Hi, thanks for your question and using MS Q&A portal.
Regarding your query to find out the encoding and filter out based on that, it is not directly possible with ADF activities. We need to use azure functions\batch in order to identify the encoding.
You can refer the below SO thread that discusses the similar question.
https://stackoverflow.com/questions/66255548/check-the-csv-file-encoding-in-data-factory
In order to use python to find out encoding, you may find lots of references in this thread.
Hope it helps.
Please let us know if you have more question on this, would be happy to assist.