jj2000.j2k.codestream.reader

Class FileBitstreamReaderAgent

java.lang.Object

jj2000.j2k.codestream.reader.BitstreamReaderAgent

jj2000.j2k.codestream.reader.FileBitstreamReaderAgent

All Implemented Interfaces:

Markers, ProgressionType, CodedCBlkDataSrcDec, StdEntropyCoderOptions, InvWTData, MultiResImgData

public class FileBitstreamReaderAgent
extends BitstreamReaderAgent
implements Markers, ProgressionType, StdEntropyCoderOptions

This class reads the bit stream (with the help of HeaderDecoder for tile headers and PktDecoder for packets header and body) and retrives location of all code-block's codewords.

Note: All tile-parts headers are read by the constructor whereas packets are processed when decoding related tile (when setTile method is called).

In parsing mode, the reader simulates a virtual layer-resolution progressive bit stream with the same truncation points in each code-block, whereas in truncation mode, only the first bytes are taken into account (it behaves like if it is a real truncated codestream).

See Also:

HeaderDecoder, PktDecoder

Field Summary

Fields

Modifier and Type	Field and Description
private int[]	baknBytes Backup of the number of bytes allocated to each tile.
private CBlkInfo[][][][][]	cbI Array containing info.
(package private) int	cdstreamStart
private int	curTilePart The current tile part being used
private int[][]	firstPackOff Offset of the first packet in each tile-part in each tile
private int	firstTilePartHeadLen First tile part header length
private int	headLen Length of main and tile-parts headers
private HeaderInfo	hi Reference to the HeaderInfo instance (used when reading SOT marker segments)
private RandomAccessIO	in The RandomAccessIO where to get data from
private boolean	isEOCFound Whether or not a EOC marker has been found instead of a SOT
private boolean	isPsotEqualsZero Whether or not the last read Psot value was zero.
private boolean	isTruncMode True if truncation mode is used.
private J2KImageReadParamJava	j2krparam Reference to the J2KImageReadParamJava instance
(package private) int	lastPos
private int	lQuit The maximum number of layers to decode for any code-block
private int	mainHeadLen Length of main header
(package private) int	maxPos
(package private) int	maxTP
private int[]	nBytes Number of bytes allocated to each tile.
private int	nt The number of tiles in the image
(package private) int	numtp
PktDecoder	pktDec Reference to the PktDecoder instance
private Vector	pktHL Length of each packet head found in the tile
(package private) int	pos
private boolean	printInfo Whether or not to print information found in codestream
(package private) boolean	rateReached
private int	remainingTileParts The number of tile-parts that remain to read
(package private) int	t
private int[][]	tilePartHeadLen Length of all tile-part headers
private int[][]	tilePartLen Length of each tile-part (written in Psot)
private int[][]	tilePartNum The number of the tile-part in the codestream
(package private) long[][]	tilePartPositions
private int[]	tileParts The number of tile-parts in each tile
private int[]	tilePartsRead The number of tile-parts read so far for each tile
(package private) int	tilePartStart
private double	totAllTileLen Total length of all tile parts in all tiles
private int[]	totTileHeadLen Total length of tiles' header
private int[]	totTileLen Total length of each tile
private int[]	totTileParts The total number of tile-parts in each tile
private int	totTilePartsRead Thetotal number of tile-parts read so far
(package private) int	tp
(package private) int	tptot
private boolean	usePOCQuit Whether or not to use only first progression order

Fields inherited from class jj2000.j2k.codestream.reader.BitstreamReaderAgent

anbytes, arate, ax, ay, ctX, ctY, culx, culy, decSpec, derived, gb, hd, imgH, imgW, mdl, nc, ntH, ntW, ntX, ntY, offX, offY, OPT_PREFIX, params, px, py, subbTrees, targetRes, tnbytes, trate

Fields inherited from interface jj2000.j2k.codestream.Markers

COC, COD, COM, CRG, EOC, EPH, EPH_LENGTH, ERS_SEG_SYMBOLS, ERS_SOP, MAX_COMP_BITDEPTH, MAX_LPPM, MAX_LPPT, PLM, PLT, POC, PPM, PPT, PRECINCT_PARTITION_DEF_SIZE, QCC, QCD, RCOM_GEN_USE, RGN, RSIZ_BASELINE, RSIZ_ER_FLAG, RSIZ_ROI, SCOX_HOR_CB_PART, SCOX_PRECINCT_PARTITION, SCOX_USE_EPH, SCOX_USE_SOP, SCOX_VER_CB_PART, SIZ, SOC, SOD, SOP, SOP_LENGTH, SOT, SQCX_EXP_MASK, SQCX_EXP_SHIFT, SQCX_GB_MSK, SQCX_GB_SHIFT, SQCX_NO_QUANTIZATION, SQCX_SCALAR_DERIVED, SQCX_SCALAR_EXPOUNDED, SRGN_IMPLICIT, SSIZ_DEPTH_BITS, TLM

Fields inherited from interface jj2000.j2k.codestream.ProgressionType

COMP_POS_RES_LY_PROG, LY_RES_COMP_POS_PROG, POS_COMP_RES_LY_PROG, RES_LY_COMP_POS_PROG, RES_POS_COMP_LY_PROG

Fields inherited from interface jj2000.j2k.entropy.StdEntropyCoderOptions

FIRST_BYPASS_PASS_IDX, MAX_CB_AREA, MAX_CB_DIM, MIN_CB_DIM, NUM_EMPTY_PASSES_IN_MS_BP, NUM_NON_BYPASS_MS_BP, NUM_PASSES, OPT_BYPASS, OPT_PRED_TERM, OPT_RESET_MQ, OPT_SEG_SYMBOLS, OPT_TERM_PASS, OPT_VERT_STR_CAUSAL, STRIPE_HEIGHT

Constructor Summary

Constructors

Constructor and Description
FileBitstreamReaderAgent(HeaderDecoder hd, RandomAccessIO ehs, DecoderSpecs decSpec, J2KImageReadParamJava j2krparam, boolean cdstrInfo, HeaderInfo hi) Reads all tiles headers and keep offset of their first packet.

Method Summary

Modifier and Type	Method and Description
private void	allocateRate() Allocates output bit-rate for each tile in parsing mode: The allocator simulates the truncation of a virtual layer-resolution progressive codestream.
CBlkInfo[][][][][]	getCBlkInfo() Gets the reference to the CBlkInfo array
DecLyrdCBlk	getCodeBlock(int c, int m, int n, SubbandSyn sb, int fl, int nl, DecLyrdCBlk ccb) Returns the specified coded code-block, for the specified component, in the current tile.
int	getNumTileParts(int t) Returns the number of tile-part found for a given tile
private void	initTile(int tileNum) Read all tile-part headers of the requested tile.
private void	initTLM()
void	nextTile() Advances to the next tile, in standard scan-line order (by rows then columns).
private boolean	readCompPosResLy(int[][] lys, int lye, int ress, int rese, int comps, int compe) Reads packets of the current tile according to the component-position-resolution-layer progressiveness.
private boolean	readLyResCompPos(int[][] lys, int lye, int ress, int rese, int comps, int compe) Reads packets of the current tile according to the layer-resolution-component-position progressiveness.
private boolean	readPosCompResLy(int[][] lys, int lye, int ress, int rese, int comps, int compe) Reads packets of the current tile according to the position-component-resolution-layer progressiveness.
private boolean	readResLyCompPos(int[][] lys, int lye, int ress, int rese, int comps, int compe) Reads packets of the current tile according to the resolution-layer-component-position progressiveness.
private boolean	readResPosCompLy(int[][] lys, int lye, int ress, int rese, int comps, int compe) Reads packets of the current tile according to the resolution-position-component-layer progressiveness.
private int	readTilePartHeader() Reads SOT marker segment of the tile-part header and calls related methods of the HeaderDecoder to read other markers segments.
private void	readTilePkts(int t) Finish initialization of members for specified tile, reads packets head of each tile and keeps location of each code-block's codewords.
void	setTile(int x, int y) Changes the current tile, given the new indexes.

Methods inherited from class jj2000.j2k.codestream.reader.BitstreamReaderAgent

createInstance, getActualNbytes, getActualRate, getCbULX, getCbULY, getCompImgHeight, getCompImgWidth, getCompSubsX, getCompSubsY, getImgHeight, getImgRes, getImgULX, getImgULY, getImgWidth, getNomTileHeight, getNomTileWidth, getNumComps, getNumTiles, getNumTiles, getParameterInfo, getPPX, getPPY, getResULX, getResULY, getSynSubbandTree, getTargetNbytes, getTargetRate, getTile, getTileCompHeight, getTileCompWidth, getTileHeight, getTileIdx, getTilePartULX, getTilePartULY, getTileWidth, initSubbandsFields

Methods inherited from class java.lang.Object

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

Field Detail

isPsotEqualsZero

private boolean isPsotEqualsZero

Whether or not the last read Psot value was zero. Only the Psot in the last tile-part in the codestream can have such a value.

pktDec

public PktDecoder pktDec

Reference to the PktDecoder instance

j2krparam

private J2KImageReadParamJava j2krparam

Reference to the J2KImageReadParamJava instance

in

private RandomAccessIO in

The RandomAccessIO where to get data from

nt

private int nt

The number of tiles in the image

firstPackOff

private int[][] firstPackOff

Offset of the first packet in each tile-part in each tile

nBytes

private int[] nBytes

Number of bytes allocated to each tile. In parsing mode, this number is related to the tile length in the codestream whereas in truncation mode all the rate is affected to the first tiles.

printInfo

private boolean printInfo

Whether or not to print information found in codestream

baknBytes

private int[] baknBytes

Backup of the number of bytes allocated to each tile. This array is used to restore the number of bytes to read in each tile when the codestream is read several times (for instance when decoding an R,G,B image to three output files)

tilePartLen

private int[][] tilePartLen

Length of each tile-part (written in Psot)

totTileLen

private int[] totTileLen

Total length of each tile

totTileHeadLen

private int[] totTileHeadLen

Total length of tiles' header

firstTilePartHeadLen

private int firstTilePartHeadLen

First tile part header length

totAllTileLen

private double totAllTileLen

Total length of all tile parts in all tiles

mainHeadLen

private int mainHeadLen

Length of main header

headLen

private int headLen

Length of main and tile-parts headers

tilePartHeadLen

private int[][] tilePartHeadLen

Length of all tile-part headers

pktHL

private Vector pktHL

Length of each packet head found in the tile

isTruncMode

private boolean isTruncMode

True if truncation mode is used. False if parsing mode

remainingTileParts

private int remainingTileParts

The number of tile-parts that remain to read

tilePartsRead

private int[] tilePartsRead

The number of tile-parts read so far for each tile

totTilePartsRead

private int totTilePartsRead

Thetotal number of tile-parts read so far

tileParts

private int[] tileParts

The number of tile-parts in each tile

totTileParts

private int[] totTileParts

The total number of tile-parts in each tile

curTilePart

private int curTilePart

The current tile part being used

tilePartNum

private int[][] tilePartNum

The number of the tile-part in the codestream

isEOCFound

private boolean isEOCFound

Whether or not a EOC marker has been found instead of a SOT

hi

private HeaderInfo hi

Reference to the HeaderInfo instance (used when reading SOT marker segments)

cbI

private CBlkInfo[][][][][] cbI

Array containing info. for all the code-blocks:
- 1st dim: component index.
- 2nd dim: resolution level index.
- 3rd dim: subband index.
- 4th/5th dim: code-block index (vert. and horiz.).

lQuit

private int lQuit

The maximum number of layers to decode for any code-block

usePOCQuit

private boolean usePOCQuit

Whether or not to use only first progression order

tilePartPositions

long[][] tilePartPositions

cdstreamStart

int cdstreamStart

t

int t

pos

int pos

tp

int tp

tptot

int tptot

tilePartStart

int tilePartStart

rateReached

boolean rateReached

numtp

int numtp

maxTP

int maxTP

lastPos

int lastPos

maxPos

int maxPos

Constructor Detail

FileBitstreamReaderAgent

public FileBitstreamReaderAgent(HeaderDecoder hd,
                                RandomAccessIO ehs,
                                DecoderSpecs decSpec,
                                J2KImageReadParamJava j2krparam,
                                boolean cdstrInfo,
                                HeaderInfo hi)
                         throws IOException

Reads all tiles headers and keep offset of their first packet. Finally it calls the rate allocation method.

Parameters:

hd - HeaderDecoder of the codestream.

ehs - The input stream where to read bit-stream.

decSpec - The decoder specifications

j2krparam - The J2KImageReadParam instance created from the command-line arguments.

cdstrInfo - Whether or not to print information found in codestream.

Throws:

IOException

See Also:

allocateRate()

Method Detail

getNumTileParts

public int getNumTileParts(int t)

Returns the number of tile-part found for a given tile

Parameters:

t - Tile index

getCBlkInfo

public CBlkInfo[][][][][] getCBlkInfo()

Gets the reference to the CBlkInfo array

initTLM

private void initTLM()
              throws IOException

Throws:

IOException

initTile

private void initTile(int tileNum)
               throws IOException

Read all tile-part headers of the requested tile. All tile-part headers prior to the last tile-part header of the current tile will also be read.

Parameters:

tileNum - The index of the tile for which to read tile-part headers.

Throws:

IOException

allocateRate

private void allocateRate()
                   throws IOException

Allocates output bit-rate for each tile in parsing mode: The allocator simulates the truncation of a virtual layer-resolution progressive codestream.

Throws:

IOException

readTilePartHeader

private int readTilePartHeader()
                        throws IOException

Reads SOT marker segment of the tile-part header and calls related methods of the HeaderDecoder to read other markers segments. The tile-part header is entirely read when a SOD marker is encountered.

Returns:

The tile number of the tile part that was read

Throws:

IOException

readLyResCompPos

private boolean readLyResCompPos(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe)
                          throws IOException

Reads packets of the current tile according to the layer-resolution-component-position progressiveness.

Parameters:

lys - Index of the first layer for each component and resolution.

lye - Index of the last layer.

ress - Index of the first resolution level.

rese - Index of the last resolution level.

comps - Index of the first component.

compe - Index of the last component.

Returns:

True if rate has been reached.

Throws:

IOException

readResLyCompPos

private boolean readResLyCompPos(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe)
                          throws IOException

Reads packets of the current tile according to the resolution-layer-component-position progressiveness.

Parameters:

lys - Index of the first layer for each component and resolution.

lye - Index of the last layer.

ress - Index of the first resolution level.

rese - Index of the last resolution level.

comps - Index of the first component.

compe - Index of the last component.

Returns:

True if rate has been reached.

Throws:

IOException

readResPosCompLy

private boolean readResPosCompLy(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe)
                          throws IOException

Reads packets of the current tile according to the resolution-position-component-layer progressiveness.

Parameters:

lys - Index of the first layer for each component and resolution.

lye - Index of the last layer.

ress - Index of the first resolution level.

rese - Index of the last resolution level.

comps - Index of the first component.

compe - Index of the last component.

Returns:

True if rate has been reached.

Throws:

IOException

readPosCompResLy

private boolean readPosCompResLy(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe)
                          throws IOException

Reads packets of the current tile according to the position-component-resolution-layer progressiveness.

Parameters:

lys - Index of the first layer for each component and resolution.

lye - Index of the last layer.

ress - Index of the first resolution level.

rese - Index of the last resolution level.

comps - Index of the first component.

compe - Index of the last component.

Returns:

True if rate has been reached.

Throws:

IOException

readCompPosResLy

private boolean readCompPosResLy(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe)
                          throws IOException

Reads packets of the current tile according to the component-position-resolution-layer progressiveness.

Parameters:

lys - Index of the first layer for each component and resolution.

lye - Index of the last layer.

ress - Index of the first resolution level.

rese - Index of the last resolution level.

comps - Index of the first component.

compe - Index of the last component.

Returns:

True if rate has been reached.

Throws:

IOException

readTilePkts

private void readTilePkts(int t)
                   throws IOException

Finish initialization of members for specified tile, reads packets head of each tile and keeps location of each code-block's codewords. The last 2 tasks are done by calling specific methods of PktDecoder.

Then, if a parsing output rate is defined, it keeps information of first layers only. This operation simulates a creation of a layer-resolution-component progressive bit-stream which will be next truncated and decoded.

Parameters:

t - Tile index

Throws:

IOException

See Also:

PktDecoder

setTile

public void setTile(int x,
                    int y)

Changes the current tile, given the new indexes. An IllegalArgumentException is thrown if the indexes do not correspond to a valid tile.

Specified by:

setTile in interface MultiResImgData

Specified by:

setTile in class BitstreamReaderAgent

Parameters:

x - The horizontal indexes the tile.

y - The vertical indexes of the new tile.

nextTile

public void nextTile()

Advances to the next tile, in standard scan-line order (by rows then columns). An NoNextElementException is thrown if the current tile is the last one (i.e. there is no next tile).

Specified by:

nextTile in interface MultiResImgData

Specified by:

nextTile in class BitstreamReaderAgent

getCodeBlock

public DecLyrdCBlk getCodeBlock(int c,
                                int m,
                                int n,
                                SubbandSyn sb,
                                int fl,
                                int nl,
                                DecLyrdCBlk ccb)

Returns the specified coded code-block, for the specified component, in the current tile. The first layer to return is indicated by 'fl'. The number of layers that is returned depends on 'nl' and the amount of available data.

The argument 'fl' is to be used by subsequent calls to this method for the same code-block. In this way supplemental data can be retrieved at a later time. The fact that data from more than one layer can be returned means that several packets from the same code-block, of the same component, and the same tile, have been concatenated.

The returned compressed code-block can have its progressive attribute set. If this attribute is set it means that more data can be obtained by subsequent calls to this method (subject to transmission delays, etc). If the progressive attribute is not set it means that the returned data is all the data that can be obtained for the specified code-block.

The compressed code-block is uniquely specified by the current tile, the component (identified by 'c'), the subband (indentified by 'sb') and the code-block vertical and horizontal indexes 'n' and 'm'.

The 'ulx' and 'uly' members of the returned 'DecLyrdCBlk' object contain the coordinates of the top-left corner of the block, with respect to the tile, not the subband.

Specified by:

getCodeBlock in interface CodedCBlkDataSrcDec

Parameters:

c - The index of the component, from 0 to N-1.

m - The vertical index of the code-block to return, in the specified subband.

n - The horizontal index of the code-block to return, in the specified subband.

sb - The subband in whic the requested code-block is.

fl - The first layer to return.

nl - The number of layers to return, if negative all available layers are returned, starting at 'fl'.

ccb - If not null this object is used to return the compressed code-block. If null a new object is created and returned. If the data array in ccb is not null then it can be reused to return the compressed data.

Returns:

The compressed code-block, with a certain number of layers determined by the available data and 'nl'.