The trouble is finding a clever person when you need one! And even then a clever person who isn't busy. Your plea is a tricky one because the MPEG encoder on the DTX1 main board only accepts 8 bit Digital video (BT.656 standard) in Standard Definition, not HD, directly from the on-board video encoder chip which also is restricted to SD. The actual bus is not brought out for access. HDMI has become synonymous with HD these days although of course you an use it for SD. I think the only route for you if you MUST have HDMI input would be to find something similar to a Raspberry Pi which has both an MPEG2 or H.264 encoder AND an HDMI video input on it. Then generate a transport stream on that and feed it to the TS Dock input. Anyone clever left out there? Help!
Will the new SW. allow the Unit to effectively switch the TS input to either the internal (MPEG2) coder or the external TS dock, or will it just add the capability to use a secondary TS (2 channel boquet/ mux as in dual DTX1) from another source? Viz not just the secondary Antennair add-on board.
..........So effectively the unit could be used as a DVB-S Modulator & framer accepting a standard parallel transport stream.
Yes, since the FPGA has an in-built MUX, the plan is that the software can either send 2 transport streams going to air, one from the main board MPEG2 encoder and the other from the TS_Dock board, or either of those streams alone. I guess you are thinking about a fully digital repeater? We are waiting for the Raspberry Pi side of external H.264 encoder of the project before releasing the software, in case there are some odd last-minute issues, although maybe Carl M0ICS will let you have a Beta release early if you have some other input in mind, for a repeater application
My initial thoughts were for using an external MP4 / H264 coder with the internal MP2 coder offline ( could be run at lower rates than MP2 with similar video performance) - might have uses in NBDATV . The tx standard could still be DVB-S but at a few hundred Kb/s & a low Symbol rate ...the modulator system & synth already being there & clean. I'm not convinced that DVB-S2 is of much benefit over S for amateur use.
& Yes you guessed - the other was for direct digital relay (no decoding & re-encoding - with attendent delay & degradation). Would need an input receiver that output a parallel TS stream (after viterbi ) - not had time to research that one yet but I know SRsys. make / sell a "NIM "
OK on the Raspberry Pi - yes could be a useful combo for NBDATV
It works fine down to 250Kb/s although in this set-up we are a bit faster than that. Picture quality from the Rpi's camera is very good!
The electrical interface on the Pi is physically on a 26 Way Header so there's a little inter-wiring to our 34 Way header but no electronics just a very few wires...
Connections from Model B Raspberry Pi to DTX1 TS-Dock PCB.
TS Signal Pi Assignment Pi Header Pin No. TS Dock Signal TS_Dock Pin No.
TPCLK (SYNC) GPIO 24 18 EXT-PS 7
D0 GPIO 2 3 EXT-SD0 22
D1 GPIO 3 5 EXT-SD1 20
D2 GPIO 4 7 EXT-SD2 18
D3 GPIO 14 8 EXT-SD3 17
D4 GPIO 15 10 EXT-SD4 16
D5 GPIO 17 11 EXT-SD5 15
D6 GPIO 18 12 EXT-SD6 12
D7 GPIO 27 13 EXT-SD7 11
CLK GPIO 22 15 EXT_TSCLK 24
DATA VALID 3.3V 1 EXT_DVLM 10
You could make up a single short cable to do this rather than use two ribbons and wires.
Oh and the spectrum is clean too! On this shot each division is 0.5MHz.
Evariste has added the DTX1 option to his graphical interface and Carl is just doing some refinements to a new cut of DTX1 firmware to open up the secondary TS port, which will be available shortly.
Laurence M0LDZ and Carl M0ICS
DTX1 Support Team
Many thanks to Carl M0ICS for this feature-rich version.
Get on the air at reduced bandwidth and have fun!
Can you confirm which version of the software you are using on the pi?
The original sd card image, i think, came out in November - this was the command line version
and then there was an update to the gui version whic you dragged into the sd card file structure.
There was talk of another update which would work with digilite or datv express over udp and also
a parallel output. I presume this is what you are running?
Is this a closed beta or is this out in the wild - if so where can you get it from?
Many thanks for your hard work and keeping us all informed
73. Ian, G8XZD.