-x for --extract-audio, one of the most popular options

README.md

@@ -92,7 +92,7 @@ which means you can modify it, redistribute it or use it however you like.
     -n, --netrc              use .netrc authentication data
 
 ## Post-processing Options:
-    --extract-audio          convert video files to audio-only files (requires
+    -x, --extract-audio      convert video files to audio-only files (requires
                              ffmpeg or avconv and ffprobe or avprobe)
     --audio-format FORMAT    "best", "aac", "vorbis", "mp3", "m4a", or "wav";
                              best by default

youtube-dl.1

@@ -120,7 +120,7 @@ redistribute it or use it however you like.
 .IP
 .nf
 \f[C]
---extract-audio\ \ \ \ \ \ \ \ \ \ convert\ video\ files\ to\ audio-only\ files\ (requires
+-x,\ --extract-audio\ \ \ \ \ \ convert\ video\ files\ to\ audio-only\ files\ (requires
 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ffmpeg\ or\ avconv\ and\ ffprobe\ or\ avprobe)
 --audio-format\ FORMAT\ \ \ \ "best",\ "aac",\ "vorbis",\ "mp3",\ "m4a",\ or\ "wav";
 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ best\ by\ default

youtube_dl/__init__.py

@@ -298,7 +298,7 @@ def parseOpts():
 			help='write video metadata to a .info.json file', default=False)
 
 
-	postproc.add_option('--extract-audio', action='store_true', dest='extractaudio', default=False,
+	postproc.add_option('-x', '--extract-audio', action='store_true', dest='extractaudio', default=False,
 			help='convert video files to audio-only files (requires ffmpeg or avconv and ffprobe or avprobe)')
 	postproc.add_option('--audio-format', metavar='FORMAT', dest='audioformat', default='best',
 			help='"best", "aac", "vorbis", "mp3", "m4a", or "wav"; best by default')