M2TS to VOB Converter

M2TS to VOB — an HD Stream Going Back to a Standard-Definition Disc

M2TS is Blu-ray's transport stream: 192-byte BDAV packets carrying H.264, VC-1 or MPEG-2 video, typically at 1080i or 1080p, and it is also what AVCHD camcorders write after import. VOB is the DVD-Video program stream from a decade earlier, capped at 720 × 576. So this conversion is a downconvert in every dimension — codec, frame size and generation — and the interesting part is not how to run it but what the numbers do when you cross that gap.

M2TS and VOB Compared

How to Convert M2TS to VOB

1. Upload Your M2TS File: Drag the .m2ts onto the page or click "+ Add Files". Camcorder shoots often arrive as many short clips; queue them together and each is converted with the same settings.
2. Keep MPEG-2 and Choose the Audio: Open Advanced Options. Video Codec offers MPEG-1 and MPEG-2, defaulting to MPEG-2 — leave it there. Audio Codec defaults to MP2, with AC3, DTS and MP3 also in the list; MP2 and AC3 are the two safe picks for a disc.
3. Set the Frame Size — Do Not Skip This: Video resolution opens on Keep original, so a 1920 × 1080 M2TS stays 1920 × 1080, which is not a legal DVD frame. Choose the 480p preset for NTSC or 576p for PAL, or enter 720 × 480 / 720 × 576 under Width × Height. Trim is available if you only need part of the clip.
4. Convert and Download: Click Convert and download the .vob. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark.

Why the Frame Size Controls the File Size Here

MPEG-2 will not encode below a floor that scales with the frame size — ask for less and the encoder raises the bitrate rather than producing a stream it cannot make. That means the resolution setting, not the bitrate setting, is what actually shrinks a VOB.

We put a six-second 1080p M2TS of 2,783,232 bytes through both paths on this pipeline. Left at 1920 × 1080 the VOB came out at 5,875,712 bytes — more than double the source, because MPEG-2 needs far more bits than H.264 for the same picture. Downscaled to 720 × 480 the same clip produced 1,794,048 bytes. Downscaling is not a compromise you make reluctantly here; it is the entire mechanism.

Frequently Asked Questions

Will the VOB be larger than the M2TS I started with?

At the original resolution, almost certainly. H.264 is roughly twice as efficient as the MPEG-2 that DVD requires, so re-encoding an HD H.264 stream to HD MPEG-2 roughly doubles the size for the same picture — we measured 2.1× on a 1080p test clip. Once you downscale to a DVD frame size the arithmetic reverses and the VOB comes out comfortably smaller. If your VOB is unexpectedly huge, the resolution is still on Keep original.

Do I really have to downscale to 720 × 480?

To make a disc, yes. DVD-Video defines exactly eight legal frame sizes and none of them is HD, so an authoring tool will reject a 1080p stream regardless of how well it is encoded. If what you actually want is an SD-sized file rather than a disc, you can leave it larger, but then VOB is a strange choice — M2TS to MP4 keeps the resolution and produces a much smaller file that plays everywhere.

My M2TS came out of a BDMV folder — do I need the rest of the folder?

No. Upload the .m2ts on its own; everything needed to decode the picture and sound is inside the stream file. What you lose by not having the rest of the structure is disc-level information — playlists, chapter marks, menu navigation — which lives in the .mpls and .clpi files alongside it. Those do not survive to VOB anyway, since chapter marks are created during DVD authoring rather than carried in the video stream.

What happens to Dolby TrueHD or DTS-HD audio?

It is decoded and re-encoded to whatever you pick in step 2, because the DVD-Video specification has no place for the lossless HD audio formats. Choosing AC3 keeps the Dolby lineage and a surround layout; choosing MP2 gives you the most universally decodable option. Either way the high-resolution audio is gone — that is inherent to targeting a DVD, not a limitation of the conversion.

Does 1080i camcorder footage get deinterlaced?

No. There is no deinterlacing step in this conversion, so interlaced fields are preserved through the downscale and into the MPEG-2 stream. For a disc that is the right behaviour, because DVD-Video is designed for interlaced content and a set-top player deals with it on output. It does mean the file shows combing if you watch it on a computer. If you need progressive frames, deinterlace before uploading with ffmpeg's yadif or Handbrake's Decomb.

I set a low bitrate and the file barely shrank — why?

Because of the floor in the table above. The MPEG-2 encoder raises any target that is too low for the frame size, so at 1920 × 1080 nothing below about 7.5 Mbit/s is achievable no matter what you type. The same applies to Specific file size: it can only be honoured if the number is reachable at the chosen resolution. Set the frame size first, then the bitrate.

Does the Constant Quality slider do anything on this page?

Not with MPEG-2 selected. The value is accepted by the interface, but MPEG-2 has no constant-quality mode in this pipeline and the setting is converted to a bitrate before it reaches the encoder. Use Constant Bitrate, Variable Bitrate or Specific file size to control the output, and treat resolution as the primary lever. This is specific to MPEG-2 — the same slider is meaningful on codecs that support it.

Can I burn the .vob straight to a disc?

No — a DVD player expects a VIDEO_TS folder holding VTS_01_1.VOB plus matching .IFO and .BUP files, not a loose .vob. This conversion produces the compliant video; DVDStyler, ImgBurn, Nero or TMPGEnc Authoring Works build the structure and burn it. Most of those tools also accept .mpg if your chain prefers it.

How much runtime fits on one DVD?

At 4 Mbit/s a 4.7 GB single-layer disc holds roughly two hours, at 6 Mbit/s about ninety minutes, and at the 9.8 Mbit/s DVD ceiling about an hour. Standard-definition footage downscaled from HD generally looks good at 5-6 Mbit/s because the downscale itself removes the detail that would have needed the extra bits. A dual-layer DVD-9 at 8.5 GB roughly doubles each figure.

Would MP4 be a better target than VOB?

For anything other than making a physical disc, yes, clearly. MP4 with H.264 is smaller, keeps the HD resolution, and plays on phones, browsers, smart TVs and media servers — none of which will touch a VOB. Choose VOB when the destination genuinely is a DVD player. See the M2TS converter hub for the full set of targets, or M2TS to MKV if you want an archival container that keeps multiple audio tracks.