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lala
Level VII

How to use scripts to extract binary files with byte offset and reserved bytes into decimal data?

The document is divided into three parts:
A: The first eight bytes are the header (two integers of 4+4),

 

B: This is followed by 240 lines of uniform specifications.
The data structure for each row is as follows:
1. Two bytes are integers.
2. Four bytes are floating point.
3. Four bytes are floating point.
4. Two bytes are integers.
5. The remaining 14 bytes are reserved.


C: The last is the reserved null value.
How to restore this data to decimal data using JSL.

Thanks!

2022-07-21_21-27-07.png

1 ACCEPTED SOLUTION

Accepted Solutions
Craige_Hales
Super User

Re: How to use scripts to extract binary files with byte offset and reserved bytes into decimal data?

Load the data as a blob.

Use blobPeek(), similar to substr() for strings, but zero based, to pick out the segments.

Use blobToMatrix() to convert the segments to numbers.

blobToMatrix() can make 4- or 8-byte floats, 1-, 2-, 4-, and 8-byte signed or unsigned integers.

blobToMatrix also understands big vs little endian data: the least significant and most significant bits are sometimes swapped around. Most modern computes use little-endian representations.

Craige

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3 REPLIES 3
lala
Level VII

Re: How to use scripts to extract binary files with byte offset and reserved bytes into decimal data?

  • This is how I try to identify the individual data structures for each row.

2022-07-21_21-50-11.png

Craige_Hales
Super User

Re: How to use scripts to extract binary files with byte offset and reserved bytes into decimal data?

Load the data as a blob.

Use blobPeek(), similar to substr() for strings, but zero based, to pick out the segments.

Use blobToMatrix() to convert the segments to numbers.

blobToMatrix() can make 4- or 8-byte floats, 1-, 2-, 4-, and 8-byte signed or unsigned integers.

blobToMatrix also understands big vs little endian data: the least significant and most significant bits are sometimes swapped around. Most modern computes use little-endian representations.

Craige
lala
Level VII

Re: How to use scripts to extract binary files with byte offset and reserved bytes into decimal data?

Thank Craige!

2022-07-22_08-12-19.png