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atrac3p:serialized_quantization_unit_levels [2010/07/23 16:55] – moved on bandlet -> QU megadiscmanatrac3p:serialized_quantization_unit_levels [2010/07/23 17:35] – fix link typo megadiscman
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 The quantization unit levels are logarithmically scaled scale factor for the band coefficients. An increase of three in the quantization unit level value gives rise to an factor of two in the scaling value. The range of the level values is between 1 and 63. There are four level encoding modes, and all but mode 0 are different for the master and the slave channel. The quantization unit levels are logarithmically scaled scale factor for the band coefficients. An increase of three in the quantization unit level value gives rise to an factor of two in the scaling value. The range of the level values is between 1 and 63. There are four level encoding modes, and all but mode 0 are different for the master and the slave channel.
  
-Trailing bands with a quantizer of zero (i.e. no data) are trimmed, i.e. no data for these quantization units are encoded. This does not apply to quantization units with a quantizer of zero in between non-zero quantization units.+Trailing bands with a quantization precision of zero (i.e. no data) are trimmed, i.e. no data for these quantization units are encoded. This does not apply to quantization units with a precision of zero in between non-zero quantization units.
  
-==== Base tables ==== +==== Prediction Vectors ==== 
-The base tabels (common distributions) of the levels fall into two classes. Three [[level base table|basic base tables]] (one of them completely zero) and 64 different [[big level table list|extended base tables]]. The base tables are used in all non-primitive master encoding modes. While modes basing on the extended tables generally wrap around, modes based on the basic tables do not. The base table for the levels are different from the quantizer base tables in that they are subtracted and not added to the data, so the no-wraparound condition means that encoding a delta of 6 (i.e. +6) while the base table says 8 (i.e. -8) is an error.+The prediction vectors (common distributions) of the levels fall into two classes. Three [[basic level prediction vectors]] (one of them completely zero) and 64 different [[extended level prediction vectors]]. The base tables are used in all non-primitive master encoding modes. While modes basing on the extended tables generally wrap around, modes based on the basic tables do not. The usage of the base table for the levels are different from the precision base tables in that they are subtracted and not added to the data, so the no-wraparound condition means that encoding a delta of 6 (i.e. +6) while the base table says 8 (i.e. -8) is an error.
  
 If an extended base table is selected, the entries from the extended base table is offset by a 6-bit value stored directly adjacent to the extended base table number. While the base table itself is (see above) to be interpreted negatively, the offset is positive. If an extended base table is selected, the entries from the extended base table is offset by a 6-bit value stored directly adjacent to the extended base table number. While the base table itself is (see above) to be interpreted negatively, the offset is positive.
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 === Coding mode 1 on master channel: base + direct delta === === Coding mode 1 on master channel: base + direct delta ===
-  * 2 bit: selection of [[level base table]], 3 meaning choose from big list+  * 2 bit: selection of [[basic level prediction vectors|basic level prediction vector]], 3 meaning choose from big list
   * if not choosing from big list   * if not choosing from big list
     * 5 bit: number of quantization units with full precision level delta (//n//)     * 5 bit: number of quantization units with full precision level delta (//n//)
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   * if choosing from big list   * if choosing from big list
     * 6 bit: level of quantization unit 0/1/2 for base     * 6 bit: level of quantization unit 0/1/2 for base
-    * 6 bit: selection of level table from [[big level table list]]+    * 6 bit: selection of level table from [[extended level prediction vectors]]
     * 5 bit: number of quantization units with high precision level delta (//n//)     * 5 bit: number of quantization units with high precision level delta (//n//)
     * 2 bit: bits of low-precision deltas (//b//)     * 2 bit: bits of low-precision deltas (//b//)
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   * 2 bit: selection of [[level delta encoding huffman tree]], 6-bit-tree used   * 2 bit: selection of [[level delta encoding huffman tree]], 6-bit-tree used
   * for each quantization unit:   * for each quantization unit:
-     * huffman code for delta (gets added to master channel quantizer, wrapping around)+     * huffman code for delta (gets added to master channel level, wrapping around)
  
 === Coding mode 2 on master channel: from big base table list + huffman delta === === Coding mode 2 on master channel: from big base table list + huffman delta ===
   * 2 bit: selection of 4-bit [[level delta encoding huffman tree]]   * 2 bit: selection of 4-bit [[level delta encoding huffman tree]]
   * 6 bit: level of quantization unit 0/1/2 for base   * 6 bit: level of quantization unit 0/1/2 for base
-  * 6 bit: selection of level table from [[big level table list]]+  * 6 bit: selection of level table from [[extended level prediction vectors]]
   * for each quantization unit with delta: one huffman code (sign-expanded, wrapping)   * for each quantization unit with delta: one huffman code (sign-expanded, wrapping)
  
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 === Coding mode 3 on master channel: base + walking delta === === Coding mode 3 on master channel: base + walking delta ===
-  * 2 bit: selection of [[level base table]], 3 meaning choose from big table+  * 2 bit: selection of [[basic level prediction vectors|basic level prediction vector]], 3 meaning choose from big table
   * if using a primary base table   * if using a primary base table
      * 2 bit: selection of 6-bit [[level delta encoding huffman tree]]      * 2 bit: selection of 6-bit [[level delta encoding huffman tree]]
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      * 2 bit: selection of 4-bit [[level delta encoding huffman tree]]      * 2 bit: selection of 4-bit [[level delta encoding huffman tree]]
      * 6 bit: level of quantization unit 0/1/2 for base      * 6 bit: level of quantization unit 0/1/2 for base
-     * 6 bit: selection of level table from [[big level table list]]+     * 6 bit: selection of level table from [[extended level prediction vectors]]
      * 4 bit: level delta for quantization unit 0      * 4 bit: level delta for quantization unit 0
      * for remaining quantization units      * for remaining quantization units
atrac3p/serialized_quantization_unit_levels.txt · Last modified: 2010/10/25 13:01 by megadiscman
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