jj2000.j2k.codestream.reader
Class FileBitstreamReaderAgent

java.lang.Object
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        +--jj2000.j2k.codestream.reader.FileBitstreamReaderAgent

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
private  CBlkInfo[][][][][] cbI
          Array containing info.
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  RandomAccessIO in
          The RandomAccessIO where to get data from
private  boolean isTruncMode
          True if truncation mode is used.
private  int mainHeadLen
          Length of main header
private  int[] nBytes
          Number of bytes allocated to each tile.
private  int nt
          The number of tiles in the image
 PktDecoder pktDec
          Reference to the PktDecoder instance
private  java.util.Vector pktHL
          Length of each packet head found in the tile
private  ParameterList pl
          Reference to the ParameterList instance
private  int remainingTileParts
          The number of tile-parts that remain to read
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
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
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 totTilePartsRead
          Thetotal number of tile-parts read so far
 
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, pinfo, px, py, res, subbTrees, tnbytes, trate
 
Fields inherited from interface jj2000.j2k.codestream.Markers
COC, COD, COM, CRG, EOC, EPH, EPH_LENGTH, ERS_SEG_MARKERS, 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_PRECINCT_PARTITION, SCOX_USE_EPH, SCOX_USE_SOP, 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_ER_TERM, OPT_REG_TERM, OPT_RESET_MQ, OPT_SEG_MARKERS, OPT_VERT_STR_CAUSAL, STRIPE_HEIGHT
 
Constructor Summary
FileBitstreamReaderAgent(HeaderDecoder hd, RandomAccessIO ehs, DecoderSpecs decSpec, ParameterList pl)
          Reads all tiles headers and keep offset of their first packet.
 
Method Summary
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.
 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.
private  void initTile(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 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, int curTilePart)
          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, int curTilePart)
          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, int curTilePart)
          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, int curTilePart)
          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, int curTilePart)
          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.
 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, getCompHeight, getCompImgHeight, getCompImgWidth, getCompSubsX, getCompSubsY, getCompWidth, getHeight, getImgHeight, getImgRes, getImgULX, getImgULY, getImgWidth, getNumCodeBlocks, getNumComps, getNumTiles, getNumTiles, getParameterInfo, getPartitionULX, getPartitionULY, getPPX, getPPY, getSubbandTree, getTargetNbytes, getTargetRate, getTile, getTileIdx, getTileOff, getULX, getULY, getWidth, initSubbandsFields
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Field Detail

pktDec

public PktDecoder pktDec
Reference to the PktDecoder instance

pl

private ParameterList pl
Reference to the ParameterList 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.

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

tilePartHeadLen

private int[][] tilePartHeadLen
Length of all tile-part headers

pktHL

private java.util.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

curTilePart

private int curTilePart
The current tile part being used

tilePartNum

private int[][] tilePartNum
The number of the tile-part in the codestream

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.).
Constructor Detail

FileBitstreamReaderAgent

public FileBitstreamReaderAgent(HeaderDecoder hd,
                                RandomAccessIO ehs,
                                DecoderSpecs decSpec,
                                ParameterList pl)
                         throws java.io.IOException
Reads all tiles headers and keep offset of their first packet. Finally the rate allocation method is called.
Parameters:
hd - HeaderDecoder of the codestream.
ehs - The input stream where to read bit-stream.
decSpec - The decoder specifications
pl - The ParameterList instance created from the command-line arguments.
See Also:
allocateRate()
Method Detail

allocateRate

private void allocateRate()
                   throws java.io.IOException
Allocates output bit-rate for each tile in parsing mode: The allocator simulates the truncation of a virtual layer-resolution progressive codestream.

readTilePartHeader

private int readTilePartHeader()
                        throws java.io.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

readLyResCompPos

private boolean readLyResCompPos(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe,
                                 int curTilePart)
                          throws java.io.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

readResLyCompPos

private boolean readResLyCompPos(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe,
                                 int curTilePart)
                          throws java.io.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

readResPosCompLy

private boolean readResPosCompLy(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe,
                                 int curTilePart)
                          throws java.io.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

readPosCompResLy

private boolean readPosCompResLy(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe,
                                 int curTilePart)
                          throws java.io.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

readCompPosResLy

private boolean readCompPosResLy(int[][] lys,
                                 int lye,
                                 int ress,
                                 int rese,
                                 int comps,
                                 int compe,
                                 int curTilePart)
                          throws java.io.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

initTile

private void initTile(int t)
               throws java.io.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
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.
Overrides:
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).
Overrides:
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 data available.

The argument 'fl' is to be used by subsequent calls to this method for the same code-block. In this way supplamental 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 subblock.

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

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'.