Prerequisites
- Configure Agora broadcaster authentication, audio, and channel lifecycle.
- Configure Agora to publish external video instead of its camera track.
- Pin and test the Agora version used by your application.
The streaming path
Nosmai owns and processes the camera feed. Agora publishes only the processed output while the application keeps its local preview and session controls.
Receive processed frames
[NosmaiCore shared].liveFrameStreamCallback =
^(CVPixelBufferRef pixelBuffer, double timestamp) {
CVPixelBufferRetain(pixelBuffer);
dispatch_async(agoraQueue, ^{
[agoraAdapter pushPixelBuffer:pixelBuffer timestamp:timestamp];
CVPixelBufferRelease(pixelBuffer);
});
};
agoraAdapter is the application layer that converts the Nosmai callback into the external-video API used by the pinned Agora release. Do not start Agora's camera while Nosmai owns it.
Preserve ownership and timing
- The callback runs off the main thread.
- Retain the pixel buffer when Agora consumes it asynchronously.
- Preserve the timestamp and configure matching orientation and dimensions.
- Do not block the callback with network, file, or UIKit work.
Stop in the correct order
Stop Agora publishing before clearing the callback:
[NosmaiCore shared].liveFrameStreamCallback = nil;
Then leave the channel and release Agora according to its lifecycle. Keep Nosmai alive if the local camera experience continues.
Common errors
| Symptom | Cause | Fix |
|---|---|---|
| Remote stream is unfiltered | Agora is publishing its own camera track | Disable the camera track and publish the Nosmai processed source |
| Frames corrupt or crash later | The buffer outlived the callback without being retained | Retain before asynchronous use and release after Agora finishes |
| Preview is smooth but remote video rotates | Provider orientation does not match the buffer contract | Test portrait and landscape with the pinned Agora version |
Verify it worked
Apply a visible effect, join from a second device, and confirm the remote video is filtered, correctly oriented, and stable through background and rejoin.
