Working at the Video Team of The New York Times

What do you guys use to create the thumbnails for the video seek bar? Is it pre-generated or on-the-fly?

On the beginning of this year we decided to transcode our old videos to have mp4/webm/hls renditions (we only had .flv at that time) so we could also generate the thumbs. For new videos I created this project https://github.com/flavioribeiro/video-thumbnail-generator and we are integrating it with our encoding pipeline.