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atrac3p:main_trees_list [2010/03/20 10:58] – Reformat Tree Set B Table megadiscmanatrac3p:main_trees_list [2010/07/23 17:41] (current) – quantizer -> quantization precision megadiscman
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 ==== General Intro ==== ==== General Intro ====
  
-The quantized values are encoded using a prefix free binary code. To make matters more complicated there are up to 16 encoding scheme per quantizer (because the symbol set depends on the quantizer). In many cases, the symbols are built from a group of two or four quantized values instead of just one quantized value. For groups of size two, the trees are shown as table, the first symbol choosing the row, the second value the column. For groups of size four, the tables are organized so that the first symbol chooses the row block, the second symbol the exact row, the third symbol the column block and the fourth symbol the column. //I think about swapping second and third symbol, so be careful when coming back later!//+The quantized values are encoded using a prefix free binary code. To make matters more complicated there are up to 16 encoding scheme per quantization precision (symbol set depends on precision, so different encoding schemes must be used for different precisions.). In many cases, the symbols are built from a group of two or four quantized values instead of just one quantized value. For groups of size two, the trees are shown as table, the first symbol choosing the row, the second value the column. For groups of size four, the tables are organized so that the first symbol chooses the row block, the second symbol the exact row, the third symbol the column block and the fourth symbol the column. //I think about swapping second and third symbol, so be careful when coming back later!//
  
 Another catch is that some of the encoding schemes encoded the signed quantized values, while others encode only the absolute values of the quantized values. If only the absolute values are encoded in a symbol, each symbol is followed by one bit per absolute value that is not zero. If that bit is set, the value is negative. Another catch is that some of the encoding schemes encoded the signed quantized values, while others encode only the absolute values of the quantized values. If only the absolute values are encoded in a symbol, each symbol is followed by one bit per absolute value that is not zero. If that bit is set, the value is negative.
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   * (+1,+1) -> ''111**00**'', (-1,+1) -> ''111**10**'', (+1,-1) -> ''111**01**'', (-1,-1) -> ''111**11**''   * (+1,+1) -> ''111**00**'', (-1,+1) -> ''111**10**'', (+1,-1) -> ''111**01**'', (-1,-1) -> ''111**11**''
  
-==== Trees for Quantizer 1 ====+==== Trees for Precision 1 ====
 (i.e. symbol set -1..+1) (i.e. symbol set -1..+1)
 === Tree 1A === === Tree 1A ===
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   </tbody></table>   </tbody></table>
 </html> </html>
-==== Trees for Quantizer 2 ====+==== Trees for Precision 2 ====
 (i.e. symbol set -2..+2) (i.e. symbol set -2..+2)
 === Tree 2A === === Tree 2A ===
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   </tbody></table>   </tbody></table>
 </html> </html>
-==== Trees for Quantizer 3 ====+==== Trees for Precision 3 ====
 (i.e. symbol set -3..+3) (i.e. symbol set -3..+3)
 === Tree 3A === === Tree 3A ===
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   </tbody></table>   </tbody></table>
 </html> </html>
-==== Trees for Quantizer 4 ====+==== Trees for Precision 4 ====
 (i.e. symbol set -5..+5) (i.e. symbol set -5..+5)
 === Tree 4A === === Tree 4A ===
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   * 5: 5 bits   * 5: 5 bits
  
-==== Trees for Quantizer 5 ====+==== Trees for Precision 5 ====
 (i.e. symbol set -7..+7) (i.e. symbol set -7..+7)
 === Tree 5A === === Tree 5A ===
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   </tbody></table>   </tbody></table>
 </html> </html>
-==== Trees for Quantizer 6 ====+==== Trees for Precision 6 ====
 (i.e. symbol set -15..+15) (i.e. symbol set -15..+15)
 === Tree 6A === === Tree 6A ===
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   </tbody></table>   </tbody></table>
 </html> </html>
-==== Trees for Quantizer 7 ====+==== Trees for Precision 7 ====
 (i.e. symbol set -31..+31) (i.e. symbol set -31..+31)
 === Tree 7A === === Tree 7A ===
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 ===== Tree Sets ===== ===== Tree Sets =====
  
-This table shows the mapping of tree set IDs, tree IDs and quantizers to the code tables defined above. If the table says //n x Tree XX// it means that n symbols of that tree (which might groups of 1, 2 or 4 quantized coefficients) are clustered together. Each cluster is preceeded by an "data present" bit. If that bit is zero, all coefficients of the whole cluster are zero, and no codes for the cluster are stored. If that bit is one that at least one non-zero entry is present and the codes for this cluster follow as in non-clustered mode.+This table shows the mapping of tree set IDs, tree IDs and quantization precisions to the code tables defined above. If the table says //n x Tree XX// it means that n symbols of that tree (which might groups of 1, 2 or 4 quantized coefficients) are clustered together. Each cluster is preceeded by an "data present" bit. If that bit is zero, all coefficients of the whole cluster are zero, and no codes for the cluster are stored. If that bit is one that at least one non-zero entry is present and the codes for this cluster follow as in non-clustered mode.
  
-The tree choice can be limited to a restricted tree set. The IDs inside the restricted tree set are in the range 0..3 instead of 0..7. They map to code sets also accessible using the full tree set. A code set that is accessible via the restricted tree set is indicate by **R//n//**, where //n// is the ID in the range 0..3+The tree choice can be limited to a restricted tree set. The IDs inside the restricted tree set are in the range 0..3 instead of 0..7, and printed as R0..R3 in the table.
  
 ==== Tree Set A==== ==== Tree Set A====
atrac3p/main_trees_list.1269082730.txt.gz · Last modified: 2010/03/20 10:58 by megadiscman
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