If you are trying to understand the "topic" of the video to write a summary or blog post: the video first using the tools above.
Because this name is a generic hash, the specific content of the video depends entirely on the tool that generated it. If you are looking to work with this file, here are the most common ways to handle such files: Convert the Video to Text (Transcription)
If "writing text for the topic" means you want to add titles, captions, or subtitles directly onto the video frames: