If you've ever tried to copy a movie off a Blu-ray disc and hit a wall of unfamiliar folders and file extensions, this walkthrough is for you. The goal: take a disc you own and end up with a plain .mp4 file you can drop onto an iPad, watch on your laptop, or upload to a home media server. The route from A to B involves three tools working in sequence, and each one exists for a specific reason.

Here's the whole thing at a glance: your computer's optical drive reads the disc, a free tool called MakeMKV strips the disc's copy protection and pulls the movie out into a big .mkv file (Blu-ray discs use a kind of encryption every disc player deals with silently), then Wave (or HandBrake, or ffmpeg) converts that MKV into MP4 for whatever device you're watching on. You'll spend most of the wall-clock time on the ripping step - the MP4 conversion at the end is fast.

#What's actually inside a Blu-ray disc

If you insert a Blu-ray into a computer and browse it in Explorer or Finder, you'll see a folder called BDMV. Inside that are four sub-folders (STREAM, PLAYLIST, CLIPINF, BACKUP) that hold everything the disc knows how to do. Here's what each one is for:

  • STREAM holds the actual video - one .m2ts file per continuous chunk. On a movie disc, the main feature is usually one giant .m2ts file (typically 5-30 GB depending on runtime and quality). On a TV series disc, each episode is its own .m2ts. This is the raw material you want.
  • PLAYLIST holds tiny .mpls files that are essentially "recipes" telling the disc player how to string M2TS chunks together - which order to play chapters, which version to show (some discs have both a theatrical and extended cut assembled from overlapping chunks), which language track to default to.
  • CLIPINF holds bookkeeping for each M2TS file - what codec is inside, exact timing, which audio track is which language, subtitle descriptions. Playback software reads this to build the audio and subtitle menus.
  • BACKUP is a duplicate of the playlist information, kept in case the main copy gets corrupted by a scratch.

Now, what's actually inside those .m2ts files? The container itself (M2TS = MPEG-2 Transport Stream) is the same format broadcast TV uses - a stream of tiny packets that could in principle be received live over the air. Inside those packets is where the actual movie lives: H.264 video on a standard Blu-ray, HEVC (also called H.265) video on a 4K Ultra HD Blu-ray. Then there are several audio tracks (usually the primary mix in AC-3 or DTS, plus a lossless "master audio" track in DTS-HD or TrueHD, plus maybe a director's commentary), and several subtitle tracks in a format called PGS (which is basically a slideshow of tiny subtitle images overlaid on the picture, rather than plain text).

#Step 1: Rip with MakeMKV

MakeMKV is a Windows/Mac/Linux tool that reads Blu-ray discs, decrypts the disc's AACS or BD+ copy protection, and writes each M2TS out as a standalone .mkv file. The reason MKV (not MP4) is the ripper's output: MKV holds every Blu-ray codec natively (HEVC, DTS-HD, TrueHD, PGS subtitles) where MP4 needs re-encoding or dropping. MakeMKV is lossless - it copies the compressed streams bit-for-bit.

The workflow: launch MakeMKV, insert the disc, wait for the initial scan (2-5 minutes on a UHD disc). MakeMKV shows a tree of "titles" - one per M2TS segment. The main feature is usually the largest title; TV episodes appear as separate titles. Select the tracks you want (usually one video track, one main audio track, one subtitle track for English hearing-impaired if available), pick an output folder, click "Make MKV". A 90-minute Blu-ray movie takes 30-90 minutes to rip depending on disc read speed.

Notes: MakeMKV requires a licence key. There's a free beta key that renews every 60 days; a lifetime licence is $60. Reading UHD Blu-ray discs requires a compatible optical drive (some drives are locked to a specific firmware that MakeMKV's HD-DVD ripping module works with). Non-UHD Blu-ray is more forgiving on drive requirements.

#Step 2: Choose your audio and subtitle tracks

Blu-ray discs often ship with multiple audio tracks - the primary English 5.1 mix, a director's commentary, foreign language dubs, hearing-impaired descriptive audio. MakeMKV rips whichever you selected; if you missed one, re-rip from the disc rather than trying to extract from the MKV.

Subtitle tracks on Blu-ray are PGS (Presentation Graphics Stream) - bitmap images rendered by the player. This has one big consequence for MP4 conversion: MP4 can't hold PGS subtitles. Wave drops them during the MKV-to-MP4 conversion because there's no MP4-compatible target format. If you need subtitles in the MP4, the practical options are: (1) burn them into the video during a re-encode (visible in the picture, not toggleable), (2) OCR the PGS to SubRip text using SubtitleEdit and ship them as a sidecar .srt file next to the MP4, (3) keep the MKV as your working file and only convert to MP4 for playback on devices that need it.

#Step 3: MKV to MP4 with Wave

MakeMKV's output MKV contains H.264 or HEVC video with AAC-compatible audio (if you selected the AC-3 or AAC track; DTS-HD and TrueHD are Blu-ray audio codecs MP4 can't hold, and MakeMKV can also pull the core AC-3 track). Wave's MKV to MP4 path handles the container swap. When the audio is AAC, the remux is instant. When it is AC-3, DTS-HD or TrueHD, Wave copies the video untouched and converts the audio to AAC - AC-3 because Chrome and Firefox can't play it inside MP4, DTS-HD and TrueHD because MP4 can't carry them at all. That adds seconds, not minutes.

For Ultra HD Blu-ray (HEVC 10-bit HDR), the MKV-to-MP4 conversion via Wave is a remux - HEVC is MP4-compatible. HDR metadata (Rec.2020 colour, PQ or HLG transfer) copies through. Playback needs an HDR-capable display; on SDR displays the player handles tone mapping.

#Alternative: keep it as MKV

If your playback target handles MKV natively (VLC, Plex, Jellyfin, Kodi, a modern smart TV with MKV support), skip the MP4 conversion entirely and use the MakeMKV output directly. MKV preserves multi-track audio, PGS subtitles, and chapter markers - all of which either lose or get worked around during the MP4 conversion. For an iOS device or a browser (which refuses MKV), the MP4 conversion is required. For a home media server, MKV is often the better keep.

#The size trade-offs

  • Blu-ray M2TS main feature: Typically 15-30 GB.
  • MakeMKV output MKV: Same size as the M2TS content (lossless copy).
  • MKV to MP4 remux (Wave): Same size.
  • Re-encode to H.264 or HEVC at high quality (HandBrake): 4-8 GB for a movie.
  • Re-encode for mobile (720p, 3 Mbps H.264): 2-3 GB.

If storage matters, a HandBrake re-encode after the MP4 conversion is where the big size drops happen. Wave's remux preserves the disc-quality file; HandBrake's re-encode makes it fit on an iPad.

#The takeaway

Blu-ray M2TS to MP4 is a three-step workflow: MakeMKV to strip protection and pull the M2TS to MKV, then Wave to convert MKV to MP4. The M2TS-to-MKV step preserves every stream bit-for-bit. The MKV-to-MP4 step is a container swap when the audio is MP4-compatible, or a re-encode when the audio is DTS-HD or TrueHD. PGS subtitles don't survive the MP4 conversion. For home-server playback, the MKV output from MakeMKV is often the better keep; for iOS/browser playback, the MP4 conversion is required.