Solved Slightly differing frames rates on phone footage

Have just discovered your website and found a lot of great info already, very well explained! Many thanks.

I've been working on a project in MSP14 for the past few days and only after doing a lot of work on it, I discovered my phone (Samsung Galaxy S7) seems to have recorded videos at very slightly different frame rates - when set to 30fps and either Full HD or 4k, the frame rates are only *approximately* 29.97 but vary from 29.915 to 30.008.

Unfortunately I hadn't realised that this would be enough of a difference from the project setting (29.97) to cause very obvious ghosting on moving objects when rendering the final video.

I haven't been able to find much about this exact issue online, so I would be grateful if you can share your experience of the best way to solve this. I've already come up with some solutions, but wondered if I could have gone about this a different way!

First of all, is it common for phones to not adhere strictly to an exact frame rate? Do all Samsung phones, and iPhones and others have this 'problem'? I got some footage from a friends DJI Mavic Pro drone and every video was exactly 29.97.

After some experimenting, I found that if you right click on a video in MSP14 in the media bin you can choose "Add at Project Frame Rate" which will work by apparently stretching or compressing the video by a fraction (as seen by the wavy line) - the downside of this is it's easy to forget to add it like that, and you can't add it as precisely to the timeline as if you were dragging it there manually. So, it solves the problem but is harder to do.

The other thing I tried, which also worked, was using ffmpeg to re-encode all my videos to 29.97 fps and then (with MSP14 closed) replacing the original videos with the re-encoded ones in the same folder, so that when the project was re-opened, MSP did not seem to be bothered the videos had been switched, and now the frame rates were all 29.97. This saved re-adding all the videos to the timeline and recreating all the transitions and effects. So, that also worked but was tedious having to re-encode everything in ffmpeg (and I now have 2 copies of all my source videos).

So, could you advise if you have found a better way to deal with all of this that is less onerous!

Many thanks.

Hi JOEBW

It sounds like you have already discovered the solution.
Some phone manufacturers insist on recording video using a Variable Frame Rate.
Traditionally all video editing programs only work with Constant Frame Rate video.

If you know a video was recorded with a variable frame rate, you must convert it into a stable constant frame rate using a Video Conversion program, before you import it into Vegas.

You can use whichever program you like, to do the video conversion, like ffmpeg.
One of the most popular programs that Vegas users use, is Handbrake, because it produces high quality video like ffmpeg.
handbrake.fr/

Regards
Derek

Thanks for your reply Derek, and for confirming that I probably hadn't missed some other easier solution!

Having now read up a bit more on Variable Frame Rate I see it appears to be very common on smartphones so I guess it makes little difference which phone you have. I would be interested to know, in your experience, whether my first 'solution' (right click on a video in MSP14 in the media bin and choose "Add at Project Frame Rate") is just as reliable as re-encoding everything to a constant frame rate, as that avoids the time taken, and saving 2 copies of every file. It seemed to work ok in some brief tests I did, but maybe it doesn't work well in all scenarios?

Regarding conversion using Handbrake, I have been using this for many years but only really to compress files to share with people - of course it works brilliantly for that. However as my primary aim for video editing was to maintain the best possible quality, I couldn't find any setting (presets or tinkering manually) that would maintain the original quality. Any setting seemed to degrade the video quality, even marginally, but just enough to bother me. Even when I was able to find settings that gave an output with a bitrate similar to the original (typically around 50,000 kbps for 4k, 30fps), I could see the difference. A good example was slight artefacts in a clear blue sky, and also the deep blue sky colour becoming slightly paler in the copy. In the end I tried ffmpeg, and despite quite a learning curve, I eventually got converted copies that I think are as good as the originals.

Regards
Joe

You can do whatever you like, but I don't know anyone that uses the Add at Project Frame Rate method.
Everyone (including much more experienced professional editors) on the official Vegas Forums, has always recommended converting phone video to a Constant Frame Rate first.

I have never promoted ffmpeg on this website or forum, because it is way to technical for the average person to use - that's why I promote the Handbrake method. Handbrake has a huge amount of technical settings which can be tweaked for different situations. However at the moment I don't have time to do experiments on that.

If you have got ffmpeg working, stick with that method.

OK, thanks for the quick reply. Will continue experimenting!

Regards
Joe