Trim VOB — Free Online Tool
Trim VOB files to extract specific segments while preserving the original MPEG-2 video and AC3 audio streams without re-encoding. Ideal for cutting out scenes from DVD rips or isolating chapters from VIDEO_TS content with zero quality loss.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Settings
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
This tool uses stream copying (-c copy) to cut the VOB file at the specified start and end timestamps without decoding or re-encoding any data. The MPEG-2 video stream and AC3 (Dolby Digital) audio stream — the native codecs of DVD-Video — are passed through entirely intact. Because VOB files use MPEG-2's GOP (Group of Pictures) structure, FFmpeg will snap the cut to the nearest keyframe at the start point, which means the actual trim may begin a fraction of a second earlier or later than specified. The output is a valid VOB container with the -f vob flag ensuring proper DVD-compliant muxing, retaining any subtitle streams present in the source.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary. In the browser-based version of this tool, this runs via FFmpeg.wasm (WebAssembly), executing the same logic as desktop FFmpeg entirely within your browser with no server upload. |
-i input.vob
|
Specifies the input VOB file, which FFmpeg reads as an MPEG-2 Program Stream containing multiplexed MPEG-2 video, AC3 audio, and potentially DVD subtitle subpicture streams. |
-ss 00:00:00
|
Sets the trim start point in HH:MM:SS format. Placed after -i (input-side seeking), this tells FFmpeg to begin the output at this timestamp; the actual cut snaps to the nearest MPEG-2 keyframe due to the GOP structure of the video. |
-to 00:00:10
|
Sets the trim end point as an absolute timestamp from the beginning of the input file — in this case, 10 seconds. The output VOB will contain only the content between the -ss and -to timestamps. |
-c copy
|
Instructs FFmpeg to copy all streams (MPEG-2 video, AC3 audio, and subtitle streams) without decoding or re-encoding, making the trim nearly instantaneous and preserving the original DVD-quality bitrate and codec data exactly. |
-f vob
|
Forces the output muxer to use the VOB/MPEG-2 Program Stream format rather than letting FFmpeg guess from the file extension, ensuring the output is correctly structured as a DVD-compatible Video Object file. |
output.vob
|
The filename for the trimmed output VOB file, which will be a valid DVD Video Object containing the extracted segment with all original streams intact and ready for DVD authoring or direct playback. |
Common Use Cases
- Extract a specific scene or bonus feature from a DVD rip's VOB file without degrading the original MPEG-2 video quality through re-encoding
- Trim a long VIDEO_TS VOB file to isolate a single episode from a multi-episode DVD disc where episodes are concatenated in one large VOB
- Remove unwanted studio logos or unskippable intros from the beginning of a VOB file before archiving or re-authoring a DVD
- Cut a short clip from a DVD concert or live performance VOB to share as a preview while keeping the AC3 surround sound audio intact
- Isolate a specific language track segment from a multi-audio VOB file for subtitle synchronization or dubbing workflow purposes
- Prepare a trimmed VOB segment for re-importing into DVD authoring software like DVD Architect or ImgBurn without format conversion
Frequently Asked Questions
No — because the command uses -c copy, neither the MPEG-2 video nor the AC3 Dolby Digital audio is decoded or re-encoded at any point. The bitstream is copied byte-for-byte from the input to the output. Quality loss in VOB files only occurs when the video or audio is transcoded, which this tool explicitly avoids.
VOB files store MPEG-2 video, which uses a GOP (Group of Pictures) structure where only keyframes (I-frames) can serve as clean cut points. When using -c copy, FFmpeg must snap the start of the trim to the nearest preceding keyframe, since cutting mid-GOP without re-encoding would produce corrupted frames. The discrepancy is typically less than half a second but depends on the GOP size used when the DVD was encoded — commonly every 0.5 to 1 second.
Yes — VOB files can carry DVD subtitle streams (stored as bitmap-based subpicture streams), and the -c copy flag copies all streams including subtitles. However, subtitle timing is relative to the stream, so if you trim from a non-zero start point the subtitle timestamps in the output will be offset accordingly. You may need to adjust subtitle timing if re-authoring the trimmed VOB into a new DVD structure.
Yes — the -c copy flag copies all audio streams present in the VOB, including multiple AC3 or other audio tracks (such as director's commentary or alternate language dubs). All audio streams are preserved in the trimmed output. If you only want a specific audio track, you would need to add stream mapping flags like -map 0:v -map 0:a:0 to select individual streams, which you can do when running the FFmpeg command locally.
In the command ffmpeg -i input.vob -ss 00:00:00 -to 00:00:10 -c copy output.vob, change -ss to your desired start time and -to to your desired end time, both in HH:MM:SS format. Alternatively, replace -to with -t followed by a duration (e.g., -t 00:02:30 for a two-and-a-half minute clip). For files over 1GB, running this command locally with a desktop FFmpeg installation is recommended and will be significantly faster than browser-based processing.
The single command shown processes one VOB file at a time, but you can batch process on the desktop using a shell loop. On Linux or macOS: for f in *.vob; do ffmpeg -i "$f" -ss 00:00:00 -to 00:00:10 -c copy "trimmed_$f"; done. On Windows Command Prompt: for %f in (*.vob) do ffmpeg -i "%f" -ss 00:00:00 -to 00:00:10 -c copy "trimmed_%f". This is especially useful for trimming intros off multiple DVD episode VOBs in one pass.
Technical Notes
VOB (Video Object) is a DVD-Video container that multiplexes MPEG-2 video (typically at 720x480 for NTSC or 720x576 for PAL), AC3 (Dolby Digital) audio, and bitmap-based DVD subpicture subtitle streams into an MPEG-2 Program Stream. When trimming with -c copy, FFmpeg preserves this Program Stream structure and uses the -f vob muxer to ensure the output is properly formatted for DVD-compatible playback rather than as a generic MPEG-2 PS file. One important limitation is that VOB files from DVD-Video discs are typically split into 1GB chunks (VTS_01_1.VOB, VTS_01_2.VOB, etc.) — this tool processes a single VOB file at a time, so if your content spans multiple VOB files you would need to concatenate them first using FFmpeg's concat demuxer before trimming. Additionally, copy-mode trimming does not regenerate MPEG-2 sequence headers at the new start point in all cases, which can occasionally cause compatibility issues with strict DVD players; if playback problems occur, re-encoding with -c:v mpeg2video -q:v 4 -c:a ac3 -b:a 192k instead of -c copy will resolve them at the cost of a second generation quality reduction.