainHeader(long majorVersion, long minorVersion, int streamCount, long maxDistance, Rational[] timeBases, FrameCode[] frameCodes, long[] elisionHeaderSize, Set<MainHeader.Flag> flags)	Creates MainHeader.

Method Summary

Modifier and Type	Method	Description
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

majorVersion

public final long majorVersion

Nut major version.

minorVersion

public final long minorVersion

Nut minor version.

streamCount

public final int streamCount

Number of streams in a file.

maxDistance

public final long maxDistance

Maximum distance between startcodes. If p1 and p2 are the byte positions of the first byte of two consecutive startcodes, then p2-p1 MUST be less than or equal to max_distance unless the entire span from p1 to p2 comprises a single packet or a syncpoint followed by a single frame. This imposition places efficient upper bounds on seek operations and allows for the detection of damaged frame headers, should a chain of frame headers pass max_distance without encountering any startcode.

Syncpoints SHOULD be placed immediately before a keyframe if the previous frame of the same stream was a non-keyframe, unless such non-keyframe - keyframe transitions are very frequent.

SHOULD be set to <=32768. If the stored value is >65536 then max_distance MUST be set to 65536.

This is also half the maximum frame size without a headerChecksum after the frame header.

timeBases

public final Rational[] timeBases

Different time bases used in a file.

frameCodes

public final FrameCode[] frameCodes

Nut frame codes.

elisionHeaderSize

public final long[] elisionHeaderSize

For frames with a final size <= 4096 this header is prepended to the frame data. That is if the stored frame is 4000 bytes and the elision_header is 96 bytes then it is prepended, if it is 97 byte then it is not.

elision_header[0] is fixed to a length 0 header.

The length of each elision_header except header 0 MUST be < 256 and >0.

The sum of the lengthes of all elision_headers MUST be <=1024.

flags

public final Set<MainHeader.Flag> flags

Main Header flags.

Constructor Details

MainHeader

public MainHeader(long majorVersion,
 long minorVersion,
 int streamCount,
 long maxDistance,
 Rational[] timeBases,
 FrameCode[] frameCodes,
 long[] elisionHeaderSize,
 Set<MainHeader.Flag> flags)

Creates MainHeader.

Parameters:

majorVersion - nut major version

minorVersion - nut minor version

streamCount - stream count

maxDistance - aximum distance between startcodes

timeBases - time bases

frameCodes - frame codes

elisionHeaderSize - elision header size

flags - flags

Method Details

toString

public String toString()

Overrides:

toString in class Object