New Apple iPhone models use half the bandwidth for FaceTime thanks to H.265 codec51
The advantage to using the new codec is that it requires half the bit rate that H.264 needs, to offer the same quality videos. First released as a draft standard by the Motion Pictures Expert Group (MPEG) in 2012, H.265 has yet to become widely used on consumer devices. It is speculated that the Apple A8 SoC could contain a specialized encoder/decoder module.
Some experts believe that the use of the H.265 codec could give Apple an leg up over its rivals when it comes to mobile chat. Signals Processing expert Matthew Fleming says, "This has the potential to give Apple a serious advantage in the mobile video calling domain where bandwidth is at a premium."