Transmitter Software Capabilities and Issues

Discussion about this major DATV Project. See also https://wiki.batc.tv/The_Portsdown_Transmitter
G8GKQ
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Re: Transmitter Software Capabilities and Issues

Postby G8GKQ » Sat Jun 24, 2017 9:31 pm

Hi Claudio

Pleased to hear that the transmitter is working for you. The Receiver is more of a signal monitor for another transmitter in the shack, not a good receiver. If you have another transmitter on any frequency within the RTL-SDR frequency range, and set that frequency on the Portsdown, it will receive signals from it at 333, 250 or 125 KS (if selected on the Portsdown). It will only demodulate and display H264 with no sound. It does display the constellation and the spectrum as well.

With some major code tweaks and the purchase of an MPEG2 decoder licence it is capable of decoding MPEG2 or H264 up to 2MS, but the performance is not good - at least 6 dB worse than a MiniTiouner. I tried receiving the ISS with it, but the signal was not strong enough to get a lock.

In summary, it is a very clever use of the RPi to receive DVB-S, but has its limitations. I will leave it in the build, because it is useful for some applications.

Dave

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Re: Transmitter Software Capabilities and Issues

Postby G8GKQ » Wed Jul 05, 2017 8:09 pm

New Software Release

I've just issued a new release 201706301. It is a maintenance and future development release, which introduces very little mainstream functionality. However, it will enable those who are interested to play with a new version of ffmpeg. This could enable us to address a number of previously very difficult issues. It also introduces some menu options that do not YET work.

Detailed feature list:

Clears the Contest numbers when contest mode is deselected on the touchscreen
Adds an audio input switching option in the menu, but not the functionality
Adds an auto option for the usb video device name, but not the functionality
Adds numeric entry for all PIDs in the menu, but not the functionality
Includes the Filter-Modulator testrig software in the core build
Implements beta functionality switching
New versions of a.sh and ffmpeg in beta functionality

There is no point in most users upgrading to this version - wait until I've made some of the new bits work and moved them into the next release!

Dave, G8GKQ

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Re: Transmitter Software Capabilities and Issues

Postby G8GKQ » Sat Jul 15, 2017 1:32 pm

New Software Release

I've just issued a new release 201707120. The aim of the release is to introduce a new output mode, which sends the RPi camera picture, test pattern or contest numbers to the RPi video output as a Composite PAL Signal. This enables mixed digital and analog portable operation with only one camera required. The new mode can be selected from Menu 2 on the touchscreen.I have also tidied some of the image sizes (see https://wiki.batc.tv/Display_Resolutions so that the test pattern does not spill over the top of the screen.

The new mode does not work with the Element 14 7 inch display (or an HDMI display) as these displays disable the composite video output from the RPi. Analog NTSC video output is not supported.

I have also added an audio input switching option in the touchscreen (Menu 2), but not the functionality - hopefully that will be in the next release.

There is no compelling reason to apply this upgrade if you don't require the new functionality.

Dave, G8GKQ

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Re: Transmitter Software Capabilities and Issues

Postby G8GKQ » Sun Jul 23, 2017 8:08 am

New Software Release

I've just issued a new release 201707221. This is a major update and I would urge everyone to update their software as soon as possible and to report any issues here. It includes:

An update to the version of ffmpeg in use
Added MPEG transmission (with sound) and streaming from the EasyCap
Configures video devices so that theEasyCap can always be connected
Automatically determines video device address
Implements auto or manual switching of audio source
Displays viewfinder in CAMMPEG-2 mode every time
Implements correct PIDs for MPEG-2 modes
Optional callsign caption in MPEG-2 modes

PLEASE read the Release notes that I have issued with this release: https://wiki.batc.tv/201707221_Release_Note. They explain the fine detail.

If you using hardware other than the BATC Fushicai EasyCap dongle and/or a cheap Chinese USB microphone adapter there is the potential that this release will cause initial problems. Test it and let me know now. I will be happy to issue fixes in the next week or 2; after that I will have moved on to other things and forgotten how to fix the problems easily!

Dave, G8GKQ

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Re: Transmitter Software Capabilities and Issues

Postby G7JTT » Sun Jul 23, 2017 10:32 am

Well done Dave, sound is now working on both PiCam and easycap.

John

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Re: Transmitter Software Capabilities and Issues

Postby M0SKM » Sun Jul 23, 2017 9:02 pm

I've not had time to check further but mine no longer works with the Pi Camera set for mpeg2; H264 OK.

Just the carrier light on, good constellation and reading FEC 6/7 with it set to 1/2. :cry:

Steve
I got food in ma belly and a license for ma telly

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Re: Transmitter Software Capabilities and Issues

Postby G8GKQ » Sun Jul 23, 2017 10:30 pm

Hi Steve

Sorry to hear that its not working.

Please could you tell me your exact hardware configuration? EasyCap? Mic Dongle? Anything else connected by USB?

Which screen?

Did you have the caption selected on or off?

Console or touchscreen control?

I'll try mine again in the morning, but want to get to the bottom of the problem asap...

73

Dave


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