For the SDP protocol, the m line, also known as the media line, describes information such as the type of media supported by the sender, where the second parameter is ( ).

Stretch mode is stretched to a full screen proportional to the output, which captures part of the image. ( )

At present, the sampling method mainly used in video communication: 4:2:0 sampling method ().

In the form of broadcasting, all ports can receive each data sent. Users can connect to this device and use packet capture tools such as Wireshark to grab packets sent to the device on the network and packets sent by the device to the network.

Wireshark can support decoding of many protocols, such as ( ).