Distributed Video Coding (DVC) is a promising coding solution for some emerging applications, where the encoder complexity, power consumption or memory requirements are constraint the system resources. Current approaches to DVC focus on improving the performance of the Wyner-Ziv coding by improving the quality of the reconstructed side information or by improving the quality of channel codes. Up to date, no attention has been paid to the problem of key frames coding where a low-encoding complexity scenario is also needed. This work focuses on key frames coding in its effect to the Wyner-Ziv frames decoding aiming to implement a very low-complexity Turbo Trellis Coded Modulation (TTCM) based DVC architecture. In this paper, we propose a new key frame coding scheme which has very low complexity and memory requirements for the TTCM based distributed video codec. Results show that the proposed intra frame codec for key frame coding outperforms the JPEG2000 and the Intra H.264 AVC codecs in terms of encoding-time and memory requirements, with better RD performance.