How do i convert 25fps Pal Vcd to Ntsc Vcd? [Archive]

Darkskies

5th April 2005, 01:10

I know how to do Svcds thnx to this guide http://www.videohelp.com/forum/userguides/166237.php

however I have not found anything for Pal Vcds.
The specs for the vcd are as follows
1150 Kbps, 25.0 fps, 352*288 (4:3), MPG1 = MPEG 1 (VCD), Supported

My only problem is the 25.0 fps which my dvd player cannot read it can only do Ntsc.

By the way im sorry but why are there 2 different versions of Ntsc I see 23.976 then i also see 29.97, does it matter which one i use?

Thank you guys

jggimi

5th April 2005, 05:55

I don't have a step by step tutorial for you, since I've never done MPEG-1 -> MPEG-1 framerate conversions myself. But I took a look at the tutorial you're using, and it looks like you just need to apply it to VCD; the difference being that the .DAT file needs to be converted back to .MPG before you can use TMPGEnc on it, and then you need to encode MPEG-1 rather than MPEG-2, etc. I don't recall the tool, but a search should pop it up. Other members may have better comments, because I'm sure there are some who've worked with VCD sources. When I've worked with VCD, it's been the termination of work, not the source.

Instead, I've got an answer to your question about the two NTSC framerates: 29.97 frames per second is NTSC Television framerate, but it is actually transmitted as 59.94 fields per second interlaced. NTSC video shot with a standard video camera, because it is interlaced, must stay at 29.97fps.

23.976 frames per second may be used for sources that were film transfers, and usually is, since the extra ~6 frames per second added during the transfer is effectively wasted space for non-broadcast needs. The process of transfering a 24 frames per second, 35mm film to 59.94 fields per second NTSC video is called Telecining. NTSC video that came from such a transfer has been Telecined. The process of re-converting that video back to progressive frames, at close to (but not quite) 24fps is called Inverse Telecining, or IVTC. Film sources at 23.976 take up less space then the same content at 29.97, so if the standard supports it (as VCD/SVCD/DVD do) then it is usually helpful to rebuild the original frames from the film, at very close to the original speed.

NTSC VCD/SVCD/DVD players connected to interlaced TVs (ye olde standard televisions) will effectively re-Telecine 23.976 content to 29.97 for you on playback, through a process called Pulldown.. Progressive players connected to progressive TVs (usually HDTVs) via component video, DVI, or HDMI can be set to display progressive frames at 23.976 fps.

In addition, for PAL -> NTSC conversions, If one has video (and matching audio) at 25fps, the transition to 23.976 is simpler than going to 29.97, and if from film, actually corrects speed differences that were introduced when going from 24 to 25fps for PAL.
For more info on NTSC and the two framerates, see www.doom9.org/ivtc-tut.htm.

Darkskies

5th April 2005, 07:32

Thanks jggimi I appreciate your explanation for me. I tried changing the Vcd using the same steps as for the Svcd and the outcome for the vob files came out like this

2519 Kbps, 29.970 fps, 480*480 (16:9), MPG2 = MPEG 2 (SVCD/DVD), Supported

When i inserted it into my dvd player it said DVD-Video and started playing with really no problems, I think when i saw that 480*480 (16:9), I was a little concerned because I thought it had to be 352x480 or 352x240 (4:3) for it to be DVD compliant.