| Running degenerate-huffman-unused.deflate through script/print-bits.go and |
| adding commentary: |
| |
| offset xoffset ASCII hex binary |
| 000000 0x0000 . 0x05 0b_...._.101 Dynamic Huffman block, final |
| 000000 0x0000 . 0x05 0b_0000_0... NumLCodes: 257 |
| 000001 0x0001 . 0xC0 0b_...0_0000 NumDCodes: 1 |
| 000001 0x0001 . 0xC0 0b_110._.... NumCLCodeLengths: 18 |
| 000002 0x0002 ! 0x21 0b_...._...1 |
| |
| Decode the H-CL Huffman table (NumCLCodeLengths = 18). Recall the peculiar |
| code_order: 16, 17, 18, 0, 8, ..., 2, 14, 1, 15: |
| |
| 000002 0x0002 ! 0x21 0b_0010_000. CLCodeLengths: 18 x 3 bits |
| 000003 0x0003 . 0x01 0b_0000_0001 CLCLs[ 1] is 2 |
| 000004 0x0004 . 0x00 0b_0000_0000 CLCLs[ 2] is 2 |
| 000005 0x0005 . 0x00 0b_0000_0000 CLCLs[17] is 2 |
| 000006 0x0006 . 0x00 0b_0000_0000 CLCLs[18] is 2 |
| 000007 0x0007 . 0x80 0b_1000_0000 |
| 000008 0x0008 . 0xA0 0b_.010_0000 |
| |
| The H-CL Huffman table is: |
| "00" -> CodeLength=1 |
| "01" -> CodeLength=2 |
| "10" -> CodeLength=17 which means a block of ( 3 + 3_extra_bits) zeroes |
| "11" -> CodeLength=18 which means a block of (11 + 7_extra_bits) zeroes |
| |
| Decode the H-L Huffman table (NumLCodes = 257): |
| |
| 000008 0x0008 . 0xA0 0b_1..._.... "11" is CL=18: 11+7extra |
| 000009 0x0009 . 0xB7 0b_...._...1 |
| 000009 0x0009 . 0xB7 0b_1011_011. 7extra=91: 102 zeroes |
| 000010 0x000A V 0x56 0b_...._..10 "01" is CL= 2 (102='f') |
| 000010 0x000A V 0x56 0b_...._01.. "10" is CL=17: 3+3extra |
| 000010 0x000A V 0x56 0b_.101_.... 3extra=5: 8 zeroes |
| 000010 0x000A V 0x56 0b_0..._.... "00" is CL= 1 (111='o') |
| 000011 0x000B . 0xFE 0b_...._...0 |
| 000011 0x000B . 0xFE 0b_...._.11. "11" is CL=18: 11+7extra |
| 000011 0x000B . 0xFE 0b_1111_1... 7extra=127: 138 zeroes |
| 000012 0x000C 7 0x37 0b_...._..11 |
| 000012 0x000C 7 0x37 0b_...._01.. "10" is CL=17: 3+3extra |
| 000012 0x000C 7 0x37 0b_.011_.... 3extra=3: 6 zeroes |
| 000012 0x000C 7 0x37 0b_0..._.... "01" is CL=2 (256=EOB) |
| 000013 0x000D . 0x89 0b_...._...1 |
| |
| The H-L Huffman table is: |
| "0" -> 'o' |
| "10" -> 'f' |
| "11" -> EOB |
| |
| Decode the H-D Huffman table (NumDCodes = 1): |
| |
| 000013 0x000D . 0x89 0b_...._.00. "00" is CL= 1 (DCode 0) |
| |
| The H-D Huffman table is: |
| "0" -> 0 |
| This table is incomplete: there is no entry starting with a "1" bit. It is |
| therefore degenerate, but not used below. |
| |
| Apply H-L and H-D. |
| |
| 000013 0x000D . 0x89 0b_...0_1... lcode: 102 literal 'f' |
| 000013 0x000D . 0x89 0b_..0._.... lcode: 111 literal 'o' |
| 000013 0x000D . 0x89 0b_.0.._.... lcode: 111 literal 'o' |
| 000013 0x000D . 0x89 0b_1..._.... lcode: 256 end of block |
| 000014 0x000E . 0x01 0b_...._...1 |
