However, the string you included ( Chaamp.2017.720p.WeB-DL.Bengali.x264.AAC.ESub-S... ) is incomplete and looks like a filename from a torrent or file-sharing site. I can’t and won’t write an article promoting or instructing how to download copyrighted content from unofficial sources.
The "x264" and "AAC" in the file name refer to the video and audio codecs used, respectively. Chaamp.2017.720p.WeB-DL.Bengali.x264.AAC.ESub-S...