Re:Mobile CPUs and the Performance Inequality Gap
by jeroenhd on Sunday March 29, 2020 @08:32AM
(#22718458)
The playback issue (and the reason video editing went so smoothly) is probably because of hardware video codex support. Mobile devices, iPhone or otherwise, are miles ahead of most desktop graphics cards when it comes to video codec support.
H.265 support in graphics cards and consumer processors has laughably lacked behind on mobile, probably because of licensing.
There's also the fact that a lot of video applications on Windows don't enable hardware decoding by default out of fear of encountering buggy drivers or hardware.
On mobile there's basically only one way to decode video, which makes use of all the phone's dedicated hardware, while on desktop applications can use a wide variety of codecs. Then comes the decision whether to decode on the CPU or GPU, as both have hardware decoding support these days, or to fall back to software decoding because the specific combination of codec and bit depth wasn't supported by the hardware of choice.
Then there's the fact that Apple logically encodes video the camera records into a format that iMovie is well optimised for. If you encode video with your PC's GPU, it'll probably be just as snappy playing back while the iPhone video might still be struggling.
H.265 support in graphics cards and consumer processors has laughably lacked behind on mobile, probably because of licensing.
There's also the fact that a lot of video applications on Windows don't enable hardware decoding by default out of fear of encountering buggy drivers or hardware.
On mobile there's basically only one way to decode video, which makes use of all the phone's dedicated hardware, while on desktop applications can use a wide variety of codecs. Then comes the decision whether to decode on the CPU or GPU, as both have hardware decoding support these days, or to fall back to software decoding because the specific combination of codec and bit depth wasn't supported by the hardware of choice.
Then there's the fact that Apple logically encodes video the camera records into a format that iMovie is well optimised for. If you encode video with your PC's GPU, it'll probably be just as snappy playing back while the iPhone video might still be struggling.