Video Production Stack Exchange is a question and answer site for engineers, producers, editors, and enthusiasts spanning the fields of video, and media creation. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

After losing a backup device with a bunch of my original videos I've had to download a large number of them (~300) back from Youtube. The new downloads are a mix of MP4 and FLV, and the originals are a mix of almost any video format due to lots of experimenting.

To make matters worse there's no clear cutoff for when my local copies disappeared; I've found a point in my youtube videos chonologically where I have some of the videos and I don't have others. I've been trying to manually weed out videos where I already have a copy, but with this many videos I'm sure I've missed some.

How can I effectively go through several hundred videos of different formats and weed out duplicates? The names will be similar but not identical. The formats may be different, and the file size may be different due to that (and or encoding differences). The file lengths should be the same, and visually the videos should be similar enough, but I'm not sure there's any tool to sort that out visually.

Am I doomed to go through the list based on running time and manually look for duplicates or is there a better way?

share|improve this question
Very interesting question! – Dr Mayhem Nov 12 '12 at 10:40
up vote 10 down vote accepted

I'd recommend a hybrid approach using both computers and people.

  1. Bucket the videos by their length (round to the nearest second)
  2. For each bucket, use ffmpeg to generate thumbnails at a predictable and uniform point in the videos (ex: a frame from 10 seconds into the video)
  3. Look at the generated thumbnails in a grid (most OS's provide a nice thumbnail view) and scan for duplicates to remove.

You shouldn't have to do any programming to perform these steps, though creating the thumbnails on the command line with ffmpeg may take some finesse. Good luck!

share|improve this answer
Thumbnails are a great idea! The new videos came in as FLV, which I can't seem to thumbnail no matter what I try. This could work quite well – Ben Brocka Nov 13 '12 at 15:30
ffmpeg should be able to convert the flv files into something else (avi, mp4, etc). – jimbojw Nov 13 '12 at 19:05
Yeah, I'll eventually convert them to MP4 but I want to make sure I lose as little quality as possible when I do that, so I've put it off until I can take the time – Ben Brocka Nov 13 '12 at 19:11
If you wanted to, you could find a program that would analyze the thumbnails to find duplicates. However, the time spent finding such a program then configuring it would not be worth it for a small project. – Cole Johnson Jun 18 '13 at 20:16

Video recognition software is I would say, a niche market which means you will either find very expensive software and/or software that targets government, movie industry and so forth.

It works by "finger printing" video so it can recognize the video despite different formats, compressions, cropping etc. This ability is not so common in the non-forensic world (at least not yet).

I did try to find something that is targeting consumers but was not able to find any. There do exists APIs (programming interfaces) that provides technology for doing this, and even free, but you will need to develop the software to use it yourself which I am fairly certain is beyond the scope of what you're asking for.

So in conclusion, unless you want to spend a noticeable amount of money on specialized software you will need to go through the stack manually. However, in my link above you will find a trial version of such software so you can see if that is what you're looking for and if it works for your purpose.

share|improve this answer
the link is dead. – Hermann Ingjaldsson May 7 at 14:47

You can try Video Comparer (shareware).

It quickly detects similar videos with image transformations and supports split videos into multiple CDs.

share|improve this answer

I had the same problem recently and I found the program that helped me. It doesn't compare file names or calculate hashes. It compare real video content. It is not free, but if you haven't many duplicates, the trial version is enough. The link to the program is

share|improve this answer

Similar images - is a bit old, but still functional.

share|improve this answer
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review – Mulvya May 11 at 5:31

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.