NTSC and PAL

Let's face it, we are living in a global world where each little corner uses different system for almost anything.

DVD producers are always asking if they can create one combined DVD with both PAL and NTSC. They can, of course, but it will not play. Or at least not reliably.

That's the simple truth. Do not try to make a DVD that uses both systems, while you may partially succeed, it is not worth the returned "unplayable" discs.

A first thing for NTSC DVD that can play in Europe is to make the disc Region 0 = All regions enabled. (read the previous article)

Many of the DVD players in Europe (even some brand names) can play NTSC DVD's, but not all of these players will accept Region 1 DVD!

On other hand in America only few non-brand name players will be able to play PAL disc and no store will openly sell all-region player (however some of these non-brand name players have known remote key sequence to disable the region check)

The bottom line is that if you create 0-region NTSC disc, then a large portion of people in Europe will be able to watch it, but if you create 0-region PAL disc then only small percentage people in America will have the player capable of playing it. (Some may not even know the fact)

Any PC user will be able to watch 0-region DVD either in NTSC or PAL as the software care only about the region flag, not the actual system.

If you are seriously planning to sell the DVD on all continents then you have to make two disc versions, one in NTSC and the second in PAL.

Japan uses NTSC. Australia uses PAL (and they drive on the other side of road and upside down!)

The question is then how to make the PAL DVD from NTSC. This is far more difficult that it seems. The problem is not the different frame size but the FPS. The 29.98 FPS to 25 FPS conversion is not a simple task. It gets even more complex if the 29.97 is from a DV source (interlaced).

It is not that it cannot be done technically, but in most cases the result will be choppy playback.

If the 29.97 file was actually created from 24 fps film, then an easy way is to create 23.97 FPS by using IVTC (inverse telecine) and then  simply speed up the video (and audio ) to 25 FPS. Unfortunately this doesn't work well for interlaced sources (DV camera)

For the 29.97 interlaced (camera, TV) source to 25 FPS conversion there are many different ways because none really works without some little glitch.

A best process seems to convert 29.97 interlaced to 59.94 progressive Fps with some smart (smooth) deinterlacer which will not loose any temporal information. Then convert 59.94 progressive FPS to 50 progressive FPS. This throws away every 6th frame, but thanks to the double frames this creates only 1/50 sec glitch (If you convert 29.97 FPS directly to 25 FPS you will get much more visible 1/25 sec glitch). Then we interlace the 50 FPS by selecting even lines from one frame and odd lines from next frame to 25 FPS interlaced.

This above is best accomplished with AVIsynth and VirtualDub

In fact AVISYNTH is the bread and butter of any video manipulation. It is a scripting frameserver that sits between your file and a video editing application. There are tons of guides on Internet, many of them dealing with the NTSC<->PAL conversion.

Most of encoders or video applications claim to do conversion between systems, but in most cases they don't do anything special - just duplicate or drop frames. This creates jerky video that is hardly acceptable.

There are few video editing application that use a better-than average conversion between systems. You could use for example Sony Vegas to successfully convert video between systems. For smoother motion you can apply Reduce Interlace Flicker option on the clip. If you use mpeg files as source of conversion (you should not!) then you have to check the clip properties in Vegas if it has the correct pixel aspect ratio and field order (Vegas may assume mpeg file is progressive while your mpeg file from NTSC DV may be in fact interlaced).

To convert NTSC DV file in Vegas to PAL:

Similarly you can do a PAL to NTSC conversion in Vegas.

You will get a quite acceptable result with fluid motions and choppy-free video.

If you have any other semi-pro or professional software you should try the conversion within the program itself to see if it creates acceptable and choppy-free video.

You should do a conversion from the original AVI file, not from already compressed mpeg file. The re-compressing and frame resizing of mpeg file will result in a serious quality drop.

H/W Conversion

If you need to convert a very large number of files it may take weeks to capture and convert them on a PC. If you need it quickly, you may consider a realtime hardware conversion. A typical scenario would be NTSC camera or video connected through S-Video to a NTSC/PAL conversion box that is connected to a PC capturing and optionally MPEG encoding device. You are converting to PAL and then encoding it all in real-time. The results are often mixed. It heavily depends on the NTSC/PAL conversion box and the quality of many of these boxes are hardly sufficient. They often do a good motion compensation, but the cheaper boxes have a very noticeable detail loss.

It takes some experimenting to find the best solution. I had seen a good result by mixing two devices, one that converts a NTSC signal to a VGA (there are some good devices for displaying video or TV signal on PC monitor) plugged to a second different device (not the same manufacturer) that converts the VGA signal back to a PAL video (for displaying PC on a large TV screen).

We little Cowboys didn't feel like creating a PAL DVD would be necessary because of the general ability for PAL players to play NTSC video. We are ultra-low budget people around here and making PAL DVD will double the cost!

Top  Previous  Next