customLanguageCode property
The specific language to extract from source, using the ISO 639-2 or ISO 639-3 three-letter language code. If input is SCTE-27, complete this field and/or PID to select the caption language to extract. If input is DVB-Sub and output is Burn-in or SMPTE-TT, complete this field and/or PID to select the caption language to extract. If input is DVB-Sub that is being passed through, omit this field (and PID field); there is no way to extract a specific language with pass-through captions.
Implementation
final String? customLanguageCode;