Annotations

Release 1.3(03-2016)

ActivityNet 200

In this release, we include:

  • 200 activity classes
  • 10,024 training videos (15,410 instances)
  • 4,926 validation videos (7,654 instances)
  • 5,044 testing videos (labels withheld)
  • Evaluation server

Release 1.2(10-2015)

ActivityNet 100

In this release, we include inhouse curated annotations:

How to read the annotation files?

The annotation files are stored in JSON format. Each annotation file contains three different key fields: "database", "taxonomy", and "version". The key field "database" contains information about the videos in the dataset and all the available annotations. In the key field "taxonomy", we include a parent-child relationship for every activity in the dataset. Finally, we add the key field "version" to keep track over different releases of ActivityNet. Below, we present a detailed explanation of each key field.

database

Below, we show an example entry from the key field "database":

The example shows the information and annotations related to this video. As noted, we assign the unique identifier "5n7NCViB5TU" to that video. From the entry, we can retrieve the duration, resolution, url, and the subset where the video belongs. Additionaly, the key field "annotations" includes a list of all annotated activity instances in the video (segments). Each item in the list contains the key fields: "label" and "segment". The key field "label" refers to the activity class, and the key field "segment" contains the starting and ending time of the activity instance (in seconds). For example, the example above contains two different instances of the activity Discus throw: Instance 1, Instance 2.

taxonomy

The key field "taxonomy" contains information about all the nodes in the ActivityNet hierarchy. Below, we show an example that contains the leaf-to-root path of the activity Discus throw:

Each entry contains information about a node in the ActivitNet hierarchy. As noted, the leaf-to-root path can be recovered by walking the hierarchy (using the "parentId" field).

version

The key field "version" identifies which version of ActivityNet is contained in the annotation file. It is intended to keep track over different releases.