MediaPlayerElement cannot display text in subtitles

[qian-o]

Describe the bug

WinUI:

Steps to reproduce the bug

1.Create a MediaPlayerElement control.
2.Create a MediaSource and add a TimedTextSource instance to ExternalTimedTextSources.
3.The Source property of the MediaPlayerElement binds to the MediaSource

Expected behavior

No response

Screenshots

No response

NuGet package version

Windows App SDK 1.2.1: 1.2.221116.1

Packaging type

Packaged (MSIX)

Windows version

Windows 11 version 22H2 (22621, 2022 Update)

IDE

Visual Studio 2022

Additional context

No response

[Loganeek]

It seems the problem of the default caption style.

Try:

1. Go to "Settings > Accessibility > Captions > Caption style > Edit".
2. Change the text effects "None" to "Uniform" or others.

before	after

It works for me.

[qian-o]

Thank you for your response, but I have already found an alternative to MediaPlayerElement.

[softworkz]

Here's a non-programmatic solution. When you merge this REG file, it will add a captioning theme with empty configuration, named "Controlled by Application" and sets it as active.

After that, all subtitle styles are controlled by the application again (TimedTextStyle).

WindowsCaptionsDefaultProfile.zip

[DmitriyKomin]

@qian-o, thank you for reporting the issue. I can confirm CC text is not rendered when Effects is set to None or Drop Shadow (but does render with Raised/Depressed/Uniform). This is a regression from the initial WASDK preview release containing MediaPlayerElement (1.2.220902.1-preview1). I will continue investigating this further.

[softworkz]

I will continue investigating this further.

@DmitriyKomin - no need. I did all the work already: #9126

[DmitriyKomin]

@qian-o, I can confirm the issue is fixed internally for WinAppSDK 1.6. Specifically, captions weren't rendering for 2 out of the 5 possible Edge Effects settings - None and Drop Shadow. In these cases - where we don't generate SpriteVisuals to simulate an effect - layout never got run on the underlying TextBlock, causing a 0 size for the SpriteVisual backing the CompositionVisualSurface WinUI3 uses to render captions. The fix ensures UpdateLayout() is called on the TextBlock for all Edge Effects settings.

@softworkz, note this was a bug in WinUI3 CC rendering unrelated to the other issues raised around MPE CC rendering in #9126. I will make sure to follow up on the other ones separately.

[softworkz]

@softworkz, note this was a bug in WinUI3 CC rendering unrelated to the other issues raised around MPE CC rendering in #9126. I will make sure to follow up on the other ones separately.

Excellent, thanks!

[qian-o]

@qian-o, I can confirm the issue is fixed internally for WinAppSDK 1.6. Specifically, captions weren't rendering for 2 out of the 5 possible Edge Effects settings - None and Drop Shadow. In these cases - where we don't generate SpriteVisuals to simulate an effect - layout never got run on the underlying TextBlock, causing a 0 size for the SpriteVisual backing the CompositionVisualSurface WinUI3 uses to render captions. The fix ensures UpdateLayout() is called on the TextBlock for all Edge Effects settings.

@softworkz, note this was a bug in WinUI3 CC rendering unrelated to the other issues raised around MPE CC rendering in #9126. I will make sure to follow up on the other ones separately.

Thank you for your participation. Looking forward to further improvements in the next version. Much appreciated.

[softworkz]

@DmitriyKomin - A general note on the whole subject:

When working with subtitles/closedcaptions, you are using TimedTextStyle, which provides very detailed settings to control the appearance of subtitles, but one thing is missing:

There is no "Effect" property. This can only be controlled from the Windows settings app and in code, it can only be read but not changed: ClosedCaptionProperties.FontEffect.

Also, the latter properties partially (really weird and stupid) overrride those which you can set with TimedTextStyle.
All that doesn't fit together and doesn't make sense the way it is and needs architectural review in general.
But first of all, I hope the worst parts can be fixed in some way....