✳ AUDIO & PLAYBACK
No sound plays back - causes and fixes
Two most likely causes: the player was muted (autoplay is silent by default on many feeds), or the export step dropped the audio stream. Open the original locally first; if the original has sound, the conversion or the upload lost it.
Check these first
- Tap the player to unmute; check device volume.
- Open the original locally and confirm it has an audio stream.
- Inspect the file in an editor or media inspector to confirm an audio track is present.
- Check whether the conversion tool copied only the video stream.
Likely causes
- Player was muted (autoplay behavior)
Many feeds start muted; tapping unmutes. This is a player state, not a file problem.
- Conversion dropped the audio stream
A command or quick-trim tool that copies only the video stream produces a silent file by construction.
- WebM container with AAC/MP3 audio
WebM needs Opus or Vorbis audio; AAC inside WebM is invalid.
- Platform muted for music rights
Detected music in any segment can be muted automatically.
Fix it
- Re-export with an explicit audio codec
Re-encode from the original with an explicit audio stream; do not rely on a stream-copy step.
Re-export with an explicit audio codec - Design for sound-off viewing
Add burned-in captions so the message reads even when muted.
Design for sound-off viewing