7kStrip

Description

7kStrip is a utility designed to filter (or “strip”) specific record types from a Reson 7k (.s7k) file. It reads through an input .s7k file, and for each record encountered, it decides whether to keep or discard it based on a user-provided list of record IDs to strip. All records that are kept are written to a new output .s7k file.

This tool is useful for reducing the size of .s7k files by removing unnecessary data (e.g., specific telemetry, unused sensor data) or for preparing specialized .s7k files containing only particular data types for specific processing steps.

Usage 

7kStrip -in <inputfile.s7k> -out <stripped_file.s7k> [-strip <ID>] [-v]

Arguments

Option Description
-in <inputfile.s7k> Required. Path to the input Reson 7k .s7k file.
-out <stripped_file.s7k> Required. Path for the output stripped .s7k file. If not specified, it defaults to <inputfile.s7k>.strip.
-strip <ID> Required (at least one). Specifies the record ID (e.g., 7000 for Sonar Settings, 7006 for Bathymetry) to be stripped (removed) from the output file. This option can be used multiple times to strip multiple record types.
-v Enable verbose output (prints information about each record being processed).

How It Works

  1. Initialization: Parses command-line arguments to get input/output filenames and a list of IDs to strip. Initializes Reson_7K_NF (Not Found) and Reson_7K_DRF (Data Record Format) structures, and an OMG_Buffer for reading/writing.
  2. File Opening: Opens the input .s7k file for reading and the output .s7k file for writing.
  3. Record Processing Loop: Reads the .s7k file record by record:
    • Sync Search: Calls seek_next_7K_sync() (an external function) to find the next Reson 7k synchronization pattern.
    • DRF Reading: Reads the Reson_7K_DRF to determine the record_type_id and size.
    • Strip Check: Checks if the record_type_id is in the list of IDs to be stripped (strip_id[drf.record_type_id]).
    • Record Handling:
      • If the record is to be stripped: Skips the record’s data in the input file.
      • If the record is to be kept: Seeks back to the start of the record, reads its entire content into inbuffer, and writes it to the output file.
    • Updates counters for records read (count_in) and records written (count_out).
  4. Summary Output: After processing the entire input file, it prints a summary of how many records of each type were processed and kept/stripped.
  5. Cleanup: Closes input and output files.

Output File

  • A new .s7k file (named <stripped_file.s7k> or <inputfile.s7k>.strip) containing all records from the input file except those specified with the -strip option.