Class PostCompRateAllocator

java.lang.Object
jj2000.j2k.image.ImgDataAdapter
jj2000.j2k.entropy.encoder.PostCompRateAllocator
All Implemented Interfaces:
ImgData
Direct Known Subclasses:
EBCOTRateAllocator

public abstract class PostCompRateAllocator extends ImgDataAdapter
This is the abstract class from which post-compression rate allocators which generate layers should inherit. The source of data is a 'CodedCBlkDataSrcEnc' which delivers entropy coded blocks with rate-distortion statistics.

The post compression rate allocator implementation should create the layers, according to a rate allocation policy, and send the packets to a CodestreamWriter. Since the rate allocator sends the packets to the bit stream then it should output the packets to the bit stream in the order imposed by the bit stream profiles.

See Also:
  • Field Details

    • OPT_PREFIX

      public static final char OPT_PREFIX
      The prefix for rate allocation options: 'A'
      See Also:
    • src

      protected CodedCBlkDataSrcEnc src
      The source of entropy coded data
    • wp

      protected J2KImageWriteParamJava wp
      The source of entropy coded data
    • numLayers

      protected int numLayers
      The number of layers.
  • Constructor Details

  • Method Details

    • setHeaderEncoder

      public void setHeaderEncoder(HeaderEncoder headEnc)
      Keep a reference to the header encoder.
      Parameters:
      headEnc - The header encoder
    • initialize

      public abstract void initialize() throws IOException
      Initializes the rate allocation points, taking into account header overhead and such. This method must be called after the header has been simulated but before calling the runAndWrite() one. The header must be rewritten after a call to this method since the number of layers may change.
      Throws:
      IOException
      See Also:
    • runAndWrite

      public abstract void runAndWrite() throws IOException
      Runs the rate allocation algorithm and writes the data to the bit stream. This must be called after the initialize() method.
      Throws:
      IOException
      See Also:
    • getNumLayers

      public int getNumLayers()
      Returns the number of layers that are actually generated.
      Returns:
      The number of layers generated.
    • getParameterInfo

      public static String[][] getParameterInfo()
      Returns the parameters that are used in this class and implementing classes. It returns a 2D String array. Each of the 1D arrays is for a different option, and they have 3 elements. The first element is the option name, the second one is the synopsis, the third one is a long description of what the parameter is and the fourth is its default value. The synopsis or description may be 'null', in which case it is assumed that there is no synopsis or description of the option, respectively. Null may be returned if no options are supported.
      Returns:
      the options name, their synopsis and their explanation, or null if no options are supported.
    • createInstance

      public static PostCompRateAllocator createInstance(CodedCBlkDataSrcEnc src, float rate, CodestreamWriter bw, J2KImageWriteParamJava wp)
      Creates a PostCompRateAllocator object for the appropriate rate allocation parameters in the parameter list 'pl', having 'src' as the source of entropy coded data, 'rate' as the target bitrate and 'bw' as the bit stream writer object.
      Parameters:
      src - The source of entropy coded data.
      rate - The target bitrate for the rate allocation
      bw - The bit stream writer object, where the bit stream data will be written.
      wp - The parameter list (or options).