seasonder_read_reduced_encoded_data: Read Reduced Encoded Data from a Binary Connection
In SeaSondeR: Radial Metrics from SeaSonde HF-Radar Data

seasonder_read_reduced_encoded_data

R Documentation

Read Reduced Encoded Data from a Binary Connection

Description

This function reads an array of numbers from a binary connection using a custom command-based protocol. A block of data is processed according to its size specified in key$size. Within the block, the first byte read is a command byte that determines how the subsequent bytes are interpreted. The function updates a running "tracking value" based on the commands encountered and returns a vector of decoded numbers. The supported commands are:

Usage

seasonder_read_reduced_encoded_data(connection, key, endian = "big")

Arguments

`connection`	A binary connection from which the encoded data is read.
`key`	A list containing a field `size` that indicates how many bytes of data to process.
`endian`	A character string specifying the byte order; either `"big"` or `"little"`. The default is `"big"`.

Details

0x9C: Read 4 bytes as an unsigned 32-bit integer.
0x94: Read one count byte, then (count+1) unsigned 32-bit integers.
0xAC: Read 3 bytes as a 24-bit signed integer; add its value to the current tracking value.
0xA4: Read one count byte, then (count+1) 24-bit signed integers; sequentially add each to the tracking value.
0x89: Read 1 byte as a signed 8-bit integer; add it to the tracking value.
0x8A: Read 2 bytes as a signed 16-bit integer; add it to the tracking value.
0x82: Read one count byte, then (count+1) signed 16-bit integers; sequentially add each to the tracking value.
0x81: Read one count byte, then (count+1) signed 8-bit integers; sequentially add each to the tracking value.

A 24-bit signed integer is computed by reading 3 bytes and then adjusting the value by subtracting 16777216 if the computed value is greater than or equal to 8388608 to account for the two's complement representation.