Using HaishinKit (via SPM) to live stream video from VisionCamera to Cloudflare. Audio works using MediaMixer with attachAudio(), but when sending video frames using RTMPStream.append(), the await hangs indefinitely

[ryanhall00]

My iOS Setup:

• HaishinKit: Latest master (commit 1ddee19, Oct 26 2025)
• iOS: 15.1+
• Swift: 5.10
• External video source: VisionCamera (30fps CMSampleBuffer)

Code:
Swift
// Stream setup (working)
stream = RTMPStream(connection: connection)
var videoSettings = VideoCodecSettings(
videoSize: .init(width: 1280, height: 720),
bitRate: 4_800_000,
profileLevel: kVTProfileLevel_H264_Main_4_1 as String,
scalingMode: .letterbox,
maxKeyFrameIntervalDuration: 3
)
try? await stream?.setVideoSettings(videoSettings)

// Audio works (using MediaMixer)
try await mixer.attachAudio(audioDevice, track: 0)
await mixer.addOutput(stream!)
await mixer.startCapturing()
await mixer.startRunning()

// Publish succeeds
try await stream?.publish(streamKey)
// Logs show: "NetStream.Publish.Start - Stream is LIVE!"

// Video append HANGS HERE
@objc public func appendVideo(_ sampleBuffer: CMSampleBuffer) {
Task {
await streamSetupTask?.value // Wait for setup

do {
  try await stream?.append(sampleBuffer) // ❌ HANGS - never completes
  NSLog("✅ Success") // Never logs
} catch {
  NSLog("❌ Error: \(error)") // Never logs
}

}
}

Observations
✅ Stream connects and publishes successfully
✅ Audio works (MediaMixer → stream → Cloudflare)
✅ appendVideo() called at 30fps with valid CMSampleBuffer
❌ stream?.append() never completes (no success, no error, just hangs)
❌ No frames reach VideoToolbox encoder
❌ Cloudflare shows FPS = 0

Questions
Is RTMPStream.append() the correct method for external video frames?
Do I need to configure the stream differently for external sources?
Does the stream need to be in a specific state before calling append?
Should I NOT use MediaMixer at all if using stream.append() for video?

What I've Tried
✅ Read HaishinKit docs, troubleshooting tips, example code, similar discussions, etc.
✅ Verified stream is not nil
✅ Waited for publish to complete before appending
✅ Verified CMSampleBuffer is valid video (kCMMediaType_Video)
❌ Still hangs indefinitely

Any guidance on the correct way to send external video frames to RTMPStream would be greatly appreciated! Thank you!