Dominik Loidolt
cmp_tool

Repository



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.

Usage
usage: cmp_tool [options] [<argument>]

General Options


Options
Description


-h, --help
Print some help text and exit


-o <prefix>
Use the <prefix> for output files¹


-n, --model_cfg
Print a default model configuration and exit²


--diff_cfg
Print a default 1d-differencing configuration and exit²


--no_header
Do not add a compression entity header in front of the compressed data


-a, --rdcu_par
Add additional RDCU control parameters


-V, --version
Print program version and exit


-v, --verbose
Print various debugging information


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


Options
Description


-c <file>
File containing the compressing configuration


-d <file>
File containing the data to be compressed


-m <file>
File containing the model of the data to be compressed


--rdcu_pkt
Generate RMAP packets for an RDCU compression³


--last_info  <.info file>
Generate RMAP packets for an RDCU compression with parallel read of the last results


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


Options
Description


-d <file>
File containing the compressed data


-m <file>
File containing the model of the compressed data


-i <file>
File containing the decompression information (required if --no_header was used)


Guessing Options


Options
Description


--guess <mode>
Search for a good configuration for compression <mode>⁴


-d <file>
File containing the data to be compressed


-m <file>
File containing the model of the data to be compressed


--guess_level <level>
Set guess level to <level> (optional)⁵


4) NOTE: <mode> can be either the compression mode
number or the keyword: RDCU. The RDCU mode automatically selects the correct
RDCU-compatible compression mode depending on if the Model (-m) option is set.

5) Supported levels:


guess level
Description


1
fast mode (not implemented yet)


2
default mode


3
brute force


Example of Compression Parmeter guessing:
./cmp_tool --guess RDCU -d test_data/test_data1.dat -o myguess
This command creates the file myguess.cfg with the guessed compression parameters.

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.


Download the tool or run make to build the tool


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


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


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


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