ffmpeg - Conversions - Convert TS to MKV

Software Encoding

This will stream copy (re-mux) all streams:

ffmpeg -i input -map 0 -c copy output.mkv

NOTE: The -map 0 option is used to include all streams.

Otherwise it will use the default stream selection behavior which would only result in one stream per stream type being selected.
Since Matroska can handle most arbitrary streams, -map 0 is used.