Posted by Skill

Yes but compiling the video and saving it into a file as it runs would be incredibly demanding, vs using external hardware.

Posted by Midori

The big difference between the first two methods and the last is the fact that the first two simply push the video feed out to another device to record. The video recording isn't actually done on the iDevice itself, hence this can reduce processor burden and give better framerates. The last method, although most convenient, will cause a lot of "lag" because the video is recorded and saved in real-time on the device at the same time as the game's many processes (connecting with the server, syncing position data, drawing the graphics, playing the sounds, displaying the animations etc), hence everything adds up to a sluggish processor with choppy video.