jj2000.j2k.codestream.writer.FileCodestreamWriter Maven / Gradle / Ivy
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/*
* $RCSfile: FileCodestreamWriter.java,v $
* $Revision: 1.1 $
* $Date: 2005/02/11 05:02:02 $
* $State: Exp $
*
* Class: FileCodestreamWriter
*
* Description: Implementation of the bit stream writer for streams.
*
*
*
* COPYRIGHT:
*
* This software module was originally developed by Raphaël Grosbois and
* Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
* Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
* Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
* Centre France S.A) in the course of development of the JPEG2000
* standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
* software module is an implementation of a part of the JPEG 2000
* Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
* Systems AB and Canon Research Centre France S.A (collectively JJ2000
* Partners) agree not to assert against ISO/IEC and users of the JPEG
* 2000 Standard (Users) any of their rights under the copyright, not
* including other intellectual property rights, for this software module
* with respect to the usage by ISO/IEC and Users of this software module
* or modifications thereof for use in hardware or software products
* claiming conformance to the JPEG 2000 Standard. Those intending to use
* this software module in hardware or software products are advised that
* their use may infringe existing patents. The original developers of
* this software module, JJ2000 Partners and ISO/IEC assume no liability
* for use of this software module or modifications thereof. No license
* or right to this software module is granted for non JPEG 2000 Standard
* conforming products. JJ2000 Partners have full right to use this
* software module for his/her own purpose, assign or donate this
* software module to any third party and to inhibit third parties from
* using this software module for non JPEG 2000 Standard conforming
* products. This copyright notice must be included in all copies or
* derivative works of this software module.
*
* Copyright (c) 1999/2000 JJ2000 Partners.
* */
package jj2000.j2k.codestream.writer;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import jj2000.j2k.codestream.Markers;
/**
* This class implements a CodestreamWriter for Java streams. The streams can
* be files or network connections, or any other resource that presents itself
* as a OutputStream. See the CodestreamWriter abstract class for more details
* on the implementation of the CodestreamWriter abstract class.
*
* Before any packet data is written to the bit stream (even in simulation
* mode) the complete header should be written to the HeaderEncoder object
* supplied to the constructor, following the procedure explained in the
* HeaderEncoder class. Otherwise incorrect estimates are given by
* getMaxAvailableBytes() for rate allocation.
*
* @see CodestreamWriter
*
* @see HeaderEncoder
* */
public class FileCodestreamWriter extends CodestreamWriter
implements Markers {
/** The upper limit for the value of the Nsop field of the SOP marker */
private final static int SOP_MARKER_LIMIT = 65535;
/** Index of the current tile */
private int tileIdx = 0;
/** The file to write */
private OutputStream out;
/** The number of bytes already written to the bit stream, excluding the
* header length, magic number and header length info. */
int ndata=0;
/** The default buffer length, 1024 bytes */
public static int DEF_BUF_LEN = 1024;
/** Array used to store the SOP markers values */
byte sopMarker[];
/** Array used to store the EPH markers values */
byte ephMarker[];
/** The packet index (when start of packet markers i.e. SOP markers) are
* used. */
int packetIdx=0;
/** Offset of end of last packet containing ROI information */
private int offLastROIPkt = 0;
/** Length of last packets containing no ROI information */
private int lenLastNoROI = 0;
/**
* Opens the file 'file' for writing the bit stream, using the 'he' header
* encoder. The magic number is written to the bit stream. Normally, the
* header encoder must be empty (i.e. no data has been written to it
* yet). A BufferedOutputStream is used on top of the file to increase
* throughput, the length of the buffer is DEF_BUF_LEN.
*
* @param file The file where to write the bit stream
*
* @param mb The maximum number of bytes that can be written to the bit
* stream.
*
* @exception IOException If an error occurs while trying to open the file
* for writing or while writing the magic number.
* */
public FileCodestreamWriter(File file, int mb)
throws IOException {
super(mb);
out = new BufferedOutputStream(new FileOutputStream(file),DEF_BUF_LEN);
initSOP_EPHArrays();
}
/**
* Opens the file named 'fname' for writing the bit stream, using the 'he'
* header encoder. The magic number is written to the bit
* stream. Normally, the header encoder must be empty (i.e. no data has
* been written to it yet). A BufferedOutputStream is used on top of the
* file to increase throughput, the length of the buffer is DEF_BUF_LEN.
*
* @param fname The name of file where to write the bit stream
*
* @param mb The maximum number of bytes that can be written to the bit
* stream.
*
* @param encSpec The encoder's specifications
*
* @exception IOException If an error occurs while trying to open the file
* for writing or while writing the magic number.
* */
public FileCodestreamWriter(String fname, int mb)
throws IOException {
super(mb);
out = new BufferedOutputStream(new FileOutputStream(fname),
DEF_BUF_LEN);
initSOP_EPHArrays();
}
/**
* Uses the output stream 'os' for writing the bit stream, using the 'he'
* header encoder. The magic number is written to the bit
* stream. Normally, the header encoder must be empty (i.e. no data has
* been written to it yet). No BufferedOutputStream is used on top of the
* output stream 'os'.
*
* @param os The output stream where to write the bit stream.
*
* @param mb The maximum number of bytes that can be written to the bit
* stream.
*
* @exception IOException If an error occurs while writing the magic
* number to the 'os' output stream.
* */
public FileCodestreamWriter(OutputStream os, int mb)
throws IOException {
super(mb);
out = os;
initSOP_EPHArrays();
}
/**
* 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.
*
* @return The number of bytes remaining available in the bit stream.
* */
public final int getMaxAvailableBytes() {
return maxBytes-ndata;
}
/**
* Returns the current length of the entire bit stream.
*
* @return the current length of the bit stream
* */
public int getLength() {
if (getMaxAvailableBytes() >= 0) {
return ndata;
}
else {
return maxBytes;
}
}
/**
* 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.
*
* @param head The packet head data.
*
* @param hlen The number of bytes in the packet head.
*
* @param sim Simulation mode flag. If true nothing is written to the bit
* stream, but the number of bytes that would be written is returned.
*
* @param 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.
*
* @param 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.
*
* @return The number of bytes spent by the packet head.
*
* @exception IOException If an I/O error occurs while writing to the
* output stream.
*
* @see #commitBitstreamHeader
* */
public int writePacketHead(byte head[],int hlen,boolean sim,
boolean sop, boolean eph) throws IOException{
int len = hlen
+ (sop?Markers.SOP_LENGTH:0)
+ (eph?Markers.EPH_LENGTH:0);
// If not in simulation mode write the data
if(!sim){
// Write the head bytes
if(getMaxAvailableBytes() 0){
// Write Start Of Packet header markers if necessary
if(sop){
// The first 4 bytes of the array have been filled in the
// classe's constructor.
sopMarker[4] = (byte)(packetIdx>>8);
sopMarker[5] = (byte)(packetIdx);
out.write(sopMarker, 0, Markers.SOP_LENGTH);
packetIdx++;
if(packetIdx>SOP_MARKER_LIMIT){
// Reset SOP value as we have reached its upper limit
packetIdx = 0;
}
}
out.write(head,0,hlen);
// Update data length
ndata += len;
// Write End of Packet Header markers if necessary
if(eph){
out.write(ephMarker,0,Markers.EPH_LENGTH);
}
// Deal with ROI Information
lenLastNoROI += len;
}
}
return len;
}
/**
* 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.
*
* @param body The packet body data.
*
* @param blen The number of bytes in the packet body.
*
* @param sim Simulation mode flag. If true nothing is written to the bit
* stream, but the number of bytes that would be written is returned.
*
* @param roiInPkt Whether or not this packet contains ROI information
*
* @param roiLen Number of byte to read in packet body to get all the ROI
* information
*
* @return The number of bytes spent by the packet body.
*
* @exception IOException If an I/O error occurs while writing to the
* output stream.
*
* @see #commitBitstreamHeader
* */
public int writePacketBody(byte body[],int blen,boolean sim,
boolean roiInPkt, int roiLen)
throws IOException{
int len = blen;
// If not in simulation mode write the data
if (!sim) {
// Write the body bytes
len = blen;
if(getMaxAvailableBytes() < len){
len = getMaxAvailableBytes();
}
if(blen > 0){
out.write(body,0,len);
}
// Update data length
ndata += len;
// Deal with ROI information
if(roiInPkt) {
offLastROIPkt += lenLastNoROI + roiLen;
lenLastNoROI = len-roiLen;
} else {
lenLastNoROI += len;
}
}
return len;
}
/**
* Writes the EOC marker and closes the underlying stream.
*
* @exception IOException If an error occurs while closing the underlying
* stream.
* */
public void close() throws IOException {
// Write the EOC marker and close the codestream.
out.write(EOC>>8);
out.write(EOC);
ndata += 2; // Add two to length of codestream for EOC marker
out.close();
}
/**
* Gives the offset of the end of last packet containing ROI information
*
* @return End of last ROI packet
* */
public int getOffLastROIPkt(){
return offLastROIPkt;
}
/**
* Writes the header data in the codestream and actualize ndata with the
* header length. The header is either a MainHeaderEncoder or a
* TileHeaderEncoder.
*
* @param he The current header encoder.
*
* @exception IOException If an I/O error occurs while writing the data.
* */
public void commitBitstreamHeader(HeaderEncoder he) throws IOException {
// Actualize ndata
ndata += he.getLength();
he.writeTo(out); // Write the header
// Reset packet index used for SOP markers
packetIdx = 0;
// Deal with ROI information
lenLastNoROI += he.getLength();
}
/**
* Performs the initialisation of the arrays that are used to store the
* values used to write SOP and EPH markers
* */
private void initSOP_EPHArrays() {
// Allocate and set first values of SOP marker as they will not be
// modified
sopMarker = new byte[Markers.SOP_LENGTH];
sopMarker[0] = (byte)(Markers.SOP>>8);
sopMarker[1] = (byte)Markers.SOP;
sopMarker[2] = (byte)0x00;
sopMarker[3] = (byte)0x04;
// Allocate and set values of EPH marker as they will not be
// modified
ephMarker = new byte[Markers.EPH_LENGTH];
ephMarker[0] = (byte)(Markers.EPH>>8);
ephMarker[1] = (byte)Markers.EPH;
}
}