diff --git a/yt_dlp/extractor/common.py b/yt_dlp/extractor/common.py
index 9cc3051c46..8c2566dc59 100644
--- a/yt_dlp/extractor/common.py
+++ b/yt_dlp/extractor/common.py
@@ -2599,8 +2599,8 @@ def extract_Initialization(source):
                     codecs = representation_attrib.get('codecs', '')
                     if content_type not in ('video', 'audio', 'text'):
                         if mime_type == 'image/jpeg':
-                            content_type = 'image/jpeg'
-                        if codecs.split('.')[0] == 'stpp':
+                            content_type = mime_type
+                        elif codecs.split('.')[0] == 'stpp':
                             content_type = 'text'
                         else:
                             self.report_warning('Unknown MIME type %s in DASH manifest' % mime_type)
diff --git a/yt_dlp/postprocessor/ffmpeg.py b/yt_dlp/postprocessor/ffmpeg.py
index 24466f21c3..1d21ffaf2f 100644
--- a/yt_dlp/postprocessor/ffmpeg.py
+++ b/yt_dlp/postprocessor/ffmpeg.py
@@ -592,7 +592,7 @@ def add(meta_list, info_list=None):
             metadata_filename = replace_extension(filename, 'meta')
             with io.open(metadata_filename, 'wt', encoding='utf-8') as f:
                 def ffmpeg_escape(text):
-                    return re.sub(r'(=|;|#|\\|\n)', r'\\\1', text)
+                    return re.sub(r'([\\=;#\n])', r'\\\1', text)
 
                 metadata_file_content = ';FFMETADATA1\n'
                 for chapter in chapters:
diff --git a/yt_dlp/postprocessor/metadataparser.py b/yt_dlp/postprocessor/metadataparser.py
index 4d3c0e0edf..f7b0d8bde7 100644
--- a/yt_dlp/postprocessor/metadataparser.py
+++ b/yt_dlp/postprocessor/metadataparser.py
@@ -64,10 +64,10 @@ def interpretter(self, inp, out):
         def f(info):
             outtmpl, tmpl_dict = self._downloader.prepare_outtmpl(template, info)
             data_to_parse = self._downloader.escape_outtmpl(outtmpl) % tmpl_dict
-            self.write_debug(f'Searching for r{out_re.pattern!r} in {template!r}')
+            self.write_debug(f'Searching for {out_re.pattern!r} in {template!r}')
             match = out_re.search(data_to_parse)
             if match is None:
-                self.report_warning('Could not interpret {inp!r} as {out!r}')
+                self.report_warning(f'Could not interpret {inp!r} as {out!r}')
                 return
             for attribute, value in match.groupdict().items():
                 info[attribute] = value
@@ -86,12 +86,12 @@ def f(info):
             elif not isinstance(val, str):
                 self.report_warning(f'Cannot replace in field {field} since it is a {type(val).__name__}')
                 return
-            self.write_debug(f'Replacing all r{search!r} in {field} with {replace!r}')
+            self.write_debug(f'Replacing all {search!r} in {field} with {replace!r}')
             info[field], n = search_re.subn(replace, val)
             if n:
                 self.to_screen(f'Changed {field} to: {info[field]}')
             else:
-                self.to_screen(f'Did not find r{search!r} in {field}')
+                self.to_screen(f'Did not find {search!r} in {field}')
 
         search_re = re.compile(search)
         return f