Live stream (sequence acquisition) fails with Allied Vision Alvium cameras — single frame works

[patriciorojasm]

Live stream (sequence acquisition) fails with Allied Vision Alvium cameras — single frame works

Summary

I have two allied vision alvium 1800 u-501 nir running in different machines with MM in WIn 7 and 10. The AlliedVisionCamera device adapter fails to produce a live stream when using the MicroManager Live button or any sequence acquisition. Single image capture works correctly. The camera works perfectly in continuous streaming mode using the Vimba X SDK standalone viewer (Vimba X Viewer).

Environment

• OS: Windows 7 and 10 (reproduced on two independent computers)
• MicroManager version: night build 20260618
• Vimba X SDK version: Vimba_Setup-2026-1-win64.exe
• Camera model: Allied Vision Alvium 1800 u-501 nir
• Device adapter: AlliedVisionCamera

Steps to reproduce

1. Install Vimba X SDK on Windows 10
2. Connect Allied Vision Alvium U camera via USB
3. Confirm camera streams correctly in Vimba X Viewer (continuous mode works)
4. Open MicroManager and configure AlliedVisionCamera as the imaging device
5. Use Snap (single image) → image is captured successfully ✅
6. Click Live (sequence acquisition) → no frames appear, stream does not start ❌

Expected behavior

Live stream runs continuously, matching the behavior of Vimba X Viewer in free-run/continuous mode.

Actual behavior

Live view shows no frames. The stream appears to silently fail — no error dialog is shown in most cases. Snap continues to work normally during and after the failed live stream attempt.

What has been tried

• Connecting camera to different USB ports
• Adjusting acquisition settings within MicroManager device properties
• Reinstalling Vimba X SDK
• Inspecting all available device properties in the MicroManager Device Property Browser
• Reproduced on two different cameras and two different Windows 10 computers → rules out hardware fault or local configuration issue

Hypothesis

The failure is likely in the sequence acquisition path of the adapter. Possible causes:

• AcquisitionMode not being set to Continuous before calling VmbCaptureStart
• Frame buffers not being re-queued after each callback (VmbCaptureFrameQueue not called in the frame callback loop)
• Thread-safety issue between Vimba's frame callback thread and MicroManager's acquisition engine
• VmbCameraOpen not being called with the correct access mode for streaming

The fact that Vimba X Viewer streams correctly rules out a driver or firmware issue — the problem is isolated to the MicroManager adapter's streaming implementation.

Additional context

This was reproduced independently across two cameras and two computers with identical results, strongly suggesting a systematic bug in the adapter rather than an environment-specific configuration issue. Happy to test patches or provide any additional diagnostic output if helpful.

[marktsuchida]

Thank you for reporting this and your offer to test patches. Can you see if #963 fixes the issue? It addresses one possible cause for this (in Live/Sequence mode, the order of function calls to set up the acquisition is incorrect).

[marktsuchida]

@patriciorojasm I decided to go ahead and merge #963, since it should be a low-risk change; it will be in the next nightly build (2026-06-24). Would be great if you could let us know if it helped or not.

[patriciorojasm]

Tested with the 2026-06-24 nightly build. Live stream is now working correctly in both cameras in win7 and win10. Thank you for the quick fix!. I have a new problem, so I'll start a new thread.