Matrix

Input vector

Desired message

1
1

Syndrome trellis preview

Interblock edges (colored) are generated according to the bits of the message.

Trellis preview

Explanation:

Black edges
Regular edges of the trellis
Magenta edges
Edges responsible for cutting off the paths that can no longer result in the correct syndrome (the least significant bit of the states is 0, whereas the message bit is 1)
Green edges
Similar to magenta edges, corresponding to the case where the message bit is 0 (states with their least significant bit equal to one are discarded)
Red edges
The shortest (cheapest) path to the state with minimal weight

Below the trellis is the partial stego vector corresponding to the red path. The bits in which it differs from the cover vector are highlighted in red.