Recent versions of firmware will be removed
Re: Recent versions of firmware will be removed
In answer to do1jml. There is no special hardware for the codec. It is run on the arm processor by the binary blobs. (we assume this is licenced code from DVSI but we have no way of confirming this).
You are correct to say that the DMR spec does not specify any particular codec so in theory it would be possible to use a different one. However this would then be incompatible with all the other radios already in use. Therefore it is unlikely to gain any significant support.
Colin G4EML
You are correct to say that the DMR spec does not specify any particular codec so in theory it would be possible to use a different one. However this would then be incompatible with all the other radios already in use. Therefore it is unlikely to gain any significant support.
Colin G4EML
Re: Recent versions of firmware will be removed
Thank you for the info. Is the interface to the "binary blob" documented in the code? How difficult would it be to take, say, the published codec2 code and replace the ambe2 codec with that?
There are plenty of hams who complain about the general use of ambe2 in radios and would like a completely free alternative. Codec2 was developed with that in mind. There is also the M17 project: https://m17project.org/G4EML wrote: ↑Sat May 15, 2021 9:05 pmYou are correct to say that the DMR spec does not specify any particular codec so in theory it would be possible to use a different one. However this would then be incompatible with all the other radios already in use. Therefore it is unlikely to gain any significant support.
I would think that making an existing radio work with an open standard and a free codec would be a worthwhile effort.
Re: Recent versions of firmware will be removed
Use the source, Luke!
Code: Select all
$ unzip -v ~/Downloads/OpenGD77-master\(1\).zip | grep -i codec
0 Stored 0 0% 04-20-2021 08:55 00000000 OpenGD77-master/docs/technical_documents/codec/
1556670 Defl:N 1488628 4% 04-20-2021 08:55 d78978f9 OpenGD77-master/docs/technical_documents/codec/Multiband Excitation Vocoder.pdf
784444 Defl:N 656853 16% 04-20-2021 08:55 470b22db OpenGD77-master/docs/technical_documents/codec/TIA-102.BABA Project 25 IMBE Vocoder Description.pdf
299055 Defl:N 261653 13% 04-20-2021 08:55 7f358c39 OpenGD77-master/docs/technical_documents/codec/TIA-102.BABA-1 P25 Half Rate Vocoder Addendum .pdf
607266 Defl:N 580932 4% 04-20-2021 08:55 7d9592dc OpenGD77-master/docs/technical_documents/codec/TIA-102.BABC Vocoder Reference Test.pdf
0 Stored 0 0% 04-20-2021 08:55 00000000 OpenGD77-master/firmware/include/dmr_codec/
1288 Defl:N 666 48% 04-20-2021 08:55 13c11a5e OpenGD77-master/firmware/include/dmr_codec/codec.h
1290 Defl:N 697 46% 04-20-2021 08:55 9049757a OpenGD77-master/firmware/include/dmr_codec/mbelib.h
41984 Defl:N 37822 10% 04-20-2021 08:55 052531ca OpenGD77-master/firmware/linkerdata/codec_dat_files_creator.exe
0 Stored 0 0% 04-20-2021 08:55 00000000 OpenGD77-master/firmware/source/dmr_codec/
68357 Defl:N 3413 95% 04-20-2021 08:55 3d3d72f5 OpenGD77-master/firmware/source/dmr_codec/codec.c
904 Defl:N 487 46% 04-20-2021 08:55 53622447 OpenGD77-master/firmware/source/dmr_codec/codec_bin.S
14032 Defl:N 4373 69% 04-20-2021 08:55 ff22ed49 OpenGD77-master/firmware/source/dmr_codec/mbelib.c
0 Stored 0 0% 04-20-2021 08:55 00000000 OpenGD77-master/tools/codec_dat_files_creator/
220546 Defl:N 61009 72% 04-20-2021 08:55 2155960b OpenGD77-master/tools/codec_dat_files_creator/codec_dat_files_creator.c
I strongly agree!
Re: Recent versions of firmware will be removed
Obviously, all questions asked on any forum can be answered by "read the fine manual". But I would expect that someone who has actually worked with the firmware code base could answer that particular question relatively easily: "would it be doable to replace the binary blob by another codec"?
It may be difficult for reasons who would not be immediately apparent from the code base. For example, the TDMA structure may need particular packetisation of the data. Or maybe part of the work is done on the undocumented C6000 chip.
On the opposite, it may be relatively easy, basically replacing one library by another one. I don't know. But someone with some familiarity with the code base could make an educated guess. This is all I am asking for.
Re: Recent versions of firmware will be removed
I can probably answer that.
Yes, in theory it could be done.
No, it wouldn’t be simple, there are lots of potential problems. For example there is very little spare memory available so any new codec would have to fit in the existing space. It is unlikely that any existing alternative codec code would be directly usable.
Colin G4EML.
Yes, in theory it could be done.
No, it wouldn’t be simple, there are lots of potential problems. For example there is very little spare memory available so any new codec would have to fit in the existing space. It is unlikely that any existing alternative codec code would be directly usable.
Colin G4EML.
Re: Recent versions of firmware will be removed
Thank you for the answer.
I thought that the original firmware used quite a bit of memory space for the Chinese language. Is that still in the openGD77 version? If yes, maybe some space could be freed?
I thought that the original firmware used quite a bit of memory space for the Chinese language. Is that still in the openGD77 version? If yes, maybe some space could be freed?
Re: Recent versions of firmware will be removed
The Chinese fonts were part of the original firmware. They were never included in OpenGD77.
Re: Recent versions of firmware will be removed
The binary sections contain all sorts of code and data, not just the codec, but its all mixed together like its been in a blender.
Install Ghidra and take a look
Install Ghidra and take a look