Patent ID: 8259802
Filing Date: 2012-09-04
Classification: H04N

Abstract:
1. A method of transmitting video signals comprising: storing a plurality of reference pictures; coding input video signals, said input video signals representing a plurality of pictures, and transmitting them to a decoder, said coding being performed by, for at least some of the plurality of pictures, choosing one or more of the stored reference pictures and coding at least part of a current picture of the plurality of pictures using inter-frame differential coding relative thereto; and locally decoding the coded signals to generate locally decoded pictures for storage as said reference pictures; wherein the method further comprises receiving error messages and in response thereto suppressing the use of younger reference picture(s) as predictor and to choose only a said older reference picture for prediction; wherein said reference pictures are stored in a buffer having a storage capacity less than the round trip time to the decoder divided by the frame period; and wherein said method further comprises selecting a reference picture to be deleted from storage to make way for a newly-decoded picture, said selection being made in accordance with a defined time window having a duration of a plurality of frame periods and timed such that the youngest reference picture in the window is older than the current picture by a time interval of at least the round trip time divided by the frame period, according to the following rules: