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+# Preparing Diving48
+
+## Introduction
+
+<!-- [DATASET] -->
+
+```BibTeX
+@inproceedings{li2018resound,
+  title={Resound: Towards action recognition without representation bias},
+  author={Li, Yingwei and Li, Yi and Vasconcelos, Nuno},
+  booktitle={Proceedings of the European Conference on Computer Vision (ECCV)},
+  pages={513--528},
+  year={2018}
+}
+```
+
+For basic dataset information, you can refer to the official dataset [website](http://www.svcl.ucsd.edu/projects/resound/dataset.html).
+Before we start, please make sure that the directory is located at `$MMACTION2/tools/data/diving48/`.
+
+## Step 1. Prepare Annotations
+
+You can run the following script to download annotations (considering the correctness of annotation files, we only download V2 version here).
+
+```shell
+bash download_annotations.sh
+```
+
+## Step 2. Prepare Videos
+
+You can run the following script to download videos.
+
+```shell
+bash download_videos.sh
+```
+
+## Step 3. Prepare RGB and Flow
+
+This part is **optional** if you only want to use the video loader.
+
+The frames provided in official compressed file are not complete. You may need to go through the following extraction steps to get the complete frames.
+
+Before extracting, please refer to [install.md](/docs/install.md) for installing [denseflow](https://github.com/open-mmlab/denseflow).
+
+If you have plenty of SSD space, then we recommend extracting frames there for better I/O performance.
+
+You can run the following script to soft link SSD.
+
+```shell
+# execute these two line (Assume the SSD is mounted at "/mnt/SSD/")
+mkdir /mnt/SSD/diving48_extracted/
+ln -s /mnt/SSD/diving48_extracted/ ../../../data/diving48/rawframes
+```
+
+If you only want to play with RGB frames (since extracting optical flow can be time-consuming), consider running the following script to extract **RGB-only** frames using denseflow.
+
+```shell
+cd $MMACTION2/tools/data/diving48/
+bash extract_rgb_frames.sh
+```
+
+If you didn't install denseflow, you can still extract RGB frames using OpenCV by the following script, but it will keep the original size of the images.
+
+```shell
+cd $MMACTION2/tools/data/diving48/
+bash extract_rgb_frames_opencv.sh
+```
+
+If both are required, run the following script to extract frames.
+
+```shell
+cd $MMACTION2/tools/data/diving48/
+bash extract_frames.sh
+```
+
+## Step 4. Generate File List
+
+you can run the follow script to generate file list in the format of rawframes and videos.
+
+```shell
+bash generate_videos_filelist.sh
+bash generate_rawframes_filelist.sh
+```
+
+## Step 5. Check Directory Structure
+
+After the whole data process for Diving48 preparation,
+you will get the rawframes (RGB + Flow), videos and annotation files for Diving48.
+
+In the context of the whole project (for Diving48 only), the folder structure will look like:
+
+```
+mmaction2
+├── mmaction
+├── tools
+├── configs
+├── data
+│   ├── diving48
+│   │   ├── diving48_{train,val}_list_rawframes.txt
+│   │   ├── diving48_{train,val}_list_videos.txt
+│   │   ├── annotations
+│   |   |   ├── Diving48_V2_train.json
+│   |   |   ├── Diving48_V2_test.json
+│   |   |   ├── Diving48_vocab.json
+│   |   ├── videos
+│   |   |   ├── _8Vy3dlHg2w_00000.mp4
+│   |   |   ├── _8Vy3dlHg2w_00001.mp4
+│   |   |   ├── ...
+│   |   ├── rawframes
+│   |   |   ├── 2x00lRzlTVQ_00000
+│   |   |   |   ├── img_00001.jpg
+│   |   |   |   ├── img_00002.jpg
+│   |   |   |   ├── ...
+│   |   |   |   ├── flow_x_00001.jpg
+│   |   |   |   ├── flow_x_00002.jpg
+│   |   |   |   ├── ...
+│   |   |   |   ├── flow_y_00001.jpg
+│   |   |   |   ├── flow_y_00002.jpg
+│   |   |   |   ├── ...
+│   |   |   ├── 2x00lRzlTVQ_00001
+│   |   |   ├── ...
+```
+
+For training and evaluating on Diving48, please refer to [getting_started.md](/docs/getting_started.md).