Need to hook into the seeking event and pass the URL parameter for time based seeking. This needs to keep state over change of quality and audio track.
Igor managed to implement a seek option. He increased the HLS Engine Buffer size to the maximum possible length of video our clients use (30 minutes so we set the value to 60 minutes). This means that the Flowplayer buffer is not shifted with the DVR Stream . This means it is easy to calculate whether the video is buffered. Now, if the User seeks within the buffered area then it works immediately. If the user seeks outside the buffer Igor gets a new stream from Serviio with the appropriate time offset (ie make a new Serviio request with start parameter greater than 0).