[EmbedThumbnail] Add compat-option embed-thumbnail-atomicparsley

to force use of atomicparsley for embedding thumbnails in mp4

Related: #411

yt_dlp/YoutubeDL.py

@@ -391,8 +391,9 @@ class YoutubeDL(object):
     compat_opts:       Compatibility options. See "Differences in default behavior".
                        Note that only format-sort, format-spec, no-live-chat,
                        no-attach-info-json, playlist-index, list-formats,
-                       no-direct-merge, no-youtube-channel-redirect,
-                       and no-youtube-unavailable-videos works when used via the API
+                       no-direct-merge, embed-thumbnail-atomicparsley,
+                       no-youtube-unavailable-videos, no-youtube-channel-redirect,
+                       works when used via the API
 
     The following parameters are not used by YoutubeDL itself, they are used by
     the downloader (see yt_dlp/downloader/common.py):

yt_dlp/__init__.py

@@ -268,6 +268,7 @@ def _real_main(argv=None):
         'filename', 'format-sort', 'abort-on-error', 'format-spec', 'no-playlist-metafiles',
         'multistreams', 'no-live-chat', 'playlist-index', 'list-formats', 'no-direct-merge',
         'no-youtube-channel-redirect', 'no-youtube-unavailable-videos', 'no-attach-info-json',
+        'embed-thumbnail-atomicparsley',
     ]
     compat_opts = parse_compat_opts()
 

yt_dlp/postprocessor/embedthumbnail.py

@@ -125,8 +125,9 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
             self.run_ffmpeg(filename, temp_filename, options)
 
         elif info['ext'] in ['m4a', 'mp4', 'mov']:
+            prefer_atomicparsley = 'embed-thumbnail-atomicparsley' in self.get_param('compat_opts', [])
             # Method 1: Use mutagen
-            if not has_mutagen:
+            if not has_mutagen or prefer_atomicparsley:
                 success = False
             else:
                 try:
@@ -145,7 +146,7 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
                     success = False
 
             # Method 2: Use ffmpeg+ffprobe
-            if not success:
+            if not success and not prefer_atomicparsley:
                 success = True
                 try:
                     options = ['-c', 'copy', '-map', '0', '-dn', '-map', '1']