diff --git a/src/bb/image-io/rt_u3v.h b/src/bb/image-io/rt_u3v.h
index 6319e24..aeacdd8 100644
--- a/src/bb/image-io/rt_u3v.h
+++ b/src/bb/image-io/rt_u3v.h
@@ -25,6 +25,9 @@ namespace ion {
 namespace bb {
 namespace image_io {
 
+#define TIMEOUT_IN_US_SHORTER 3 * 1000 * 1000
+#define TIMEOUT_IN_US_LONGER 30 * 1000 * 1000
+
 class U3V {
 protected:
     struct GError
@@ -630,7 +633,7 @@ class U3VFakeCam : public U3V{
         return *instances_[id].get();
     }
     void get(std::vector<Halide::Buffer<>>& outs) override {
-        auto timeout_us = 30 * 1000 * 1000;
+        auto timeout_us = TIMEOUT_IN_US_LONGER;
         std::vector<ArvBuffer *> bufs(num_sensor_);
         for (int i = 0;i< num_sensor_;i++){
                 auto size = devices_[i].u3v_payload_size_;
@@ -729,7 +732,7 @@ class U3VRealCam: public U3V{
     }
 
     void get(std::vector<Halide::Buffer<>>& outs) override{
-        auto timeout_us = 30 * 1000 * 1000;
+        auto timeout_us = TIMEOUT_IN_US_LONGER;
         int32_t num_device = devices_.size();
         if (sim_mode_){
             std::vector<ArvBuffer *> bufs(num_device);
@@ -796,7 +799,7 @@ class U3VRealCam: public U3V{
 
                 //first buffer
                 device_idx_ = (device_idx_ + 1) >= num_device ? 0 : device_idx_ + 1;
-                bufs[device_idx_] = arv_stream_timeout_pop_buffer(devices_[device_idx_].stream_, 30 * 1000 * 1000);
+                bufs[device_idx_] = arv_stream_timeout_pop_buffer(devices_[device_idx_].stream_, timeout_us);
                 if (bufs[device_idx_] == nullptr) {
                     log::error("pop_buffer(L4) failed due to timeout ({}s)", timeout_us * 1e-6f);
                     throw ::std::runtime_error("buffer is null");
@@ -820,7 +823,7 @@ class U3VRealCam: public U3V{
 
                 while (frame_cnt_ >= latest_cnt) {
                     arv_stream_push_buffer(devices_[device_idx_].stream_, bufs[device_idx_]);
-                    bufs[device_idx_] = arv_stream_timeout_pop_buffer (devices_[device_idx_].stream_, 30 * 1000 * 1000);
+                    bufs[device_idx_] = arv_stream_timeout_pop_buffer (devices_[device_idx_].stream_, timeout_us);
                     if (bufs[device_idx_] == nullptr){
                         log::error("pop_buffer(L4) failed due to timeout ({}s)", timeout_us*1e-6f);
                         throw ::std::runtime_error("buffer is null");
@@ -1186,7 +1189,7 @@ class U3VRealCam: public U3V{
         }
     }
 
-    void consume_old_buffer(std::vector<ArvBuffer *> &bufs, int timeout_us = 3 * 1000 * 1000){
+    void consume_old_buffer(std::vector<ArvBuffer *> &bufs, int timeout_us = TIMEOUT_IN_US_SHORTER){
         std::vector<int32_t> N_output_buffers(num_sensor_);
         for (auto i = 0; i < num_sensor_; ++i) {
             int32_t num_input_buffer;
@@ -1240,7 +1243,7 @@ class U3VGenDC: public U3V{
 
     void get(std::vector<void *>& outs) override{
         // TODO: Is 3 second fine?
-        auto timeout_us = 3 * 1000 * 1000;
+        auto timeout_us = TIMEOUT_IN_US_LONGER;
 
         int32_t num_device = devices_.size();
         std::vector<ArvBuffer *> bufs(num_device);
@@ -1302,7 +1305,7 @@ class U3VGenDC: public U3V{
 
             //first buffer
             device_idx_ = (device_idx_+1) >= num_device ? 0 : device_idx_+1;
-            bufs[device_idx_] = arv_stream_timeout_pop_buffer (devices_[device_idx_].stream_, 30 * 1000 * 1000);
+            bufs[device_idx_] = arv_stream_timeout_pop_buffer (devices_[device_idx_].stream_, timeout_us);
             if (bufs[device_idx_] == nullptr){
                 log::error("pop_buffer(L4) failed due to timeout ({}s)", timeout_us*1e-6f);
                 throw ::std::runtime_error("buffer is null");
@@ -1326,10 +1329,9 @@ class U3VGenDC: public U3V{
 
             while (frame_cnt_ >= latest_cnt) {
                 arv_stream_push_buffer(devices_[device_idx_].stream_, bufs[device_idx_]);
-                auto timeout2_us = 30 * 1000 * 1000;
-                bufs[device_idx_] = arv_stream_timeout_pop_buffer (devices_[device_idx_].stream_, timeout2_us);
+                bufs[device_idx_] = arv_stream_timeout_pop_buffer (devices_[device_idx_].stream_, timeout_us);
                 if (bufs[device_idx_] == nullptr){
-                    log::error("pop_buffer(L8) failed due to timeout ({}s)", timeout2_us*1e-6f);
+                    log::error("pop_buffer(L8) failed due to timeout ({}s)", timeout_us*1e-6f);
                         throw ::std::runtime_error("buffer is null");
                 }
                 devices_[device_idx_].frame_count_ = frame_count_method_ == FrameCountMethod::TYPESPECIFIC3
@@ -1643,7 +1645,7 @@ class U3VGenDC: public U3V{
         }
     };
 
-    void consume_old_buffer(std::vector<ArvBuffer *> &bufs, int timeout_us = 3 * 1000 * 1000){
+    void consume_old_buffer(std::vector<ArvBuffer *> &bufs, int timeout_us = TIMEOUT_IN_US_SHORTER){
         std::vector<int32_t> N_output_buffers(num_sensor_);
         for (auto i = 0; i < num_sensor_; ++i) {
             int32_t num_input_buffer;