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HTTP video streaming of ROS image topics

About

This package provides a video stream of a ROS image transport topic that can be accessed via HTTP.

Parameters

~port (integer, default: 8888) ~codec (string, default: webm) ~bitrate (integer, default: 100000) ~framerate (integer, default: 30) ~gop (integer, default: 60) ~frame_width (integer, default: -1 (input resolution)) ~frame_height (integer, default: -1 (input resolution)) ~profile (string, default: best) ~transport (string, default: raw) ~www_file_server (bool, default: false) ~wwwroot (string, default: "./")

Usage

The ros_web_video opens a local port and waits for incoming HTTP requests. As soon as a video stream of a ROS image topic is requested via HTTP, it subscribes to the corresponding topic and creates an instance of the video encoder. The encoded raw video packets are served to the client. To connect to the node with your browser, use the following URLS:

Several parameters can be configure via the video stream URL - Example: http://localhost:8888/streams/depthcloud_encoded.webm?bitrate=250000&framerate=15.

These are the parameters that can be used to configure the video feed via HTTP:

More information on the quality and profile parameter of the VP8 codec can be found here: http://www.webmproject.org/docs/encoder-parameters

Latency

The ros_web_streamer tries to minimize internal coding latency by avoiding a B-frame encoding scheme and by forcing the codec to keep its internal network buffer as small as possible. On the browser side, however, HTML5 does not allow any control of the video playback buffer. Depending on the Internet connection, the browser might cache a few seconds of video data first before starting the video playback. Best performance with respect to latency and stability has been achieve with recent versions of the Chrome browser.

Source Code

Source code is available at https://github.com/RobotWebTools/ros_web_video.

Support

Please send bug reports to the GitHub Issue Tracker. Feel free to contact us at any point with questions and comments.


2019-10-19 13:07