Make sure .mp4 can have subtitles

auto_editor/edit.py

@@ -262,7 +262,6 @@ def make_media(tl: v3, output: str) -> None:
         apply_later = False
 
         ensure = Ensure(ffmpeg, bar, samplerate, log)
-
         if ctr.default_sub != "none" and not args.sn:
             sub_output = make_new_subtitles(tl, ensure, log.temp)
 

auto_editor/subcommands/test.py

@@ -355,6 +355,13 @@ def import_v1_tests():
     def premiere_named_export():
         run.main(["example.mp4"], ["--export", 'premiere:name="Foo Bar"'])
 
+    def export_subtitles():
+        cn = fileinfo(run.main(["resources/subtitle.mp4"], []))
+
+        assert len(cn.videos) == 1
+        assert len(cn.audios) == 1
+        assert len(cn.subtitles) == 1
+
     def resolution_and_scale():
         cn = fileinfo(run.main(["example.mp4"], ["--scale", "1.5"]))
 
@@ -743,6 +750,7 @@ def palet_scripts():
                 track_tests,
                 codec_tests,
                 premiere_named_export,
+                export_subtitles,
                 export,
                 motion,
                 resolution_and_scale,

auto_editor/utils/container.py

@@ -72,6 +72,8 @@ def container_constructor(ext: str) -> Container:
             vdefault = container.default_video_codec
         adefault = container.default_audio_codec
         sdefault = container.default_subtitle_codec
+        if sdefault == "none" and ext == "mp4":
+            sdefault = "srt"
 
     vcodecs = set()
     acodecs = set()