Is our phone ACTUALLY recording 30 frames per second?

[congusano]

I took a video of my son sledding the other day and i wanted a screen shot, so I opened up the movie (copied directly to my computer, so no further compression was done) in Quicktime and using the right/left arrow keys, I was able to move around the video frame by frame until I found a good one to use.

In doing so, I would come across frames that did not advance a tiny bit forward or backward, it was as if it recorded the same exact frame twice.

i opened up the video inspector and as I keyed through each frame, everyone once in a while the current time would stay at the same number..


So, are our phones actually recording at a full 30fps, or does it "fill" in frames that it doesn't record?

Is this something that normally happens with all video though, so its really of no big deal?

 

[congusano]

I have exported the movie to an image sequence and can confirm that when scrolling through the image (each being a single frame), every so often a frame is duplicated. Is this indicative of my my phone not recording an actual 30 frames per second, or is this common among many other recording devices.

I did the same thing with a video I recorded from my old iphone 4 and that had zero frames duplicated, even when at 1280x720, just like i had with the lumia.

 

[JonesCK1]

I'm not entirely sure what Nokia is doing, but based on this video comparison, the Lumia 920 trounces other phones when it comes to retaining quality during motion, you would think the camera is capturing at 60fps if the others are in fact rated at 30fps.

I took a screenshot from different parts of the video comparison yesterday and was wondering myself what the framerate of capture is on the Lumia 920 seeing how drastically different the image quality is, I thought it might have something to do with the OIS but it can't be that alone since panning wouldn't really activate the shock absorption of the optical stabilization.

Click here to view the original image of 1024x576px and 932KB.

Click here to view the original image of 1024x576px and 554KB.

Click here to view the original image of 1024x576px and 554KB.

Click here to view the original image of 1024x576px and 706KB.

Click here to view the original image of 1024x576px and 706KB.

Click here to view the original image of 1024x576px and 573KB.

Click here to view the original image of 1024x576px and 573KB.

Click here to view the original image of 1024x576px and 1220KB.

 

[antsin3d]

I guess the question would be "how often?" If its running at 29.97fps (a common rate that would be considered 30fps) then we'd expect what, 1 out of every 1000 to be duplicated if played back at 30fps?

 

[congusano]

When recording at 720p, I see it often....I would say at least once or twice a second (so when viewing frame by frame, somewhat between every 5-15 frames).

However, I just tested this out doing the same thing when recording at 1080 and there are NO duplicate frames.

That is odd.