DatvRx/longmynd

Longmynd

An Open Source Linux ATV Receiver.

Copyright 2019 Heather Lomond

Dependencies

sudo apt-get install libusb-1.0-0-dev libasound2-dev tstools

To run longmynd without requiring root, unplug the minitiouner and then install the udev rules file with:

sudo cp minitiouner.rules /etc/udev/rules.d/

Compile

make

Run

Please refer to the longmynd manual page via:

man -l longmynd.1

Standalone

If running longmynd standalone (i.e. not integrated with the Portsdown software), you must create the status FIFO and (if you plan to use it) the TS FIFO:

mkfifo longmynd_main_status
mkfifo longmynd_main_ts

The test harness fake_read or a similar process must be running to consume the output of the status FIFO:

./fake_read &

A video player (e.g. VLC) must be running to consume the output of the TS FIFO.

Output

The status fifo is filled with status information as and when it becomes available.
The format of the status information is:

     $n,m<cr>
 
Where:
     n = identifier integer of Status message
     m = integer value associated with this status message
  
And the values of n and m are defined as:

ID  Meaning             Value and Units
==============================================================================================
1   State               0: initialising
                        1: searching
                        2: found headers
                        3: locked on a DVB-S signal
                        4: locked on a DVB-S2 signal 
2   LNA Gain            On devices that have LNA Amplifiers this represents the two gain 
                        sent as N, where n = (lna_gain<<5) | lna_vgo
                        Though not actually linear, n can be usefully treated as a single
                        byte representing the gain of the amplifier
3   Puncture Rate       During a search this is the pucture rate that is being trialled
                        When locked this is the pucture rate detected in the stream
                        Sent as a single value, n, where the pucture rate is n/(n+1)
4   I Symbol Power      Measure of the current power being seen in the I symbols
5   Q Symbol Power      Measure of the current power being seen in the Q symbols
6   Carrier Frequency   During a search this is the carrier frequency being trialled
                        When locked this is the Carrier Frequency detected in the stream
                        Sent in KHz
7   I Constellation     Single signed byte representing the voltage of a sampled I point
8   Q Constellation     Single signed byte representing the voltage of a sampled Q point
9   Symbol Rate         During a search this is the symbol rate being trialled
                        When locked this is the symbol rate detected in the stream
10  Viterbi Error Rate  Viterbi correction rate as a percentage * 100
11  BER                 Bit Error Rate as a Percentage * 100
12  MER                 Modulation Error Ratio in dB * 10
13  Service Provider    TS Service Provider Name
14  Service             TS Service Name
15  Null Ratio          Ratio of Nulls in TS as percentage
16  ES PID              Elementary Stream PID (repeated as pair with 17 for each ES)
17  ES Type             Elementary Stream Type (repeated as pair with 16 for each ES)
18  MODCOD              Received Modulation & Coding Rate. See MODCOD Lookup Table below
19  Short Frames        1 if received signal is using Short Frames, 0 otherwise (DVB-S2 only)
20  Pilot Symbols       1 if received signal is using Pilot Symbols, 0 otherwise (DVB-S2 only)
21  LDPC Error Count    LDPC Corrected Errors in last frame (DVB-S2 only)
22  BCH Error Count     BCH Corrected Errors in last frame (DVB-S2 only)
23  BCH Uncorrected     1 if some BCH-detected errors were not able to be corrected, 0 otherwise (DVB-S2 only)
24  LNB Voltage Enabled 1 if LNB Voltage Supply is enabled, 0 otherwise (LNB Voltage Supply requires add-on board)
25  LNB H Polarisation  1 if LNB Voltage Supply is configured for Horizontal Polarisation (18V), 0 otherwise (LNB Voltage Supply requires add-on board)

MODCOD Lookup

DVB-S

0: QPSK 1/2
1: QPSK 2/3
2: QPSK 3/4
3: QPSK 5/6
4: QPSK 6/7
5: QPSK 7/8

DVB-S2

0: DummyPL
1: QPSK 1/4
2: QPSK 1/3
3: QPSK 2/5
4: QPSK 1/2
5: QPSK 3/5
6: QPSK 2/3
7: QPSK 3/4
8: QPSK 4/5
9: QPSK 5/6
10: QPSK 8/9
11: QPSK 9/10
12: 8PSK 3/5
13: 8PSK 2/3
14: 8PSK 3/4
15: 8PSK 5/6
16: 8PSK 8/9
17: 8PSK 9/10
18: 16APSK 2/3
19: 16APSK 3/4
20: 16APSK 4/5
21: 16APSK 5/6
22: 16APSK 8/9
23: 16APSK 9/10
24: 32APSK 3/4
25: 32APSK 4/5
26: 32APSK 5/6
27: 32APSK 8/9
28: 32APSK 9/10

License

Longmynd is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Longmynd is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with longmynd.  If not, see <https://www.gnu.org/licenses/>.