In a digital video recording system (DVR), a method of identifying the MPEG picture coding type of individual pictures of a GOP that is contained within a DSS transport packet, without parsing and evaluating each DSS transport packet. The picture coding type identifies whether a picture is an intra-coded (I) picture, predictive-coded (P) picture or bi-directionally predictive-coded (B) picture. The method facilitates implementation of DVR system playback modes, and especially trick modes by identifying and indexing the transport packet payload containing the I-picture (frame or field).