DATV-Express Project - January update report
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This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.
Thank you
Re: DATV-Express Project - January update report
Hi Charles,
Good idea to overlay the callsign or perhaps in the future a dynamic text file (I think weather data for my application).
It would be nice to leave the possibility for the user to enter himself his FFmpeg code into a box inside your program.
FFmepg is so powerful.
Thank you for you work.
73's Michaël.
Good idea to overlay the callsign or perhaps in the future a dynamic text file (I think weather data for my application).
It would be nice to leave the possibility for the user to enter himself his FFmpeg code into a box inside your program.
FFmepg is so powerful.
Thank you for you work.
73's Michaël.
Re: DATV-Express Project - January update report
Hi Michaël,
I did manage to get a simple overlay working for those that need it but it was never
my intention to try and duplicate vMix after all they have a team of developers that
have been working on that for a number of years.
I use libavcodec directly so the FFmpeg command line interface is not
available to me so I won't be adding the ability to enter FFmpeg comand line parameters.
Today I added I420 and MJPEG format support. MJPEG will mean it will be possible to use a
'full HD' web camera with the software. However Webcam full HD and that produced
by a proper HD camera are not the same thing as far as quality is concerned.
I still have to add a dialog (sic) to allow the selection of SD or HD output formats.
If there is not much going on, on the TV tonight I may get around to it this evening.
- Charles
I did manage to get a simple overlay working for those that need it but it was never
my intention to try and duplicate vMix after all they have a team of developers that
have been working on that for a number of years.
I use libavcodec directly so the FFmpeg command line interface is not
available to me so I won't be adding the ability to enter FFmpeg comand line parameters.
Today I added I420 and MJPEG format support. MJPEG will mean it will be possible to use a
'full HD' web camera with the software. However Webcam full HD and that produced
by a proper HD camera are not the same thing as far as quality is concerned.
I still have to add a dialog (sic) to allow the selection of SD or HD output formats.
If there is not much going on, on the TV tonight I may get around to it this evening.
- Charles
Re: DATV-Express Project - January update report
Now that DATV Express has gone to the Dark Side (Windows) I decided to give it another try.
Have it working fine on Windows 10 using only my Logitech C920 webcam for both sound and vision
I hadn't been able to get that one to work on the previous version.
No messing with graphs and codecs it just worked
Have it working fine on Windows 10 using only my Logitech C920 webcam for both sound and vision

I hadn't been able to get that one to work on the previous version.
No messing with graphs and codecs it just worked

Re: DATV-Express Project - January update report
Hello Colin,
Sadly the graphs and codecs are just hidden from you and handled by the code.
I have just moved all the heartache from the user to the developer.
I am due to start counselling sessions next week.
Glad you have it working though
- Charles
Sadly the graphs and codecs are just hidden from you and handled by the code.
I have just moved all the heartache from the user to the developer.
I am due to start counselling sessions next week.

Glad you have it working though
- Charles
Re: DATV-Express Project - January update report
Thanks Charles,
Best way to do it .......for us
Now had the same painless (for me) experience on the PiPo.
Best way to do it .......for us

Now had the same painless (for me) experience on the PiPo.
Re: DATV-Express Project - January update report
Works also here in HB with vMIX. I have difficulties (little) to have a smooth image. It is not the pc, a i7-2600k 3.40 GHz. For the time being, I had no success with my Logitec webcam...
A small cosmetic point, the TX Bitrate value is rounded. Would be nice to have it to the last digit. I have seen with TSReader that the mux bitrate is correct for a given SR and FEC.
Thank you Charles for this development !
A small cosmetic point, the TX Bitrate value is rounded. Would be nice to have it to the last digit. I have seen with TSReader that the mux bitrate is correct for a given SR and FEC.
Thank you Charles for this development !
Re: DATV-Express Project - January update report
Hello Michel,
The TX bitrate is not rounded but is simply the Symbol rate x 2 - Convolutional FEC overhead. I have not allowed
for the Reed Solomon overhead. I may change that.
Sorry about the jitter, is it due to signal dropouts? Does the tx queue fill up? or maybe it is just a regular flicker
on movement.
I have added some more capture formats today but mainly I have moved from VS2012 to VS2015 community edition
(no one told me that the full edition of the Microsoft tools are now free for open source projects). VS2015 will allow me to
post the source on Github (when I figure out how) so people see how it all works (if they a interested).
- Charles
The TX bitrate is not rounded but is simply the Symbol rate x 2 - Convolutional FEC overhead. I have not allowed
for the Reed Solomon overhead. I may change that.
Sorry about the jitter, is it due to signal dropouts? Does the tx queue fill up? or maybe it is just a regular flicker
on movement.
I have added some more capture formats today but mainly I have moved from VS2012 to VS2015 community edition
(no one told me that the full edition of the Microsoft tools are now free for open source projects). VS2015 will allow me to
post the source on Github (when I figure out how) so people see how it all works (if they a interested).
- Charles
Re: DATV-Express Project - January update report
I have posted a new version of the software for those that are interested.
I have added a very crude text callsign overlay, the ability to specify different capture
and onair video formats and very basic support for the Blackmagic Decklink Mini Recorder
capture card and also for the Magewell HDMI to USB3 HD capture dongle. The sound doesn't
work on the Blackmagic card and you may have issues with interlaced video. I hope I have
not broken anything
https://www.dropbox.com/s/r1su463zrpyk5 ... r.zip?dl=0
- Charles
I have added a very crude text callsign overlay, the ability to specify different capture
and onair video formats and very basic support for the Blackmagic Decklink Mini Recorder
capture card and also for the Magewell HDMI to USB3 HD capture dongle. The sound doesn't
work on the Blackmagic card and you may have issues with interlaced video. I hope I have
not broken anything

https://www.dropbox.com/s/r1su463zrpyk5 ... r.zip?dl=0
- Charles
Re: DATV-Express Project - January update report
Charles,
I was able to test the new version today. Unfortunately it is crashing after pressing PTT:
Pressing PTT: Debug Info: Configuration is Win-10 64bit i7-2400k/16Gig
Previous version was working ok.
73 Koert PA1KW
***UPDATE***
First time starting the program you have to enter the Video Capture Settings and especially the Device Format. In my case the device format was empty. After entering the device format it is working ok!!
I was able to test the new version today. Unfortunately it is crashing after pressing PTT:
Pressing PTT: Debug Info: Configuration is Win-10 64bit i7-2400k/16Gig
Previous version was working ok.
73 Koert PA1KW
***UPDATE***
First time starting the program you have to enter the Video Capture Settings and especially the Device Format. In my case the device format was empty. After entering the device format it is working ok!!
Re: DATV-Express Project - January update report
Fine, that is useful to know. I did put some traps in the code to stop it
crashing with empty fields but I missed the format one.
I re-compiled the code with Visual Studio 2015 community edition (I was using VS2012 before)
and I had to make some changes to various paths in the system so I was a bit worried
I had broken it.
- Charles
crashing with empty fields but I missed the format one.
I re-compiled the code with Visual Studio 2015 community edition (I was using VS2012 before)
and I had to make some changes to various paths in the system so I was a bit worried
I had broken it.
- Charles