Doesn't this correspond to what we previously also discussed for ffmpeg 7.0.2?

ffmpeg as cli does its own option processing, as far as I understand.

Using av_dict_* functions in c++ code was working with libav*/ffmpeg libs up to 7.0

but evidently not after..

I'll look into what ffmpeg cli does now, but if more changes in pipeline may be we better to skip 7.1 completely?