Webcam.md

Webcam

For usage related information, see webcam feature.

Implementations

Component	Link
client	xpra.client.mixins.webcam
client connection	xpra.server.source.webcam
server	xpra.server.mixins.webcam

Capabilities

The client exposes a single webcam boolean capability.
The server exposes the following attributes using the webcam capability prefix:

• enabled boolean
• encodings list of strings - encodings supported: only png or jpeg are guaranteed to be supported
• devices integer - the number of virtual video devices available

Network Packets

Packet Type	Arguments	Direction
webcam-start	device_id, width, height	client to server
webcam-ack	unused, frame_no, width, height	server to client
webcam-frame	device_id, frame_no, encoding, width, height, data	client to server
webcam-stop	device_no

device_id, frame_no, width and height are always integers, encoding is a string.

The device_id must be smaller than the number of virtual video devices.

Flow

• client requests webcam-start
• the server responds with a webcam-ack for frame_no 0, the width and height may be different from the one requested
• the client can then send a webcam-frame for frame_no 1
• the server responds with a webcam-ack for each frame it receives
• the client must wait for the webcam-ack before sending the next frame
• whenever the client decides to stop forwarding the webcam, it must send a webcam-stop packet

If any of these steps fail, a webcam-stop packet must be sent to the peer.