Johannes Stezenbach wrote: > On Sun, Oct 14, 2007, Manu Abraham wrote: >> You can have MIS in 2 cases again: >> >> 1) Transport Streams >> >> a) When it is SIS, it is similar to our normal DVB-S transmissions >> b) When it is flagged MIS in the Baseband Header, we have Multiple Streams. >> When it is MIS, if the logical streams are scrambled, we will need to route the relevant >> stream to the CA module, which means we have some additional job at the demuxer level. >> (this will be a bit of headache, coupled with a CA device) >> >> 2) Generic Streams (note this need not be a MPEG2 stream at all) >> This at least we can pipe everything to userspace at least as a last resort. >> >> Temporarily, we do not need to worry about Generic streams (Single or Multiple), since they >> aren't basically used in the broadcast profiles, _but_ MTS might be. > > ACK -- see old posting: > http://article.gmane.org/gmane.linux.drivers.dvb/26040 > > However, contrary to what is written there I believe the demod > recognizes SIS vs. MIS and dis/enables the stream filter automatically. > I guess if you fail to set the correct ISI for MIS, you get no > output (or the wrong one). For SIS the stream id filter is irrelevant, > you can set it to any value. If the demod was to filter Multiple streams automatically, it will mean something like choosing all the options in a multiple choice question, where you are supposed to choose one. I can't see anyway how the demod can select the streams that which you are interested in, without the user telling it what you want. > > IMHO all you need is to add an u8 input_stream_identifier > to struct dvbs2_params. You take the value and write it > in a demod register -- done. > > You can get the input_stream_identifier (ISI) from the > S2 satellite delivery system descriptor, see EN 300 468. yep > > (In the worst case the demod wouldn't en/disable the stream id > filter automatically, so you'd need to read SIS/MIS flags > from a register after tuning and do it manually -- but that's > all internal to the driver and not in the API. I think.) > > (BTW, ARIB has a similar feature, transport_stream_id, see > http://linuxtv.org/cgi-bin/viewcvs.cgi/dvb-kernel-v4/linux/include/linux/dvb/frontend.h?rev=1.20.2.2&only_with_tag=ARIB_extension&view=auto > ) > > 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. Regards, Manu _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
