This package contains a tool to convert a ROS bag with ffmpeg-compressed video into a ROS bag that can be replayed directly in Foxglove Studio, without additional tooling. In other words, it converts messages of type ffmpeg_image_transport_msgs.msg.FFMPEGPacket to type foxglove_msgs.msg.CompressedVideo.
The tool transforms specified ffmpeg_image_transport topics of an input ROS bag into Foxglove video topics in an output ROS bag. The command to convert the ROS bag into a new ROS bag with Foxglove video is:
ros2 run ffmpeg_to_foxglove_video convert path_to_input_rosbag/
This is basic usage, where the only converted topics are ffmpeg camera image streams and the output ROS bag is named after the input ROS bag with the suffix _foxglove. The user can specify input topics using the --from_topic or --regex, for example:
ros2 run ffmpeg_to_foxglove_video convert path_to_input_rosbag/ --regex "zed2/zed_node/left/image_rect_color/ffmpeg$"
The command above converts every topic ending with zed2/zed_node/left/image_rect_color/ffmpeg. It will specifically convert the left camera output video stream compressed by ffmpeg of the ZED2 camera.
Users can customize the output ROS bag path using ---output or --output-suffix (e.g., _foxglove), convert the input ROS bag while keep the input ffmpeg video stream using the -k flag, or disable printing of the progress using the -p flag. See ros2 run ffmpeg_to_foxglove_video convert --help for more details.
Note
The foxglove_video transport messages do not have the header
(std_msgs/Header), which means there are no timestamps of each
frame. This renders foxglove_video transport useless as default
compression method, because we wouldn't be able to process video
based on frame timestamp or to restamp with ros2bag_tools.