Talk:Smacker: Difference between revisions

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I've found some errors and places that were unclear to me, which are listed below:
I've found some errors and places that were unclear to me, which are listed below:


   1. in the "Huffman DPCM" section, no indication is given as to the order of the trees to be read in.  There is documentation on which order the Bases are in (high byte first, right then left) and which order to read the compressed data in (low byte first, left then right), but not which order to build the trees.
   1. in the "Huffman DPCM" section, no indication is given as to the order of the trees to be read in.  There is documentation  
   2. Under "Huffman Trees" it makes mention of the low byte/high byte trees and says both are optional, but doesn't say how to interpret values from the 3rd tree if either one or both of the low/high trees are missing.
      on which order the Bases are in (high byte first, right then left) and which order to read the compressed data in (low byte
   3. The tree shown in "Reconstructing the tree" should have the nodes labeled from left to right 3, 4, 5, 6, 7, 8.  It presently shows 5, 3, 4, 6, 7, 8.
      first, left then right), but not which order to build the trees.
   4. In the "Bit Streams" section, the resulting bytes from reading 5, 6, and 7 bits sequentially seem wrong.  I get 0x1C, 0x32, 0x72, when I assume the bits are packed together.  If I skip ahead to byte boundaries after each read, I get 0x1c, 0x16, 0x6f.
   2. Under "Huffman Trees" it makes mention of the low byte/high byte trees and says both are optional, but doesn't say how to
      interpret values from the 3rd tree if either one or both of the low/high trees are missing.
   3. The tree shown in "Reconstructing the tree" should have the nodes labeled from left to right 3, 4, 5, 6, 7, 8.  It
      presently shows 5, 3, 4, 6, 7, 8.
   4. In the "Bit Streams" section, the resulting bytes from reading 5, 6, and 7 bits sequentially seem wrong.  I get 0x1C, 0x32,
      0x72, when I assume the bits are packed together.  If I skip ahead to byte boundaries after each read, I get 0x1c, 0x16, 0x6f.

Revision as of 20:43, 12 March 2006

I've found some errors and places that were unclear to me, which are listed below:

  1. in the "Huffman DPCM" section, no indication is given as to the order of the trees to be read in.  There is documentation 
     on which order the Bases are in (high byte first, right then left) and which order to read the compressed data in (low byte
     first, left then right), but not which order to build the trees.
  2. Under "Huffman Trees" it makes mention of the low byte/high byte trees and says both are optional, but doesn't say how to
     interpret values from the 3rd tree if either one or both of the low/high trees are missing.
  3. The tree shown in "Reconstructing the tree" should have the nodes labeled from left to right 3, 4, 5, 6, 7, 8.  It
     presently shows 5, 3, 4, 6, 7, 8.
  4. In the "Bit Streams" section, the resulting bytes from reading 5, 6, and 7 bits sequentially seem wrong.  I get 0x1C, 0x32,
     0x72, when I assume the bits are packed together.  If I skip ahead to byte boundaries after each read, I get 0x1c, 0x16, 0x6f.