Only First Participant’s Pixel Buffer Received in PiP Mode with Multiple ZoomVideoSDKRawDataPipe Subscriptions

Video SDK iOS
,
1

Description:
I’m implementing a custom composite video layout using the ZoomVideoSDKRawDataPipe API to receive raw video data from multiple participants. The goal is to merge these streams into a single video output that works in both fullscreen and Picture-in-Picture (PiP) modes.

Implementation Details:

  • For each participant, I create a separate ZoomVideoSDKRawDataPipe instance.

  • Subscription code:

let rawDataPipe = user.getVideoPipe()
rawDataPipe?.subscribe(self)

  • I conform to ZoomVideoSDKRawDataPipeDelegate and expect to receive pixel buffers via:

func onPixelBuffer(_ pixelBuffer: CVPixelBuffer!, frameInfo: ZoomVideoSDKVideoFrameInfo!)

Issue:

  • In full-screen mode, I correctly receive pixel buffers for all subscribed participants.

  • In PiP mode, only the first subscribed participant delivers frames.

  • All other ZoomVideoSDKRawDataPipe instances stop invoking their delegate methods once PiP starts — as if the streams are being throttled or ignored.

Goal:

  • Render multiple participants in a composite layout (grid or stacked) inside PiP.

  • Continue receiving raw pixel buffers for all subscribed users in PiP mode.

  • Maintain custom rendering (not using ZoomVideoSDKVideoCanvas), combining pixel buffers into a shared AVSampleBuffer stream for PiP playback.

Questions:

  1. Does the SDK currently support receiving multiple raw video streams in PiP mode via ZoomVideoSDKRawDataPipe?

  2. Is there a known limitation that restricts ZoomVideoSDKRawDataPipeDelegate callbacks to only one participant in PiP?

  3. Is there a recommended workaround to enable multi-user raw data in PiP?

  4. If not supported, is multi-participant raw video in PiP planned for a future SDK release?

Environment:

  • Zoom Video SDK iOS: v1.13.10

  • iOS: 18.2

  • Device: iPhone 15 Pro

  • PiP: Enabled via Background Modes + CallKit integration

  • Rendering: Custom composite rendering using CoreVideo + AVSampleBufferDisplayLayer

2

Are you subscribing to all streams at 720p or 1080p? I had an issue with the android SDK where only one 720p stream was allowed at once. I Impelemented a system where I subscribe to the first remote user at 720p and 360p thereafter. If the first user leaves, I resubscribe one of the remaining users as 720p (the switchover is not noticible).

4

Thanks for the insight! In my case, I’m subscribing to all participants at 360p, so the 720p limitation shouldn’t apply here. The behavior still occurs in PiP — only the first subscribed stream continues delivering frames while others stop.