CODEWITHSUNDEEP
winapivideoms-media-foundation
liang.good
liang.good

Reputation: 273

how to use async IMFTranform?

  1. I create IMFTransform
  2. Set Input Media Type of NV12
  3. Set Output Media Type of H264

how to use async? should i use IMFMediaEventGenerator?

but I can not query it using hr= transform.QueryInterface(__uuidof(IMFMediaEventGenerator),(void**)&pEventGenerator);

and what I want it when I need ProcessInput or ProcessOutput it will inform me. so I do not need while(true) right?

Upvotes: -1

Views: 67

Answers (1)

Roman Ryltsov
Roman Ryltsov

Reputation: 69724

The transforms can be synchronous (originally there were only these), and then also asynchronous. Asynchronous MFTs are different, they have significantly different workflow.

When you use higher level Media Foundation APIs, they are all capable to work with both types of transforms, however if you want to consume them directly you have to implement both models, or at the very least apply the appropriate model.

You must use event generator interface IMFMediaEventGenerator and consume events. The events tell you when it is time to do ProcessInput and ProcessOutput, you are not supposed to call this randomly or in a poll fashion, only in response to events you receive.

Upvotes: 1

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