Question

I created a rails class with a video attachment, and i want to know how to get the length of a video that is uploaded to my application. How can I achieve that ?

Answer 1

Use ffmpeg and the RVideo gem, which is a thin Ruby wrapper around it. There’s a lot of forks of the RVideo project, personally I use http://github.com/greatseth/rvideo because it supports capturing frames from video and saving them as images. When it’s all set up, you can do this:

# For Paperclip 2
video_attributes = RVideo::Inspector.new(:file => self.upload.to_file.path, :ffmpeg_binary => "/usr/local/bin/ffmpeg" )
video_attributes.duration # duration in milliseconds

# For Paperclip 3
video_attributes = RVideo::Inspector.new(:file => self.upload.queued_for_write[:original].path)
video_attributes.duration # duration in milliseconds