Bits! Image! Sound! .. the dvb-t stick ... / 2008-12-16

2008-12-16 Bits! Image! Sound! .. the dvb-t stick ... 11 years ago
Bits! Image! Sound! .. the dvb-t stick works. Really plug and play, I just plugged it in and Ubuntu Linux recognized it and loaded the correct driver. To start the tuning process I had to give it an initial frequency and settings which I stored in /usr/share/doc/dvb-utils/examples/scan/dvb-t/nl-Utrecht:
# Digitenne (Utrecht / Maarssen / Lopik / Amersfoort, The Netherlands)
# T freq bw fec_hi fec_lo mod transmission-mode guard-interval hierarchy
T 706000000 8MHz 1/2 NONE QAM64 8k 1/4 NONE
That's enough to start the tuning process, the rest of the frequencies is found automatically:
initial transponder 706000000 0 1 9 3 1 3 0
>>> tune to: 706000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE
Network Name 'Digitenne'
0x0000 0x044d: pmt_pid 0x1b62 Digitenne -- Nederland 1 (running)
0x0000 0x044e: pmt_pid 0x1b6c Digitenne -- Nederland 2 (running)
.. somehow it knows the other frequencies and keeps on going:
retrying with f=818000000
>>> tune to: 818000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_1_2:QAM_64:TRA
NSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE (tuning failed)
0x08a3 0x000b: pmt_pid 0x03f2 Digitenne -- RTL 4 (running, scrambled)
0x08a3 0x000c: pmt_pid 0x03fc Digitenne -- RTL 5 (running, scrambled)
Eventually finding 38 services. When I set up /usr/share/doc/dvb-utils/examples/scan/dvb-t/nl-Utrecht with all the known transmitters, like
# Digitenne (Utrecht / Maarssen / Lopik / Amersfoort, The Netherlands)
# T freq bw fec_hi fec_lo mod transmission-mode guard-interval hierarchy
T 706000000 8MHz 1/2 NONE QAM64 8k 1/4 NONE
T 818000000 8MHz 1/2 NONE QAM64 8k 1/4 NONE
T 762000000 8MHz 1/2 NONE QAM64 8k 1/4 NONE
T 498000000 8MHz 1/2 NONE QAM64 8k 1/4 NONE
It still finds nothing on 498 MHz, strangely enough. I don't get 'tuning failed' but I do get errors from the pid filters.
The only thing failing at the moment is the remote: I can't find the right settings for lirc yet. But I haven't tried very hard.

Anyway: digital TV. It works!
Minor update: I learned using dvbsnoop that the 'somehow it knows the other frequencies' comes from the fact that the list of frequencies is included in the DVB standard as the Network Information Table (NIT).
Update 2008-12-18: I found the error correcting rates for two transmitters were wrong, fixed in the DVB experiments page.


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