+Do I need any other programs?
+
+youtube-dl works fine on its own on most sites. However, if you want to
+convert video/audio, you'll need avconv or ffmpeg. On some sites - most
+notably YouTube - videos can be retrieved in a higher quality format
+without sound. youtube-dl will detect whether avconv/ffmpeg is present
+and automatically pick the best option.
+
+Videos or video formats streamed via RTMP protocol can only be
+downloaded when rtmpdump is installed. Downloading MMS and RTSP videos
+requires either mplayer or mpv to be installed.
+