The new Apple TV supports QMS VRR (Quick Media Switching, Variable Refresh Rate) so that when switching from one framerate to another (like 24 to 60Hz) there isn’t a screen blackout.
However, changing resolution or dynamic ranges, still result in blackouts. But why?
I’m thinking this is an HDMI limitation/issue, but why is this not a problem for iPhones or built in apps?
The speed of the change of TV is dependent on the TV, not the device supplying signal. TVs dont prioritize the switching and there is loads going on to match audio and video. HDMI standard supports many resolutions, if in the AppleTV select match resolution then it will convert so the TV will not have to change.
My initial thought is because with iPhone, Apple makes both the hardware and software, this the integration is better.
With Apple TV and a television, Apple can’t control how every brand/model of television will respond.
TVs cant instantly switch because of the syncing of audio and video, all video signals are heavily processed in all modern TVs, Audio is generally decoded. to Match this delay of recording vs processing TVs need a few ms to buffer process and sync. This will always be the case using HDMI as the standard offers no advance warning just a new data rate / resolution.