MacOS Catalina’s Fourth Update Drops For Devs Today, Apple Finally Phases Out iTunes

Apple is pretty consistent with updates and they have released macOS Catalina 4 for devs today. This update doesn’t have any API changes, but don’t install it on your primary machine since it’s an early build.

Prominent Changes

Apple is finally phasing out the iTunes app, but don’t worry they aren’t going away. They will just be divided in separate apps. iTunes had music, podcasts and TV clubbed in, but these are very broad so I think users will appreciate separate apps for these. The entire store, all your purchased songs and playlists will migrate to Apple’s new Music app. Podcasts that you subscribed will migrate to the new Podcasts app.

This update also brings the new sidecar feature which makes your existing iPad a second display for your MacBook. This allows you to drop and drag windows seamlessly from the iPad to your Mac and vice-versa. This also gets Apple Pencil integration, which can serve as a mouse alternative. Sidebar even adds a Touchbar to your iPad, functions similar to the TouchPads found in some MacBook Pro models.

To improve the Photos upgrade experience, Photos is testing database upgrades using a clone of the Photo Library. This clone doesn’t include the content of each photo but does include faces metadata and a thumbnail image of each person in your library. It also contains metadata such as the asset name and the geographic location of the photo. It is created at ~/Pictures/macOS 10.15 Pre-Upgrade Backup, and you can manually remove this backup at any time. The clone will be removed automatically before the final release of macOS 10.15.

From this release AppleEvents and AppleScripts that target an app on a remote system must authenticate as the same user on the remote system. An AppleEvent that targets an app running as a different user will receive a procNotFound error.

Smaller Changes

  • A new rendering mode in AVAudio Environment Node selects the best spatial audio rendering algorithm automatically based on the output device, users can also enable voice processing mode on AvAudio.
  • AVFoundation now supports encoding video with alpha channels using HEVC. Videos encoded in this manner are broadly supported in AVFoundation APIs and by Safari within web pages.
  • If the Mac you’re screen sharing with is running macOS 10.15 beta, you can now drag and drop onto the screen share.

This update has prominent changes although a lot was promised in WWDC 2019 and many of them are yet to come. Meanwhile, developers can download the Catalina 4 update using the Software Update mechanism in System Preferences. You can read the complete changelog here.


Indranil Chowdhury

Indranil is a Med school student and an avid gamer. He puts his absolute faith in Lord Gaben and loves to write. Crazy about the Witcher lore, he plays soccer too. When not playing games or writing, you can find him on 9gag spreading the Pcmasterrace propaganda.