Variable Frame Rates From Phone Footage Creating Problems In Premiere - No External Playback

 We have to deal with a lot of phone footage nowadays, and the phones are prone to creating clips with variable frame rates, with some hit and miss results in post, particularly when using Premiere.

 Have a look at this phone video clip specs:

Variable frame rate clip from iPhone, seen as such in Media Conch

 If you are like me using BMD 3G Monitor with Desktop Video, with non legit frame rates in Premiere Source window, you get no output. Even though Premiere is content playing back the clip internally, no go with external monitoring.

 Now if you create a legit frame rate Timeline and drop the variable FR clip into it, all is well because Premiere conforms the non-legit frame rate clip to the (legit) Timeline frame rate.

 When bringing such variable FR clips into Premiere, the FR stamping gets somewhat fantastical. In this example I have 5 clips, all from the same phone. They are all recognized in the metadata as 29.98 fps:

All VFR clips stamped as 29.98fps in Premiere

Same thing in the Media File Properties: 29.98. It should be 30fps, but because of variable FR, Premiere stamps them at 29.98.

Same thing in the Media File Properties window.

 For some reasons the first three clips playback just fine on the external monitor via Desktop Video/3G Monitor, the last two clips do not playback at all. Again, I'm talking about the Source window playback, not Timeline playback.

 On closer inspection, these clips show fantastical frame rates when invoking the Modify/Interpret Footage function. The Frame Rate is all over the place:

 Clip 1 = 29.9775

 Clip 2 = 29.9782

 Clip 3 = 29.9793

 Clip 4 = 29.9869

 Clip 5 = 29.9845

 Remember all five clips frame rate is rounded and stamped as 29.98 by Premiere.

 For some reason, only the first three clips will play through external playback in Premiere, not the last two. Maybe 29.97xx is an acceptable frame rate to BMD, but not 29.98xx? Who knows.

 A workaround is to manually stamp all these VFR iPhones clips to the proper 30 fps, (or 29.98 fps) in the selected "Assume this frame rate" and clicking OK. Batch processing is possible.

 Now all clips playback through the Source window / external monitor 3G Monitor device just fine. But it is changing the source frame rate, so it might not be desirable beyond permitting Source Monitor external playback via BlackmagicDesign DV/3G Monitor. You be the judge of that.

PP 25.5.0

macOS Sequoia 15.6.1