StreamMediaSource for MediaElement

[matt-goldman]

MediaElement currently supports loading media from URL, file, or embedded resource. I needed a way to load media from a memory stream.

I'm not sure whether this is something others need - I personally needed this because I'm building an app with some specific security requirements. Playing back media stored in the app would require saving it to file outside the app's protected environment, which would violate some of the security standards. Not sure if there are other use cases, but for example recording a video or audio, then viewing it or listening to it before saving. Again not sure whether this is something people actually need or not, but it seems valuable to me.

Anyway because I needed this, I forked the repo and added it on my fork. You can see it here: https://github.com/matt-goldman/Maui-1/tree/add-stream-media-source

I've added StreamMediaSource and updated the sample app to include a demo page for it. API is simple:

/// <summary>
/// Creates a <see cref="StreamMediaSource"/> from a <see cref="Stream"/>.
/// </summary>
/// <param name="stream">The stream to use as a media source.</param>
/// <returns>A <see cref="StreamMediaSource"/> instance.</returns>
public static StreamMediaSource FromStream(Stream stream) => new StreamMediaSource { Stream = stream };

Just trying to gauge here whether others see value in this and whether there's any interest in a feature proposal for this.

[ne0rrmatrix]

This seems like a great idea! I will add it to our monthly meeting if there is enough interest. If you can find more like minded people who would like this it is more likely it can be implemented. Looks like you have done most if not all of the work already. We have monthly meetings where we discuss the toolkit on Youtube. I hope we can get 10 upvotes from the community so we can start the ball rolling.

Here is a link to our monthly standup page where we link what we have talked about with details about what happened. https://github.com/CommunityToolkit/Maui/wiki/Monthly-Standups

Here is a link to how we add new features: https://github.com/CommunityToolkit/Maui/wiki/Submitting-a-New-Feature This should provide enough information to get you started. I will say the hard part is already done! Once you have the upvotes to around 10 we can move forward with adding it our monthly meeting. Then once it is voted on and accepted as a proposal I would be happy to champion it. More about the whole process is available above. I did simplify it a bit in this paragraph and skip a few things but I hope to see this in the toolkit!

[matt-goldman]

Thanks @ne0rrmatrix! I'll see if I can generate some interest.

[ne0rrmatrix]

I added it to todays schedule for discussion in our monthly meeting

[ne0rrmatrix]

I'm going to paste a markup file from @matt-goldman that provides some details about how this can be implemented.

StreamMediaSource Implementation

Overview

This document summarizes the implementation of StreamMediaSource, a new media source type that allows passing a .NET Stream directly to MediaElement for playback.

What Was Added

Core Class

• StreamMediaSource.shared.cs: New MediaSource subclass that wraps a .NET Stream
  • Includes Stream bindable property
  • Implicit operators for convenient Stream conversion
  • Factory method MediaSource.FromStream(Stream)
  • Follows the same pattern as FileMediaSource, UriMediaSource, and ResourceMediaSource

Platform-Specific Implementations

Windows (MediaManager.windows.cs)

• Implementation: Uses WinMediaSource.CreateFromStream() with IRandomAccessStream
• Status: ✅ Fully Supported
• Method: Leverages WindowsRuntimeStreamExtensions.AsRandomAccessStream() to convert .NET streams to Windows Runtime streams
• Helper: StreamExtensions.windows.cs - Provides GetMimeType() extension method

Android (MediaManager.android.cs)

• Implementation: Custom StreamDataSource implementing ExoPlayer's IDataSource interface
• Status: ✅ Fully Supported
• Method: Created custom data source that reads from .NET Stream and integrates with ExoPlayer's ProgressiveMediaSource
• Helper: StreamDataSource.android.cs - Contains StreamDataSource and StreamDataSourceFactory classes
• Features:
  • Supports seeking if stream is seekable
  • Handles range requests
  • Proper resource cleanup and disposal

iOS/macOS (MediaManager.macios.cs)

• Implementation: Uses AVAssetResourceLoaderDelegate to provide custom data source
• Status: ✅ Fully Supported
• Method: Creates custom URL scheme (stream://media) and uses AVAssetResourceLoader to intercept loading requests
• Helper: StreamAssetResourceLoader.macios.cs - Custom delegate that feeds stream data to AVPlayer
• Features:
  • Works with both audio and video
  • Supports seeking if stream is seekable
  • Integrates seamlessly with existing AVPlayer architecture

Tizen (MediaManager.tizen.cs)

• Status: ❌ Not Supported
• Reason: Platform limitation - throws NotSupportedException with helpful message

Usage Examples

// Using factory method
MediaSource source = MediaSource.FromStream(myStream);

// Using implicit conversion
MediaSource source = myStream;

// Direct instantiation
var streamSource = new StreamMediaSource { Stream = myStream };

// Assigning to MediaElement
mediaElement.Source = MediaSource.FromStream(myStream);

Files Modified

New Files

1. MediaSource/StreamMediaSource.shared.cs - Core class
2. Platforms/Android/StreamDataSource.android.cs - Android implementation
3. Views/StreamAssetResourceLoader.macios.cs - iOS/macOS implementation
4. Views/StreamExtensions.windows.cs - Windows helper extensions

Modified Files

1. MediaSource/MediaSource.shared.cs - Added FromStream() factory method
2. Views/MediaManager.android.cs - Added stream support via custom DataSource
3. Views/MediaManager.windows.cs - Added stream support via CreateFromStream()
4. Views/MediaManager.macios.cs - Added stream support via AVAssetResourceLoader
5. Views/MediaManager.tizen.cs - Added NotSupportedException for streams
6. Converters/MediaSourceConverter.shared.cs - Added StreamMediaSource case

Technical Details

Android Implementation

The Android implementation uses ExoPlayer's extensibility model:

• StreamDataSource implements IDataSource interface
• Reads data from .NET Stream on demand
• StreamDataSourceFactory creates instances for ExoPlayer
• Integrates with ProgressiveMediaSource.Factory

iOS/macOS Implementation

The iOS/macOS implementation uses Apple's official extension mechanism:

• Creates AVUrlAsset with custom URL scheme
• AVAssetResourceLoaderDelegate intercepts resource loading requests
• Provides stream data through AVAssetResourceLoadingDataRequest
• Supports both content information and data requests

Windows Implementation

The Windows implementation uses built-in .NET stream conversion:

• Converts .NET Stream to IRandomAccessStream using AsRandomAccessStream()
• Uses WinMediaSource.CreateFromStream() API
• Provides default MIME type (can be enhanced for better type detection)

Considerations

Stream Lifecycle

• Streams are not automatically disposed by the MediaElement
• Callers are responsible for managing stream lifetime
• Consider keeping streams open for the duration of playback
• Seeking requires seekable streams

MIME Type Detection

• Windows: Returns generic "application/octet-stream" by default
• iOS/macOS: Defaults to "video/mp4" assumption
• Future enhancement: Could detect MIME type from stream content (magic bytes)

Performance

• Streams should support efficient random access for best performance
• Non-seekable streams may have limited functionality
• Consider buffering strategies for network streams

Future Enhancements

1. MIME Type Detection: Implement magic byte detection to automatically determine content type
2. Tizen Support: Investigate if Tizen platform can support stream-based playback
3. Stream Properties: Add optional properties to StreamMediaSource for MIME type hint
4. Buffering Options: Add configurable buffering strategies for different stream types
5. Progress Reporting: Add stream read progress callbacks for monitoring

Link to example source changes:

main...matt-goldman:Maui-1:add-stream-media-source