diff --git a/youtube_dl/downloader/hls.py b/youtube_dl/downloader/hls.py
index 9f29e2f81..32852f333 100644
--- a/youtube_dl/downloader/hls.py
+++ b/youtube_dl/downloader/hls.py
@@ -3,6 +3,7 @@
 
 from .common import FileDownloader
 from ..utils import (
+    check_executable,
     encodeFilename,
 )
 
@@ -19,13 +20,11 @@ def real_download(self, filename, info_dict):
             encodeFilename(tmpfilename, for_subprocess=True)]
 
         for program in ['avconv', 'ffmpeg']:
-            try:
-                subprocess.call([program, '-version'], stdout=(open(os.path.devnull, 'w')), stderr=subprocess.STDOUT)
+            if check_executable(program, ['-version']):
                 break
-            except (OSError, IOError):
-                pass
         else:
             self.report_error(u'm3u8 download detected but ffmpeg or avconv could not be found. Please install one.')
+            return False
         cmd = [program] + args
 
         retval = subprocess.call(cmd)
@@ -42,5 +41,5 @@ def real_download(self, filename, info_dict):
             return True
         else:
             self.to_stderr(u"\n")
-            self.report_error(u'ffmpeg exited with code %d' % retval)
+            self.report_error(u'%s exited with code %d' % (program, retval))
             return False
diff --git a/youtube_dl/downloader/rtmp.py b/youtube_dl/downloader/rtmp.py
index 68646709a..5eb108302 100644
--- a/youtube_dl/downloader/rtmp.py
+++ b/youtube_dl/downloader/rtmp.py
@@ -8,9 +8,10 @@
 
 from .common import FileDownloader
 from ..utils import (
+    check_executable,
+    compat_str,
     encodeFilename,
     format_bytes,
-    compat_str,
 )
 
 
@@ -103,9 +104,7 @@ def run_rtmpdump(args):
         test = self.params.get('test', False)
 
         # Check for rtmpdump first
-        try:
-            subprocess.call(['rtmpdump', '-h'], stdout=(open(os.path.devnull, 'w')), stderr=subprocess.STDOUT)
-        except (OSError, IOError):
+        if not check_executable('rtmpdump', ['-h']):
             self.report_error('RTMP download detected but "rtmpdump" could not be run. Please install it.')
             return False
 
diff --git a/youtube_dl/extractor/cbs.py b/youtube_dl/extractor/cbs.py
index 822f9a7be..db48dc24f 100644
--- a/youtube_dl/extractor/cbs.py
+++ b/youtube_dl/extractor/cbs.py
@@ -25,7 +25,7 @@ class CBSIE(InfoExtractor):
     }, {
         'url': 'http://www.cbs.com/shows/liveonletterman/artist/221752/st-vincent/',
         'info_dict': {
-            'id': 'P9gjWjelt6iP',
+            'id': 'WWF_5KqY3PK1',
             'ext': 'flv',
             'title': 'Live on Letterman - St. Vincent',
             'description': 'Live On Letterman: St. Vincent in concert from New York\'s Ed Sullivan Theater on Tuesday, July 16, 2014.',
diff --git a/youtube_dl/extractor/yahoo.py b/youtube_dl/extractor/yahoo.py
index 0e3b33b16..3ab6017cd 100644
--- a/youtube_dl/extractor/yahoo.py
+++ b/youtube_dl/extractor/yahoo.py
@@ -71,7 +71,8 @@ def _real_extract(self, url):
         if items_json is None:
             CONTENT_ID_REGEXES = [
                 r'YUI\.namespace\("Media"\)\.CONTENT_ID\s*=\s*"([^"]+)"',
-                r'root\.App\.Cache\.context\.videoCache\.curVideo = \{"([^"]+)"'
+                r'root\.App\.Cache\.context\.videoCache\.curVideo = \{"([^"]+)"',
+                r'"first_videoid"\s*:\s*"([^"]+)"',
             ]
             long_id = self._search_regex(CONTENT_ID_REGEXES, webpage, 'content ID')
             video_id = long_id