Video Contrastive Learning with Global Context

Video Contrastive Learning with Global Context (VCLR)

This is the official PyTorch implementation of our VCLR paper.

Install dependencies

• environments

  conda create --name vclr python=3.7
  conda activate vclr
  conda install numpy scipy scikit-learn matplotlib scikit-image
  pip install torch==1.7.1 torchvision==0.8.2
  pip install opencv-python tqdm termcolor gcc7 ffmpeg tensorflow==1.15.2
  pip install mmcv-full==1.2.7

Prepare datasets

Please refer to PREPARE_DATA to prepare the datasets.

Prepare pretrained MoCo weights

In this work, we follow SeCo and use the pretrained weights of MoCov2 as initialization.

cd ~
git clone https://github.com/amazon-research/video-contrastive-learning.git
cd video-contrastive-learning
mkdir pretrain && cd pretrain
wget https://dl.fbaipublicfiles.com/moco/moco_checkpoints/moco_v2_200ep/moco_v2_200ep_pretrain.pth.tar
cd ..

Self-supervised pretraining

bash shell/main_train.sh

Checkpoints will be saved to ./results

Downstream tasks

Linear evaluation

In order to evaluate the effectiveness of self-supervised learning, we conduct a linear evaluation (probing) on Kinetics400 dataset. Basically, we first extract features from the pretrained weight and then train a SVM classifier to see how the learned features perform.

bash shell/eval_svm.sh

• Results

  Arch	Pretrained dataset	Epoch	Pretrained model	Acc. on K400
  ResNet50	Kinetics400	400	Download link	64.1

Video retrieval

bash shell/eval_retrieval.sh

• Results

  Arch	Pretrained dataset	Epoch	Pretrained model	[email protected] on UCF101	[email protected] on HMDB51
  ResNet50	Kinetics400	400	Download link	70.6	35.2
  ResNet50	UCF101	400	Download link	46.8	17.6

Action recognition & action localization

Here, we use mmaction2 for both tasks. If you are not familiar with mmaction2, you can read the official documentation.

Installation

• Step1: Install mmaction2

  To make sure the results can be reproduced, please use our forked version of mmaction2 (version: 0.11.0):

  conda activate vclr
  cd ~
  git clone https://github.com/KuangHaofei/mmaction2
  
  cd mmaction2
  pip install -v -e .

• Step2: Prepare the pretrained weights

  Our pretrained backbone have different format with the backbone of mmaction2, it should be transferred to mmaction2 format. We provide the transferred version of our K400 pretrained weights, TSN and TSM. We also provide the script for transferring weights, you can find it here.

  Moving the pretrained weights to checkpoints directory:

  cd ~/mmaction2
  mkdir checkpoints
  wget https://haofeik-data.s3.amazonaws.com/VCLR/pretrained/vclr_mm.pth
  wget https://haofeik-data.s3.amazonaws.com/VCLR/pretrained/vclr_mm_tsm.pth

Action recognition

Make sure you have prepared the dataset and environments following the previous step. Now suppose you are in the root directory of mmaction2, follow the subsequent steps to fine tune the TSN or TSM models for action recognition.

For each dataset, the train and test setting can be found in the configuration files.

• UCF101

  • config file: tsn_ucf101.py
  • train command:

    ./tools/dist_train.sh configs/recognition/tsn/vclr/tsn_ucf101.py 8 \
      --validate --seed 0 --deterministic

  • test command:

    python tools/test.py configs/recognition/tsn/vclr/tsn_ucf101.py \
      work_dirs/vclr/ucf101/latest.pth \
      --eval top_k_accuracy mean_class_accuracy --out result.json

• HMDB51

  • config file: tsn_hmdb51.py
  • train command:

    ./tools/dist_train.sh configs/recognition/tsn/vclr/tsn_hmdb51.py 8 \
      --validate --seed 0 --deterministic

  • test command:

    python tools/test.py configs/recognition/tsn/vclr/tsn_hmdb51.py \
      work_dirs/vclr/hmdb51/latest.pth \
      --eval top_k_accuracy mean_class_accuracy --out result.json

• SomethingSomethingV2: TSN

  • config file: tsn_sthv2.py
  • train command:

    ./tools/dist_train.sh configs/recognition/tsn/vclr/tsn_sthv2.py 8 \
      --validate --seed 0 --deterministic

  • test command:

    python tools/test.py configs/recognition/tsn/vclr/tsn_sthv2.py \
      work_dirs/vclr/tsn_sthv2/latest.pth \
      --eval top_k_accuracy mean_class_accuracy --out result.json

• SomethingSomethingV2: TSM

  • config file: tsm_sthv2.py
  • train command:

    ./tools/dist_train.sh configs/recognition/tsm/vclr/tsm_sthv2.py 8 \
      --validate --seed 0 --deterministic

  • test command:

    python tools/test.py configs/recognition/tsm/vclr/tsm_sthv2.py \
      work_dirs/vclr/tsm_sthv2/latest.pth \
      --eval top_k_accuracy mean_class_accuracy --out result.json

• ActivityNet

  • config file: tsn_activitynet.py
  • train command:

    ./tools/dist_train.sh configs/recognition/tsn/vclr/tsn_activitynet.py 8 \
      --validate --seed 0 --deterministic

  • test command:

    python tools/test.py configs/recognition/tsn/vclr/tsn_activitynet.py \
      work_dirs/vclr/tsn_activitynet/latest.pth \
      --eval top_k_accuracy mean_class_accuracy --out result.json

• Results

  Arch	Dataset	Finetuned model	Acc.
  TSN	UCF101	Download link	85.6
  TSN	HMDB51	Download link	54.1
  TSN	SomethingSomethingV2	Download link	33.3
  TSM	SomethingSomethingV2	Download link	52.0
  TSN	ActivityNet	Download link	71.9

Action localization

• Step 1: Follow the previous section, suppose the finetuned model is saved at work_dirs/vclr/tsn_activitynet/latest.pth

• Step 2: Extract ActivityNet features

  cd ~/mmaction2/tools/data/activitynet/
  
  python tsn_feature_extraction.py --data-prefix /home/ubuntu/data/ActivityNet/rawframes \
    --data-list /home/ubuntu/data/ActivityNet/anet_train_video.txt \
    --output-prefix /home/ubuntu/data/ActivityNet/rgb_feat \
    --modality RGB --ckpt /home/ubuntu/mmaction2/work_dirs/vclr/tsn_activitynet/latest.pth
  
  python tsn_feature_extraction.py --data-prefix /home/ubuntu/data/ActivityNet/rawframes \
    --data-list /home/ubuntu/data/ActivityNet/anet_val_video.txt \
    --output-prefix /home/ubuntu/data/ActivityNet/rgb_feat \
    --modality RGB --ckpt /home/ubuntu/mmaction2/work_dirs/vclr/tsn_activitynet/latest.pth
  
  python activitynet_feature_postprocessing.py \
    --rgb /home/ubuntu/data/ActivityNet/rgb_feat \
    --dest /home/ubuntu/data/ActivityNet/mmaction_feat

  Note, the root directory of ActivityNey is /home/ubuntu/data/ActivityNet/ in our case. Please replace it according to your real directory.

• Step 3: Train and test the BMN model

  • train

    cd ~/mmaction2
    ./tools/dist_train.sh configs/localization/bmn/bmn_acitivitynet_feature_vclr.py 2 \
      --work-dir work_dirs/vclr/bmn_activitynet --validate --seed 0 --deterministic --bmn

  • test

    python tools/test.py configs/localization/bmn/bmn_acitivitynet_feature_vclr.py \
      work_dirs/vclr/bmn_activitynet/latest.pth \
      --bmn --eval [email protected] --out result.json

• Results

  Arch	Dataset	Finetuned model	AUC	[email protected]
  BMN	ActivityNet	Download link	65.5	73.8

Feature visualization

We provide our feature visualization code at here.

Security

See CONTRIBUTING for more information.

License

This project is licensed under the Apache-2.0 License.