I think the deepspeech model for german is not actually compatible with a pi. Because afaik voice2json uses this model: https://github.com/AASHISHAG/deepspeech-german which will not work for arm. Unfortunately deepspeech works with two different model formats where one of them doesn’t work on arm due to missing tensorflow features or something. I think only the english model works on the pi for deepspeech. I can’t really recommend it for now anyway see this post Ways to control Node-RED with speech commands where i talk about it in more detail. For german I really recommend the Kaldi profile which i also use personally as it’s really fast. It’s the model from https://github.com/gooofy/zamia-speech which is a great project that have some of the best open source models for kaldi in german and french.
If you’d want to use transcribe stream from the commandline which our nodes don’t support for a couple of reasons you will actually need a microphone and a properly configured asound.conf file.
We didn’t implement transcribe stream which is a combination of record-command and stt because it didn’t actually offer any performance improvements due to a couple of reasons. Every time you start transcribe-stream it has to load all the libraries for the stt part again which is one of the biggest slow down factors. I actually implemented a little trick in our stt node that wouldn’t work in transcribe-stream. We keep stt (transcribe-wav) running with all libraries already loaded once your first transcription was done. It will just idle in the background but this way on every subsequent transcription it works a lot faster. Also it’s a lot more stable and modular with record command and stt separated.
No you don’t need any slots at all. You could write everything just in the sentences.ini.
I hope this answers all of your questions for now.