Qt上位机利用libharu库生成pdf，可生成中文

Cyclic Redundancy Check (CRC) is a well-known technique that allows the

recipient of a message transmitted over a noisy channel to detect whether the

message has been corrupted.

or as a polynomial of a single variable of degree (N − 1)

where m

is the reminder from division of

complex formula is used:

of zeroes is different from zero. That allows detection of insertion of zeroes in

the beginning of a message and replacement of both content of the message and

its CRC value with zeroes. Typically,

shown in section 3.1.

scribed in section 4.8); however, it still computes the CRC byte by byte in strong

sequential order.

ant of a CRC that could read input data by words and process them byte by

byte – but, thanks to the use of multiple tables, different bytes from the input

word could be processed in parallel. In 2002, Ji and Killian [JK02] provided de-

tailed description and analysis of a nearly identical scheme. Both solutions were

targeted for hardware implementation. In 2005, Kouvanis and Berry [KB05]

demonstrated clear performance benefits of this scheme even when it is im-

overlapping sections of input data, desribed in section 4.10.

words belonging to overlapping sections of input data is described in section

4.11. A special case restricted to the use of 64-bit tables, 64-bit reads, and 32

or 64-bit generating polynomials was implemented by the authors in February-

March 2007 and was used by a couple of Microsoft products. In 2009, the

algorithm was generalized and these limitations were removed.

which does not depend on the message, described in section 3.5, is well known

and has been widely used in the telecommunication industry for long time.

described in section 3.2, and the method of computing a CRC of the concatena-

tion of messages having known CRC values without touching the actual data,

described in section 3.3, were implemented by one of the authors in 2005 but

were not published.