diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 2a405c5cac..38ba43a977 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -305,8 +305,8 @@ class YoutubeDL(object):
     http_chunk_size.
 
     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.
+    prefer_ffmpeg:     If False, use avconv instead of ffmpeg if both are available,
+                       otherwise prefer ffmpeg.
     postprocessor_args: A list of additional command-line arguments for the
                         postprocessor.
 
diff --git a/youtube_dl/options.py b/youtube_dl/options.py
index e83d546a08..e7d8e89103 100644
--- a/youtube_dl/options.py
+++ b/youtube_dl/options.py
@@ -841,11 +841,11 @@ def _comma_separated_values_options_callback(option, opt_str, value, parser):
     postproc.add_option(
         '--prefer-avconv',
         action='store_false', dest='prefer_ffmpeg',
-        help='Prefer avconv over ffmpeg for running the postprocessors (default)')
+        help='Prefer avconv over ffmpeg for running the postprocessors')
     postproc.add_option(
         '--prefer-ffmpeg',
         action='store_true', dest='prefer_ffmpeg',
-        help='Prefer ffmpeg over avconv for running the postprocessors')
+        help='Prefer ffmpeg over avconv for running the postprocessors (default)')
     postproc.add_option(
         '--ffmpeg-location', '--avconv-location', metavar='PATH',
         dest='ffmpeg_location',
diff --git a/youtube_dl/postprocessor/ffmpeg.py b/youtube_dl/postprocessor/ffmpeg.py
index 3ea1afcf31..757b496a1c 100644
--- a/youtube_dl/postprocessor/ffmpeg.py
+++ b/youtube_dl/postprocessor/ffmpeg.py
@@ -77,7 +77,7 @@ def get_versions(downloader=None):
 
     def _determine_executables(self):
         programs = ['avprobe', 'avconv', 'ffmpeg', 'ffprobe']
-        prefer_ffmpeg = False
+        prefer_ffmpeg = True
 
         self.basename = None
         self.probe_basename = None
@@ -85,7 +85,7 @@ def _determine_executables(self):
         self._paths = None
         self._versions = None
         if self._downloader:
-            prefer_ffmpeg = self._downloader.params.get('prefer_ffmpeg', False)
+            prefer_ffmpeg = self._downloader.params.get('prefer_ffmpeg', True)
             location = self._downloader.params.get('ffmpeg_location')
             if location is not None:
                 if not os.path.exists(location):
@@ -117,19 +117,19 @@ def _determine_executables(self):
                 (p, get_exe_version(p, args=['-version'])) for p in programs)
             self._paths = dict((p, p) for p in programs)
 
-        if prefer_ffmpeg:
-            prefs = ('ffmpeg', 'avconv')
-        else:
+        if prefer_ffmpeg is False:
             prefs = ('avconv', 'ffmpeg')
+        else:
+            prefs = ('ffmpeg', 'avconv')
         for p in prefs:
             if self._versions[p]:
                 self.basename = p
                 break
 
-        if prefer_ffmpeg:
-            prefs = ('ffprobe', 'avprobe')
-        else:
+        if prefer_ffmpeg is False:
             prefs = ('avprobe', 'ffprobe')
+        else:
+            prefs = ('ffprobe', 'avprobe')
         for p in prefs:
             if self._versions[p]:
                 self.probe_basename = p