Editing CXML Containers
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Latest revision | Your text | ||
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*Notes | *Notes | ||
**The first 2 bytes of the compressed QRCF is the ZLIB header, | **The first 2 bytes of the compressed QRCF is the ZLIB header, in this example: 0x78DA (b: 0111 1000 1101 1010 / 30938) is using the default/max level 9. | ||
**source: http://tools.ietf.org/html/rfc1950#section-2.2 | |||
<small> | |||
{| class="wikitable" style="text-align: center;" | |||
|- | |||
!width="100"|byte index | |||
!width="60"|bit 7 | |||
!width="60"|bit 6 | |||
!width="60"|bit 5 | |||
!width="60"|bit 4 | |||
!width="60"|bit 3 | |||
!width="60"|bit 2 | |||
!width="60"|bit 1 | |||
!width="60"|bit 0 | |||
|- | |||
|[0] '''CMF''' | |||
|colspan="4"|'''Compression info''' | |||
*7 = indicates a 32K window size | |||
|colspan="4"|'''Compression method''' | |||
*8 = denotes the "deflate" compression | |||
|- | |||
|[1] '''FLG''' | |||
|colspan="2"|'''FLEVEL''' | |||
* 0 - compressor used fastest algorithm | |||
* 1 - compressor used fast algorithm | |||
* 2 - compressor used default algorithm | |||
* 3 - compressor used maximum compression, slowest algorithm | |||
|colspan="1"|'''FDICT''' | |||
(Preset dictionary) | |||
If set, a DICT dictionary identifier is present | |||
immediately after the FLG byte. The dictionary is a sequence of | |||
bytes which are initially fed to the compressor without | |||
producing any compressed output. DICT is the Adler-32 checksum | |||
of this sequence of bytes (see the definition of ADLER32 | |||
below). The decompressor can use this identifier to determine | |||
which dictionary has been used by the compressor. | |||
|colspan="5"|'''FCHECK''' | |||
value must be such that CMF and FLG, when viewed as | |||
a 16-bit unsigned integer stored in MSB order (CMF *256 + FLG), | |||
is a multiple of 31. | |||
|- | |||
|} | |||
</small> | |||
<small> | <small> |