diff --git a/Dockerfile b/Dockerfile
index 44543409..195e2dec 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,11 +8,11 @@ RUN pip install -U gsutil
 # RUN conda install -y -c anaconda future numpy opencv matplotlib tqdm pillow
 # RUN conda install -y -c conda-forge scikit-image tensorboard pycocotools
 
-# Install OpenCV with Gstreamer support
+## Install OpenCV with Gstreamer support
 #WORKDIR /usr/src
 #RUN pip uninstall -y opencv-python
 #RUN apt-get update
-#RUN apt-get install -y gstreamer1.0-python3-dbg-plugin-loader libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
+#RUN apt-get install -y gstreamer1.0-tools gstreamer1.0-python3-dbg-plugin-loader libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
 #RUN git clone https://github.com/opencv/opencv.git && cd opencv && git checkout 4.1.1 && mkdir build
 #RUN git clone https://github.com/opencv/opencv_contrib.git && cd opencv_contrib && git checkout 4.1.1
 #RUN cd opencv/build && cmake ../ \
@@ -22,7 +22,7 @@ RUN pip install -U gsutil
 #    -D PYTHON3_INCLUDE_PATH=/opt/conda/include/python3.6m \
 #    -D PYTHON3_LIBRARIES=/opt/conda/lib/python3.6/site-packages \
 #    -D WITH_GSTREAMER=ON \
-#    -D WITH_FFMPEG=ON \
+#    -D WITH_FFMPEG=OFF \
 #    && make && make install && ldconfig
 #RUN cd /usr/local/lib/python3.6/site-packages/cv2/python-3.6/ && mv cv2.cpython-36m-x86_64-linux-gnu.so cv2.so
 #RUN cd /opt/conda/lib/python3.6/site-packages/ && ln -s /usr/local/lib/python3.6/site-packages/cv2/python-3.6/cv2.so cv2.so
diff --git a/test.py b/test.py
index be4cf627..54cac3c1 100644
--- a/test.py
+++ b/test.py
@@ -20,7 +20,7 @@ def test(cfg,
          model=None):
     # Initialize/load model and set device
     if model is None:
-        device = torch_utils.select_device()
+        device = torch_utils.select_device(opt.device)
         verbose = True
 
         # Initialize model
@@ -204,6 +204,7 @@ if __name__ == '__main__':
     parser.add_argument('--conf-thres', type=float, default=0.001, help='object confidence threshold')
     parser.add_argument('--nms-thres', type=float, default=0.5, help='iou threshold for non-maximum suppression')
     parser.add_argument('--save-json', action='store_true', help='save a cocoapi-compatible JSON results file')
+    parser.add_argument('--device', default='', help='device id (i.e. 0 or 0,1) or cpu')
     opt = parser.parse_args()
     print(opt)