fix: Properly display PosterSource for MediaPlayerElement on all platforms

src/AddIns/Uno.UI.MediaPlayer.Skia.Gtk/GTKMediaPlayer.cs

@@ -33,8 +33,6 @@ public partial class GtkMediaPlayer : FrameworkElement
 	private double _playbackRate;
 	private Rect _transportControlsBounds;
 	private Windows.UI.Xaml.Media.Stretch _stretch = Windows.UI.Xaml.Media.Stretch.Uniform;
-	private readonly ImmutableArray<string> audioTagAllowedFormats = ImmutableArray.Create(".MP3", ".WAV");
-	private readonly ImmutableArray<string> videoTagAllowedFormats = ImmutableArray.Create(".MP4", ".WEBM", ".OGG");
 	private readonly MediaPlayerPresenter _owner;
 
 	public GtkMediaPlayer(MediaPlayerPresenter owner)
@@ -77,10 +75,10 @@ public partial class GtkMediaPlayer : FrameworkElement
 	public double VideoRatio { get; set; }
 
 	public bool IsVideo
-		=> videoTagAllowedFormats.Contains(Path.GetExtension(Source), StringComparer.OrdinalIgnoreCase);
+		=> _mediaPlayer?.Media?.Tracks?.Any(x => x.TrackType == TrackType.Video) == true;
 
 	public bool IsAudio
-		=> audioTagAllowedFormats.Contains(Path.GetExtension(Source), StringComparer.OrdinalIgnoreCase);
+		=> _mediaPlayer?.Media?.Tracks?.Any(x => x.TrackType == TrackType.Video) == true;
 
 	public void Play()
 	{

src/AddIns/Uno.UI.MediaPlayer.Skia.Gtk/GTKMediaPlayer.events.cs

@@ -327,6 +327,7 @@ public partial class GtkMediaPlayer
 			media.Parse(MediaParseOptions.ParseNetwork);
 			_mediaPlayer.Media = media;
 			AddMediaEvents();
+			Duration = (double)(_videoView?.MediaPlayer?.Media?.Duration / 1000 ?? 0);
 			OnSourceLoaded?.Invoke(this, EventArgs.Empty);
 
 			UpdateVideoStretch();
@@ -431,11 +432,6 @@ public partial class GtkMediaPlayer
 			media.MetaChanged += OnStaticMetaChanged;
 			media.StateChanged += OnStaticStateChanged;
 			media.ParsedChanged += OnStaticParsedChanged;
-
-			Duration = (double)(_videoView?.MediaPlayer?.Media?.Duration / 1000 ?? 0);
-			OnSourceLoaded?.Invoke(this, EventArgs.Empty);
-
-			UpdateVideoStretch();
 		}
 		else
 		{
@@ -587,11 +583,6 @@ public partial class GtkMediaPlayer
 		}
 	}
 
-	private void OnMediaPlayerTimeChangeIsMediaParse(object? sender, MediaPlayerTimeChangedEventArgs el)
-	{
-		AddMediaEvents();
-	}
-
 	private void OnEndReached()
 	{
 		if (this.Log().IsEnabled(Microsoft.Extensions.Logging.LogLevel.Debug))

src/AddIns/Uno.UI.MediaPlayer.Skia.Gtk/MediaPlayerExtension.cs

@@ -193,7 +193,6 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 				throw new InvalidOperationException("Unsupported media source type");
 		}
 		ApplyVideoSource();
-		Events?.RaiseMediaOpened();
 		Events?.RaiseSourceChanged();
 
 		// Set the player back to the paused state, so that the
@@ -337,6 +336,8 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 
 	public double AudioBalance { get; set; }
 
+	public bool? IsVideo { get; set; }
+
 	public void SetTransportControlsBounds(Rect bounds)
 	{
 		_player?.SetTransportControlsBounds(bounds);

src/AddIns/Uno.UI.MediaPlayer.Skia.Gtk/MediaPlayerExtension.events.cs

@@ -37,6 +37,8 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 		{
 			if (_player is not null)
 			{
+				IsVideo = _player.IsVideo;
+
 				if (mp.IsVideo && Events is not null)
 				{
 					Events?.RaiseVideoRatioChanged(global::System.Math.Max(1, (double)mp.VideoRatio));
@@ -66,6 +68,11 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 				}
 			}
 		}
+
+		if (Events is not null)
+		{
+			Events?.RaiseMediaOpened();
+		}
 	}
 
 	public void OnError(object? sender, object what)

src/AddIns/Uno.UI.MediaPlayer.WebAssembly/MediaPlayerExtension.cs

@@ -147,6 +147,8 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 	public bool CanSeek
 		=> true;
 
+	public bool? IsVideo { get; set; }
+
 	public MediaPlayerAudioDeviceType AudioDeviceType { get; set; }
 
 	public MediaPlayerAudioCategory AudioCategory { get; set; }
@@ -301,7 +303,6 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 			}
 
 			ApplyVideoSource();
-			Events?.RaiseMediaOpened();
 			Events?.RaiseSourceChanged();
 		}
 		catch (global::System.Exception ex)
@@ -480,6 +481,8 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 
 			NaturalDuration = TimeSpan.FromSeconds(_player.Duration);
 
+			IsVideo = _player.IsVideo;
+
 			if (mp.IsVideo && Events is not null)
 			{
 				try
@@ -509,6 +512,11 @@ public partial class MediaPlayerExtension : IMediaPlayerExtension
 
 			_isPlayerPrepared = true;
 		}
+
+		if (Events is not null)
+		{
+			Events?.RaiseMediaOpened();
+		}
 	}
 
 	void OnError(object? sender, object what)

src/SamplesApp/UITests.Shared/UITests.Shared.projitems

@@ -3294,6 +3294,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\MediaPlayerElement\MediaPlayerElement_Mp3_Extension.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\MediaPlayerElement\MediaPlayerElement_Mov_Extension.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -7150,6 +7154,9 @@
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\MediaPlayerElement\MediaPlayerElement_Mkv_Extension.xaml.cs">
       <DependentUpon>MediaPlayerElement_Mkv_Extension.xaml</DependentUpon>
     </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\MediaPlayerElement\MediaPlayerElement_Mp3_Extension.xaml.cs">
+      <DependentUpon>MediaPlayerElement_Mp3_Extension.xaml</DependentUpon>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\MediaPlayerElement\MediaPlayerElement_Mov_Extension.xaml.cs">
       <DependentUpon>MediaPlayerElement_Mov_Extension.xaml</DependentUpon>
     </Compile>

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/MediaPlayerElement/MediaPlayerElement_Mp3_Extension.xaml

+<Page x:Class="UITests.Shared.Windows_UI_Xaml_Controls.MediaPlayerElement.MediaPlayerElement_Mp3_Extension"
+	  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+	  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+	<MediaPlayerElement Source="https://uno-assets.platform.uno/tests/audio/Getting_Started_with_Uno_Platform_and_Visual_Studio_Code.mp3"
+						PosterSource="https://uno-assets.platform.uno/tests/thumbnails/Getting_Started_with_Uno_Platform_and_Visual_Studio_Code.png"
+						AreTransportControlsEnabled="True"
+						AutoPlay="True" />
+
+</Page>

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/MediaPlayerElement/MediaPlayerElement_Mp3_Extension.xaml.cs

+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Uno.UI.Samples.Controls;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Controls.Primitives;
+using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Navigation;
+
+namespace UITests.Shared.Windows_UI_Xaml_Controls.MediaPlayerElement
+{
+	[SampleControlInfo("MediaPlayerElement", "Using .mp3 (Audio only)", description: "MediaPlayerElement test using .mp3 (Audio only) with PosterSource")]
+	public sealed partial class MediaPlayerElement_Mp3_Extension : Page
+	{
+		public MediaPlayerElement_Mp3_Extension()
+		{
+			this.InitializeComponent();
+		}
+	}
+}

src/Uno.UI/UI/Xaml/Controls/MediaPlayerElement/MediaPlayerElement.cs

@@ -249,7 +249,11 @@ namespace Windows.UI.Xaml.Controls
 		{
 			_ = Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
 			{
-				TogglePosterImage(false);
+				// Always show the poster source for audio content.
+				if (session.IsVideo)
+				{
+					TogglePosterImage(false);
+				}
 			});
 		}
 
@@ -326,11 +330,15 @@ namespace Windows.UI.Xaml.Controls
 					&& AutoPlay)
 				{
 					MediaPlayer.Play();
-					TogglePosterImage(false);
 				}
 			}
 		}
 
+		// The PosterSource is displayed in the following situations:
+		//  - When a valid source is not set.For example, Source is not set, Source was set to Null, or the source is invalid (as is the case when a MediaFailed event fires).
+		//  - While media is loading. For example, a valid source is set, but the MediaOpened event has not fired yet.
+		//  - When media is streaming to another device.
+		//  - When the media is audio only.
 		private void TogglePosterImage(bool showPoster)
 		{
 			if (PosterSource != null)
@@ -365,10 +373,8 @@ namespace Windows.UI.Xaml.Controls
 				_mediaPlayerPresenter?.ApplyStretch();
 			}
 
-			if (!IsLoaded && MediaPlayer.PlaybackSession.PlaybackState == MediaPlaybackState.None)
-			{
-				TogglePosterImage(true);
-			}
+			// For video content, show the poster source until it is ready to be displayed.
+			TogglePosterImage(true);
 
 			if (!_isTransportControlsBound)
 			{

src/Uno.UWP/Media/Playback/IMediaPlayerExtension.cs

@@ -89,6 +89,11 @@ namespace Uno.Media.Playback
 		/// </summary>
 		TimeSpan Position { get; set; }
 
+		/// <summary>
+		/// Determines if the current media content is video
+		/// </summary>
+		bool? IsVideo { get; }
+
 		/// <summary>
 		/// Sets the transport controls bounds so that video can be displayed around controls
 		/// </summary>

src/Uno.UWP/Media/Playback/MediaPlayer.Android.cs

@@ -155,8 +155,6 @@ namespace Windows.Media.Playback
 				SetVideoSource(uri);
 
 				_player.PrepareAsync();
-
-				MediaOpened?.Invoke(this, null);
 			}
 			catch (global::System.Exception ex)
 			{
@@ -270,13 +268,17 @@ namespace Windows.Media.Playback
 
 		public void OnPrepared(AndroidMediaPlayer mp)
 		{
-			PlaybackSession.NaturalDuration = TimeSpan.FromMilliseconds(_player.Duration);
+			if (mp is not null)
+			{
+				PlaybackSession.NaturalDuration = TimeSpan.FromMilliseconds(_player.Duration);
 
-			VideoRatioChanged?.Invoke(this, (double)mp.VideoWidth / global::System.Math.Max(mp.VideoHeight, 1));
+				VideoRatioChanged?.Invoke(this, (double)mp.VideoWidth / global::System.Math.Max(mp.VideoHeight, 1));
 
-			if (PlaybackSession.PlaybackState == MediaPlaybackState.Opening)
-			{
-				UpdateVideoStretch(_currentStretch);
+				IsVideo = mp.GetTrackInfo()?.Any(x => x.TrackType == MediaTrackType.Video) == true;
+
+				if (PlaybackSession.PlaybackState == MediaPlaybackState.Opening)
+				{
+					UpdateVideoStretch(_currentStretch);
 
 				if (_isPlayRequested)
 				{
@@ -293,7 +295,10 @@ namespace Windows.Media.Playback
 				}
 			}
 
-			_isPlayerPrepared = true;
+				_isPlayerPrepared = true;
+
+				MediaOpened?.Invoke(this, null);
+			}
 		}
 
 		public bool OnError(AndroidMediaPlayer mp, MediaError what, int extra)
@@ -383,6 +388,8 @@ namespace Windows.Media.Playback
 			}
 		}
 
+		public bool IsVideo { get; set; }
+
 		internal void UpdateVideoStretch(VideoStretch stretch)
 		{
 			_currentStretch = stretch;

src/Uno.UWP/Media/Playback/MediaPlayer.iOSmacOS.cs

@@ -246,9 +246,6 @@ namespace Windows.Media.Playback
 
 				// Adapt pitch to prevent "metallic echo" when changing playback rate
 				_player.CurrentItem.AudioTimePitchAlgorithm = AVAudioTimePitchAlgorithm.TimeDomain;
-
-				MediaOpened?.Invoke(this, null);
-
 			}
 			catch (Exception ex)
 			{
@@ -358,6 +355,8 @@ namespace Windows.Media.Playback
 		{
 			if (_player?.CurrentItem != null)
 			{
+				IsVideo = _player.CurrentItem.Tracks?.Any(x => x.AssetTrack.FormatDescriptions.Any(x => x.MediaType == CMMediaType.Video)) == true;
+
 				if (_player.CurrentItem.Status == AVPlayerItemStatus.Failed || _player.Status == AVPlayerStatus.Failed)
 				{
 					OnMediaFailed();
@@ -377,6 +376,11 @@ namespace Windows.Media.Playback
 						_player.Play();
 					}
 				}
+
+				if (_player.Status == AVPlayerStatus.ReadyToPlay)
+				{
+					MediaOpened?.Invoke(this, null);
+				}
 			}
 		}
 
@@ -473,6 +477,8 @@ namespace Windows.Media.Playback
 			}
 		}
 
+		public bool IsVideo { get; set; }
+
 		private void OnSeekCompleted(bool finished)
 		{
 			if (finished)

src/Uno.UWP/Media/Playback/MediaPlayer.others.cs

@@ -160,6 +160,8 @@ namespace Windows.Media.Playback
 			}
 		}
 
+		public bool IsVideo => _extension?.IsVideo ?? false;
+
 		public void SetUriSource(global::System.Uri value)
 			=> _extension?.SetUriSource(value);