PLATO Compression/Decompression Tool

If you find a bug or have a feature request please file an issue or send me an email.
Compiled executables can be found here. The building instructions can be found here.

Usage

usage: cmp_tool [options] [<argument>]

General Options

1) NOTE: If the -o option is not used the <prefix> will be set to "OUTPUT".
2) NOTE: In the default configurations the samples and buffer_length parameter is set to 0!

Compression Options

3) NOTE: When using the --rdcu_pkt option the configuration of the RMAP parameters can be found in the .rdcu_pkt_mode_cfg file. The generated packets can be found in the TC_FILES directory.

Decompression Options

Guessing Options

4) Supported levels:

Lower values increase step size (coarser search), while higher values decrease step size (finer search).

Examples of Compression Parameter guessing:

# RDCU data compression guessing
./cmp_tool --guess rdcu -d test_data/test_data1.dat -o rdcu_guess

# Chunk mode guessing
./cmp_tool --guess chunk -d chunk_data.dat -o chunk_guess

# Custom guess level with model
./cmp_tool --guess chunk -d chunk_data.dat -m chunk_model.dat --guess_level 3 -o chunk_guess_3

These commands create .cfg files for RDCU compression parameters. For chunk mode, a .par file is created containing all parameters for chunk compression.

Data Format

The input data is formatted as hexadecimal numbers. For example: 12 AB 34 CD or 12AB34CD.

User Manual

You can find the user manual here.

How to use the tool

A simple example to show how the compression tool works. Instructions on how to perform compression without headers can be found here.

0. Download the tool or build the tool yourself

1. Create a configuration file

• Create a cfg directory
  mkdir cfg
• To create a default 1d-differencing mode configuration:
  ./cmp_tool --diff_cfg > cfg/default_config_1d.cfg
• To create a default model mode configuration:
  ./cmp_tool --model_cfg > cfg/default_config_model.cfg

2. Compress data with the default configurations:

• Create a directory for the compressed data
  mkdir compressed
• 1d-differencing mode compression
  ./cmp_tool -c cfg/default_config_1d.cfg -d test_data/test_data1.dat -o compressed/data1
  This creates a files in the compressed directory:
  data1.cmp -> compressed test_data1.dat file
• Model mode compression
  ./cmp_tool -c cfg/default_config_model.cfg -d test_data/test_data2.dat -m test_data/test_data1.dat -o compressed/data2
  We use test_data1.dat as the first model for test_data2.dat.
  Creates these two files in the compressed directory:
  data2.cmp -> compressed test_data3.dat file
  data2_upmodel.dat -> updated model used to compress the next data in model mode

3. Decompress the data

• Create a directory for the decompressed data
  mkdir decompressed
• Decompress data1.cmp
./cmp_tool -d compressed/data1.cmp -o decompressed/test_data1
  This creates a file in the decompressed directory:
  test_data1.dat -> decompressed data1.cmp file
• Decompress data2.cmp
./cmp_tool -d compressed/data2.cmp -m decompressed/test_data1.dat -o decompressed/test_data2
  As for the compression we use test_data1.dat as our model for decompression.
  Creates these two files in the decompressed directory:
  test_data2.dat -> decompressed data2.cmp file
  data2_upmodel.dat -> updated model used to decompress the next data in model mode

4. Bonus: Check if the decompressed data are equal to the original data
   The moment of truth!
   diff test_data/test_data1.dat decompressed/test_data1.dat
diff test_data/test_data2.dat decompressed/test_data2.dat

   And also check if the updated model is the same
   diff compressed/data2_upmodel.dat decompressed/test_data2_upmodel.dat