5 files changed, 29 insertions, 19 deletions
diff --git a/yt_dlp/downloader/__init__.py b/yt_dlp/downloader/__init__.py
index 6769cf8e6..53393e89f 100644
--- a/yt_dlp/downloader/__init__.py
+++ b/yt_dlp/downloader/__init__.py
@@ -3,17 +3,19 @@ from __future__ import unicode_literals
 from ..compat import compat_str
 from ..utils import (
     determine_protocol,
+    NO_DEFAULT
 )
 
 
-def _get_real_downloader(info_dict, protocol=None, *args, **kwargs):
+def get_suitable_downloader(info_dict, params={}, default=NO_DEFAULT, protocol=None):
+    info_dict['protocol'] = determine_protocol(info_dict)
     info_copy = info_dict.copy()
     if protocol:
         info_copy['protocol'] = protocol
-    return get_suitable_downloader(info_copy, *args, **kwargs)
+    return _get_suitable_downloader(info_copy, params, default)
 
 
-# Some of these require _get_real_downloader
+# Some of these require get_suitable_downloader
 from .common import FileDownloader
 from .dash import DashSegmentsFD
 from .f4m import F4mFD
@@ -69,14 +71,15 @@ def shorten_protocol_name(proto, simplify=False):
     return short_protocol_names.get(proto, proto)
 
 
-def get_suitable_downloader(info_dict, params={}, default=HttpFD):
+def _get_suitable_downloader(info_dict, params, default):
     """Get the downloader class that can handle the info dict."""
-    protocol = determine_protocol(info_dict)
-    info_dict['protocol'] = protocol
+    if default is NO_DEFAULT:
+        default = HttpFD
 
     # if (info_dict.get('start_time') or info_dict.get('end_time')) and not info_dict.get('requested_formats') and FFmpegFD.can_download(info_dict):
     #     return FFmpegFD
 
+    protocol = info_dict['protocol']
     downloaders = params.get('external_downloader')
     external_downloader = (
         downloaders if isinstance(downloaders, compat_str) or downloaders is None
@@ -94,7 +97,7 @@ def get_suitable_downloader(info_dict, params={}, default=HttpFD):
             return FFmpegFD
         elif external_downloader == 'native':
             return HlsFD
-        elif _get_real_downloader(info_dict, 'm3u8_frag_urls', params, None):
+        elif get_suitable_downloader(info_dict, params, None, protocol='m3u8_frag_urls'):
             return HlsFD
         elif params.get('hls_prefer_native') is True:
             return HlsFD
diff --git a/yt_dlp/downloader/dash.py b/yt_dlp/downloader/dash.py
index 9dae6b9bd..ccc41e158 100644
--- a/yt_dlp/downloader/dash.py
+++ b/yt_dlp/downloader/dash.py
@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from ..downloader import _get_real_downloader
+from ..downloader import get_suitable_downloader
 from .fragment import FragmentFD
 
 from ..utils import urljoin
@@ -15,11 +15,14 @@ class DashSegmentsFD(FragmentFD):
     FD_NAME = 'dashsegments'
 
     def real_download(self, filename, info_dict):
+        if info_dict.get('is_live'):
+            self.report_error('Live DASH videos are not supported')
+
         fragment_base_url = info_dict.get('fragment_base_url')
         fragments = info_dict['fragments'][:1] if self.params.get(
             'test', False) else info_dict['fragments']
 
-        real_downloader = _get_real_downloader(info_dict, 'dash_frag_urls', self.params, None)
+        real_downloader = get_suitable_downloader(info_dict, self.params, None, protocol='dash_frag_urls')
 
         ctx = {
             'filename': filename,
@@ -54,9 +57,6 @@ class DashSegmentsFD(FragmentFD):
             info_copy = info_dict.copy()
             info_copy['fragments'] = fragments_to_download
             fd = real_downloader(self.ydl, self.params)
-            # TODO: Make progress updates work without hooking twice
-            # for ph in self._progress_hooks:
-            #     fd.add_progress_hook(ph)
             return fd.real_download(filename, info_copy)
 
         return self.download_and_append_fragments(ctx, fragments_to_download, info_dict)
diff --git a/yt_dlp/downloader/external.py b/yt_dlp/downloader/external.py
index d0ee745b3..b2a605458 100644
--- a/yt_dlp/downloader/external.py
+++ b/yt_dlp/downloader/external.py
@@ -345,12 +345,22 @@ class FFmpegFD(ExternalFD):
     @classmethod
     def available(cls, path=None):
         # TODO: Fix path for ffmpeg
+        # Fixme: This may be wrong when --ffmpeg-location is used
         return FFmpegPostProcessor().available
 
     def on_process_started(self, proc, stdin):
         """ Override this in subclasses  """
         pass
 
+    @classmethod
+    def can_merge_formats(cls, info_dict, params={}):
+        return (
+            info_dict.get('requested_formats')
+            and info_dict.get('protocol')
+            and not params.get('allow_unplayable_formats')
+            and 'no-direct-merge' not in params.get('compat_opts', [])
+            and cls.can_download(info_dict))
+
     def _call_downloader(self, tmpfilename, info_dict):
         urls = [f['url'] for f in info_dict.get('requested_formats', [])] or [info_dict['url']]
         ffpp = FFmpegPostProcessor(downloader=self)
diff --git a/yt_dlp/downloader/hls.py b/yt_dlp/downloader/hls.py
index 64637badf..79d4ad5e9 100644
--- a/yt_dlp/downloader/hls.py
+++ b/yt_dlp/downloader/hls.py
@@ -4,7 +4,7 @@ import re
 import io
 import binascii
 
-from ..downloader import _get_real_downloader
+from ..downloader import get_suitable_downloader
 from .fragment import FragmentFD, can_decrypt_frag
 from .external import FFmpegFD
 
@@ -80,16 +80,13 @@ class HlsFD(FragmentFD):
             fd = FFmpegFD(self.ydl, self.params)
             self.report_warning(
                 '%s detected unsupported features; extraction will be delegated to %s' % (self.FD_NAME, fd.get_basename()))
-            # TODO: Make progress updates work without hooking twice
-            # for ph in self._progress_hooks:
-            #     fd.add_progress_hook(ph)
             return fd.real_download(filename, info_dict)
 
         is_webvtt = info_dict['ext'] == 'vtt'
         if is_webvtt:
             real_downloader = None  # Packing the fragments is not currently supported for external downloader
         else:
-            real_downloader = _get_real_downloader(info_dict, 'm3u8_frag_urls', self.params, None)
+            real_downloader = get_suitable_downloader(info_dict, self.params, None, protocol='m3u8_frag_urls')
         if real_downloader and not real_downloader.supports_manifest(s):
             real_downloader = None
         if real_downloader:
diff --git a/yt_dlp/downloader/niconico.py b/yt_dlp/downloader/niconico.py
index c5a3587a4..256840d68 100644
--- a/yt_dlp/downloader/niconico.py
+++ b/yt_dlp/downloader/niconico.py
@@ -4,7 +4,7 @@ from __future__ import unicode_literals
 import threading
 
 from .common import FileDownloader
-from ..downloader import _get_real_downloader
+from ..downloader import get_suitable_downloader
 from ..extractor.niconico import NiconicoIE
 from ..compat import compat_urllib_request
 
@@ -20,7 +20,7 @@ class NiconicoDmcFD(FileDownloader):
         ie = NiconicoIE(self.ydl)
         info_dict, heartbeat_info_dict = ie._get_heartbeat_info(info_dict)
 
-        fd = _get_real_downloader(info_dict, params=self.params)(self.ydl, self.params)
+        fd = get_suitable_downloader(info_dict, params=self.params)(self.ydl, self.params)
 
         success = download_complete = False
         timer = [None]