To join two MP4 files where one lacks audio, use FFmpeg to merge the streams without re-encoding to save time. To give you a better "text," could you let me know:
Switch to the , which handles MP4 playback natively without extra codecs. 382 mp4
You can convert part of an MP4/audio file into a ringtone using GarageBand for iOS . To join two MP4 files where one lacks
Is "382" part of a or a specific error code you're seeing? 382 mp4
Force use of if you prefer staying with DirectShow. ✍️ Text Overlays (Mobile-FFmpeg)
If you are recording live streams to MP4, Issue #382 on the deals with recording failures.
Are you trying to in a specific app (like Unity or FFmpeg)?