Free online KUX to VOB converter

You may need this conversion when a Youku-downloaded video must be used in DVD authoring software or played by hardware that expects DVD-Video files. Converting the file also changes the proprietary KUX container into the MPEG-2-based VOB structure used on video DVDs.

What the KUX format is

KUX is a proprietary video container associated with Youku, a Chinese video platform. Youku desktop software and download tools create KUX files for locally saved videos, often in segmented or protected form. Standard media players and editors may not open KUX because the format can include Youku-specific encoding or encryption.

What the VOB format is

VOB is the container used by DVD-Video. It stores MPEG-2 video together with DVD-compatible audio, subtitles, navigation data, and timing information; common audio formats include AC-3, MPEG audio, and LPCM.

A VOB is useful for DVD authoring and playback on DVD players, older televisions, and software that expects DVD-Video media. A standalone VOB is not a complete DVD: a playable disc normally also needs an VIDEO_TS folder containing IFO and BUP files.

How to convert KUX to VOB

Use the built-in online converter

1. Open the KUX-to-VOB converter on 101convert.com.
2. Select or upload the .kux file.
3. Choose VOB as the output format and start the conversion.
4. Download the generated .vob file, then test it in VLC or import it into DVD authoring software.

This route avoids installing software, but it can process the file only if the KUX contains video that the converter can decode. A partially downloaded or protected file may fail.

Use FFmpeg after decoding the KUX

Standard FFmpeg builds generally do not decode Youku's proprietary or protected KUX variant directly. If Youku software or another compatible decoder can export the video as MP4, use that exported file as the source:

ffmpeg -i input.mp4 -map 0:v:0 -map 0:a:0 -c:v mpeg2video -q:v 2 -maxrate 8000k -bufsize 1835k -pix_fmt yuv420p -c:a ac3 -b:a 192k -ar 48000 -f dvd output.vob

Choose the DVD standard required by the destination: add -target ntsc-dvd for NTSC or -target pal-dvd for PAL. For a complete disc, import the resulting file into DVDStyler, DVD Flick, or another DVD authoring application rather than simply copying the VOB to a disc.

Quality and compatibility limitations

The conversion cannot restore detail already lost in the KUX source. DVD-Video normally uses MPEG-2 at standard-definition resolution, so converting a high-resolution KUX video reduces resolution and may increase compression artifacts.

Keep the original aspect ratio when authoring the DVD. Converting between NTSC and PAL changes frame rate and may require frame-rate conversion; select the standard supported by the player. Generic VOB conversion may omit KUX subtitles, chapters, multiple audio tracks, or DRM-related metadata, so check the output before deleting the source.