Abstract: A method for regenerating the original data of a digitally coded video film is described, in which a specific picture type of a number of picture types (I, B, P) has been allocated to each of the individual pictures during coding and the coding order (DEO) does not correspond, at least in part, to the display order (DIO). This method provides for an independent time base to be used in order to recover the display order, which time base is obtained from internal information items in the decoder, the information items having been stored during the preceding decoding of a number of pictures. This method has the advantage that even with the omission of a header of a Group of Pictures (GOPH), the correct display order can still be achieved, even if the otherwise customary temporal reference codes in the bit stream signal an incorrect display order.

Abstract: MPEG2 data streams contain data packets for a set of programs and time stamps for data synchronization purposes. An MPEG2 transport stream is assembled of fixed-length transport packets. The received transport packets of at least one specific program of this set of programs can be stored using for example a DVD Streamer recorder or DVD-RAM recorder. For the real-time playback of recorded specific program data packets each packet needs a separate time stamp. For that reason a timestamp is to be captured for each data packet at recording time. However, capturing of timestamps from a transport stream is a very time consuming action in software implementation processing. Therefore transport stream timestamps are captured for every Nth packet only and the missing timestamps are calculated. Thereby software-processing time is saved for generating the timestamps required for real-time bitstream recording.

Abstract: The output bitrate of an MPEG-2 video encoder depends on the source data rate, the content or detail or degree of motion in the source pictures, the prediction type and on quantiser settings. The control of the encoder output bitrate is based on the filling level of a buffer containing VLC words. Corresponding to the actual filling level of this VLC buffer the quantiser settings are adapted in order to achieve a constant-bitrate encoder output. DVD-RAM devices are now on the market that are capable of storing such MPEG-2 video encoded video sequences. The bitrate control algorithm used has a severe impact on the achievable visual picture quality of the encoded video sequence. Therefore the current filling levels of two further buffers in the processing chain are additionally taken into account for the bitrate control: for the application with DVD-RAM, the mechanical buffer of a DVD recorder and the therein loaded DVD-RAM disc itself.