From e464e56115ae3f8859eb43a7200ce83ae98b821d Mon Sep 17 00:00:00 2001
From: ClosedPort22 <44864697+ClosedPort22@users.noreply.github.com>
Date: Tue, 20 Aug 2024 18:48:20 +0800
Subject: [PATCH 1/3] [SubtitleConvertor] Do not attempt to convert unsupported
 formats

---
 yt_dlp/postprocessor/ffmpeg.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/yt_dlp/postprocessor/ffmpeg.py b/yt_dlp/postprocessor/ffmpeg.py
index 164c46d14..0f64a9b94 100644
--- a/yt_dlp/postprocessor/ffmpeg.py
+++ b/yt_dlp/postprocessor/ffmpeg.py
@@ -972,9 +972,9 @@ def run(self, info):
             if ext == new_ext:
                 self.to_screen(f'Subtitle file for {new_ext} is already in the requested format')
                 continue
-            elif ext == 'json':
+            elif ext not in self.SUPPORTED_EXTS:
                 self.to_screen(
-                    'You have requested to convert json subtitles into another format, '
+                    f'You have requested to convert {ext} subtitles into another format, '
                     'which is currently not possible')
                 continue
             old_file = sub['filepath']

From 649eaf2077aff42e67b0e186a4ddcbe63f13e8f3 Mon Sep 17 00:00:00 2001
From: ClosedPort22 <44864697+ClosedPort22@users.noreply.github.com>
Date: Tue, 20 Aug 2024 23:00:05 +0800
Subject: [PATCH 2/3] [SubtitleConvertor] Fix TTML conversion

---
 yt_dlp/postprocessor/ffmpeg.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/yt_dlp/postprocessor/ffmpeg.py b/yt_dlp/postprocessor/ffmpeg.py
index 0f64a9b94..4f352a079 100644
--- a/yt_dlp/postprocessor/ffmpeg.py
+++ b/yt_dlp/postprocessor/ffmpeg.py
@@ -948,6 +948,8 @@ class FFmpegFixupDuplicateMoovPP(FFmpegCopyStreamPP):
 
 class FFmpegSubtitlesConvertorPP(FFmpegPostProcessor):
     SUPPORTED_EXTS = MEDIA_EXTENSIONS.subtitles
+    _DFXP_EXTS = ('dfxp', 'ttml', 'tt')
+    _SUPPORTED_INPUT_EXTS = (*SUPPORTED_EXTS, *_DFXP_EXTS)
 
     def __init__(self, downloader=None, format=None):
         super().__init__(downloader)
@@ -972,7 +974,7 @@ def run(self, info):
             if ext == new_ext:
                 self.to_screen(f'Subtitle file for {new_ext} is already in the requested format')
                 continue
-            elif ext not in self.SUPPORTED_EXTS:
+            elif ext not in self._SUPPORTED_INPUT_EXTS:
                 self.to_screen(
                     f'You have requested to convert {ext} subtitles into another format, '
                     'which is currently not possible')
@@ -981,7 +983,7 @@ def run(self, info):
             sub_filenames.append(old_file)
             new_file = replace_extension(old_file, new_ext)
 
-            if ext in ('dfxp', 'ttml', 'tt'):
+            if ext in self._DFXP_EXTS:
                 self.report_warning(
                     'You have requested to convert dfxp (TTML) subtitles into another format, '
                     'which results in style information loss')

From 44311d71264094f1f8519ee21e632fed3bc2991b Mon Sep 17 00:00:00 2001
From: ClosedPort22 <44864697+ClosedPort22@users.noreply.github.com>
Date: Tue, 20 Aug 2024 23:06:21 +0800
Subject: [PATCH 3/3] [SubtitleConvertor] Fix warning for when sub file is
 missing

---
 yt_dlp/postprocessor/ffmpeg.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/yt_dlp/postprocessor/ffmpeg.py b/yt_dlp/postprocessor/ffmpeg.py
index 4f352a079..2054fdc6c 100644
--- a/yt_dlp/postprocessor/ffmpeg.py
+++ b/yt_dlp/postprocessor/ffmpeg.py
@@ -968,7 +968,7 @@ def run(self, info):
         sub_filenames = []
         for lang, sub in subs.items():
             if not os.path.exists(sub.get('filepath', '')):
-                self.report_warning(f'Skipping embedding {lang} subtitle because the file is missing')
+                self.report_warning(f'Skipping converting {lang} subtitle because the file is missing')
                 continue
             ext = sub['ext']
             if ext == new_ext: