IOS AVPlayer get fps

Question

Im trying to figure out how to retrieve a videos frame rate via AVPlayer. AVPlayerItem has a rate variable but it only returns a value between 0 and 2 (usually 1 when playin

Answer 1

The rate value on AVPlayer is the speed relative to real time to which it's playing, eg 0.5 is slow motion, 2 is double speed.

As Paresh Navadiya points out a track also has a nominalFrameRate variable however this seems to sometimes give strange results. the best solution I've found so far is to use the following:

CMTime frameDuration = [myAsset tracksWithMediaType:AVMediaTypeVideo][0].minFrameDuration;
float fps = frameDuration.timescale/(float)frameDuration.value;

The above gives slightly unexpected results for variable frame rate but variable frame rate has slightly odd behavior anyway. Other than that it matches ffmpeg -i in my tests.

EDIT ----

I've found sometimes the above gives time kCMTimeZero. The workaround I've used for this is to create an AVAssetReader with a track output,get the pts of the first frame and second frame then do a subtraction of the two.