Abstract: Methods and systems for inserting and extracting message data into and out of an encoded bitstream representative of an unencoded video frame are described herein. The unencoded video frame and at least one accompanying message for inclusion in the encoded bitstream are obtained and the unencoded video frame is encoded, thereby generating a video data payload of the encoded bitstream. A message size corresponding to the accompanying message(s) is obtained and a frame header of the encoded bitstream is generated. The frame header may include a message-enabled flag, a message-count flag, at least one message-size flag corresponding to each of the accompanying messages, and message-data corresponding to the contents of the accompanying message(s). The message-count flag indicates a number of accompanying messages being included in the frame header, and each message-size flag indicates the size of a corresponding accompanying message.