nilaoda/N_m3u8DL-CLI ? reverse-engineered prompt

Build me a simple command line app that can download m3u8 and other streaming video links or local playlist files, and save them as mp4 or ts. It should handle common encrypted streams automatically, including AES 128 CBC, and let me pass in custom request headers, proxy settings, and a save location. I also want it to download fast with multiple threads, support pause and resume, retry failed parts, and let me limit the speed if needed.

Please make it able to merge the segments automatically when the download finishes, and support extra things like downloading only part of a stream, grabbing audio or subtitle tracks too, and optionally recording live streams. If it makes sense, add a simple way to generate common options without having to remember every command. Keep it easy to use, and make it work in Chinese and English. If you need to check current docs or examples online, go ahead.