Sony has been rumored to be working on a handset capable of recording 4K video.
Sony's next flagship smartphone, believed to be codenamed "Sirius" (D6503 model) will also support a timeshifting feature, allowing users to automatically apply slow-motion effects, Xperia Blog
reported today. Sirius is also shown to support a "smart call handling" feature that allows users to automatically answer a call when it's brought to their ear and reject a call when they shake the handset. The gadget will also feature a 5.2-inch (1080p) LCD, a full 3GB allotment of RAM, plus a Qualcomm MSM8974AB chipset - meaning we'll probably have to deal with a Snapdragon 800 processor (2.3GHz quadcore running Adreno 330 graphics)
Previously, Sony had been rumored to be working on Ultra HD recording for a handset codenamed "Honami".
Sony is trying to make a significant push into mobile in 2014.