Hi, Am Sonntag, 3. Juni 2007 10:56 schrieb Peter D.: > Hi, > > I'm taking some things on trust here, so feel free to tell me I am wrong. > > My main source is http://www.dba.org.au/index.asp?sectionID=120 > > It says, among other things; > > these parameters may be changed from time to time without warning, > > receivers need to comply with Standards Australia standards AS 4933 > and AS 4599, as well as DVB standards, that say a receiver needs to > identify and receive all COFDM modes, including hierarchical (see > below), and > > the receiver should check the Transmission Parameter Signaling (TPS) > > some broadcasters use centre frequency offsets > > I'm not sure how clever that means tuners sold in Australia should be or, > more importantly, actually are. > > In this post > http://www.linuxtv.org/pipermail/linux-dvb/2007-May/018262.html John > offered a tuning file for Australia that was mostly full of "AUTO"s with > what looks like an entry for every frequency used in Australia. It works > for me with a Kworld/VStream Xpert card in Melbourne. > > I don't know how much the Australian "standards" vary from international > standards, but I believe that one or two channels have been moved by a > Mega Hertz and an extra channel (9A) added. Channel 12 might be non > standard > too, I don't know. > > Looking through the au-* tuning files and the www.dba.org.au site there are > some things that are still a mystery to me. > > There seem to be many more transmitters scattered around the country than > are mentioned in the au-* tuning files. There are two possible reasons for this: - People submitted stuff for regions where they live, so certain areas aren't covered at all. - Single-frequency network; multiple transmitters use the same frequency (and also the same modulation parameters), so you don't need a scan file for each of them. > The www.dba.org.au site only lists a single FEC for each group of channels, > while the tuning files have a fec_hi and a fec_lo. In many files that is > given as a fraction and a "NONE", sometimes as two fractions, usually the > same fraction - sometimes as different ones. > > Is the fec_low value used? Only valid sometimes? Should it be "AUTO", > "NONE", the same as fec_hi, or is it an independent variable? If no hierarchy is involved, it doesn't matter. Ideally it should be set to NONE in that case, but this doesn't happen very often. > The big problem is that *most* of the channel 7 transmitters have changed > their guard interval. > > The changes that I am offering here seem to be improvements, but I can > only test Melbourne stuff. > > au-Perth and au-Melbourne have recently changed to have the new ch7 GI. > > The files attached are; > > A generic Australian file, au-auto, from John. > > au-Adelaide, new ch7 GI > au-Cairns, new ch7 GI > au-Canberra-Black-Mt, new Prime FEC and GI > au-Darwin, new Southern Cross FEC and GI, new ch9 FEC and GI > au-Melbourne-Upway, new ch7 GI > au-MidNorthCoast, lots of changes > au-SpencerGulf, new SBS FEC > au-Sydney_Kings_Cross, new ch7 GI > au-Townsville, new ch7 GI > > There are other au-*tuning files that I am not offering changes for. Thanks for your effort! I'll deal with them soon - maybe there's also the possibility to create those files by a script so updates can be done more easily ... Christoph _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
