diff --git a/README.md b/README.md
index d8926d2b72..9779c2058a 100644
--- a/README.md
+++ b/README.md
@@ -214,8 +214,8 @@ which means you can modify it, redistribute it or use it however you like.
     --audio-format FORMAT            Specify audio format: "best", "aac", "vorbis", "mp3", "m4a", "opus", or "wav"; "best" by default
     --audio-quality QUALITY          Specify ffmpeg/avconv audio quality, insert a value between 0 (better) and 9 (worse) for VBR or a specific bitrate like 128K (default
                                      5)
-    --recode-video FORMAT            Encode the video to another format if necessary (currently supported: mp4|flv|ogg|webm|mkv|xvid)
-    --postprocessor-args             Extra parameters for video post-processor.
+    --recode-video FORMAT            Encode the video to another format if necessary (currently supported: mp4|flv|ogg|webm|mkv|avi)
+    --postprocessor-args ARGS        Give these arguments to the postprocessor
     -k, --keep-video                 Keep the video file on disk after the post-processing; the video is erased by default
     --no-post-overwrites             Do not overwrite post-processed files; the post-processed files are overwritten by default
     --embed-subs                     Embed subtitles in the video (only for mkv and mp4 videos)
diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 8580f99a7c..00af78e060 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -262,7 +262,8 @@ class YoutubeDL(object):
     The following options are used by the post processors:
     prefer_ffmpeg:     If True, use ffmpeg instead of avconv if both are available,
                        otherwise prefer avconv.
-    postprocessor_args: Extra parameters for external apps, like avconv.
+    postprocessor_args: A list of additional command-line arguments for the
+                        postprocessor.
     """
 
     params = None
diff --git a/youtube_dl/__init__.py b/youtube_dl/__init__.py
index fb31d1569d..2d416943fe 100644
--- a/youtube_dl/__init__.py
+++ b/youtube_dl/__init__.py
@@ -169,7 +169,7 @@ def _real_main(argv=None):
         if not opts.audioquality.isdigit():
             parser.error('invalid audio quality specified')
     if opts.recodevideo is not None:
-        if opts.recodevideo not in ['mp4', 'flv', 'webm', 'ogg', 'mkv', 'xvid']:
+        if opts.recodevideo not in ['mp4', 'flv', 'webm', 'ogg', 'mkv', 'avi']:
             parser.error('invalid video recode format specified')
     if opts.convertsubtitles is not None:
         if opts.convertsubtitles not in ['srt', 'vtt', 'ass']:
diff --git a/youtube_dl/options.py b/youtube_dl/options.py
index c15dadb216..85365d769a 100644
--- a/youtube_dl/options.py
+++ b/youtube_dl/options.py
@@ -691,11 +691,11 @@ def parseOpts(overrideArguments=None):
     postproc.add_option(
         '--recode-video',
         metavar='FORMAT', dest='recodevideo', default=None,
-        help='Encode the video to another format if necessary (currently supported: mp4|flv|ogg|webm|mkv|xvid)')
+        help='Encode the video to another format if necessary (currently supported: mp4|flv|ogg|webm|mkv|avi)')
     postproc.add_option(
         '--postprocessor-args',
-        dest='postprocessor_args', default=None, metavar='ARGS',
-        help='Extra parameters for video post-processor.')
+        dest='postprocessor_args', metavar='ARGS',
+        help='Give these arguments to the postprocessor')
     postproc.add_option(
         '-k', '--keep-video',
         action='store_true', dest='keepvideo', default=False,
diff --git a/youtube_dl/postprocessor/ffmpeg.py b/youtube_dl/postprocessor/ffmpeg.py
index d4ba3572b5..62d13a5671 100644
--- a/youtube_dl/postprocessor/ffmpeg.py
+++ b/youtube_dl/postprocessor/ffmpeg.py
@@ -295,12 +295,10 @@ class FFmpegVideoConvertorPP(FFmpegPostProcessor):
     def run(self, information):
         path = information['filepath']
         prefix, sep, ext = path.rpartition('.')
-        ext = self._preferedformat
+        outpath = prefix + sep + self._preferedformat
         options = self._extra_cmd_args
-        if self._preferedformat == 'xvid':
-            ext = 'avi'
+        if self._preferedformat == 'avi':
             options.extend(['-c:v', 'libxvid', '-vtag', 'XVID'])
-        outpath = prefix + sep + ext
         if information['ext'] == self._preferedformat:
             self._downloader.to_screen('[ffmpeg] Not converting video file %s - already is in target format %s' % (path, self._preferedformat))
             return [], information
@@ -308,7 +306,7 @@ class FFmpegVideoConvertorPP(FFmpegPostProcessor):
         self.run_ffmpeg(path, outpath, options)
         information['filepath'] = outpath
         information['format'] = self._preferedformat
-        information['ext'] = ext
+        information['ext'] = self._preferedformat
         return [path], information