Abstract: The present invention relates to an improved zapping service for broadcasting digital video data to mobile receiving terminals, and in particular to a video encoder and a video decoder therefore. The zapping service contains still pictures (intra-coded frames) that are synchronized with a corresponding P-frame of a main video service. The respective synchronization data is generated by the video encoder and transmitted to the mobile receiving terminal. The video decoder of the mobile receiving terminal is capable of employing the synchronization data to use a zapping service I-frame as a Random Access Point for decoding an encoded main service image sequence. Accordingly, waiting time until the main video service is ready for display after selection of a main new video service (zapping) is reduced, and a smaller number of bandwidth consuming I-frames have to be transmitted in the main service channel. Thereby the bandwidth requirements are reduced.

Abstract: In the invention, zapping streams respectively relating to a plurality of normal service are set in one burst, and the burst is transmitted as a zapping burst. The zapping burst is transmitted in a cycle of one second or less. A PID dedicated to a zapping burst is added to the zapping burst. Association between the zapping burst and the normal service is designated by an IP source address, an IP destination address, or a port number. The transmission performed in this manner make it possible to perform a zapping process without considerably changing an IP encapsulator on a transmission side and an existing receiver.

Abstract: The zapping stream is transmitted in the same band as the time slice, and therefore the consumption of the transmission band is desirably suppressed to not more than a predetermined amount as far as possible. After restoring the contents from the high-quality contents stream, a specified portion corrected in timing in accordance with the degree of complication of the original image is selectively extracted not at exactly predetermined intervals (not by timing). In this way, the zapping stream is generated with a minimum information amount without deteriorating the quality as far as possible.

Abstract: The present invention relates to a battery-type DVB-H mobile receiver. DVB-H service data are transmitted on transmission channels as bursts with off times of several seconds being provided in between. The off times are used for background reception. During background reception, information from another service is acquired and stored in a memory of the receiver. When a user switches to another service, information stored in relation to this service is immediately displayed for filling the time until a first burst of the new service is received. The acquired information may include text or still images. This background reception system can be performed while using a single tuner/demodulator within the receiver for scanning other services and preferably updating acquired information. Update of respective services that are switched during background reception and possibly acquired information is performed depending on current battery conditions, equipments of the receiver and/or preference of the user.

Abstract: Although the capacity of a packet is reduced, a parity code generated by a shortened error correction code of RS (255,191) is inserted into a private data field of an adaptation field of a TS packet. In the adaptation field, as positions where the parity codes are inserted, two positions can be used. The first position is a “stuffing byte” field the length of which is indirectly known on the basis of an adaptation field length field. The second position is a “transport private data” field the length of which can be directly described by a transport private data length field.