PAL to NTSC

[Xesdeeni]

Conversion from PAL to NTSC is producing results that are not 100% satisfactory (the converted file does not have as high quality, especially on motion as the original), which is annoying. Yes, I blame deinterlacing for it...

Deinterlacing isn't really the culprit. Even if we had completely progressive frames to start with, converting from 50 to 60 or vice-versa would introduce some type of artifact. I have some HDTV content (http://www.eecs.umich.edu/~balazer/hd_ads/ESPN_HD.ts.zip) that is 60 progressive fps (well OK, it's 59.94 progressive fps ), and it would suffer from the same type of jutter if I converted it to 50 progressive fps.

The most common standards conversion devices use a technique known as "four-field" standards conversion and that doesn't use anything like deinterlacing. Some technical details are available at Snell & Wilcox's homepage (http://www.snellwilcox.com/) under the Reference section (see the Engineer's Guide to Standards Conversion). But the technique I created using a smart deinterlacer actually outputs video that looks a lot like the four-field technique, when you use ConvertFPS().

...and have read about the advanced motion estimation deinterlacing techniques used by pro's. This may not ever be available to us enthusiasts, if I understand Xesdeeni's response correctly.

I don't know if I'd go so far as to say "ever," but I think it'll definitely be a long time

I feel strongly that the best thing, if one is seriously interested in getting the best possible quality, is to get a multistandard TV and multistandard DVD-player, so no conversions are needed.

Well of course, but good luck finding a multi-standard TV in the US.

Xesdeeni, if you need interlaced PAL-material for testing purposes, I'd be glad to supply some.

I think I have enough interlaced PAL material (I don't have any film), but I don't have access to a PAL display system, so someone who can judge how well NTSC to PAL conversions are doing would be helpful.

Also, if TMPGEnc cannot handle the audio part in television system conversions, how does your script manage to keep the audio in sync when going from PAL to NTSC?
Is this even a difficult task? Since the length of the converted video is the same as the original, what needs to be done to make the audio fit?

As I suspect you realize, there are basically two types of video content: that which originated on film, and that which originated on video.

For content that originated on video, which is truly interlaced, the technique I created works best. And, since the resulting conversion is the same length as the original, no conversion of the audio is necessary.

I have only used your script on interlaced 25 fps PAL video. No film conversions, the footage was shot on native video.

For content that originated on film, the same conversion can be used, but the quality will not be the best that could be accomplished, and it will not be quite as good as the interlaced-to-interlaced conversion. In this case, it is best to reduce the video back to progressive frames and change the speed. This is the type of conversion that TMGPEnc can do (that's how I do it on my Standards Conversion page: http://www.geocities.com/xesdeeni2001/StandardsConversion), but this is also where the audio needs to be adjusted.

Lots of people use BeSweet to do the conversion, but on my Standards Conversion page, I actually just use AVISynth for simplicity. But of course both of these techniques change the pitch of the sound while changing its speed.

I've recently posted some messages about a utility (http://www.geocities.com/xesdeeni2001/WSOLA.zip) I snagged to do the conversion of the audio without changing the pitch. The creator claims that it produces no artifacts (http://aulos.calarts.edu/pipermail/music-dsp/2002-May/015962.html), but I still haven't gotten any feedback on it.

Xesdeeni

[M66]

I created using a smart deinterlacer actually outputs video that looks a lot like the four-field technique, when you use ConvertFPS().

Yes, your conversion does not have the same amount of the obvious poor "deinterlaced video-effect" (odd, slow motion, blur, etc) as the deinterlacing I've seen on conversions from interlaced video (from DVD, for example) to Xvid or DivX.

Well of course, but good luck finding a multi-standard TV in the US.

Have you checked out the Sony models? For some reason, all the Sonys I've seen here in Scandinavia support both PAL and NTSC. I understand why it's easier to get a multistandard DVD player and TV set here in Europe (let's be honest, we Europeans import more video, be it sitcoms or whatever, he, he) from you guys than you import from us. But it's not like Europeans can go into any electronics shop and buy a TV and it's a sure-shot multistandard. One has to check out what models on display are of interest, then hunt around the web for technical specs to see if it is multistandard or not. I got a cheap 14" Thomson for next to nothing and it's multistandard.

As I suspect you realize, there are basically two types of video content: that which originated on film, and that which originated on video

Yes, I am fully aware of it, and the differences therein.

think I have enough interlaced PAL material (I don't have any film), but I don't have access to a PAL display system, so someone who can judge how well NTSC to PAL conversions are doing would be helpful.

I am willing to be your test pilot. I can also send you some PAL film material (Mpeg-2). Either as an SVCD or Mpeg-2 (720 x 576, hopefully DVD-authoring ready). I am waiting for a DVD writer to arrive, so I can only send material on CD-R as of now.

I am thankful for your script and have been meaning to tell you so for a while, but this is the first appropriate occasion.
If I can help you in your development of conversions, it'd be my pleasure.

[Xesdeeni]

Have you checked out the Sony models?

My current TV (35") is a Sony, but only NTSC. Even in the high end stores, I have never seen a multi-standard TV. The closest I've seen is some professional video equipment rental places that have PAL equipment for rent, including monitors.

I am willing to be your test pilot. I can also send you some PAL film material (Mpeg-2). Either as an SVCD or Mpeg-2 (720 x 576, hopefully DVD-authoring ready). I am waiting for a DVD writer to arrive, so I can only send material on CD-R as of now.

At this point, the best help you could provide would be to tell me if you can hear any artifacts in an audio conversion done with WSOLA (http://www.geocities.com/xesdeeni2001/). [It crashes on me at the end of a conversion on Windows ME, but not on 2K. But the file should be OK except for the last half second or so.] If the quality is determined to be good enough, my next goal is to move the code to an AVISynth plugin. Other than that, I'm just trying to apply some statistical analysis techniques to see if I can come up with a better deinterlace algorithm without motion detection (i.e. that we can do on our current machines).

Xesdeeni