Stardust.2007.1080p.720p.bluray.x264.[... | Subtitle

Indicates the source material was a physical Blu-ray disc, ensuring high-fidelity image and sound compared to "Web-DL" or "DVD-Rip" versions.

This is the compression library used to encode the video into the H.264 format. It is the industry standard for balancing high visual quality with manageable file sizes. Subtitle Formats and Compatibility subtitle Stardust.2007.1080p.720p.BluRay.x264.[...

When looking for subtitles for a file with this specific name, you will typically encounter two formats: Indicates the source material was a physical Blu-ray