During December 2024, J2K4 enhanced Chromecast device support in the streamyfin/streamyfin repository by refining media transcoding profiles. Using TypeScript and leveraging expertise in device profiles and media transcoding, J2K4 specified H.264 video with AAC or MP3 audio for HLS streaming and H.264 with AAC for HTTP streaming, directly addressing Chromecast compatibility issues. This targeted codec selection improved playback reliability and reduced user-facing issues across streaming endpoints. The work demonstrated a focused approach to expanding device compatibility, ensuring smoother user experiences. J2K4’s contribution reflected a deep understanding of streaming protocols and practical application of media format standards.