Audio/video decoder, decoding on-wall system and audio/video monitoring system

The invention discloses an audio/video decoder for decoding data of one or more monitoring channels in an audio/video monitoring system. The decoder is a physically independent device and comprises a network data transmission module, a main control CPU module and at least one decoding module, wherein each decoding module corresponds to the one or more monitoring channels; and the main control CPUmodule is used for controlling the network data transmission module to acquire audio/video data stream from a network, supplying the data stream to the decoding module, controlling and managing the decoding process of the decoding module and controlling the decoding module to supply the decoded data to an external display device through a physical display interface thereof. Compared with PC-baseddecoding, the audio/video decoder does not need the support of third-party software, greatly improves the contrariety and the stability, and well meets the requirement for decoding on-wall in the monitoring system. Moreover, the invention also provides a decoding on-wall system and the audio/video monitoring system.