This is the trickiest term. A indicates that a previous release (e.g., "BluRay Remux 4K") had a technical flaw, and this new version fixes it.
This refers to the resolution: 3840 x 2160 pixels. That’s four times the detail of standard 1080p Blu-ray. In the context of Blu-ray, this almost always means with High Dynamic Range (HDR10, Dolby Vision, or HDR10+).
The most important part. A (remultiplex) takes the original, untouched video and audio streams directly from a commercial 4K Blu-ray disc and places them into a new container (usually .mkv or .m2ts ) without any re-encoding.
: Unlike standard "rips" or "encodes" that compress video to save space, a remux does not re-encode anything.
Ensure your TV supports the format (e.g., don't stress over Dolby Vision if your TV only does HDR10). Confirm Audio:
| Format | Video Quality | Audio Quality | File Size | Best For | | :--- | :--- | :--- | :--- | :--- | | | Perfect | Perfect (Lossless) | 60-100 GB | Physical collectors | | BluRay Remux 4K | Perfect (1:1) | Perfect (Lossless) | 45-90 GB | Plex servers / Home theater PCs | | 4K Re-encode (x265) | Near-perfect (85-95%) | Often lossy (DD+/AAC) | 15-35 GB | General streaming / Small storage | | Web-DL 4K | Good (Streaming bitrate) | Lossy (Atmos via DD+) | 12-25 GB | Casual viewing / HDR compatibility | | 1080p Remux | Good (Fine for small screens) | Perfect | 20-40 GB | Projectors (non-4K) / Legacy systems |
Unlike "Encodes" (which compress the file to save space), a Remux preserves every bit of data from the original disc.