Update CEF to support multi-process structure required for macOS

PatTheMav commented 3 years ago

Description

This PR adds the necessary build-system changes for modern CEF versions running on macOS and re-enables features.

Motivation and Context

To ensure compatibility with macOS Catalina and beyond Chromium requires to be run via multiple processes on macOS with the single-process model not being supported anymore.

As such Chromium requires 3 additional helper apps to exist (GPU, Plugin and Renderer) and also the main helper to be packaged in a macOS app bundle. The helpers also require specific entitlements to allow JIT compilation.

This PR adds the necessary changes to cmake to build these helpers. Changes to OBS packaging are also required but are addressed in a PR on the main repo.

Note: The helpers for all intents and purposes replace obs-browser-page on macOS. Also the option to deploy the browser is now assumed by default as CEF will not run when not linked/placed in a macOS app bundle.

How Has This Been Tested?

OBS built with CEF and tested with multiple browser sources.
H.264 and VP9 video playback tested in browser sources

Types of changes

Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

[x] My code has been run through clang-format.
[x] I have read the contributing document.
[x] My code is not on the master branch.
[x] The code has been tested.
[x] All commit messages are properly formatted and commits squashed where appropriate.
[x] I have included updates to all appropriate documentation.

PatTheMav commented 3 years ago

This requires our planned CEF 4183 update to work.

PatTheMav commented 3 years ago

After a quick chat with @pkviet we decided to add a BROWSER_LEGACY flag that will allow to easily fall back on 3770-era behaviour.

I'll also investigate adding a similar flag to the build scripts and Github workflow to allow a fallback if excrements start hitting a blade-based appliance.

PatTheMav commented 3 years ago

Added the BROWSER_LEGACY flag, it's automatically set by the updated scripts in https://github.com/obsproject/obs-studio/pull/3805 if CEF_BUILD_VERSION=3770 or lower is defined.

WizardCM commented 3 years ago

@pkviet have you tested this branch locally? If so, please mark it as approved.

PatTheMav commented 3 years ago

There are still a few fixes missing that I noticed while dogfooding this, will push an update tomorrow/later.

PatTheMav commented 3 years ago

After defeating clang_format once more, I successfully pushed the small changes I made recently. With those:

CEF is loaded at runtime on macOS as suggested by the CEF developers, CefScopedLibraryLoader is used, which requires the helper-app infrastructure to work
The Win32-only call CefEnableHighDPISupport has been disabled for other platforms
Cmake files have been adapted to not link CEF directly on macOS

The second commit adds the BROWSER_LEGACY flag to all those changes, "undoing" them if set.

The third commit adds a little change required to make texture sharing work with CEF 4183 later.

PatTheMav commented 3 years ago

Just pushed a new iteration of the commits - main changes:

SHARED_TEXTURE_SUPPORT_ENABLED is now a simple define set by cmake, no futzing around with a pre-configured header file now (it's also not really that experimental anymore)
I've disabled keychain access for the plugin; we disable sandboxing and other security features and thus should not get access to the device keychain on macOS
As before macOS now uses the CefLibraryLoader and does not link to CEF directly anymore
CefExecuteProcess is only executed on Windows, it should not be called on macOS due to its helper-process architecture
SendExternalBeginFrame doesn't seem to work properly on macOS, so I made it a Windows-only feature for now
As an alternative the canvas framerate is now set for browser sources by default, but is not adjusted automatically
The texture created from the shared IOSurface does not have pre-multiplied alpha, so OBS_EFFECT_DEFAULT_RECT is used if texture sharing is enabled
As before the second commit introduces the flag BROWSER_LEGACY which, combined with CEF v3770, allows building a "last-known good" version of the plugin

I'll give this a whirl with different build configs tomorrow, but it's looking good so far. With SendExternalBeginFrame disabled I was not able to get the GPU Helper to crash and got solid 60fps in FishGL with 200+ fish and somewhere between 4-8% CPU and ~20% GPU usage (GPU Helper + OBS itself).

obsproject / obs-browser