# HMDB51 HMDB51 is an action recognition dataset containing a total of 6,766 clips distributed across 51 action classes. **Details** - Dataset name: `hmdb51` - Dataset source: [https://serre-lab.clps.brown.edu/resource/hmdb-a-large-human-motion-database](https://serre-lab.clps.brown.edu/resource/hmdb-a-large-human-motion-database) - Dataset license: CC-BY-4.0 - Dataset size: 2.16 GB - Tags: `video, action-recognition` - Supported splits: `train, test, other` - ZooDataset class: [`HMDB51Dataset`](../../api/fiftyone.zoo.datasets.base.md#fiftyone.zoo.datasets.base.HMDB51Dataset) **Example usage** Python CLI ```python import fiftyone as fo import fiftyone.zoo as foz import fiftyone.utils.video as fouv dataset = foz.load_zoo_dataset("hmdb51", split="test") # Re-encode source videos as H.264 MP4s so they can be viewed in the App fouv.reencode_videos(dataset) session = fo.launch_app(dataset) ``` ```shell fiftyone zoo datasets load hmdb51 --split test # Re-encode source videos as H.264 MP4s so they can be viewed in the App fiftyone utils transform-videos hmdb51-test --reencode fiftyone app launch hmdb51-test ``` #### NOTE In order to work with video datasets, you’ll need to have [ffmpeg installed](../../installation/troubleshooting.md#troubleshooting-video).