CodestreamWriter (SCIFIO Javadocs 0-SNAPSHOT API)

java.lang.Object
- io.scif.jj2000.j2k.codestream.writer.CodestreamWriter

Direct Known Subclasses:

FileCodestreamWriter
```
public abstract class CodestreamWriter
extends Object
```
This is the abstract class for writing to a bit stream. Data is written in packets, each packet having a head and a body. The bit stream always has a maximum number of bytes that can be written to it. After that many number of bytes no more data is written to the bit stream but the number of bytes is counted so that the value returned by getMaxAvailableBytes() is negative. If the number of bytes is unlimited a ridicoulosly large value, such as Integer.MAX_VALUE, is equivalent.
Data may be written to the bit stream in sumulation mode. When in simulation mode no data is written to the bit stream but the resulting number of bytes is calculated and returned (although it is not accounted in the bit stream). This can be used in rate control loops.
Implementing classes should write the header of the bit stream before writing any packets. The bit stream header should be written with the aid of the HeaderEncoder class.

See Also:

HeaderEncoder

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`maxBytes` The maximum number of bytes that can be written to the bit stream
`protected int`	`ndata` The number of bytes already written to the bit stream

Constructor Summary

Constructors
Modifier Constructor and Description

protected CodestreamWriter(int mb)
Allocates this object and initializes the maximum numner of bytes.

Constructors
Modifier	Constructor and Description
`protected`	`CodestreamWriter(int mb)` Allocates this object and initializes the maximum numner of bytes.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`abstract void`	`close()` Closes the underlying resource (file, stream, network connection, etc.).
`abstract void`	`commitBitstreamHeader(HeaderEncoder he)` Writes the header data to the bit stream, if it has not been already done.
`abstract int`	`getLength()` Returns the current length of the entire bit stream.
`abstract int`	`getMaxAvailableBytes()` Returns the number of bytes remaining available in the bit stream.
`abstract int`	`getOffLastROIPkt()` Gives the offset of the end of last packet containing ROI information
`abstract int`	`writePacketBody(byte[] body, int blen, boolean sim, boolean roiInPkt, int roiLen)` Writes a packet body to the bit stream and returns the number of bytes used by this body .If in simulation mode then no data is written to the bit stream but the number of bytes is calculated.
`abstract int`	`writePacketHead(byte[] head, int hlen, boolean sim, boolean sop, boolean eph)` Writes a packet head to the bit stream and returns the number of bytes used by this header.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ndata
```
protected int ndata
```
    The number of bytes already written to the bit stream
  - maxBytes
```
protected int maxBytes
```
    The maximum number of bytes that can be written to the bit stream
- Constructor Detail
  - CodestreamWriter
```
protected CodestreamWriter(int mb)
```
    Allocates this object and initializes the maximum numner of bytes.
    
    Parameters:
    
    mb - The maximum number of bytes that can be written to the bit stream.
- Method Detail
  - getMaxAvailableBytes
```
public abstract int getMaxAvailableBytes()
```
    Returns the number of bytes remaining available in the bit stream. This is the maximum allowed number of bytes minus the number of bytes that have already been written to the bit stream. If more bytes have been written to the bit stream than the maximum number of allowed bytes, then a negative value is returned.
    
    Returns:
    
    The number of bytes remaining available in the bit stream.
  - getLength
```
public abstract int getLength()
```
    Returns the current length of the entire bit stream.
    
    Returns:
    
    the current length of the bit stream
  - writePacketHead
```
public abstract int writePacketHead(byte[] head,
                                    int hlen,
                                    boolean sim,
                                    boolean sop,
                                    boolean eph)
                             throws IOException
```
    Writes a packet head to the bit stream and returns the number of bytes used by this header. It returns the total number of bytes that the packet head takes in the bit stream. If in simulation mode then no data is written to the bit stream but the number of bytes is calculated. This can be used for iterative rate allocation.
    If the length of the data that is to be written to the bit stream is more than the space left (as returned by getMaxAvailableBytes()) only the data that does not exceed the allowed length is written, the rest is discarded. However the value returned by the method is the total length of the packet, as if all of it was written to the bit stream.
    If the bit stream header has not been commited yet and 'sim' is false, then the bit stream header is automatically commited (see commitBitstreamHeader() method) before writting the packet.
    
    Parameters:
    
    head - The packet head data.
    
    hlen - The number of bytes in the packet head.
    
    sim - Simulation mode flag. If true nothing is written to the bit stream, but the number of bytes that would be written is returned.
    
    sop - Start of packet header marker flag. This flag indicates whether or not SOP markers should be written. If true, SOP markers should be written, if false, they should not.
    
    eph - End of Packet Header marker flag. This flag indicates whether or not EPH markers should be written. If true, EPH markers should be written, if false, they should not.
    
    Returns:
    
    The number of bytes spent by the packet head.
    
    Throws:
    
    IOException - If an I/O error occurs while writing to the output stream.
    
    See Also:
    
    commitBitstreamHeader(io.scif.jj2000.j2k.codestream.writer.HeaderEncoder)
  - writePacketBody
```
public abstract int writePacketBody(byte[] body,
                                    int blen,
                                    boolean sim,
                                    boolean roiInPkt,
                                    int roiLen)
                             throws IOException
```
    Writes a packet body to the bit stream and returns the number of bytes used by this body .If in simulation mode then no data is written to the bit stream but the number of bytes is calculated. This can be used for iterative rate allocation.
    If the length of the data that is to be written to the bit stream is more than the space left (as returned by getMaxAvailableBytes()) only the data that does not exceed the allowed length is written, the rest is discarded. However the value returned by the method is the total length of the packet body , as if all of it was written to the bit stream.
    
    Parameters:
    
    body - The packet body data.
    
    blen - The number of bytes in the packet body.
    
    sim - Simulation mode flag. If true nothing is written to the bit stream, but the number of bytes that would be written is returned.
    
    roiInPkt - Whether or not there is ROI information in this packet
    
    roiLen - Number of byte to read in packet body to get all the ROI information
    
    Returns:
    
    The number of bytes spent by the packet body.
    
    Throws:
    
    IOException - If an I/O error occurs while writing to the output stream.
    
    See Also:
    
    commitBitstreamHeader(io.scif.jj2000.j2k.codestream.writer.HeaderEncoder)
  - close
```
public abstract void close()
                    throws IOException
```
    Closes the underlying resource (file, stream, network connection, etc.). After a CodestreamWriter is closed no more data can be written to it.
    
    Throws:
    
    IOException - If an I/O error occurs while closing the resource.
  - commitBitstreamHeader
```
public abstract void commitBitstreamHeader(HeaderEncoder he)
                                    throws IOException
```
    Writes the header data to the bit stream, if it has not been already done. In some implementations this method can be called only once, and an IllegalArgumentException is thrown if called more than once.
    
    Throws:
    
    IOException - If an I/O error occurs while writing the data.
    
    IllegalArgumentException - If this method has already been called.
  - getOffLastROIPkt
```
public abstract int getOffLastROIPkt()
```
    Gives the offset of the end of last packet containing ROI information
    
    Returns:
    
    End of last ROI packet

Class CodestreamWriter

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ndata

maxBytes

Constructor Detail

CodestreamWriter

Method Detail

getMaxAvailableBytes

getLength

writePacketHead

writePacketBody

close

commitBitstreamHeader

getOffLastROIPkt