Merge branch 'best-fallback-on-outdated-avconv' of https://github.com/dstftw/youtube...

Conflicts:
	youtube_dl/YoutubeDL.py

diff --cc youtube_dl/YoutubeDL.py
index 0fbfe9642337ff2e08acd6c519f3aa0dce7fbe24,00f86b342dfd6bbf14c609353d3c4493719db738..4c8196d082fa9cfffbb45a1c5f5684664ecc1a80
--- 1/youtube_dl/YoutubeDL.py
--- 2/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@@ -1085,10 -1085,11 +1085,11 @@@ class YoutubeDL(object)
          req_format = self.params.get('format')
          if req_format is None:
              req_format_list = []
 -            if (self.params.get('outtmpl', DEFAULT_OUTTMPL) != '-'
 -                    and info_dict['extractor'] in ['youtube', 'ted']):
 +            if (self.params.get('outtmpl', DEFAULT_OUTTMPL) != '-' and
-                     info_dict['extractor'] in ['youtube', 'ted'] and
-                     FFmpegMergerPP(self).available):
-                 req_format_list.append('bestvideo+bestaudio')
++                    info_dict['extractor'] in ['youtube', 'ted']):
+                 merger = FFmpegMergerPP(self)
+                 if merger.available and merger.can_merge():
+                     req_format_list.append('bestvideo+bestaudio')
              req_format_list.append('best')
              req_format = '/'.join(req_format_list)
          formats_to_download = []