YouCat: Weakly Supervised Youtube Video Categorization System from Meta Data & User Comments using WordNet & Wikipedia

In this paper, we propose a weakly supervised system, YouCat, for categorizing Youtube videos into different genres like Comedy, Horror, Romance, Sports and Technology The system takes a Youtube video url as input and gives it a belongingness score for each genre. The key aspects of this work can be summarized as: (1) Unlike other genre identification works, which are mostly supervised, this system is mostly unsupervised, requiring no labeled data for training. (2) The system can easily incorporate new genres without requiring labeled data for the genres. (3) YouCat extracts information from the video title, meta description and user comments (which together form the video descriptor). (4) It uses Wikipedia and WordNet for concept expansion. (5) The proposed algorithm with a time complexity of O(|W|) (where (|W|) is the number of words in the video descriptor) is efficient to be deployed in web for real-time video categorization. Experimentations have been performed on real world Youtube videos where YouCat achieves an F-score of 80.9%, without using any labeled training set, compared to the supervised, multiclass SVM F-score of 84.36% for single genre prediction. YouCat performs better for multi-genre prediction with an F-Score of 90.48%. Weak supervision in the system arises out of the usage of manually constructed WordNet and genre description by a few root words.