Max size of Huffman tables

[lexaknyazev]

@richgel999 Could you please confirm the following maximum sizes for Basis Huffman tables? We need that for a memory-constrained decoder implementation.

• Initial length codes of each table: up to 21; values are [0, 20].
• Intensity deltas: up to 8; values are [0, 7].
• Color deltas: up to 32; values are [0, 31].
• Selector deltas: up to 256; values are [0, 255].
• Endpoint prediction: up to 257; values are [0, 256].
• Endpoint deltas: up to endpointCount (worst case); values are [0, endpointCount - 1].
• Selector symbols: up to selectorCount + selectorHistoryBufferSize + 1:
  • [0,selectorCount - 1] refer to actual selectors;
  • [selectorCount, selectorCount + selectorHistoryBufferSize - 1] refer to the history buffer;
  • selectorCount + selectorHistoryBufferSize denotes RLE.
• RLE short lengths: up to 64; values are [0; 63].

Additionally,

• History buffer is implicitly limited to 8191 elements.
• Total endpoint count cannot be greater than 16383 due to delta encoding worst case, although cmd-line tool suggests 16128 as the maximum value.
• The sum of selector count and history buffer size cannot be greater than 16382 due to selector symbol encoding, although the cmd-line tool also suggests 16128 as the maximum number of selectors.

[richgel999]

Okay - I'll set aside a few hours to go through this list this week.

[richgel999]

Sorry, I've been bogged down on a milestone that's coming very soon. I will work on this after the milestone.

[richgel999]

Sorry for the delay - the milestone is early next week.