Feature request: DPMR support

[sh123]

Hello,

I have practical problem where I have two DPMR stations, which are claimed to follow DPMR standard, but which do not work with each other. Problem seems to be not only with the voice codec, but also with the protocol itself as even messaging does not work.

DSD open source version does not have support for DPMR, only DSDPlus has, but DSDPlus does not have an option for more deeper stream analysis. It only detects when data or voice frame is received, it is able to detect data/voice frames on the data, which I'm supplying.

Is there any chance to add support for DPMR or are there any guidelines on what kind of modifications to demodulator should be done to get valid bit stream. Tried to play with current demodulators in DSD, but could not find valid DPMR frame sync which is given by DPMR specification: https://www.etsi.org/deliver/etsi_tr/102800_102899/102884/01.01.01_60/tr_102884v010101p.pdf DPMR is using 4FSK, but seems that there is no demodulator in DSD, which is capable to deal with it.

It would be really nice if DSD will have support for DPMR and DPMR stream dump for deeper analysis (for example, to Wireshark compatible format), it will allow to find classes of these cheap DPMR stations which are interoperable.

Thank you.

[sh123]

Raw dump from this dpmr station: http://www.filedropper.com/dpmr