I know, smartphone cameras are maybe not the primary interest of professional videographers, but I am interested into the technical aspects. They can also be relevant for real cameras.
There are irrational video recording specifications in some smartphones compared to others:
- 2160p@30fps = 1080p@120fps = 248832000 pixels per second. Keep this magic number in mind.
- The Galaxy Note 3 from 2013 records at 2160p@30fps (248832000 pixels per second), yet only 1080p@60fps (124416000 pixels per second) instead of 1080p@120fps (248832000 pixels per second). The same is still valid for Galaxy Note 8 (late 2017).
- The Galaxy S4 has around 80% as much processing power as the Note 3. Yet th S4 is limited to 1080p@30fps (62208000 pixels per second), while the Note 3 hit 24832000 pixels per second?
- The front camera of the most phones is still limited to 1080p at 30fps, despite the image sensor has a much higher resolution and should also cope with 60fps.
- Galaxy S7 doubles framerate at 720p (120fps→240fps or 110592000→221184000 pixels per second), yet the framerate at 1080p@60fps and 2160p@30fps compared to predecessor stayed the same?
- The new iPhones (8,8+,X) are able to capture 2160p@60fps(497664000 pixels per second) and 1080p@240fps(497664000), which is even beyond the Lumix GH5's 1080p@180fps (373248000) How is that technically possible?
- The OnePlus 5 from 2017 still had 720p@120fps, which the Note 3 had in 2013 already (let's disregard framerate distortion, because this is about the recording capabilities), and the OnePlus 6 suddenly jumped to 720p@480fps (I wonder what causes the 1 minute limitation)? The iPhone 6 from 2014 reached 240fps despite the OnePlus 5 (720p@only120fps) has more powerful hardware.
- The Galaxy S7 (2016) allowed 2160p video recording without any fixed time limitation on Android Marshmallow. On Android Nougat, it got limited to 10 minutes. Earlier Samsung phones: 5 minutes, Galaxy Alpha: 4 minutes.
- The Galaxy Note 3 plays back 1080p@120fps and 720p@240fps without any lagging. Frameskipping?
- The Huawei Mate 8 still did not offer 2160p video capture, despite being a flagship in 2016, and equipped with similar hardware as other flagships that offer 2160p.
- Some phones phones such as UleFone Armor 2 and Galaxy A series are limited to 1080p@30fps and have no high framerate mode at all, despite it has 65000 points in AnTuTu, while Galaxy Note 3 with 1080p@60fps and 2160p@30fps and 720p@120fps has just 44000 points, and even the Galaxy Note 2 has 480p@120fps with only ~30000 points?
- iPhone 5s (2013) records 720p at 120fps, and Apple has always proven to be a framerate king in the years after. Yet 5s only has 1080p at 30fps despite 60fps should have technically been possible. The Note 3 (2013) was the peak of Samsung's superiority.
I need help understanding the background behind these limitations.
I would appreciate a technical explaination.