What does HRESULT 0xC00D1B6F (NS_E_NO_MEDIAFORMAT_IN_SOURCE) mean?

NS_E_NO_MEDIAFORMAT_IN_SOURCE

The source object exists, but its media format does not

NS_E_NO_MEDIAFORMAT_IN_SOURCE (0xC00D1B6F) means Windows Media Encoder has a source object but no usable media format is set for it. This is different from an empty source-group collection.

Locate the missing format

Record the source group, source index/type, input plug-in or capture device, and the format object returned immediately before the failing call. For live capture, verify format negotiation completed; for file inputs, verify the reader exposed a recognized audio/video type.

Retest the same source

Assign or negotiate a valid media format for that source, then repeat profile/source preparation without changing the source group. If format negotiation fails with a more specific codec or device result, keep that HRESULT. Recreating the entire encoder configuration first can hide which source lacked its format.

Technical references

• Preparing a source group for encoding.
• Retrieving the profile assigned to a source group.
• Retrieving the configured encoder input.
• Saving a Windows Media Encoder configuration.