Finally I figured out this workflow using free software on OS X, for my projects (they are produced into DVD but I need to take samples for Youtube). By doing this, I am leaving all the encoding work to Youtube, since it will re-encode your video anyway. Supplying the original file to Youtube directly will avoid any quality degradation from your local encoding works.
Here is how I do it:
- Open your favourite video player that can playback the DVD or the VOB file (I use VLC Media Player), take a note of the start and end time of video you want to extract.
- Use MPEG Streamclip to open the DVD or the VOB file), it will complain that it need Apple’s Quicktime MPEG-2 Playback codec ($20) to play the video. Ignore this, I am not going pay for that.
- Press ⌘+G (jump to time), enter the start time you noted, press I (set In point). Press ⌘+G (jump to time), enter the end time you noted, press O (set Out point).
- Press ⌘+T (trim), now you should have the section you wanted. Press ⌘+S (save) to save the extracted video clip. MPEG Streamclip will save it using original format (VOB) without conversion or re-encoding.
- Verify your VOB clip by opening it with your favourite video player. Use the same procedure above to make adjustments.
- Upload to Youtube*, even though Youtube said it doesn’t support VOB file, it actually works well (since it is just MPEG-2 video).