This sounds promising (familiar with VLC) but you lost me on this iTunes part. I am really struggling with the move to iOS for the phone, and that includes iTunes. I will play around with it later today. Thanks for the suggestions.
Sorry I lost you! iTunes really is the ungainly elephant in the room and really isn't as user-intuitive as it could be - especially if your previous experience is simply to drag files into your Android via Android File Transfer, or similar. iTunes is huge and has many features and all, but jeez...
So, let me try and make it clearer (I was going to say easier, but...) - let's assume you've downloaded B]VLC[/B] onto your iPhone
1. Chances are pretty good that iTunes will automatically open when you plug your iPhone into your computer. It may take a moment or two (see aforementioned big elephant) to load. If not, open it.
2. iTunes should discover your iPhone and it should appear in a column to the left under 'Devices'. If the left column (or Devices) fails to show, then that's a setting I think that you'll want to change. Apple, I believe, considered this hidden to be a 'feature' a few iTunes back. Let us know if that's the case for you. I'm sure someone remembers how to re-enable it.
3.
Assuming your iPhone shows up in a column that shows up, left click on the iPhone. That will open up its control panel within iTunes. Listed along the top of this window will be Summary, Info, Apps, etc.
4. This is where my guidance above led us before. Click on Apps. In this window, you'll see virtual screens of your iPhone and the apps on each screen. For the moment, ignore all that and scroll down the window to File Sharing > Apps and where (hopefully) you will find
VLC in the left column. Left click on it to highlight it. Now at the bottom of the right column, you should see Add... in dark font. Click on it and then navigate to the videos on your computer / other drive you want VLC to run. This part is fairly straightforward and works like any other file copy. The files should show up in the right column.
5. Once you have done all this, you can initiate a Sync (bottom right of the open window) to transfer these files over to your iPhone and accessed by VLC. With luck.
As a bit of cleanup here, if VLC is playing these files, then the iTunes Video app on your iPhone (which can't play them as you've noted), need not have them, too. You'd have two sets of the same video clogging up your storage.
Still within the iPhone's control panel window, click on Movies along the top (I'm assuming that's where they'll be, not TV) and with Sync Movies checked on, ensure Automatically include is not. In the window below this, you can then choose which Movies get synced to your iPhone - and I'd uncheck the ones you've just given to VLC. Then Sync.
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I'd like to think there was a less convoluted method (anyone?), but I fear not. And while I've not tried
VLC myself (noting
rayz336's words of wisdom above), I have used this process to access files best dealt with by 3rd Party apps on my iPhone in the past.
Oh, and always feel free - despite the auto iCloud backups - to do a local backup of your iPhone at any time. You'll find that capability on the iPhone's control panel Summary window. Ya just never know....
Hope this might help.