Match cutting

• Want a high level overview? Read this blog post
• Want all the details? Read the preprint

Getting started

1. Create and activate the conda environment.

conda env create -f conda_env.yml
conda activate matchcut

2. Download the embeddings

Embeddings are stored as a 3 GB tar file and can be found here. Download this tar file into this directory.

3. Extract

tar -xf embeddings.tar.gz -C data/

At this point you should have all the embeddings placed in the data/embeddings folder (expands to 8 GB).

3. Run experiment 1

python experiment.py --number 1

This command will run 195 combinations of encoders, models, and aggregation functions.

4. Run experiment 2

python experiment.py --number 2

This command will run 14 combinations of tasks and encoders.

Experiment results caching

By default, experiment results are stored in the results folder as pickle files. If you want to re-run experiments you need to remove this folder or to set cache = False in config/common.py.

Required resources and runtimes

Each experiment takes over a day to complete on a machine with 64 CPU cores and 256 GB of memory. If you are running on a GPU machine you will need 32 GB for experiment 2.

Instead, you can pass --quick to either experiment and only generate the results for a single combination. For example:

python experiment.py --number 1 --quick

This should take less than a minute to complete for experiment 1 and less than 2 hours for experiment 2.

Experiment configs

The following 3 files contain the configs that drive the two experiments:

├── matchcut
│   ├── config
│   │   ├── common.py
│   │   ├── experiment1.py
│   │   ├── experiment2.py

You can modify these files to run experiments with different configs.

Data

Take a look at data-exploration.ipynb for example data.

All the data, except for embeddings, is in the data/ folder:

• train/validation/test.txt
  • list of IMDB IDs in each data partition
  • each line contains an IMDB ID
• dataset-*.json
  • dataset-frame.json and dataset-motion.json contain train, validation, and test partitions for the frame and motion tasks.
  • dataset-random-negatives.json is the shared set of randomly selected negative pairs.
  • the code in matchcut/data.py will take care of combining and filtering these files.
• shot_indices.json contains a mapping between IMDB IDs and all the shot indices used in this work.
• shot-time-ranges.csv contains a mapping from shot indices to time ranges in seconds. This CSV file has four columns: imdb_id, shot_idx, start, and end. shot_idx is the shot index that pairs are associated with and start and end are the beginning and end of the shot relative to the beginning of the movie in seconds.
• imdb-title-set.csv IMDB title set with IMDB ID, title, genres, country, and split.

Embeddings

See download instructions above.

• format: {encoder_name}-{imdb_id}.json
• each JSON file is a dictionary with shot indices as keys, and the corresponding embeddings (i.e. a vector of floats) as values.
• e.g. if file clip-tt0050706.json starts with {"0": [0.1, .2, -0.32, ...]} then the CLIP embeddings for shot 0 of IMDB ID tt0050706 is [0.1, .2, -0.32, ...]

How do I extend this?

You can extract your own embeddings, store in the format described above, and repeat experiments 1 and 2 by changing the config files in matchcut/config.

Citation

@article{chen2022match,
  title={Match Cutting: Finding Cuts with Smooth Visual Transitions},
  author={Chen, Boris and Ziai, Amir and Tucker, Rebecca and Xie, Yuchen},
  journal={arXiv preprint arXiv:2210.05766},
  year={2022}
}