# Creating a Real-Time License Plate Detection and Recognition App **URL:** \ **Category:** TAO Toolkit\ **Created:** [February 25, 2021, 4:02pm UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445 "2021-02-25T16:02:07Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![jwitsoe](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/jwitsoe/32/16591_2.png) [@jwitsoe](https://forums.developer.nvidia.com/u/jwitsoe)\ **Post date:** [February 25, 2021, 4:02pm UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/1 "2021-02-25T16:02:07Z")
Originally published at: [Creating a Real-Time License Plate Detection and Recognition App | NVIDIA Technical Blog](https://developer.nvidia.com/blog/creating-a-real-time-license-plate-detection-and-recognition-app/) Automatic license plate recognition (ALPR) on stationary to fast-moving vehicles is one of the common intelligent video analytics applications for smart cities. Some of the common use cases include parking assistance systems, automated toll booths, vehicle registration and identification for delivery and logistics at ports, and medical supply transporting warehouses. Being able to do this… ---
**Author:** ![AutoCar](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/autocar/32/166725_2.png) [@AutoCar](https://forums.developer.nvidia.com/u/AutoCar)\ **Post date:** [March 14, 2021, 12:02am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/2 "2021-03-14T00:02:17Z")
The whole process is too complicated. Too many dependencies. ---
**Author:** ![AutoCar](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/autocar/32/166725_2.png) [@AutoCar](https://forums.developer.nvidia.com/u/AutoCar)\ **Post date:** [March 14, 2021, 12:10am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/3 "2021-03-14T00:10:39Z")
Removed ---
**Author:** ![AutoCar](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/autocar/32/166725_2.png) [@AutoCar](https://forums.developer.nvidia.com/u/AutoCar)\ **Post date:** [March 15, 2021, 5:52am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/4 "2021-03-15T05:52:08Z")
Could you share the algorithm or implementation of the LPRNet? ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 29, 2021, 7:04pm UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/5 "2021-04-29T19:04:24Z")
I am trying to “Convert the encrypted LPR ONNX model to a TLT engine”, however, in running the command: > ./tlt-converter -k nvidia\_tlt -p image\_input,1x3x48x96,4x3x48x96,16x3x48x96 ./us\_lprnet\_baseline18\_deployable.etltunpruned.etlt -t fp16 -e /opt/nvidia/deepstream/deepstream-5.1/samples/models/LP/LPR/lpr\_us\_onnx\_b16.engine I am receiving the error: `Error: no input dimensions given` Do you happen to know the dimensions we should be using for this? cc/ @Morganh (the github repo seems to have the same issues as noted [here](https://github.com/NVIDIA-AI-IOT/deepstream_lpr_app/issues) cc/ @TomNVIDIA ---
**Author:** ![Morganh](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/morganh/32/9748_2.png) [@Morganh](https://forums.developer.nvidia.com/u/Morganh)\ **Post date:** [April 30, 2021, 1:38am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/6 "2021-04-30T01:38:55Z")
@bbb Can you run following command $ ./tlt-converter -h Did you download the latest version of tlt-converter ? See [Overview — TAO Toolkit 3.22.05 documentation](https://docs.nvidia.com/metropolis/TLT/tlt-user-guide/text/overview.html#id1) or [Overview — TAO Toolkit 3.22.05 documentation](https://docs.nvidia.com/metropolis/TLT/tlt-user-guide/text/overview.html#id2) ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 2:00am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/7 "2021-04-30T02:00:42Z")
Yes, I can run it and it runs as it should. Output: ``` bryan@bryan-desktop:~/cuda10.2_trt7.1_jp4.5$ ./tlt-converter -h usage: ./tlt-converter [-h] [-v] [-e ENGINE_FILE_PATH] [-k ENCODE_KEY] [-c CACHE_FILE] [-o OUTPUTS] [-d INPUT_DIMENSIONS] [-b BATCH_SIZE] [-m MAX_BATCH_SIZE] [-w MAX_WORKSPACE_SIZE] [-t DATA_TYPE] [-i INPUT_ORDER] [-s] [-u DLA_CORE] input_file Generate TensorRT engine from exported model positional arguments: input_file Input file (.etlt exported model). required flag arguments: -d comma separated list of input dimensions(not required for TLT 3.0 new models). -k model encoding key. optional flag arguments: -b calibration batch size (default 8). -c calibration cache file (default cal.bin). -e file the engine is saved to (default saved.engine). -i input dimension ordering -- nchw, nhwc, nc (default nchw). -m maximum TensorRT engine batch size (default 16). If meet with out-of-memory issue, please decrease the batch size accordingly. -o comma separated list of output node names (default none). -p comma separated list of optimization profile shapes in the format ,,,, where each shape has the format: xxx. Can be specified multiple times if there are multiple input tensors for the model. This argument is only useful in dynamic shape case. -s TensorRT strict_type_constraints flag for INT8 mode(default false). -t TensorRT data type -- fp32, fp16, int8 (default fp32). -u Use DLA core N for layers that support DLA(default = -1, which means no DLA core will be utilized for inference. Note that it'll always allow GPU fallback). -w maximum workspace size of TensorRT engine (default 1<<30). If meet with out-of-memory issue, please increase the workspace size accordingly. ``` I downloaded the latest version of the tlt-converter as well. To note, I am starting the tutorial from the bottom section: Deploying LPD and LPR using the DeepStream SDK. Which should be ok to do. ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 2:10am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/8 "2021-04-30T02:10:44Z")
Submitting another comment, in addition to the above one @Morganh I decided to try another route, in cloning this repo here: [GitHub - NVIDIA-AI-IOT/deepstream\_lpr\_app: Sample app code for LPR deployment on DeepStream](https://github.com/NVIDIA-AI-IOT/deepstream_lpr_app) I am able to get the input\_dimensions to load correctly. However, it appears another issue is springing up. Multiple commands/outputs here: **Successful/no issue** ``` bryan@bryan-desktop:~/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app$ ../../../../../../../cuda10.2_trt7.1_jp4.5/tlt-converter -k nvidia_tlt -p image_input,1x3x48x96,4x3x48x96,16x3x48x96 \ > models/LP/LPR/us_lprnet_baseline18_deployable.etlt -t fp16 -e models/LP/LPR/lpr_us_onnx_b16.engine [WARNING] onnx2trt_utils.cpp:220: Your ONNX model has been generated with INT64 weights, while TensorRT does not natively support INT64. Attempting to cast down to INT32. [WARNING] Tensor DataType is determined at build time for tensors not marked as input or output. [INFO] Detected input dimensions from the model: (-1, 3, 48, 96) [INFO] Model has dynamic shape. Setting up optimization profiles. [INFO] Using optimization profile min shape: (1, 3, 48, 96) for input: image_input [INFO] Using optimization profile opt shape: (4, 3, 48, 96) for input: image_input [INFO] Using optimization profile max shape: (16, 3, 48, 96) for input: image_input [INFO] Detected 1 inputs and 2 output network tensors. ``` **Successful/no issue** ``` bryan@bryan-desktop:~/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app$ make make[1]: Entering directory '/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/nvinfer_custom_lpr_parser' g++ -o libnvdsinfer_custom_impl_lpr.so nvinfer_custom_lpr_parser.cpp -Wall -Werror -std=c++11 -shared -fPIC -Wno-error=deprecated-declarations -I/opt/nvidia/deepstream/deepstream/sources/includes -Wl,--start-group -lnvinfer -lnvparsers -Wl,--end-group make[1]: Leaving directory '/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/nvinfer_custom_lpr_parser' make[1]: Entering directory '/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app' g++ -c -o deepstream_lpr_app.o -fpermissive -Wall -Werror -DPLATFORM_TEGRA -I/opt/nvidia/deepstream/deepstream/sources/includes `pkg-config --cflags gstreamer-1.0` -D_GLIBCXX_USE_CXX11_ABI=1 deepstream_lpr_app.c g++ -c -o deepstream_nvdsanalytics_meta.o -Wall -Werror -DPLATFORM_TEGRA -I/opt/nvidia/deepstream/deepstream/sources/includes `pkg-config --cflags gstreamer-1.0` -D_GLIBCXX_USE_CXX11_ABI=1 deepstream_nvdsanalytics_meta.cpp cc -o deepstream-lpr-app deepstream_lpr_app.o deepstream_nvdsanalytics_meta.o `pkg-config --libs gstreamer-1.0` -L/opt/nvidia/deepstream/deepstream/lib/ -lnvdsgst_meta -lnvds_meta -lm -lstdc++ -Wl,-rpath,/opt/nvidia/deepstream/deepstream/lib/ make[1]: Leaving directory '/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app' ``` **Unsuccessful/issue** ``` bryan@bryan-desktop:~/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app$ ./deepstream-lpr-app 1 2 0 us_car_test2.mp4 us_car_test2.mp4 output.264 Request sink_0 pad from streammux Request sink_1 pad from streammux Warning: 'input-dims' parameter has been deprecated. Use 'infer-dims' instead. Warning: 'input-dims' parameter has been deprecated. Use 'infer-dims' instead. Unknown or legacy key specified 'process_mode' for group [property] Now playing: 1 Opening in BLOCKING MODE Opening in BLOCKING MODE Opening in BLOCKING MODE Opening in BLOCKING MODE 0:00:12.783947731 8708 0x558f5fb230 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 3]: Info from NvDsInferContextImpl::deserializeEngineAndBackend() [UID = 3]: deserialized trt engine from :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/LP/LPR/lpr_us_onnx_b16.engine INFO: [FullDims Engine Info]: layers num: 3 0 INPUT kFLOAT image_input 3x48x96 min: 1x3x48x96 opt: 4x3x48x96 Max: 16x3x48x96 1 OUTPUT kINT32 tf_op_layer_ArgMax 24 min: 0 opt: 0 Max: 0 2 OUTPUT kFLOAT tf_op_layer_Max 24 min: 0 opt: 0 Max: 0 ERROR: [TRT]: INVALID_ARGUMENT: Cannot find binding of given name: output_bbox/BiasAdd 0:00:12.784171641 8708 0x558f5fb230 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 3]: Warning from NvDsInferContextImpl::checkBackendParams() [UID = 3]: Could not find output layer 'output_bbox/BiasAdd' in engine ERROR: [TRT]: INVALID_ARGUMENT: Cannot find binding of given name: output_cov/Sigmoid 0:00:12.784218673 8708 0x558f5fb230 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 3]: Warning from NvDsInferContextImpl::checkBackendParams() [UID = 3]: Could not find output layer 'output_cov/Sigmoid' in engine 0:00:12.784243465 8708 0x558f5fb230 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 3]: Info from NvDsInferContextImpl::generateBackendContext() [UID = 3]: Use deserialized engine model: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/LP/LPR/lpr_us_onnx_b16.engine 0:00:12.825354703 8708 0x558f5fb230 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 3]: Load new model:lpr_config_sgie_us.txt sucessfully 0:00:12.825646583 8708 0x558f5fb230 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 2]: Info from NvDsInferContextImpl::buildModel() [UID = 2]: Trying to create engine from model files WARNING: INT8 not supported by platform. Trying FP16 mode. WARNING: INT8 not supported by platform. Trying FP16 mode. INFO: [TRT]: Some tactics do not have sufficient workspace memory to run. Increasing workspace size may increase performance, please check verbose output. INFO: [TRT]: Detected 1 inputs and 2 output network tensors. 0:01:46.893865326 8708 0x558f5fb230 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 2]: Info from NvDsInferContextImpl::buildModel() [UID = 2]: serialize cuda engine to file: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/LP/LPD/usa_pruned.etlt_b16_gpu0_fp16.engine successfully INFO: [Implicit Engine Info]: layers num: 3 0 INPUT kFLOAT input_1 3x480x640 1 OUTPUT kFLOAT output_bbox/BiasAdd 4x30x40 2 OUTPUT kFLOAT output_cov/Sigmoid 1x30x40 0:01:47.053010315 8708 0x558f5fb230 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 2]: Load new model:lpd_us_config.txt sucessfully gstnvtracker: Loading low-level lib at /opt/nvidia/deepstream/deepstream/lib/libnvds_nvdcf.so gstnvtracker: Batch processing is ON gstnvtracker: Past frame output is OFF !! [WARNING][NvDCF] Unknown param found: minMatchingScore4Motion [NvDCF][Warning] `minTrackingConfidenceDuringInactive` is deprecated !! [WARNING][NvDCF] Unknown param found: matchingScoreWeight4Motion [NvDCF] Initialized ERROR: Deserialize engine failed because file path: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine open error 0:01:49.219258844 8708 0x558f5fb230 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 1]: Warning from NvDsInferContextImpl::deserializeEngineAndBackend() [UID = 1]: deserialize engine from file :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine failed 0:01:49.219294521 8708 0x558f5fb230 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 1]: Warning from NvDsInferContextImpl::generateBackendContext() [UID = 1]: deserialize backend context from engine from file :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine failed, try rebuild 0:01:49.219326814 8708 0x558f5fb230 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 1]: Info from NvDsInferContextImpl::buildModel() [UID = 1]: Trying to create engine from model files WARNING: INT8 not supported by platform. Trying FP16 mode. WARNING: INT8 not supported by platform. Trying FP16 mode. INFO: [TRT]: Some tactics do not have sufficient workspace memory to run. Increasing workspace size may increase performance, please check verbose output. INFO: [TRT]: Detected 1 inputs and 2 output network tensors. 0:02:36.543306401 8708 0x558f5fb230 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 1]: Info from NvDsInferContextImpl::buildModel() [UID = 1]: serialize cuda engine to file: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_fp16.engine successfully INFO: [Implicit Engine Info]: layers num: 3 0 INPUT kFLOAT input_1 3x544x960 1 OUTPUT kFLOAT output_bbox/BiasAdd 16x34x60 2 OUTPUT kFLOAT output_cov/Sigmoid 4x34x60 0:02:36.577236606 8708 0x558f5fb230 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 1]: Load new model:trafficamnet_config.txt sucessfully [NvDCF] De-initialized Running... ERROR from element file_src_1: Resource not found. Error details: gstfilesrc.c(533): gst_file_src_start (): /GstPipeline:pipeline/GstFileSrc:file_src_1: No such file "us_car_test2.mp4" Returned, stopping playback Average fps 0.000233 Totally 0 plates are inferred Deleting pipeline ``` ---
**Author:** ![Morganh](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/morganh/32/9748_2.png) [@Morganh](https://forums.developer.nvidia.com/u/Morganh)\ **Post date:** [April 30, 2021, 2:12am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/9 "2021-04-30T02:12:53Z")
You have generated lpr\_us\_onnx\_b16.engine successfully. There is no error in the log. ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 2:18am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/10 "2021-04-30T02:18:22Z")
@Morganh I hit submit too quickly, and needed to edit my above comment. Could you possibly see/review/help me with the unsuccessful point I am seeing above? It’s in building/running the application per github commands here: > **[GitHub - NVIDIA-AI-IOT/deepstream\_lpr\_app: Sample app code for LPR deployment on DeepStream](https://github.com/NVIDIA-AI-IOT/deepstream_lpr_app#build-and-run)** > > Sample app code for LPR deployment on DeepStream ---
**Author:** ![Morganh](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/morganh/32/9748_2.png) [@Morganh](https://forums.developer.nvidia.com/u/Morganh)\ **Post date:** [April 30, 2021, 2:21am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/11 "2021-04-30T02:21:25Z")
I move this topic from content discussions–developer blog to TLT forum. ---
**Author:** ![Morganh](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/morganh/32/9748_2.png) [@Morganh](https://forums.developer.nvidia.com/u/Morganh)\ **Post date:** [April 30, 2021, 2:25am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/12 "2021-04-30T02:25:12Z")
> [@bbb](#): > > ```auto > ERROR from element file_src_1: Resource not found. > Error details: gstfilesrc.c(533): gst_file_src_start (): /GstPipeline:pipeline/GstFileSrc:file_src_1: > No such file "us_car_test2.mp4" > > ``` Please check if us\_car\_test2.mp4 is available. ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 2:41am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/14 "2021-04-30T02:41:08Z")
I should have posted the log below as I noticed that “us\_car\_test2.mp4” might not be available. Video I am trying to test with is within the deepstream-5.1/samples/streams (sample\_qHD.mp4). It appears the logs are similar: ``` bryan@bryan-desktop:~/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app$ ./deepstream-lpr-app 1 2 0 ../../../streams/sample_qHD.mp4 ../../../streams/sample_qHd.mp4 output.264 Request sink_0 pad from streammux Request sink_1 pad from streammux Warning: 'input-dims' parameter has been deprecated. Use 'infer-dims' instead. Warning: 'input-dims' parameter has been deprecated. Use 'infer-dims' instead. Unknown or legacy key specified 'process_mode' for group [property] Now playing: 1 Opening in BLOCKING MODE Opening in BLOCKING MODE Opening in BLOCKING MODE Opening in BLOCKING MODE 0:00:11.534274321 18445 0x5592fe2830 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 3]: Info from NvDsInferContextImpl::deserializeEngineAndBackend() [UID = 3]: deserialized trt engine from :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/LP/LPR/lpr_us_onnx_b16.engine INFO: [FullDims Engine Info]: layers num: 3 0 INPUT kFLOAT image_input 3x48x96 min: 1x3x48x96 opt: 4x3x48x96 Max: 16x3x48x96 1 OUTPUT kINT32 tf_op_layer_ArgMax 24 min: 0 opt: 0 Max: 0 2 OUTPUT kFLOAT tf_op_layer_Max 24 min: 0 opt: 0 Max: 0 ERROR: [TRT]: INVALID_ARGUMENT: Cannot find binding of given name: output_bbox/BiasAdd 0:00:11.534479118 18445 0x5592fe2830 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 3]: Warning from NvDsInferContextImpl::checkBackendParams() [UID = 3]: Could not find output layer 'output_bbox/BiasAdd' in engine ERROR: [TRT]: INVALID_ARGUMENT: Cannot find binding of given name: output_cov/Sigmoid 0:00:11.534532088 18445 0x5592fe2830 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 3]: Warning from NvDsInferContextImpl::checkBackendParams() [UID = 3]: Could not find output layer 'output_cov/Sigmoid' in engine 0:00:11.534562922 18445 0x5592fe2830 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 3]: Info from NvDsInferContextImpl::generateBackendContext() [UID = 3]: Use deserialized engine model: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/LP/LPR/lpr_us_onnx_b16.engine 0:00:11.576047481 18445 0x5592fe2830 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 3]: Load new model:lpr_config_sgie_us.txt sucessfully 0:00:11.576306498 18445 0x5592fe2830 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 2]: Info from NvDsInferContextImpl::buildModel() [UID = 2]: Trying to create engine from model files WARNING: INT8 not supported by platform. Trying FP16 mode. WARNING: INT8 not supported by platform. Trying FP16 mode. INFO: [TRT]: Some tactics do not have sufficient workspace memory to run. Increasing workspace size may increase performance, please check verbose output. INFO: [TRT]: Detected 1 inputs and 2 output network tensors. 0:01:46.495432090 18445 0x5592fe2830 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 2]: Info from NvDsInferContextImpl::buildModel() [UID = 2]: serialize cuda engine to file: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/LP/LPD/usa_pruned.etlt_b16_gpu0_fp16.engine successfully INFO: [Implicit Engine Info]: layers num: 3 0 INPUT kFLOAT input_1 3x480x640 1 OUTPUT kFLOAT output_bbox/BiasAdd 4x30x40 2 OUTPUT kFLOAT output_cov/Sigmoid 1x30x40 0:01:46.743905225 18445 0x5592fe2830 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 2]: Load new model:lpd_us_config.txt sucessfully gstnvtracker: Loading low-level lib at /opt/nvidia/deepstream/deepstream/lib/libnvds_nvdcf.so gstnvtracker: Batch processing is ON gstnvtracker: Past frame output is OFF !! [WARNING][NvDCF] Unknown param found: minMatchingScore4Motion [NvDCF][Warning] `minTrackingConfidenceDuringInactive` is deprecated !! [WARNING][NvDCF] Unknown param found: matchingScoreWeight4Motion [NvDCF] Initialized ERROR: Deserialize engine failed because file path: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine open error 0:01:48.909930484 18445 0x5592fe2830 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 1]: Warning from NvDsInferContextImpl::deserializeEngineAndBackend() [UID = 1]: deserialize engine from file :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine failed 0:01:48.909990381 18445 0x5592fe2830 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 1]: Warning from NvDsInferContextImpl::generateBackendContext() [UID = 1]: deserialize backend context from engine from file :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine failed, try rebuild 0:01:48.910035643 18445 0x5592fe2830 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 1]: Info from NvDsInferContextImpl::buildModel() [UID = 1]: Trying to create engine from model files WARNING: INT8 not supported by platform. Trying FP16 mode. WARNING: INT8 not supported by platform. Trying FP16 mode. INFO: [TRT]: Some tactics do not have sufficient workspace memory to run. Increasing workspace size may increase performance, please check verbose output. INFO: [TRT]: Detected 1 inputs and 2 output network tensors. 0:02:38.473025813 18445 0x5592fe2830 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 1]: Info from NvDsInferContextImpl::buildModel() [UID = 1]: serialize cuda engine to file: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/deepstream_lpr_app/models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_fp16.engine successfully INFO: [Implicit Engine Info]: layers num: 3 0 INPUT kFLOAT input_1 3x544x960 1 OUTPUT kFLOAT output_bbox/BiasAdd 16x34x60 2 OUTPUT kFLOAT output_cov/Sigmoid 4x34x60 0:02:38.647800783 18445 0x5592fe2830 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 1]: Load new model:trafficamnet_config.txt sucessfully [NvDCF] De-initialized Running... ERROR from element file_src_1: Resource not found. Error details: gstfilesrc.c(533): gst_file_src_start (): /GstPipeline:pipeline/GstFileSrc:file_src_1: No such file "../../../streams/sample_qHd.mp4" Returned, stopping playback Average fps 0.000233 Totally 0 plates are inferred Deleting pipeline ``` ---
**Author:** ![Morganh](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/morganh/32/9748_2.png) [@Morganh](https://forums.developer.nvidia.com/u/Morganh)\ **Post date:** [April 30, 2021, 2:52am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/15 "2021-04-30T02:52:11Z")
> [@bbb](#): > > ```auto > ERROR from element file_src_1: Resource not found. > Error details: gstfilesrc.c(533): gst_file_src_start (): /GstPipeline:pipeline/GstFileSrc:file_src_1: > No such file "../../../streams/sample_qHd.mp4" > > ``` Please check the mp4 file is available. ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 2:59am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/16 "2021-04-30T02:59:44Z")
I am seeing this file in my terminal (it came with deepstream). I used autocomplete (tab) to get the file. ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 3:14am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/17 "2021-04-30T03:14:21Z")
@Morganh Something kinda interesting. I created another clone to re-run the tlt converter to add an output. **Previous Command** ```auto ./tlt-converter -k nvidia_tlt -p image_input,1x3x48x96,4x3x48x96,16x3x48x96 models/LP/LPR/us_lprnet_baseline18_deployable.etlt -t fp16 -e models/LP/LPR/lpr_us_onnx_b16.engine ``` **New Command: adding -o output\_cov/Sigmoid,output\_bbox/BiasAdd** ```auto ./tlt-converter -k nvidia_tlt -o output_cov/Sigmoid,output_bbox/BiasAdd -p image_input,1x3x48x96,4x3x48x96,16x3x48x96 models/LP/LPR/us_lprnet_baseline18_deployable.etlt -t fp16 -e models/LP/LPR/lpr_us_onnx_b16.engine ``` **New unsuccessful command to build/run, but maybe right direction?** ``` bryan@bryan-desktop:~/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/deepstream-lpr-app$ ./deepstream-lpr-app 1 2 0 ../../../../streams/sample_720p.mp4 ../../../../streams/sample_720p.mp4 output.264 Request sink_0 pad from streammux Request sink_1 pad from streammux Warning: 'input-dims' parameter has been deprecated. Use 'infer-dims' instead. Warning: 'input-dims' parameter has been deprecated. Use 'infer-dims' instead. Unknown or legacy key specified 'process_mode' for group [property] Now playing: 1 Opening in BLOCKING MODE Opening in BLOCKING MODE Opening in BLOCKING MODE Opening in BLOCKING MODE 0:00:10.921601849 19412 0x55639b70d0 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 3]: Info from NvDsInferContextImpl::deserializeEngineAndBackend() [UID = 3]: deserialized trt engine from :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/models/LP/LPR/lpr_us_onnx_b16.engine INFO: [FullDims Engine Info]: layers num: 3 0 INPUT kFLOAT image_input 3x48x96 min: 1x3x48x96 opt: 4x3x48x96 Max: 16x3x48x96 1 OUTPUT kINT32 tf_op_layer_ArgMax 24 min: 0 opt: 0 Max: 0 2 OUTPUT kFLOAT tf_op_layer_Max 24 min: 0 opt: 0 Max: 0 ERROR: [TRT]: INVALID_ARGUMENT: Cannot find binding of given name: output_bbox/BiasAdd 0:00:10.921851646 19412 0x55639b70d0 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 3]: Warning from NvDsInferContextImpl::checkBackendParams() [UID = 3]: Could not find output layer 'output_bbox/BiasAdd' in engine ERROR: [TRT]: INVALID_ARGUMENT: Cannot find binding of given name: output_cov/Sigmoid 0:00:10.921900970 19412 0x55639b70d0 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 3]: Warning from NvDsInferContextImpl::checkBackendParams() [UID = 3]: Could not find output layer 'output_cov/Sigmoid' in engine 0:00:10.921961909 19412 0x55639b70d0 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 3]: Info from NvDsInferContextImpl::generateBackendContext() [UID = 3]: Use deserialized engine model: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/models/LP/LPR/lpr_us_onnx_b16.engine 0:00:10.962857824 19412 0x55639b70d0 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 3]: Load new model:lpr_config_sgie_us.txt sucessfully 0:00:10.963561485 19412 0x55639b70d0 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 2]: Info from NvDsInferContextImpl::buildModel() [UID = 2]: Trying to create engine from model files WARNING: INT8 not supported by platform. Trying FP16 mode. WARNING: INT8 not supported by platform. Trying FP16 mode. INFO: [TRT]: Some tactics do not have sufficient workspace memory to run. Increasing workspace size may increase performance, please check verbose output. INFO: [TRT]: Detected 1 inputs and 2 output network tensors. 0:01:43.118323033 19412 0x55639b70d0 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 2]: Info from NvDsInferContextImpl::buildModel() [UID = 2]: serialize cuda engine to file: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/models/LP/LPD/usa_pruned.etlt_b16_gpu0_fp16.engine successfully INFO: [Implicit Engine Info]: layers num: 3 0 INPUT kFLOAT input_1 3x480x640 1 OUTPUT kFLOAT output_bbox/BiasAdd 4x30x40 2 OUTPUT kFLOAT output_cov/Sigmoid 1x30x40 0:01:43.281237925 19412 0x55639b70d0 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 2]: Load new model:lpd_us_config.txt sucessfully gstnvtracker: Loading low-level lib at /opt/nvidia/deepstream/deepstream/lib/libnvds_nvdcf.so gstnvtracker: Batch processing is ON gstnvtracker: Past frame output is OFF !! [WARNING][NvDCF] Unknown param found: minMatchingScore4Motion [NvDCF][Warning] `minTrackingConfidenceDuringInactive` is deprecated !! [WARNING][NvDCF] Unknown param found: matchingScoreWeight4Motion [NvDCF] Initialized ERROR: Deserialize engine failed because file path: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine open error 0:01:45.437559981 19412 0x55639b70d0 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 1]: Warning from NvDsInferContextImpl::deserializeEngineAndBackend() [UID = 1]: deserialize engine from file :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine failed 0:01:45.437606544 19412 0x55639b70d0 WARN nvinfer gstnvinfer.cpp:616:gst_nvinfer_logger: NvDsInferContext[UID 1]: Warning from NvDsInferContextImpl::generateBackendContext() [UID = 1]: deserialize backend context from engine from file :/home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/deepstream-lpr-app/../models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_int8.engine failed, try rebuild 0:01:45.437640139 19412 0x55639b70d0 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 1]: Info from NvDsInferContextImpl::buildModel() [UID = 1]: Trying to create engine from model files WARNING: INT8 not supported by platform. Trying FP16 mode. WARNING: INT8 not supported by platform. Trying FP16 mode. INFO: [TRT]: Some tactics do not have sufficient workspace memory to run. Increasing workspace size may increase performance, please check verbose output. INFO: [TRT]: Detected 1 inputs and 2 output network tensors. 0:02:33.741014630 19412 0x55639b70d0 INFO nvinfer gstnvinfer.cpp:619:gst_nvinfer_logger: NvDsInferContext[UID 1]: Info from NvDsInferContextImpl::buildModel() [UID = 1]: serialize cuda engine to file: /home/bryan/opt/nvidia/deepstream/deepstream-5.1/samples/models/test/deepstream_lpr_app/models/tlt_pretrained_models/trafficcamnet/resnet18_trafficcamnet_pruned.etlt_b1_gpu0_fp16.engine successfully INFO: [Implicit Engine Info]: layers num: 3 0 INPUT kFLOAT input_1 3x544x960 1 OUTPUT kFLOAT output_bbox/BiasAdd 16x34x60 2 OUTPUT kFLOAT output_cov/Sigmoid 4x34x60 0:02:34.035270946 19412 0x55639b70d0 INFO nvinfer gstnvinfer_impl.cpp:313:notifyLoadModelStatus: [UID 1]: Load new model:trafficamnet_config.txt sucessfully Running... qtdemux pad video/x-h264 qtdemux pad video/x-h264 h264parser already linked. Ignoring. h264parser already linked. Ignoring. NvMMLiteOpen : Block : BlockType = 261 NvMMLiteOpen : Block : BlockType = 261 NVMEDIA: Reading vendor.tegra.display-size : status: 6 NVMEDIA: Reading vendor.tegra.display-size : status: 6 NvMMLiteBlockCreate : Block : BlockType = 261 NvMMLiteBlockCreate : Block : BlockType = 261 Frame Number = 0 Vehicle Count = 0 Person Count = 0 License Plate Count = 0 Frame Number = 1 Vehicle Count = 0 Person Count = 0 License Plate Count = 0 Frame Number = 2 Vehicle Count = 0 Person Count = 0 License Plate Count = 0 Frame Number = 3 Vehicle Count = 6 Person Count = 4 License Plate Count = 0 Frame Number = 4 Vehicle Count = 6 Person Count = 4 License Plate Count = 0 Frame Number = 5 Vehicle Count = 6 Person Count = 4 License Plate Count = 0 Frame Number = 6 Vehicle Count = 6 Person Count = 4 License Plate Count = 0 Frame Number = 7 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 8 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 9 Vehicle Count = 10 Person Count = 4 License Plate Count = 0 Frame Number = 10 Vehicle Count = 10 Person Count = 4 License Plate Count = 0 Frame Number = 11 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 12 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 13 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 14 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 15 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 16 Vehicle Count = 8 Person Count = 4 License Plate Count = 0 Frame Number = 17 Vehicle Count = 10 Person Count = 4 License Plate Count = 0 open dictionary file failed. 0:02:40.895026375 19412 0x5563261d40 ERROR nvinfer gstnvinfer.cpp:613:gst_nvinfer_logger: NvDsInferContext[UID 3]: Error in NvDsInferContextImpl::fillClassificationOutput() [UID = 3]: Failed to parse classification attributes using custom parse function open dictionary file failed. 0:02:40.895353049 19412 0x5563261d40 ERROR nvinfer gstnvinfer.cpp:613:gst_nvinfer_logger: NvDsInferContext[UID 3]: Error in NvDsInferContextImpl::fillClassificationOutput() [UID = 3]: Failed to parse classification attributes using custom parse function Segmentation fault (core dumped) ``` Alike that in the previous log/error, I see this still: ERROR: [TRT]: INVALID\_ARGUMENT: Cannot find binding of given name: output\_bbox/BiasAdd ---
**Author:** ![Morganh](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/morganh/32/9748_2.png) [@Morganh](https://forums.developer.nvidia.com/u/Morganh)\ **Post date:** [April 30, 2021, 3:17am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/18 "2021-04-30T03:17:28Z")
Please ignore " Cannot find binding of given name: output\_bbox/BiasAdd" For the latest error “open dictionary file failed”, please follow > **[GitHub - NVIDIA-AI-IOT/deepstream\_lpr\_app: Sample app code for LPR deployment on DeepStream](https://github.com/NVIDIA-AI-IOT/deepstream_lpr_app#build-and-run)** > > Sample app code for LPR deployment on DeepStream For US car plate recognition ```auto cp dict_us.txt dict.txt ``` For Chinese car plate recognition ```auto cp dict_ch.txt dict.txt ``` ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 3:32am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/19 "2021-04-30T03:32:03Z")
It seems as though it is running correctly, now (on my revised tlt-converter command; which is still a bit odd, but it’s late here and I might be getting a bit fatigued). Last question (I hope), which might be a bit dumb: the output of the results is only in terminal, is it possible to view the mp4 video as well? ---
**Author:** ![Morganh](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/morganh/32/9748_2.png) [@Morganh](https://forums.developer.nvidia.com/u/Morganh)\ **Post date:** [April 30, 2021, 3:35am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/20 "2021-04-30T03:35:16Z")
See ```auto ./deepstream-lpr-app <1:US car plate model|2: Chinese car plate model> \ <1: output as h264 file| 2:fakesink 3:display output> <0:ROI disable|1:ROI enable> \ ... ``` Please run with ./deepstream-lpr-app 1 **1** 0 … ---
**Author:** ![bbb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/bbb/32/87289_2.png) [@bbb](https://forums.developer.nvidia.com/u/bbb)\ **Post date:** [April 30, 2021, 3:53am UTC](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445/21 "2021-04-30T03:53:15Z")
@Morganh Thanks for all the help. Got it working with 1 3 0 [Next page](https://forums.developer.nvidia.com/t/creating-a-real-time-license-plate-detection-and-recognition-app/169445.md?page=2)