CODEWITHSUNDEEP
c#directshowdirectshow.netvideo-recording
Malik Çelik
Malik Çelik

Reputation: 302

Graph restarts after monitor change

I have a DirectShow graph which records and displays a video source. When I move Video Renderer window to other monitor, what I recorded gets deleted and recording starts again. I searched and found this link which says changing monitor stops and starts the graph. How can I stop the graph from being restarted? I don't want to lose my recording while switching between monitors.

Thanks

Upvotes: 1

Views: 358

Answers (2)

Roman Ryltsov
Roman Ryltsov

Reputation: 69716

The behavior you are describing is basically behavior by design (even though the side effect is pretty much annoying and confusing). Moving a video renderer between the monitors makes it re-allocate hardware resources used to present video, and this in turn needs a state transition. For recording, state transition means opening and closing the file.

Your solution is to either split into presentation and recording graphs, or to use custom allocator/presenter to take care of presentation yourself the way you want. Supposedly, graph splitting (what Wimmel suggests in another answer) is the preferable way adding other degrees of freedom in particular.

Upvotes: 3

wimh
wimh

Reputation: 15232

There is probably a good reason that the EC_DISPLAY_CHANGED Message behaves that way, so I don't know what the disadvantages are when you handle this message yourself and don't restart the graph.

Instead you could separate the rendering graph from the recording using GMFBridge. Use one graph to capture and record. Use the second graph only for rendering, so restarting that graph would not stop the recording.

Edit: Possibly you need to disconnect before the second graph is restarted. That will mean you do need to process the EC_DISPLAY_CHANGED message, even if you use GMFBridge.

m_pController->BridgeGraphs(NULL, NULL);

Upvotes: 2

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