ffmpeg output file includes two video sequences but input file only one I want to copy from the source mkv-file the video stream (only once) and the German audio stream and all subtitles if available.
The Problem is that sometimes is the video stream copied twice in the output-mkv-file. I have following:

ffmpeg -y -i input.mkv -map 0:v:0 -map 0:m:language:ger -map 0:s? -c copy output.mkv


What must I change?
Use

ffmpeg -y -i input.mkv -map 0:v:0 -map 0:a:m:language:ger -map 0:s? -c copy output.mkv

You'll need ffmpeg 4.2 or newer.