iPhone slow motion video transcode

forks!

I'm developing upload video (taken from iPhone) to my server.

However, I have no idea how to implement.

Any source code(objective-c or swift) will be welcomed.

I have 120fps or 240fps video (It's a slo-mo). When I playback these video on my iPhone6. I can see slo-mo effect. (I know playback frame rate is 30fps.)

I want to convert that video before upload to my server, from 120/240 fps to 30fps video. (I mean not adjusting playback frame rate, it means video transcode to 30fps.) Additionally, I want to check slo-mo effect start-point and end-point. (Maybe iPhone record this information to video binary(it might be reside in file's header.)

Well, I guess if I use ffmpeg library, it should be easy(?).

So any suggestions will be welcomed.

Please, help me out. Thanks.