The term signaling in video streaming can refer to extra information that is sent by the receiver of a stream back to the sender. One reason for video signaling is to control the quality and bitrate of the stream for managing the CPU and bandwidth resources required by the stream. Another reason is to recover from packet loss or other bit-stream anomalies.
The standard signaling method for video streams using the RTP protocol is to send feedback messages using RTCP. The format of these messages is described in RFC-5104. Stream quality can be managed by the temporal-spatial trade-off notification which informs the sender if high resolution or high framerate is preferred. Bandwidth can be managed by sending a maximum media-stream bit-rate request. Bit-stream recovery can be done using the full intra request. When a full intra request is received by the generating side, it should generate a full picture that the receiver can decode without any prior context.
