Allow camera streaming to select a device from a physical port via udev

CMakeLists.txt

@@ -203,9 +203,11 @@ if (CUDA_FOUND)
     #    target_include_directories(nv_vid_codec_h265_enc SYSTEM PUBLIC deps/nvenc)
 endif ()
 
-mrover_add_nodelet(gst_websocket_streamer src/esw/gst_websocket_streamer/*.c* src/esw/gst_websocket_streamer src/esw/gst_websocket_streamer/pch.hpp)
-mrover_nodelet_link_libraries(gst_websocket_streamer PRIVATE websocket_server ${Gst_LIBRARIES} ${GstApp_LIBRARIES})
-mrover_nodelet_include_directories(gst_websocket_streamer ${Gst_INCLUDE_DIRS} ${GstApp_INCLUDE_DIRS})
+if (Gst_FOUND AND GstApp_FOUND AND LibUsb_FOUND AND LibUdev_FOUND)
+    mrover_add_nodelet(gst_websocket_streamer src/esw/gst_websocket_streamer/*.c* src/esw/gst_websocket_streamer src/esw/gst_websocket_streamer/pch.hpp)
+    mrover_nodelet_link_libraries(gst_websocket_streamer PRIVATE websocket_server ${Gst_LIBRARIES} ${GstApp_LIBRARIES} ${LibUsb_LIBRARIES} ${LibUdev_LIBRARIES} opencv_core opencv_imgproc)
+    mrover_nodelet_include_directories(gst_websocket_streamer ${Gst_INCLUDE_DIRS} ${GstApp_INCLUDE_DIRS} ${LibUsb_INCLUDE_DIRS} ${LibUdev_INCLUDE_DIRS})
+endif ()
 
 if (ZED_FOUND)
     mrover_add_nodelet(object_detector src/perception/object_detector/*.c* src/perception/object_detector src/perception/object_detector/pch.hpp)

ansible/roles/esw/tasks/main.yml

@@ -22,4 +22,4 @@
 
 - name: Install Moteus GUI
   pip:
-    name: moteus_gui
+    name: moteus-gui

cmake/deps.cmake

@@ -69,3 +69,5 @@ pkg_search_module(NetLink libnl-3.0 QUIET)
 pkg_search_module(NetLinkRoute libnl-route-3.0 QUIET)
 pkg_search_module(Gst gstreamer-1.0 QUIET)
 pkg_search_module(GstApp gstreamer-app-1.0 QUIET)
+pkg_search_module(LibUsb libusb-1.0 QUIET)
+pkg_search_module(LibUdev libudev QUIET)

launch/esw_base.launch

@@ -1,77 +1,73 @@
 <launch>
-      <rosparam command="load" file="$(find mrover)/config/esw.yaml" />
+  <rosparam command="load" file="$(find mrover)/config/esw.yaml"/>
 
-      <!-- Bridges between ROS and SocketCAN -->
-      <!-- <node name="can_driver_0" pkg="mrover" type="can_driver"
-            respawn="true" respawn_delay="2"
-            output="screen">
-            <param name="interface" value="can0" />
-      </node> -->
-      <node name="can_driver_1" pkg="mrover" type="can_driver"
-            respawn="true" respawn_delay="2"
-            output="screen">
-            <param name="interface" value="can1" />
-      </node>
-      <node name="can_driver_2" pkg="mrover" type="can_driver"
-            respawn="true" respawn_delay="2"
-            output="screen">
-            <param name="interface" value="can2" />
-      </node>
-      <node name="can_driver_3" pkg="mrover" type="can_driver"
-            respawn="true" respawn_delay="2"
-            output="screen">
-            <param name="interface" value="can3" />
-      </node>
+  <!-- Bridges between ROS and SocketCAN -->
+  <!-- <node name="can_driver_0" pkg="mrover" type="can_driver"
+        respawn="true" respawn_delay="2"
+        output="screen">
+        <param name="interface" value="can0" />
+  </node> -->
+  <node name="can_driver_1" pkg="mrover" type="can_driver"
+        respawn="true" respawn_delay="2"
+        output="screen">
+    <param name="interface" value="can1"/>
+  </node>
+  <node name="can_driver_2" pkg="mrover" type="can_driver"
+        respawn="true" respawn_delay="2"
+        output="screen">
+    <param name="interface" value="can2"/>
+  </node>
+  <node name="can_driver_3" pkg="mrover" type="can_driver"
+        respawn="true" respawn_delay="2"
+        output="screen">
+    <param name="interface" value="can3"/>
+  </node>
 
-      <node pkg="mrover" type="gst_websocket_streamer" name="gst_websocket_streamer_0"
-            output="screen">
-            <param name="device" value="/dev/video0" />
-            <param name="port" value="8081" />
-            <param name="width" value="1280" />
-            <param name="height" value="720" />
-      </node>
+  <node pkg="nodelet" type="nodelet" name="streamer_nodelet_mobility"
+        args="load mrover/GstWebsocketStreamerNodelet perception_nodelet_manager"
+        output="screen">
+    <param name="dev_node" value="/dev/video0"/>
+    <param name="port" value="8081"/>
+    <param name="width" value="1280"/>
+    <param name="height" value="720"/>
+  </node>
 
-      <node pkg="mrover" type="gst_websocket_streamer" name="gst_websocket_streamer_1"
-            output="screen">
-            <param name="device" value="/dev/video2" />
-            <param name="port" value="8082" />
-            <param name="width" value="1280" />
-            <param name="height" value="720" />
-      </node>
+  <node pkg="nodelet" type="nodelet" name="streamer_nodelet_static"
+        args="load mrover/GstWebsocketStreamerNodelet perception_nodelet_manager"
+        output="screen">
+    <param name="dev_node" value="/dev/video2"/>
+    <param name="port" value="8082"/>
+    <param name="width" value="1280"/>
+    <param name="height" value="720"/>
+  </node>
 
-      <node pkg="mrover" type="gst_websocket_streamer" name="gst_websocket_streamer_2"
-            output="screen">
-            <param name="device" value="/dev/video4" />
-            <param name="port" value="8083" />
-            <param name="width" value="1280" />
-            <param name="height" value="720" />
-      </node>
+  <node pkg="nodelet" type="nodelet" name="streamer_nodelet_finger"
+        args="load mrover/GstWebsocketStreamerNodelet perception_nodelet_manager"
+        output="screen">
+    <param name="dev_node" value="/dev/video4"/>
+    <param name="port" value="8083"/>
+    <param name="width" value="1280"/>
+    <param name="height" value="720"/>
+  </node>
 
-      <node pkg="mrover" type="gst_websocket_streamer" name="gst_websocket_streamer_zed"
-            output="screen">
-            <param name="image_topic" value="/camera/left/image" />
-            <param name="port" value="8084" />
-            <param name="width" value="1280" />
-            <param name="height" value="720" />
-      </node>
-
-      <!-- <node pkg="mrover" type="gst_websocket_streamer" name="gst_websocket_streamer_3"
-            output="screen">
-            <param name="device" value="/dev/video6" />
-            <param name="port" value="8084" />
-            <param name="width" value="640" />
-            <param name="height" value="480" />
-      </node> -->
+  <node pkg="nodelet" type="nodelet" name="streamer_nodelet_zed"
+        args="load mrover/GstWebsocketStreamerNodelet perception_nodelet_manager"
+        output="screen">
+    <param name="image_topic" value="/camera/left/image"/>
+    <param name="port" value="8084"/>
+    <param name="width" value="1280"/>
+    <param name="height" value="720"/>
+  </node>
 
-      <node name="drive_bridge" pkg="mrover" type="drive_bridge" output="screen" />
+  <node name="drive_bridge" pkg="mrover" type="drive_bridge" output="screen"/>
 
-      <!-- Interprets status from navigation and teleoperation to deliver the correct LED mode to
-      the bridge -->
-      <node name="led" pkg="mrover" type="led" output="screen" />
-      <!-- This is the STM bridge, not working right now for unknown reasons -->
-      <!-- <node name="led_hw_bridge" pkg="mrover" type="led_hw_bridge" /> -->
-      <node name="arduino_led_hw_bridge" pkg="mrover" type="arduino_led_hw_bridge.py"
-            output="screen" />
+  <!-- Interprets status from navigation and teleoperation to deliver the correct LED mode to
+  the bridge -->
+  <node name="led" pkg="mrover" type="led" output="screen"/>
+  <!-- This is the STM bridge, not working right now for unknown reasons -->
+  <!-- <node name="led_hw_bridge" pkg="mrover" type="led_hw_bridge" /> -->
+  <node name="arduino_led_hw_bridge" pkg="mrover" type="arduino_led_hw_bridge.py"
+        output="screen"/>
 
-      <node name="mast_gimbal_bridge" pkg="mrover" type="mast_gimbal_bridge" output="screen" />
+  <node name="mast_gimbal_bridge" pkg="mrover" type="mast_gimbal_bridge" output="screen"/>
 </launch>

src/esw/gst_websocket_streamer/gst_websocket_streamer.cpp

@@ -2,6 +2,8 @@
 
 namespace mrover {
 
+    using namespace std::string_view_literals;
+
     template<typename T>
     auto gstCheck(T* t) -> T* {
         if (!t) throw std::runtime_error{"Failed to create"};
@@ -40,16 +42,16 @@ namespace mrover {
 
         // Source
         std::string launch;
-        if (mCaptureDevice.empty()) {
+        if (mDeviceNode.empty()) {
             // App source is pushed to when we get a ROS BGRA image message
             // is-live prevents frames from being pushed when the pipeline is in READY
             launch += "appsrc name=imageSource is-live=true ";
         } else {
-            launch += std::format("v4l2src device={} ", mCaptureDevice);
+            launch += std::format("v4l2src device={} ", mDeviceNode);
         }
         // Source format
-        std::string captureFormat = mCaptureDevice.empty() ? "video/x-raw,format=BGRA" : mDecodeJpegFromDevice ? "image/jpeg"
-                                                                                                               : "video/x-raw,format=YUY2";
+        std::string captureFormat = mDeviceNode.empty() ? "video/x-raw,format=BGRA" : mDecodeJpegFromDevice ? "image/jpeg"
+                                                                                                            : "video/x-raw,format=YUY2";
         launch += std::format("! {},width={},height={},framerate={}/1 ",
                               captureFormat, mImageWidth, mImageHeight, mImageFramerate);
         // Source decoder and H265 encoder
@@ -99,7 +101,7 @@ namespace mrover {
         ROS_INFO_STREAM(std::format("GStreamer launch: {}", launch));
         mPipeline = gstCheck(gst_parse_launch(launch.c_str(), nullptr));
 
-        if (mCaptureDevice.empty()) mImageSource = gstCheck(gst_bin_get_by_name(GST_BIN(mPipeline), "imageSource"));
+        if (mDeviceNode.empty()) mImageSource = gstCheck(gst_bin_get_by_name(GST_BIN(mPipeline), "imageSource"));
         mStreamSink = gstCheck(gst_bin_get_by_name(GST_BIN(mPipeline), "streamSink"));
 
         if (gst_element_set_state(mPipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_FAILURE)
@@ -125,14 +127,22 @@ namespace mrover {
             if (mStreamServer->clientCount() == 0) return;
 
             if (msg->encoding != sensor_msgs::image_encodings::BGRA8) throw std::runtime_error{"Unsupported encoding"};
-            if (msg->width != mImageWidth || msg->height != mImageHeight) throw std::runtime_error{"Unsupported resolution"};
+
+            cv::Size receivedSize{static_cast<int>(msg->width), static_cast<int>(msg->height)};
+            cv::Mat bgraFrame{receivedSize, CV_8UC4, const_cast<std::uint8_t*>(msg->data.data()), msg->step};
+
+            if (cv::Size targetSize{static_cast<int>(mImageWidth), static_cast<int>(mImageHeight)};
+                receivedSize != targetSize) {
+                ROS_WARN_ONCE("Image size does not match pipeline app source size, will resize");
+                resize(bgraFrame, bgraFrame, targetSize);
+            }
 
             // "step" is the number of bytes (NOT pixels) in an image row
-            std::size_t size = msg->step * msg->height;
+            std::size_t size = bgraFrame.step * bgraFrame.rows;
             GstBuffer* buffer = gstCheck(gst_buffer_new_allocate(nullptr, size, nullptr));
             GstMapInfo info;
             gst_buffer_map(buffer, &info, GST_MAP_WRITE);
-            std::memcpy(info.data, msg->data.data(), size);
+            std::memcpy(info.data, bgraFrame.data, size);
             gst_buffer_unmap(buffer, &info);
 
             gst_app_src_push_buffer(GST_APP_SRC(mImageSource), buffer);
@@ -150,12 +160,48 @@ namespace mrover {
         throw std::runtime_error{"Unsupported resolution"};
     }
 
+    auto findDeviceNode(std::string_view devicePath) -> std::string {
+        udev* udevContext = udev_new();
+        if (!udevContext) throw std::runtime_error{"Failed to initialize udev"};
+
+        udev_enumerate* enumerate = udev_enumerate_new(udevContext);
+        if (!enumerate) throw std::runtime_error{"Failed to create udev enumeration"};
+
+        udev_enumerate_add_match_subsystem(enumerate, "video4linux");
+        udev_enumerate_scan_devices(enumerate);
+
+        udev_list_entry* devices = udev_enumerate_get_list_entry(enumerate);
+        if (!devices) throw std::runtime_error{"Failed to get udev device list"};
+
+        udev_device* device{};
+        udev_list_entry* entry;
+        udev_list_entry_foreach(entry, devices) {
+            device = udev_device_new_from_syspath(udevContext, udev_list_entry_get_name(entry));
+
+            if (udev_device_get_devpath(device) != devicePath) continue;
+
+            if (!device) throw std::runtime_error{"Failed to get udev device"};
+
+            break;
+        }
+        if (!device) throw std::runtime_error{"Failed to find udev device"};
+
+        std::string deviceNode = udev_device_get_devnode(device);
+
+        udev_device_unref(device);
+        udev_enumerate_unref(enumerate);
+        udev_unref(udevContext);
+
+        return deviceNode;
+    }
+
     auto GstWebsocketStreamerNodelet::onInit() -> void {
         try {
             mNh = getMTNodeHandle();
             mPnh = getMTPrivateNodeHandle();
 
-            mCaptureDevice = mPnh.param<std::string>("device", "");
+            mDeviceNode = mPnh.param<std::string>("dev_node", "");
+            mDevicePath = mPnh.param<std::string>("dev_path", "1");
             mDecodeJpegFromDevice = mPnh.param<bool>("decode_jpeg_from_device", true);
             mImageTopic = mPnh.param<std::string>("image_topic", "image");
             mImageWidth = mPnh.param<int>("width", 640);
@@ -167,6 +213,8 @@ namespace mrover {
 
             mChunkHeader.resolution = widthAndHeightToResolution(mImageWidth, mImageHeight);
 
+            if (!mDevicePath.empty()) mDeviceNode = findDeviceNode(mDevicePath);
+
             gst_init(nullptr, nullptr);
 
             initPipeline();
@@ -201,7 +249,7 @@ namespace mrover {
                         ROS_INFO("Stopped GStreamer pipeline");
                     });
 
-            if (mCaptureDevice.empty()) {
+            if (mDeviceNode.empty()) {
                 mImageSubscriber = mNh.subscribe(mImageTopic, 1, &GstWebsocketStreamerNodelet::imageCallback, this);
             }
 

src/esw/gst_websocket_streamer/gst_websocket_streamer.hpp

@@ -25,9 +25,19 @@ namespace mrover {
 
         ros::NodeHandle mNh, mPnh;
 
-        std::string mCaptureDevice;
+        // For example, /dev/video0
+        // These device paths are not garunteed to stay the same between reboots
+        // Prefer sys path for non-debugging purposes
+        std::string mDeviceNode;
         bool mDecodeJpegFromDevice{}; // Uses less USB hub bandwidth, which is limited since we are using 2.0
         std::string mImageTopic;
+        // To find the sys path:
+        // 1) Disconnect all cameras
+        // 2) Confirm there are no /dev/video* devices
+        // 2) Connect the camera you want to use
+        // 3) Run "ls /dev/video*" to verify the device is connected
+        // 4) Run "udevadm info -q path -n /dev/video0" to get the sys path
+        std::string mDevicePath;
         std::uint64_t mBitrate{};
         std::uint32_t mImageWidth{}, mImageHeight{}, mImageFramerate{};
 

src/esw/gst_websocket_streamer/pch.hpp

@@ -1,20 +1,26 @@
 #pragma once
 
-#include <thread>
 #include <atomic>
 #include <format>
+#include <thread>
 
 #include <nodelet/loader.h>
-#include <sensor_msgs/Image.h>
-#include <sensor_msgs/image_encodings.h>
 #include <nodelet/nodelet.h>
-#include <ros/this_node.h>
 #include <ros/init.h>
 #include <ros/names.h>
 #include <ros/node_handle.h>
+#include <ros/this_node.h>
+#include <sensor_msgs/Image.h>
+#include <sensor_msgs/image_encodings.h>
 
 #include <gst/app/gstappsink.h>
 #include <gst/app/gstappsrc.h>
 #include <gst/gst.h>
 
+#include <libusb.h>
+
+#include <libudev.h>
+
+#include <opencv2/imgproc.hpp>
+
 #include <websocket_server.hpp>