Convert VOB to MTS — Free Online Tool
Convert VOB files from DVD discs into MTS (AVCHD) format, transcoding the MPEG-2 video to H.264 and the AC-3 audio to AAC — producing a compact, high-quality file compatible with camcorder workflows and modern media players. This is especially useful for archiving DVD content in a format that modern editing software and devices handle natively.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
VOB files store DVD video as MPEG-2 streams with AC-3 (Dolby Digital) audio inside a program stream container. MTS (AVCHD) uses the MPEG-2 Transport Stream container and expects H.264 video with AAC or AC-3 audio. Because neither the video codec (MPEG-2 → H.264) nor the audio codec (AC-3 → AAC) can be stream-copied between these formats, both streams must be fully re-encoded. FFmpeg decodes the MPEG-2 video and re-encodes it with libx264 using CRF 23 — a perceptually transparent quality level for most DVD-resolution content — while simultaneously decoding the AC-3 audio and re-encoding it as AAC at 128k bitrate. The resulting MTS file wraps these streams in a transport stream structure compatible with AVCHD players and editing software.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser-based version of this tool, FFmpeg runs via WebAssembly (FFmpeg.wasm) entirely within your browser — no file data is sent to any server. |
-i input.vob
|
Specifies the input VOB file from your DVD. FFmpeg automatically detects the MPEG-2 Program Stream container and identifies the MPEG-2 video and AC-3 audio streams inside it. |
-c:v libx264
|
Re-encodes the DVD's MPEG-2 video stream using the libx264 H.264 encoder — the video codec required by the AVCHD/MTS format — replacing the less efficient MPEG-2 compression. |
-c:a aac
|
Transcodes the DVD's AC-3 (Dolby Digital) audio to AAC, which is the standard audio codec used in MTS/AVCHD files and is broadly supported across modern devices and editing software. |
-crf 23
|
Sets the Constant Rate Factor for libx264 to 23, which is the default and provides a good balance of visual quality and file size. For SD DVD-resolution content this typically results in a file that looks visually identical to the MPEG-2 source at a fraction of the bitrate. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second. This is sufficient for stereo audio transcoded from DVD AC-3 sources — if the source has 5.1 surround audio and you need to preserve it, increase this to 320k or higher and add '-ac 6' to the command. |
output.mts
|
The output filename with the .mts extension, which causes FFmpeg to mux the H.264 video and AAC audio into an MPEG-2 Transport Stream container structured as an AVCHD-compatible MTS file. |
Common Use Cases
- Importing archived DVD footage (home movies, event recordings) into Sony or Panasonic camcorder-based editing projects that expect AVCHD/MTS source files
- Archiving DVD-Video content in H.264-based MTS format to drastically reduce file size compared to raw MPEG-2 VOB files while retaining good visual quality
- Preparing DVD-sourced video for playback on smart TVs and media players that support AVCHD but may not handle MPEG-2 VOB files natively
- Converting corporate or educational training DVDs into MTS files for import into video editing timelines alongside other AVCHD camcorder footage
- Re-encoding DVD concert or performance recordings into MTS for use with broadcast or streaming ingest workflows that accept MPEG-2 Transport Stream input
- Consolidating a DVD disc rip (which may contain multiple .VOB files per title) into individual MTS clips for easier media management
Frequently Asked Questions
Yes — both the video and audio must be re-encoded, so some generation loss is unavoidable. However, because DVD-Video uses MPEG-2 at relatively modest resolutions (typically 720×480 for NTSC or 720×576 for PAL), re-encoding to H.264 at CRF 23 generally produces a file that looks visually identical to the source at a significantly smaller file size. The AC-3 audio is transcoded to AAC at 128k, which is transparent for most stereo content but may represent a slight quality reduction for 5.1 surround mixes.
Not with this default command. VOB files store subtitles as DVD bitmap subtitle streams (dvd_subtitle codec), which are not compatible with MTS/AVCHD subtitle formats. To include subtitles you would need to either burn them into the video using FFmpeg's subtitles filter (-vf subtitles) or extract them separately to SRT format first using a tool like SubRip. The MTS container does support subtitle streams in theory, but AVCHD subtitle handling varies widely across players.
The default command transcodes the audio to AAC stereo at 128k, which will downmix a 5.1 AC-3 track to two channels. If you need to preserve the surround mix, you can increase the AAC bitrate and force a multichannel layout by adding '-ac 6 -b:a 384k' to the command. Alternatively, you could copy the AC-3 stream directly using '-c:a copy' if the MTS player or software you're targeting supports AC-3 audio in a transport stream container.
The video quality is controlled by the '-crf' flag — lower values produce higher quality and larger files, while higher values reduce quality and file size. The range for libx264 is 0 (lossless) to 51 (worst quality). For DVD-source MPEG-2 content, a CRF between 18 and 23 is typically ideal: CRF 18 is near-lossless for SD content and CRF 23 is the default offering a good size/quality balance. For example, replace '-crf 23' with '-crf 18' for higher quality output.
Yes. On Linux or macOS you can run: 'for f in *.vob; do ffmpeg -i "$f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "${f%.vob}.mts"; done'. On Windows Command Prompt use: 'for %f in (*.vob) do ffmpeg -i "%f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "%~nf.mts"'. Note that some DVDs split a single title across multiple VOB files (VTS_01_1.VOB, VTS_01_2.VOB, etc.) — in that case you should concatenate them first using FFmpeg's concat demuxer before converting.
This is expected. DVD MPEG-2 video is relatively inefficient compared to modern H.264 compression. A typical DVD VOB file might use 4–8 Mbps for MPEG-2 video, while H.264 at CRF 23 can achieve equivalent or better visual quality at 1–3 Mbps for the same SD resolution. This compression efficiency is one of the primary practical reasons to convert VOB archives to MTS/H.264 format.
Technical Notes
VOB files are essentially MPEG-2 Program Streams (PS) with a .vob extension, and FFmpeg requires the '-f vob' flag when writing VOB output to correctly structure the container — though reading VOB files for input works automatically via format detection. When converting to MTS, the output uses the MPEG-2 Transport Stream (TS) muxer, which structures packets differently from the program stream used in VOB, making MTS more resilient to seek errors and better suited for streaming and broadcast. One important limitation: VOB files from a DVD disc often contain multiple audio tracks (e.g., different language dubs) and DVD bitmap subtitle streams. This command processes only the default audio track and drops subtitles entirely. Users with multi-language DVDs should identify the desired audio stream index with 'ffmpeg -i input.vob' and add '-map 0:v:0 -map 0:a:N' to select the correct track. Additionally, DVD chapter markers present in the IFO sidecar files are not embedded in individual VOB files themselves, so chapter metadata will not be present in the MTS output regardless. The libx264 encoder's output in an MTS transport stream container is broadly compatible with professional NLEs like Adobe Premiere Pro and DaVinci Resolve when reading AVCHD media.