video-tools

Contains tools and workflows for restoring video files using Avisynth, VirtualDub, and other tools.

Initial setup

Create and activate a Python virtual environment. For example, on Windows from the Command Prompt:

<path_to>\python.exe -m venv .\.venv
.\Scripts\activate.bat

Next, install the package locally:

pip install .

When running some tools, note that you must also ensure that FFmpeg is in your PATH, if it is not already.

Development setup

To develop this Python project, first start with the activated virtual environment you previously created.

pip install --editable .[dev]

To run verifications, first install Nox:

pip install --upgrade nox

And then run them.

nox -s verify

Running nox without arguments will verify, and then build the distribution wheel:

nox

To reformat code:

nox -s format

Don't forget you can add the -R parameter to nox if you want to reuse existing virtual environments.

To integrate the linting tools with VS Code:

1. Install the Ruff extension for VS Code. Note it will use its own bundled copy of Ruff.
2. Go to .vscode/settings.json for the project and add:

   {
     "[python]": {
         "editor.formatOnSave": true,
         "editor.codeActionsOnSave": {
           "source.organizeImports": "explicit"
       },
       "editor.defaultFormatter": "charliermarsh.ruff"
     }
   }
   

3. Install the Mypy Type Checker for VS Code. Again, note it will use its own bundled copy of mypy.

Workflows

See the README for more information on preservation and video restoration procedures.

List of tools

• analyze_virtualdub_timing_log analyzes timing logs from VirtualDub that are recorded while capturing AVI files. Frames with anomalous timestamps are flagged for manual investigation.
• dv_merge is an experimental tool for merging raw DV video files from multiple capture passes.
• dv_repair can be used to repair errors in a DV file, such as subcode incoherencies.
• dv_resample_audio resamples DV audio so that it is locked to the video frames that it was interleaved with. This corrects audio drift that is present from unlocked DV cameras, such as consumer camcorders.
• top_line_errors uses the Avisynth SpotLess filter to identify frames that have VHS dropouts. The script then writes a list of affected frame numbers to a text file, so that later an Avisynth script can selectively run the filter only on affected frames.