Skip to content

Play a media file in Unity

Media Blocks SDK .Net

The SimplePlayer scene plays a local video file with the Media Blocks SDK .NET and renders it into a Unity RawImage. This article assumes you have imported the Unity package and applied the two required project settings — see Using VisioForge in Unity first.

Run the sample

  1. In the Project window open Assets/Scenes/SimplePlayer.unity (double-click it).
  2. In the Hierarchy select the RawImage GameObject. The MediaBlocksPlayer component is attached to it.
  3. In the Inspector, set File Path to an absolute path to a local media file.
  4. Press ▶ Play — the video appears in the Game view and audio plays through the system default device.

SimplePlayer scene Hierarchy: Canvas with RawImage, EventSystem, Main Camera

MediaBlocksPlayer component in the Inspector with the File Path field

The RawImage is blank until you press Play

The video texture is created at runtime, so the RawImage shows nothing in edit mode.

Inspector fields

Field Default Description
File Path C:\Samples\!video.avi Absolute path to the media file to play.
Auto Play On Start true Start playback automatically in Start().
Render Audio true Render audio through the system default device.
Use Test Pattern false Play a synthetic test pattern instead of the file (diagnostic baseline).
Aspect Mode Letterbox How the video is fitted into the RawImage: Stretch, Letterbox, or Crop.

The pipeline

MediaBlocksPlayer builds this pipeline:

graph LR;
    src[UniversalSourceBlock] -->|video| sink["BufferSinkBlock (RGBA)"];
    sink --> view["VisioForgeVideoView (Texture2D)"];
    src -->|audio, optional| audio[AudioRendererBlock];

The core of PlayAsync:

_pipeline = new MediaBlocksPipeline();

_videoSink = new BufferSinkBlock(VideoFormatX.RGBA);
_videoSink.OnVideoFrameBuffer += _videoView.OnFrameBuffer;

// ignoreMediaInfoReader:true skips the media pre-probe (it can fail under the Unity
// runtime); the codec is negotiated when the pipeline starts.
var settings = await UniversalSourceSettings.CreateAsync(
    filePath, renderVideo: true, renderAudio: _renderAudio, ignoreMediaInfoReader: true);

_source = new UniversalSourceBlock(settings);
_pipeline.Connect(_source.VideoOutput, _videoSink.Input);

if (_renderAudio && _source.AudioOutput != null)
{
    _audioRenderer = new AudioRendererBlock();
    _pipeline.Connect(_source.AudioOutput, _audioRenderer.Input);
}

await _pipeline.StartAsync();

UniversalSourceBlock auto-detects the container and codec. The audio branch is connected only when the file has an audio stream (_source.AudioOutput != null).

Use it in your own scene

You do not have to use the sample scene:

  1. Add a Canvas → Raw Image (GameObject → UI → Raw Image).
  2. Select the Raw Image and Add Component → MediaBlocksPlayer.
  3. Set File Path and press ▶ Play.

The aspect handling (Stretch / Letterbox / Crop), the RawImage layout, and the vertical flip are handled for you by the bundled VisioForgeVideoView — you do not write any texture code. To switch the same GameObject to RTSP playback, swap MediaBlocksPlayer for RTSPViewerPlayer (see View an RTSP camera).

Frequently Asked Questions

Which video and audio formats can it play?

The package bundles FFmpeg/libav, so common formats decode out of the box — MP4, MKV, AVI, MOV with H.264/H.265, MPEG-4, plus MP3/AAC audio, among others. UniversalSourceBlock auto-detects the format.

Can I change the file at runtime?

Yes. Set the FilePath property (or call PlayAsync(path)) and the player rebuilds the pipeline for the new file.

How do I control how the video fits the RawImage?

Use the Aspect Mode field: Stretch (fill, may distort), Letterbox (fit with bars), or Crop (fill and crop the overflow).

Does audio play too?

Yes, when Render Audio is enabled and the file has an audio track — audio plays through the system default device. The audio branch is skipped automatically for video-only files.

See Also