The previous code was ATSC-specific. Separated it into gstatscmux.c and added the DVB-specific one from ETSI EN 300 468 V1.11.1 (2010-04) https://www.etsi.org/deliver/etsi_en/300400_300499/300468/01.11.01_60/en_300468v011101p.pdf Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4681>