Seeking using cuvidDecodePicture and cuvidParseVideoData

Hope somebody can help, I need to seek to a point in a video and extrapolate the exact timestamp of that frame as I am synchronizing across multiple machines that need to be playing the same frame.

Now the:
int CUDAAPI onHandlePictureDisplay(void *user, CUVIDPARSERDISPINFO *displayInfo);
callback function that gets called in response to cuvidParseVideoData seems to only have the correct timestamp (displayInfo->timestamp) if the video is parsed from the beginning of the file. If I start parsing the video file from a different location in the file (say half way through) the timestamp disregards this fact and carries on as if it is the beginning of the video (from 0.0).

So is there a simple way of getting the true timestamp of the frames being parsed if you are seeking the playhead.

Thanks in advance :)