OpenGD77

I just became aware of an open source development called Droid-Star. OpenGD77 users might find this useful as an alternate node for testing.

This software incorporates elements of a number of open source projects including MMDVM, an open AMBE3000 Codec and other technologies. It implements a Amateur Radio VOIP node that will operate on DMR, YSF, P25, NXDN, and more. It will connect to a range of back end VOIP switching networks including the one I use, Brandmeister.

With this software on an Android tablet or phone, you can communicate directly through the VOIP back end you connect to. In my case, I've configured it to work with DMR on Brandmeister and the 98977 talk group. I configured mine with it's own ESSID on each device I'm using. It will show up on the Brandmeister dashboard. Still in development, it's user interface is still pretty basic.

https://github.com/nostar/dudestar

The Google Play store has it available:

https://play.google.com/store/apps/deta ... .droidstar

I'm not sure, but there may also be an Apple Iphone version on their store...

With this software on your tablet or phone, you can communicate with other ham operators worldwide, as well as connect to and test your own radios.

FYI.

AFIK the source code for the Android App is not available

The Windows build files are also not available. (only the Windows exe)

I asked the author about how to build for Windows but was told in no uncertain terms to RTFM, where it says that the Windows builds are not supported and he / they do not provide a way to build for Windows

I've not tried to build for Linux, so I can't comment on whether this is possible either.

The author seems to want to remain anonymous, possibly for legal reasons around the AMBE codec.

I doubt if there would ever be a version for Apple devices, as it costs $ to register as an Apple developer , so that you can put stuff in the iTunes store etc.
Its also difficult to put stuff in the iTunes store and remain anonymous, as Apple are quite hot on making sure that they try not to allow malware from unknown authors into the store.

(As part of my day job I have to maintain 2 iPad Apps, and its always the most difficult version of the product to maintain, as Apple are their own judge and jury about what goes into the iTunes store, and have quite tough / random submission requirements.)

I don't know anything about the author, other than having loaded the app and that it functions.

I think that the source for the AMBE3000 Codec is at the GitHub link I posted, and while copyrighted by the author, it indicates it's open. Is this the complete codec, or is it only calling an external module?

https://github.com/nostar/dudestar/blob ... rcodec.cpp

Yes.

It does contain the source code to a DMR (AMBE) codec, but we can't use this with the OpenGD77 firmware as its probably got a load of copyrights and patents which apply to it

We have to use the binary blobs of the codec from the Radioddity firmware in their original location etc, and the OpenGD77 firmware is kinda of poured around the outside of the codec, so avoid these problems.

Radioddity are aware of the OpenGD77 and do not seem to have a problem with this reuse of the codec in the GD77

use this with caution, i got blocked on dstar by using it as it seems to transmit some garbage, fortunately i have managed to get unblocked and i dont use it anymore, just my personal experience

m1dyp wrote: ↑

Mon Jan 18, 2021 9:34 am

use this with caution, i got blocked on dstar by using it as it seems to transmit some garbage, fortunately i have managed to get unblocked and i dont use it anymore, just my personal experience

I know somehow who uses it, and he's been OK so far, but I'd not be surprised if BM just decide to block its use because it may not confirm to their Terms and Conditions.

One thing that doesn't seem to work on the Android App is receiving private calls.

Apparently its possible to make private calls, but when I tried to call the person running the App as a private call, nothing happened at their end.

Saw the same thing when trying to use the parrot... No response to the private call.

You raise an interesting problem about open technology and patent rights on the AMBE3000 Codec.

When I worked developing technology for Java, we developed a completely independently (black box) developed Java engine that was more advanced than what was available at the time. We were licensed to do this (it wasn't open source), but had to be careful what we called it.

That said, the original patents still protected the "inventor"...

If there will be issues due to AMBE codec IP, then a lot of DMR-YSF bridges should also be impacted, since many use the md-380 emulation server-side.

4I1RAC wrote: ↑

Mon Jan 18, 2021 4:08 pm

If there will be issues due to AMBE codec IP, then a lot of DMR-YSF bridges should also be impacted, since many use the md-380 emulation server-side.

I doubt that TYT actually permits their binary files to be used in this way.

Ham radio should really change to using a different codec, like Codec2.

The OpenGD77 firmware could be modified to use this. However since the vast majority of other DMR radios would still use AMBE, there would be no interoperability.

There isn't space in the GD77 etc CPU ROM for both the AMBE and Codec 2 codecs, as the AMBE codec is huge and seems to consume around half the entire ROM.

I don't know why the AMBE codec is so big. Possibly the binary sections for the encoder and decoder have unrelated and unusex functions mixed in.

Or perhaps the codec is really that complicated