diff --git a/plugins/preprocess/preprocess_node.cpp b/plugins/preprocess/preprocess_node.cpp
index 0488ddd..19cea3f 100644
--- a/plugins/preprocess/preprocess_node.cpp
+++ b/plugins/preprocess/preprocess_node.cpp
@@ -4,6 +4,7 @@
 #include <cstring>
 #include <iostream>
 #include <memory>
+#include <mutex>
 #include <thread>
 #include <vector>
 
@@ -39,6 +40,21 @@ int ToRgaFormat(PixelFormat fmt) {
         default: return RK_FORMAT_UNKNOWN;
     }
 }
+
+std::mutex& GlobalRgaMutex() {
+    static std::mutex* mu = new std::mutex();
+    return *mu;
+}
+
+void EnsureRgaInitializedOnce() {
+    static std::once_flag once;
+    std::call_once(once, []() {
+        const IM_STATUS st = imcheckHeader();
+        if (st != IM_STATUS_NOERROR && st != IM_STATUS_SUCCESS) {
+            std::cerr << "[preprocess] imcheckHeader failed: " << imStrError(st) << "\n";
+        }
+    });
+}
 #endif
 
 PixelFormat ParseFormat(const std::string& s) {
@@ -285,6 +301,8 @@ private:
 
 #if defined(RK3588_ENABLE_RGA)
     bool ProcessRga(FramePtr frame) {
+        EnsureRgaInitializedOnce();
+
         PixelFormat out_fmt = (dst_fmt_ != PixelFormat::UNKNOWN) ? dst_fmt_ : frame->format;
         int out_w = dst_w_;
         int out_h = dst_h_;
@@ -374,10 +392,8 @@ private:
         rga_buffer_t dst_buf{};
         DmaBufferPtr src_dma_buf;  // Keep alive if we allocate
 
-        if (frame->dma_fd >= 0) {
-            src_buf = wrapbuffer_fd_t(frame->dma_fd, frame->width, frame->height,
-                                      src_wstride, src_hstride, src_fmt_rga);
-        } else if (frame->data) {
+        // Allocate/copy outside the global RGA lock; librga calls are protected below.
+        if (frame->data && frame->dma_fd < 0) {
             // Source doesn't have DMA fd, copy to DMA buffer first to avoid >4GB address issue
             size_t src_size = CalcImageSizeStrided(src_wstride, src_hstride, frame->format);
             src_dma_buf = DmaAlloc(src_size);
@@ -393,6 +409,15 @@ private:
                 return false;
             }
             DmaSyncEndFd(src_dma_buf->fd);
+        }
+
+        // Serialize librga/im2d usage; multiple pipelines call RGA concurrently.
+        std::lock_guard<std::mutex> lock(GlobalRgaMutex());
+
+        if (frame->dma_fd >= 0) {
+            src_buf = wrapbuffer_fd_t(frame->dma_fd, frame->width, frame->height,
+                                      src_wstride, src_hstride, src_fmt_rga);
+        } else if (src_dma_buf && src_dma_buf->valid()) {
             src_buf = wrapbuffer_fd_t(src_dma_buf->fd, frame->width, frame->height,
                                       src_wstride, src_hstride, src_fmt_rga);
         } else {
@@ -403,6 +428,17 @@ private:
         dst_buf = wrapbuffer_fd_t(dma_buf->fd, out_w, out_h,
                                   dst_wstride, dst_hstride, dst_fmt_rga);
 
+        auto Check = [&](const rga_buffer_t& s, const rga_buffer_t& d) -> bool {
+            const im_rect sr{0, 0, s.width, s.height};
+            const im_rect dr{0, 0, d.width, d.height};
+            const IM_STATUS chk = imcheck(s, d, sr, dr);
+            if (chk != IM_STATUS_NOERROR && chk != IM_STATUS_SUCCESS) {
+                std::cerr << "[preprocess] RGA imcheck failed: " << imStrError(chk) << "\n";
+                return false;
+            }
+            return true;
+        };
+
         IM_STATUS status = IM_STATUS_SUCCESS;
 
         if (need_resize && need_cvt) {
@@ -414,14 +450,23 @@ private:
             }
             rga_buffer_t tmp = wrapbuffer_fd_t(tmp_dma->fd, out_w, out_h,
                                                dst_wstride, dst_hstride, src_fmt_rga);
-            status = imresize(src_buf, tmp);
+            if (!Check(src_buf, tmp) || !Check(tmp, dst_buf)) {
+                return false;
+            }
+            status = imresize(src_buf, tmp, 0, 0, 0, 1, nullptr);
             if (status == IM_STATUS_SUCCESS) {
-                status = imcvtcolor(tmp, dst_buf, src_fmt_rga, dst_fmt_rga, IM_COLOR_SPACE_DEFAULT);
+                status = imcvtcolor(tmp, dst_buf, src_fmt_rga, dst_fmt_rga, IM_COLOR_SPACE_DEFAULT, 1, nullptr);
             }
         } else if (need_resize) {
-            status = imresize(src_buf, dst_buf);
+            if (!Check(src_buf, dst_buf)) {
+                return false;
+            }
+            status = imresize(src_buf, dst_buf, 0, 0, 0, 1, nullptr);
         } else if (need_cvt) {
-            status = imcvtcolor(src_buf, dst_buf, src_fmt_rga, dst_fmt_rga, IM_COLOR_SPACE_DEFAULT);
+            if (!Check(src_buf, dst_buf)) {
+                return false;
+            }
+            status = imcvtcolor(src_buf, dst_buf, src_fmt_rga, dst_fmt_rga, IM_COLOR_SPACE_DEFAULT, 1, nullptr);
         }
 
         if (status != IM_STATUS_SUCCESS) {