Fluid motion in VCD

[pedro222]

I capture video from PAL VHS cassette @ 352x576,25 fps,RGB24,Picvideo Q20 4:2:2.But after deinterlace it in Vdub and then frameserve it to TMPGENC to make VCD/MPEG1 format,the resulting motion would not as fluid/smooth as the VHS's,it wasn't natural,like watching TV series,not home videos.I tried to increase the frame rate to 29.976 in VDub and again frameserve it to TMPGENC and encode it to NTSC MPEG1 format,the motion was fluid,but it played faster and looked funny,so I dropped it.I heard that there's a process called 3:2 pulldown,from 23.976 to 29.976, but I also heard that it's for MPEG2 only, and worse I only got VCD player not DVD.I once saw a friend of mine converting his VHS which was NTSC to NTSC VCD format, and the motion was so fluid,just like the VHS.Is it true that increasing the framerate of VCD would produce smoother motion ? Thanks in advance.

[ralfbeckers]

Hi Predro,

I have occasionally converted PAL home video to PAL VCD so this should be equivalent to what you want to do. I use a WinTV capture card and VirtualDub to save an UNCOMPRESSED AVI File (1/2 spatial resolution but 25fps) to disc. I feed this to TMPGEnc using the PAL VCD template and I'm in business besided some audio sync problems that presumeably are already caused in the hardware capturing. I don't think you need to deinterlace at the resolution I'm using since I capurture one field only.

But your capture used the full horizontal resolution of PAL at 576 lines so at one point you have to come down to PAL VCD's 288 pixels. Consider: If your VHS stems from a PAL telecined movie film it was telecined at 25fps and not the usual 24fps so every pair of fields contains motion from the SAME film frame. If your output format had full PAL resolution (which VCD doesn't) it would be sufficient to weave the two fields in to one frame. If you tape is from a TV show broadcast or a home video, it's interlaced fields are always from DIFFERENT points in time and deinterlacing this for full rez output is tricky. But again, since you author a VCD you don't have to worry about this.

IMHO your fasted path to success is to load your captured file directly into TMPGEnc without doing anything to it before. Then you have two options: Make no changes to the original PAL VCD template and watch what's happening or use the deinterlacing feature. I suggest "even field". Try this once with top field first and then bottom field first. If you still get jerky motion and you feel really experimental go into the inverse telecine sectiona dn select the desired fields manually. Careful: Marking one field will invisibly also take the next field into account for the large preview window unless you specify a deinterlacing procedure for the marked frame in its context menue. You can basically do the same thing here as TMPGEnc does with Deinterlace but also MUCH more.

3:2 pull-down needn't be of your concern here because it is only for 60 field per second sources that contain a telecined 24fps movie which you want to record progressively on a 24fps FilmSVCD. This you are a PAL guy and not an NTSC guy where this kind of stuff would apply, don't bother.

Good Luck!