✳ CODEC PROBLEMS
Destination cannot decode the codec inside an accepted container - causes and fixes
A container can hold many codecs. The destination accepts the container but cannot decode the inner video or audio stream; the file plays locally with the right decoder and fails on the destination. Re-encode the original with a widely decoded codec (H.264 video, AAC audio) and re-upload.
Check these first
- Confirm the destination's published codec list, not just the container list.
- Inspect the actual codec with a media inspector; the extension is not proof.
- Try the file in a player that supports editing codecs (VLC, QuickTime) to confirm the local playback path.
Likely causes
- Editing codec (ProRes, DNxHR) inside MP4/MOV
Editing codecs are common in NLE exports; some destinations cannot decode them.
- Unusual audio codec inside an accepted container
MP4 audio can be AAC, but also ALAC, FLAC; only AAC is reliably accepted.
- WebM with AAC or MP3 audio
WebM needs Opus or Vorbis; AAC/MP3 audio inside WebM is invalid.
Fix it
- Re-encode with H.264 video and AAC audio
Re-export from the original with H.264 (high profile) and AAC; keep audio at 44.1 kHz / 48 kHz, 16-bit.
Re-encode with H.264 video and AAC audio
Prepare a copy in Koldflux, review its output and check the current destination requirements before publishing.
Automate this in Koldflux