Python DPX validator

This script validates a set of header fields in a DPX file.

Requirements

Installation and usage requires Python 3.9 or newer. The software is tested with Python 3.9 on AlmaLinux 9 release.

Installation using RPM packages (preferred)

Installation on Linux distributions is done by using the RPM Package Manager. See how to configure the PAS-jakelu RPM repositories to setup necessary software sources.

After the repository has been added, the package can be installed by running the following command:

sudo dnf install python3-dpx-validator

Usage

Run validator:

dpxv <path-to-dpx-file>

Validation errors are printed to standard error stream.

Validator can also be imported from the dpx_validator.api module:

dpx_validator.api.validate_file

For more information about DPX, see the SMPTE standard ST 268-1:2014: File Format for Digital Moving-Picture Exchange (DPX)

Validated fields

These fields from specification are validated:

Field 1

Magic number of 'SDPX' or 'XPDS' for reversed byte order.

Field 2

A valid image data offset value.

Field 3

Header format version as either 'V1.0' or 'V2.0'

Field 4

DPX file size in header matches what filesystem shows.

Field 15

Encryption key is undefined and therefore image is unencrypted.

Format characters

Format characters define form into which binary data is read from a header field.

Installation and usage for development purposes using Python Virtualenv

Create a virtual environment:

python3 -m venv venv

Run the following to activate the virtual environment:

source venv/bin/activate

Install the required software with commands:

pip install --upgrade pip==20.2.4 setuptools
pip install -r requirements_dev.txt
pip install .

To deactivate the virtual environment, run deactivate. To reactivate it, run the source command above.

Validation procedures in dpx_validator.validations can return a single informational message and must raise InvalidField exception when value in a field is invalid. Validator will continue to the next validation procedure. Each validation procedure output and error should contain final outcome of the procedure, that is, a procedure should not finish with partial info or errors from the procedure. Complex validation procedures for a single field in header should store intermediate results until finishing the procedure or be splitted to multiple procedures.

Return value from a validation procedure is not required. Exception must be raised for a invalid value. New procedures are added to dpx_validator.api.VALIDATED_FIELDS list in ascending offset order.

Copyright

Copyright (C) 2018 CSC - IT Center for Science Ltd.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.