mirror of
https://github.com/blakeblackshear/frigate.git
synced 2024-11-21 19:07:46 +01:00
88 lines
4.3 KiB
Markdown
88 lines
4.3 KiB
Markdown
# Realtime Object Detection for RTSP Cameras
|
|
This results in a MJPEG stream with objects identified that has a lower latency than directly viewing the RTSP feed with VLC.
|
|
- Prioritizes realtime processing over frames per second. Dropping frames is fine.
|
|
- OpenCV runs in a separate process so it can grab frames as quickly as possible to ensure there aren't old frames in the buffer
|
|
- Object detection with Tensorflow runs in a separate process and ignores frames that are more than 0.5 seconds old
|
|
- Uses shared memory arrays for handing frames between processes
|
|
- Provides a url for viewing the video feed at a hard coded ~5FPS as an mjpeg stream
|
|
- Frames are only encoded into mjpeg stream when it is being viewed
|
|
- A process is created per detection region
|
|
|
|
## Getting Started
|
|
Build the container with
|
|
```
|
|
docker build -t realtime-od .
|
|
```
|
|
|
|
Download a model from the [zoo](https://github.com/tensorflow/models/blob/master/research/object_detection/g3doc/detection_model_zoo.md).
|
|
|
|
Download the cooresponding label map from [here](https://github.com/tensorflow/models/tree/master/research/object_detection/data).
|
|
|
|
Run the container with
|
|
```
|
|
docker run --rm \
|
|
-v <path_to_frozen_detection_graph.pb>:/frozen_inference_graph.pb:ro \
|
|
-v <path_to_labelmap.pbtext>:/label_map.pbtext:ro \
|
|
-p 5000:5000 \
|
|
-e RTSP_URL='<rtsp_url>' \
|
|
-e REGIONS='<box_size_1>,<x_offset_1>,<y_offset_1>,<min_object_size_1>:<box_size_2>,<x_offset_2>,<y_offset_2>,<min_object_size_2>' \
|
|
-e MQTT_HOST='your.mqtthost.com' \
|
|
-e MQTT_MOTION_TOPIC='cameras/1/motion' \
|
|
-e MQTT_OBJECT_TOPIC='cameras/1/objects' \
|
|
-e MQTT_OBJECT_CLASSES='person,car,truck' \
|
|
realtime-od:latest
|
|
```
|
|
|
|
Access the mjpeg stream at http://localhost:5000
|
|
|
|
## Tips
|
|
- Lower the framerate of the RTSP feed on the camera to what you want to reduce the CPU usage for capturing the feed
|
|
- Use SSDLite models
|
|
|
|
## Future improvements
|
|
- [x] Switch to MQTT prefix
|
|
- [x] Add last will and availability for MQTT
|
|
- [ ] Add ability to turn detection on and off via MQTT
|
|
- [ ] Add a max size for motion and objects (height/width > 1.5, total area > 1500 and < 100,000)
|
|
- [ ] Make motion less sensitive to rain
|
|
- [ ] Use Events or Conditions to signal between threads rather than polling a value
|
|
- [ ] Implement a debug option to save images with detected objects
|
|
- [ ] Only report if x% of the recent frames have a person to avoid single frame false positives (maybe take an average of the person scores in the past x frames?)
|
|
- [ ] Filter out detected objects that are not the right size
|
|
- [ ] Make resilient to network drop outs
|
|
- [ ] Merge bounding boxes that span multiple regions
|
|
- [ ] Switch to a config file
|
|
- [ ] Allow motion regions to be different than object detection regions
|
|
- [x] Change color of bounding box if motion detected
|
|
- [x] Look for a subset of object types
|
|
- [ ] Try and reduce CPU usage by simplifying the tensorflow model to just include the objects we care about
|
|
- [x] MQTT messages when detected objects change
|
|
- [x] Implement basic motion detection with opencv and only look for objects in the regions with detected motion
|
|
- [x] Dynamic changes to processing speed, ie. only process 1FPS unless motion detected
|
|
- [x] Parallel processing to increase FPS
|
|
- [ ] Look into GPU accelerated decoding of RTSP stream
|
|
- [ ] Send video over a socket and use JSMPEG
|
|
|
|
## Building Tensorflow from source for CPU optimizations
|
|
https://www.tensorflow.org/install/source#docker_linux_builds
|
|
used `tensorflow/tensorflow:1.12.0-devel-py3`
|
|
|
|
## Optimizing the graph (cant say I saw much difference in CPU usage)
|
|
https://github.com/tensorflow/tensorflow/blob/master/tensorflow/tools/graph_transforms/README.md#optimizing-for-deployment
|
|
```
|
|
docker run -it -v ${PWD}:/lab -v ${PWD}/../back_camera_model/models/ssd_mobilenet_v2_coco_2018_03_29/frozen_inference_graph.pb:/frozen_inference_graph.pb:ro tensorflow/tensorflow:1.12.0-devel-py3 bash
|
|
|
|
bazel build tensorflow/tools/graph_transforms:transform_graph
|
|
|
|
bazel-bin/tensorflow/tools/graph_transforms/transform_graph \
|
|
--in_graph=/frozen_inference_graph.pb \
|
|
--out_graph=/lab/optimized_inception_graph.pb \
|
|
--inputs='image_tensor' \
|
|
--outputs='num_detections,detection_scores,detection_boxes,detection_classes' \
|
|
--transforms='
|
|
strip_unused_nodes(type=float, shape="1,300,300,3")
|
|
remove_nodes(op=Identity, op=CheckNumerics)
|
|
fold_constants(ignore_errors=true)
|
|
fold_batch_norms
|
|
fold_old_batch_norms'
|
|
``` |