4K streaming on Apple TV app on 4K Chromecast with Google TV

I have a Chromecast with Google TV 4K connected to Optoma UHZ45 4K projector. When playing 4K movies (using Apple TV app) that I purchased on iTunes, I do not get 4K. The video quality seems to be 1080p only, much inferior to 4K movies that I purchased and play on YouTube.

Hey ZClawII,

We'd be happy to help out. As long as the content you're viewing has a 4K version and you're using a supported device and outputting on a 4K TV, it should work.

This is further outlined in the following details:

Here's what you need to watch the highest-quality video available

• Video content with a high-quality version that you purchased or rented.

• A device capable of playing high-quality video content:

• See Mac models that support HDR video.

• Refer to the tech specs for your iPhone, iPad, or Apple TV, or your smart TV or streaming device to see if it supports playing 4K, HDR, or Dolby Vision videos.

• On tv.apple.com, you need a compatible device and display that can play the highest quality stream available:

• In Safari on a Mac with the latest version of macOS, compatible content may play in up to 4K HDR.

• In the latest version of Google Chrome, Mozilla Firefox, or Microsoft Edge on a Mac, Windows PC, or Android, compatible content will play in up to 1080p (HD).

• The latest versions of iOS or iPadOS, macOS, or tvOS.

• An Internet connection fast enough to watch high-quality content.

If you buy or rent a movie from the Apple TV app, you can stream it on the device that you bought it on and any of your other devices, as long as you're signed in to all of your devices with the same Apple ID. Learn what to do if you can't stream movies or TV shows. Your iPhone, iPad, iPod touch, Mac, PC, or Apple TV automatically play the best quality of video available for the device and your Internet connection.

If you purchase or rent a standard definition (SD) video, you can't play higher-quality versions.

If you see a message that your device might not be able to play 1080p (HD) or 4K videos

When you buy or rent a movie or TV show from the Apple TV app, the device that you're using might warn you that it can't play 1080p (HD) or 4K video content. Instead, your device automatically plays the highest-quality version of that video that it can. Your other Apple devices will play the higher-quality version if they're compatible.

As it states above, you'll also be notified if the content you're viewing isn't able to be played in 4K and instead would use the highest-quality version that it can.

This is all outlined in the following resource: Find movies with 4K, HDR, Dolby Vision, or Dolby Atmos in the Apple TV app - Apple Support

We hope this helps.

Take care!