Hi Andrea, Andrea Venturi wrote: > hi, > > here in italy, many dvb-h trials are springing all over.. > > i'm wondering if there's already a dvb-h compliant (at least supporting > 4k) demodulator available on the market, and with a linux driver ready.. As far as I know, the DVB-H trials in the air are always using 8k or 2k. I don't remember why (I just forgot it) but someone told me that there is no real need to use 4k. > for example i know the dibcom family: > > http://195.137.248.72/539_Dibcom/Website/site/eng_accueil_applicationsproducts_products_chipset.htm > > in this table, i can see both dibcom dib7000-h dib7000-m are supposed to > be "dvb-h" compliant That is correct. The DiB7000 was at first just used for DVB-H and currently DiBcom is also using this demod for DVB-T devices (because power consumption is lower with this design and there is also the DiB7700 and DiB7710 which is demod and USB/PCI bridge in one chip - devices are really small). > i've just checked in linux-dvb CVS, and actually there's nothing about > these chips, but there is already the dibcom3000mc driver, so, maybe the > path is ready, but, if i can elaborate, the registry actually carries > just one bit for the transmission mode (switching from 2k - 8k) Yes, Dib3000* was the previous version of the demod created by DiBcom and at that time there was no 4k FFT. The DVB-H testsignal in Berlin was/is transmitted with 8K and I was successfully using DVB-T device to receive the DVB-H signal. > anyway, do you know if this dvb-h thing is going to run (soon or later) > on linux devices? DVB-H is a bit more than DVB-T + 4k-mode: The main differences/additions (from memory): - every data transmitted with DVB-H is encapsulated in IPv6 MPE sections - a sophisticated RS FEC is used for error correction of the MPE-sections - 4k-mode Afaiu, the used RS-FEC cannot be simulated by a normal CPU - because it is too hard - so you need a dedicated IC to do the work - thus the MPE sections have to be processed by the hardware and what you get out of the hardware a IPv6 packets. Anyway, the RS-FEC is mostly necessary to get good data while moving around - for local reception MPE-FEC might not be necessary. > do you know of a ready available HW (PCMCIA/USB) external adapter for pc? No. DiBcom has SDIO cards for DVB-H which are delivered along with a SDK. Don't know the price. You can use a slightly modified dvb-net.c, your dvb-t receiver and some application doing the multicast-joins automagically to simulate dvb-h with current dvb-kernel. For the DVB-H test in Berlin (I don't know if it is still on air) it was working. Unfortunately I didn't have a h264-decoder... regards, Patrick.
