3 files changed, 19 insertions, 13 deletions
diff --git a/youtube_dl/postprocessor/__init__.py b/youtube_dl/postprocessor/__init__.py
index fb367ebe4..7f505b58e 100644
--- a/youtube_dl/postprocessor/__init__.py
+++ b/youtube_dl/postprocessor/__init__.py
@@ -8,11 +8,16 @@ from .ffmpeg import (
     FFmpegExtractAudioPP,
     FFmpegMergerPP,
     FFmpegMetadataPP,
-    FFmpegVideoConvertor,
+    FFmpegVideoConvertorPP,
 )
 from .xattrpp import XAttrMetadataPP
 from .execafterdownload import ExecAfterDownloadPP
 
+
+def get_postprocessor(key):
+    return globals()[key + 'PP']
+
+
 __all__ = [
     'AtomicParsleyPP',
     'ExecAfterDownloadPP',
@@ -22,6 +27,6 @@ __all__ = [
     'FFmpegMergerPP',
     'FFmpegMetadataPP',
     'FFmpegPostProcessor',
-    'FFmpegVideoConvertor',
+    'FFmpegVideoConvertorPP',
     'XAttrMetadataPP',
 ]
diff --git a/youtube_dl/postprocessor/execafterdownload.py b/youtube_dl/postprocessor/execafterdownload.py
index 09db43611..75c0f7bbe 100644
--- a/youtube_dl/postprocessor/execafterdownload.py
+++ b/youtube_dl/postprocessor/execafterdownload.py
@@ -14,7 +14,7 @@ class ExecAfterDownloadPP(PostProcessor):
 
     def run(self, information):
         cmd = self.exec_cmd
-        if not '{}' in cmd:
+        if '{}' not in cmd:
             cmd += ' {}'
 
         cmd = cmd.replace('{}', shlex_quote(information['filepath']))
diff --git a/youtube_dl/postprocessor/ffmpeg.py b/youtube_dl/postprocessor/ffmpeg.py
index 9303b8378..d1b342c7a 100644
--- a/youtube_dl/postprocessor/ffmpeg.py
+++ b/youtube_dl/postprocessor/ffmpeg.py
@@ -37,11 +37,11 @@ class FFmpegPostProcessor(PostProcessor):
         if not self._executable:
             raise FFmpegPostProcessorError('ffmpeg or avconv not found. Please install one.')
 
-        REQUIRED_VERSION = '1.0'
+        required_version = '10-0' if self._uses_avconv() else '1.0'
         if is_outdated_version(
-                self._versions[self._executable], REQUIRED_VERSION):
+                self._versions[self._executable], required_version):
             warning = 'Your copy of %s is outdated, update %s to version %s or newer if you encounter any errors.' % (
-                self._executable, self._executable, REQUIRED_VERSION)
+                self._executable, self._executable, required_version)
             if self._downloader:
                 self._downloader.report_warning(warning)
 
@@ -80,8 +80,9 @@ class FFmpegPostProcessor(PostProcessor):
 
         files_cmd = []
         for path in input_paths:
-            files_cmd.extend(['-i', encodeFilename(path, True)])
-        cmd = ([self._executable, '-y'] + files_cmd
+            files_cmd.extend([encodeArgument('-i'), encodeFilename(path, True)])
+        cmd = ([encodeFilename(self._executable, True), encodeArgument('-y')] +
+               files_cmd
                + [encodeArgument(o) for o in opts] +
                [encodeFilename(self._ffmpeg_filename_argument(out_path), True)])
 
@@ -122,8 +123,8 @@ class FFmpegExtractAudioPP(FFmpegPostProcessor):
             raise PostProcessingError('ffprobe or avprobe not found. Please install one.')
         try:
             cmd = [
-                self._probe_executable,
-                '-show_streams',
+                encodeFilename(self._probe_executable, True),
+                encodeArgument('-show_streams'),
                 encodeFilename(self._ffmpeg_filename_argument(path), True)]
             handle = subprocess.Popen(cmd, stderr=compat_subprocess_get_DEVNULL(), stdout=subprocess.PIPE)
             output = handle.communicate()[0]
@@ -236,9 +237,9 @@ class FFmpegExtractAudioPP(FFmpegPostProcessor):
         return self._nopostoverwrites, information
 
 
-class FFmpegVideoConvertor(FFmpegPostProcessor):
+class FFmpegVideoConvertorPP(FFmpegPostProcessor):
     def __init__(self, downloader=None, preferedformat=None):
-        super(FFmpegVideoConvertor, self).__init__(downloader)
+        super(FFmpegVideoConvertorPP, self).__init__(downloader)
         self._preferedformat = preferedformat
 
     def run(self, information):
@@ -520,7 +521,7 @@ class FFmpegMetadataPP(FFmpegPostProcessor):
 class FFmpegMergerPP(FFmpegPostProcessor):
     def run(self, info):
         filename = info['filepath']
-        args = ['-c', 'copy', '-map', '0:v:0', '-map', '1:a:0', '-shortest']
+        args = ['-c', 'copy', '-map', '0:v:0', '-map', '1:a:0']
         self._downloader.to_screen('[ffmpeg] Merging formats into "%s"' % filename)
         self.run_ffmpeg_multiple_files(info['__files_to_merge'], filename, args)
         return True, info