Johannes Stezenbach wrote: > On Mon, Oct 15, 2007, Manu Abraham wrote: >> Johannes Stezenbach wrote: >>> I'm very confident the output of the demod is a single TS in all >>> cases, and this has nothing to do with the demux. >> Maybe, not very sure on that. Also the specifications additionally adds this: >> >> 5.2 SDTV and HDTV broadcasting with differentiated channel protection >> >> The DVB-S2 system may deliver broadcasting services over multiple Transport Streams, >> providing differentiated error protection per multiplex (VCM mode) (see note). A typical >> application is broadcasting of a highly protected multiplex for SDTV, and of a less >> protected multiplex for HDTV. Figure 17 shows an example configuration at the transmitting >> side. Assuming to transmit 27,5 Mbaud and to use 8PSK 3/4 and QPSK 2/3, 40 Mbit/s >> would be available for two HDTV programmes and 12 Mbit/s for two-three SDTV programmes. > > That doesn't contradict what I said at all. > > E.g. the HDTV TS is packaged with ISI 0x23 and the SDTV has ISI 0x42. > The ISI for each TS is in the EN 300 468 S2 delivery desc. > > When receiption conditions are good you can receive both TSs, > when they are bad you can only receive the SDTV TS (the HDTV > one will have too many errors). > > In all cases the output of the demod is a single TS. That's not what i mean to state: there are 2 methods. * Output Back Off method (OBO) (this uses ACM) The method assumes IBO on-board the satellite adjustable on a frame-by-frame basis according to the transmitted modulation format to provide the maximum capacity that can be supported by ACM systems. (basically used for feeds.) * Hierarchical modulation (This uses CCM) http://linuxtv.org/wiki/index.php/Image:Hmod.jpg Since you are very confident, so which of these two do you think are implemented on the Hotbird 9 satellite ? Manu _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
