From 57f5335a47eea9f34486db07c77ab04f0271c9c9 Mon Sep 17 00:00:00 2001
From: "Mark A. Tsuchida" <matsuchida@wisc.edu>
Date: Sat, 20 Jun 2026 08:34:26 +0900
Subject: [PATCH] AlliedVisionCamera: start seq acq in correct order

Queue the frame buffers after starting the capture, not before, as
the documentation says to do. This matches the snap implementation,
which works correctly.

(Also: avoid potentially blocking requeuing of frames when acquisition
has just started: set m_isAcquisitionRunning before starting
acquisition.)

(Assisted by Claude Code; any errors are mine.)
---
 .../AlliedVisionCamera/AlliedVisionCamera.cpp | 35 +++++++++++--------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/DeviceAdapters/AlliedVisionCamera/AlliedVisionCamera.cpp b/DeviceAdapters/AlliedVisionCamera/AlliedVisionCamera.cpp
index 3dbbbb4b7..028cf6a87 100644
--- a/DeviceAdapters/AlliedVisionCamera/AlliedVisionCamera.cpp
+++ b/DeviceAdapters/AlliedVisionCamera/AlliedVisionCamera.cpp
@@ -1276,26 +1276,12 @@ int AlliedVisionCamera::StartSequenceAcquisition(long numImages, double interval
         m_frames[i].context[0] = this;                        //<! Pointer to camera
         m_frames[i].context[1] = reinterpret_cast<void *>(i); //<! Pointer to frame index
 
-        auto frameCallback = [](const VmbHandle_t cameraHandle, const VmbHandle_t streamHandle, VmbFrame_t *frame)
-        {
-            (void)cameraHandle;
-            (void)streamHandle;
-            reinterpret_cast<AlliedVisionCamera *>(frame->context[0])->insertFrame(frame);
-        };
-
         err = m_sdk->VmbFrameAnnounce_t(m_handle, &(m_frames[i]), sizeof(VmbFrame_t));
         if (err != VmbErrorSuccess)
         {
             LOG_ERROR(err, "Error during frame praparation for continous acquisition!");
             return err;
         }
-
-        err = m_sdk->VmbCaptureFrameQueue_t(m_handle, &(m_frames[i]), frameCallback);
-        if (err != VmbErrorSuccess)
-        {
-            LOG_ERROR(err, "Error during frame praparation for continous acquisition!");
-            return err;
-        }
     }
 
     err = m_sdk->VmbCaptureStart_t(m_handle);
@@ -1305,9 +1291,28 @@ int AlliedVisionCamera::StartSequenceAcquisition(long numImages, double interval
         return err;
     }
 
-    err = m_sdk->VmbFeatureCommandRun_t(m_handle, g_AcquisitionStart);
+    auto frameCallback = [](const VmbHandle_t cameraHandle, const VmbHandle_t streamHandle, VmbFrame_t *frame)
+    {
+        (void)cameraHandle;
+        (void)streamHandle;
+        reinterpret_cast<AlliedVisionCamera *>(frame->context[0])->insertFrame(frame);
+    };
+
+    for (size_t i = 0; i < MAX_FRAMES; i++)
+    {
+        err = m_sdk->VmbCaptureFrameQueue_t(m_handle, &(m_frames[i]), frameCallback);
+        if (err != VmbErrorSuccess)
+        {
+            LOG_ERROR(err, "Error during frame praparation for continous acquisition!");
+            return err;
+        }
+    }
+
+    // Set the flag before AcquisitionStart so frame callbacks that fire
+    // immediately can re-queue their buffers (insertFrame requires IsCapturing).
     m_isAcquisitionRunning = true;
 
+    err = m_sdk->VmbFeatureCommandRun_t(m_handle, g_AcquisitionStart);
     if (err != VmbErrorSuccess)
     {
         LOG_ERROR(err, "Error during start acquisition!");