I tried configuring the X-Content-Duration HTTP header (which is no longer supported by Firefox) in nginx configuration but no value is logged.

I can add a custom HTTP header (like video_duration) pointing to the path of a video file and manually assign the value, acting as a band-aid solution.

Is there a way to log the duration of a mp4 video file served to visitors in the access log, similar to how a file's content-length (in bytes) can be logged? Thanks!