It looks like you’re looking for a guide on 300 MB MKV movies
Compression & Codecs: To achieve such a small size (standard HD movies are usually 2 GB to 8 GB), these files use aggressive compression . Modern files often use the AV1 or HEVC (H.265) codecs, which provide better quality at lower bitrates than older formats like H.264 .
Older 300 MB rips used x264 (H.264) with low bitrates (300–400 kbps), resulting in blocky, soft images. Modern 300 MB MKVs leverage HEVC (H.265), which achieves 50% better compression than H.264 at the same perceptual quality. Some cutting-edge releases even use AV1, though decoding it on low-end hardware remains a challenge.
Standard high-definition (HD) downloads typically range from 2 GB to 4 GB. Achieving a 300 MB file requires heavy compression, which may result in a loss of fine detail compared to larger formats. or more details on different video codecs