fi.helsinki.cs.ohtu.mpeg2.util
Class StartCode

java.lang.Object
  fi.helsinki.cs.ohtu.mpeg2.util.StartCode

public class StartCode
extends java.lang.Object

Represents a MPEG start code. Start codes are well-defined bit sequences that uniquely identify structures in the bitstream. Their purpose is to aid seeking, as they can be used to find the next desired structure, such as a group of pictures.

Field Summary

private int	encodedValue
static StartCode	EXTENSION An extension not included in those specified in the MPEG-1 standard begins.
static StartCode	GROUP_HEADER The header for a group of pictures begins.
static StartCode	PACK The header for a program stream pack begins.
static StartCode	PICTURE A picture header begins.
static StartCode	PS_END A program stream ends.
static StartCode	PS_SYSTEM_HEADER The header for a program stream system header begins.
static StartCode	SEQUENCE_END A video sequence ends.
static StartCode	SEQUENCE_ERROR An uncorrectable error has been detected.
static StartCode	SEQUENCE_HEADER The header of a video sequence begins.
static StartCode	USER_DATA User-defined data begins.

Constructor Summary

private

StartCode(int encodedValue)

Method Summary

boolean	equals(java.lang.Object a)
int	hashCode()
static StartCode	slice(int verticalPosition) A slice header begins.
void	writeTo(BitOutputStream stream) Writes the header to a bit stream.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Detail

PICTURE

public static final StartCode PICTURE

A picture header begins.

USER_DATA

public static final StartCode USER_DATA

User-defined data begins.

SEQUENCE_HEADER

public static final StartCode SEQUENCE_HEADER

The header of a video sequence begins.

SEQUENCE_ERROR

public static final StartCode SEQUENCE_ERROR

An uncorrectable error has been detected.

EXTENSION

public static final StartCode EXTENSION

An extension not included in those specified in the MPEG-1 standard begins.

SEQUENCE_END

public static final StartCode SEQUENCE_END

A video sequence ends.

GROUP_HEADER

public static final StartCode GROUP_HEADER

The header for a group of pictures begins.

PS_END

public static final StartCode PS_END

A program stream ends.

PACK

public static final StartCode PACK

The header for a program stream pack begins.

PS_SYSTEM_HEADER

public static final StartCode PS_SYSTEM_HEADER

The header for a program stream system header begins.

encodedValue

private int encodedValue

Constructor Detail

StartCode

private StartCode(int encodedValue)

Method Detail

slice

public static StartCode slice(int verticalPosition)

A slice header begins. All or part of the slices vertical position is encoded in the start code.

Parameters:

verticalPosition - The vertical position for the slice's start code.

Returns:

A StartCode instance corresponding to the given vertical position.

writeTo

public void writeTo(BitOutputStream stream)
             throws java.io.IOException

Writes the header to a bit stream.

Parameters:

stream - The stream to write to.

Throws:

java.io.IOException - Propagated from the stream write.

equals

public boolean equals(java.lang.Object a)

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(Object)

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

See Also:

Object.hashCode()