Windows based DVB-S/S2/T transmitter for LimeSDR

#1

source code:https://github.com/G4GUO/DatvExpressTransmitter
I have added LimeSDR support to DatvExpressTransmitter

work on my dvbs2 box

exe file download:https://mega.nz/#!7QMHyJDL!mdfZOiMD7OIPR7GuMq_8aa3TIPuuXM5Nu_MEvdlqUbc

4 Likes
#2

Well done : DVB-S2 tx through LimeSDR and received with minitioune .

Hope you could publish sources by forking G4GUO project

#3

That was quick!

Well done.

-Charles

#4

Nice! Any chance of support being added upstream into your repo, @g4guo?

#5

One day maybe.

#6

I mean to say, if @jocover submitted a pull request would you accept this and merge? (assuming any coding standards etc. met).

#7

I am not an expert on github, wouldn’t it be better to fork the project as I suspect it won’t
be easy to support both the Lime and Express hardware with the same code?
For example DVB-S is implemented on the Express FPGA whereas on Lime it would probably have to be
done on the host (there is a C DVB-S implementation in one of my other repositories).
The symbol rate on Express can be changed in 1 Hz increments (it effectively changes the DAC sample rate).
This may be more of a problem on the Lime.

  • Charles
#8

Is thete a linux equivalent?

#9

@kc7noa unlikely

  • Charles
#10

i’m developing cross platform support

4 Likes
#11

Hello Charles and Everiste,

I have downloaded the first version of “LimeExpress” that you pointed towards, however I believe I can see Everiste has maybe merged some code changes on Github 5 days ago but cant see a executable file of that version, is it possible to get a current build or what steps do I need to go through to build it myself from a clone of the github repository?

Keep up the great work,
vk5bd

#12

Hello Bevan,

That is one for Evariste to answer. I’ll rattle his cage later today.
I am working on the Express range extender at the moment so
am not up to speed on what he is doing.

  • Charles
#13

Hello @g4guo Charles and @f5oeo Everiste,

I have been doing some broadcast using the “LimeSDRExpress” and finding some interesting situations, If I have a static image filling the entire screen, it starts to deteriorate the picture, if I have a ticker tape running across the screen the deterioration is sometimes non existent and other time the ticker tape becomes a smudge along the screen until I presume GOP fixes things up. The GOP repair only seems to have an effect when there is motion on the screen. I played with the GOP value in DATVExpress and tried lowering the starting value of 10 to 3 which seemed to help with static images, but then motion seems to become blocky. I do use 5Msymboles to access our local repeater so I guess data rates are higher than other uses of the DATV Express software.
I downloaded your latest version seeing that you had check boxes to allow selection of output device (DATV Express, Pluto. LimeSDR etc) only to find it is only valid for Pluto operation.
I am just curious as to whether either of you two guru have done any investigation into having the DATV Express software incorporate the LimeSDR functionality?
Regards,
Bevan

#14

There are some known issues in the quality of the timestamps in the transport stream, also if the queue indicator at the top hits 100% it starts to throw away transport packets. As far as the glitches every second or so on the picture I don’t know enough about MPEG2/MPEG4 video compression to express an opinion on the cause.

As far as Lime support is concerned it will get done, it is just I am very busy at the moment working on a RBTV
DVB-S2 demodulator so I have not had time to do it. CUDA DVB-S2 demodulator

When I upgraded the software to support the Pluto I put the hooks in to support the Lime. I plan to have it done before the LimeMini starts to be shipped.

  • Charles
#15

Thanks for the reply Charles, I know you are a busy chap.
I will have a bit more of a play with the limited settings I can influence in the GUI, The queue runs quite empty most of the time, flashing up to about 3% or so, so would expect it is not loss of packets. I have conducted a test today and lowered the video performance to superfast and that seemed to have a positive effect.
Anyway, keep up the great work, look forward to possible developments around the end of the year

73
VK5BD
Bevan

#16

Hi Bevan,

You could find a latest version which include a UDP Transport input and maybe some imporvements with latest ffmpeg lib.

Only 64bits version is supported as I didn’t success in having LimeSuite working under Win32.

73’s Evariste F5OEO

#17

Hello Evariste,

Thank you for the update, I will have to fire up one of my other machine later as none of the windows ones here at work run 64bit.

Keep up the excellent work,

73
VK5BD

#18

Hello Evariste,

I have now tried the software on 3 Windows 64bit machine, with varying results. Unfortunately none of the machines were able to produce a reliable 5Ms output, the best being from a Windows 7 laptop that claims to have 8 cores

This was with DVB-S2

This was DVB-S

What was your experience with these higher symbol rates?

I have found that below 4.5Ms I can get reasonable MER but the video was broken at times.

Below 3Ms everything seemed pretty good, I was even at one point measuring >25dB MER (maximum the test instrument shows)

Also I have had the text in the IP address box turn red, is this an indication of an error, all my testing was done with the built in webcams of the various machine.

I have been using the “jocover” version of LimeSDR DATV-Express on a 32bit machine running 5Ms for a while now, I have noticed that this newer version you have supplied has some delays in making changes (like signal level or PTT) take a while to be acted upon.

Looks like it will be quite a universal software package once all the bugs are ironed out :slight_smile: , A big congratulations to you and your development team.

Regards,
Bevan