aria2c --header="User-Agent: ..." --header="Referer: ..." -i ts_urls.txt
An .m3u8 file is essentially a text file (a playlist). It contains a list of URLs pointing to video segments (usually .ts files) or information on how to request them. When you download an M3U8 file alone, you only get a few kilobytes of text, not the video. To get the video, a downloader must read the playlist, fetch every segment listed, and stitch them together. aria2c m3u8