MP4 imports as audio only — how do I identify the missing video decoder?

Question

An MP4 imports as audio with no picture. Instead of installing random codec packs, what information should I collect first to identify the unsupported video stream?

FrameFix · Answer

Use MediaInfo and record codec, profile, level, bit depth, chroma, resolution and frame rate. 'MP4' alone is not a useful diagnosis.

SyncDesk · Answer

Compare that with the editor's supported formats and your hardware decoder capabilities. Generic codec packs can complicate troubleshooting when an application uses its own decoding framework.