static async Task DoAsync(this MediaEngine engine, CancellationToken token, Action action, Func <MediaEngineEvent, bool> completionEvent)
{
var tcs = new TaskCompletionSource <Unit>();
token.Register(() => tcs.TrySetCanceled());
MediaEngineNotifyDelegate @delegate = (e, p1, p2) =>
{
if (completionEvent(e))
{
tcs.TrySetResult(Unit.Default);
}
else if (e == MediaEngineEvent.Abort)
{
tcs.TrySetCanceled();
}
else if (e == MediaEngineEvent.Error)
{
tcs.TrySetException(new Exception($"An error occured in the pipeline."));
}
};
try
{
engine.PlaybackEvent += @delegate;
action();
await tcs.Task;
}
finally
{
engine.PlaybackEvent -= @delegate;
}
}
private void OnPlaybackEvent(MediaEngineEvent mediaevent, long param1, int param2)
{
MediaEngineNotifyDelegate handler = PlaybackEvent;
if (handler != null)
{
handler(mediaevent, param1, param2);
}
}
/// <summary>
/// Initializes an instance of the <see cref="MediaEngine"/> class.
/// </summary>
/// <param name="factory"></param>
/// <param name="attributes"></param>
/// <param name="createFlags"> </param>
public MediaEngine(MediaEngineClassFactory factory, MediaEngineAttributes attributes = null, MediaEngineCreateFlags createFlags = MediaEngineCreateFlags.None, MediaEngineNotifyDelegate playbackCallback = null)
{
// Create engine attributes if null
attributes = attributes ?? new MediaEngineAttributes();
PlaybackEvent = playbackCallback;
// Setup by default the MediaEngine notify as it is mandatory
mediaEngineNotifyImpl = new MediaEngineNotifyImpl(this);
try
{
attributes.Set(MediaEngineAttributeKeys.Callback, new ComObject(MediaEngineNotifyShadow.ToIntPtr(mediaEngineNotifyImpl)));
factory.CreateInstance(createFlags, attributes, this);
} catch
{
mediaEngineNotifyImpl.Dispose();
mediaEngineNotifyImpl = null;
throw;
}
}
/// <summary>
/// Initializes an instance of the <see cref="MediaEngine"/> class.
/// </summary>
/// <param name="factory"></param>
/// <param name="attributes"></param>
/// <param name="createFlags"> </param>
/// <param name="playbackCallback"></param>
/// <msdn-id>hh447921</msdn-id>
/// <unmanaged>HRESULT IMFMediaEngineClassFactory::CreateInstance([In] MF_MEDIA_ENGINE_CREATEFLAGS dwFlags,[In] IMFAttributes* pAttr,[Out, Fast] IMFMediaEngine** ppPlayer)</unmanaged>
/// <unmanaged-short>IMFMediaEngineClassFactory::CreateInstance</unmanaged-short>
public MediaEngine(MediaEngineClassFactory factory, MediaEngineAttributes attributes = null, MediaEngineCreateFlags createFlags = MediaEngineCreateFlags.None, MediaEngineNotifyDelegate playbackCallback = null)
{
// Create engine attributes if null
attributes = attributes ?? new MediaEngineAttributes();
if (playbackCallback != null)
{
PlaybackEvent += playbackCallback;
}
// Setup by default the MediaEngine notify as it is mandatory
mediaEngineNotifyImpl = new MediaEngineNotifyImpl(this);
try
{
attributes.Set(MediaEngineAttributeKeys.Callback, new ComObject(MediaEngineNotifyShadow.ToIntPtr(mediaEngineNotifyImpl)));
factory.CreateInstance(createFlags, attributes, this);
} catch
{
mediaEngineNotifyImpl.Dispose();
mediaEngineNotifyImpl = null;
throw;
}
}
